A Cross-Sectional Study on the Presence of Mamelons in Northeastern India

Introduction Dental anthropology plays a pivotal role in human evolution and forensic sciences. This study explores a unique method for age estimation-analyzing mamelons on incisors. Mamelons are small projections on the incisal edge of permanent incisors, exhibiting age-related changes. This departure from conventional methods presents an innovative and potentially efficient approach to age estimation. Materials and methods A cross-sectional study was conducted in two tertiary care medical institutes and one private clinic in northeastern India over three months. Participants from the community, selected through convenient sampling, underwent data collection on demographic and habit-related variables. The sample size was 1000 teeth, and the age of participants was 5-40 years. Descriptive statistics were used to summarize the demographic and habit-related variables. The primary statistical analysis involved Pearson correlation tests to explore the relationships between categorical, demographic, and habit-related variables. The presence or absence of mamelons on incisors was determined using intraoral examination and study casts. Statistical analysis was performed using Python software. Results A total of 60.8% of teeth showed the presence of mamelons. Typical Three Mamelon Configurations with lobes of similar size constituted the majority (53%). Coefficients were statistically significant in age groups 5-7 years (0.5407), 8-10 years (0.5579), and 11-13 years (0.5476). Malocclusion could lead to the retention of mamelons even in higher age groups. Conclusion Estimating age through mamelons on incisors is a promising avenue in dental anthropology and forensics. Despite the need for further validation and research across diverse populations, its non-invasiveness and forensic applications make it a valuable addition to age estimation methodologies. The presence of mamelons showed a significant reduction with age and was significantly found in tribal communities. However, there was no strong relation with sex, diet, or brushing habits.

The Evaluation of Gingival Crevicular Fluid Biomarkers as Predictors of Gingival Enlargement in Patients Undergoing Fixed Orthodontic Treatment: A Prospective Study

Introduction Gingival enlargement (GE) poses a significant problem during fixed orthodontic treatment (FOT). Thus, the primary aim of the current study was to evaluate the concentrations of biomarkers present in the gingival crevicular fluid (GCF) of individuals receiving FOT. The ancillary aim was to examine and compare biomarker levels among patients exhibiting GE undergoing FOT, those without GE undergoing FOT, and a control group comprising individuals not undergoing FOT and to assess the predictors for GE in patients undergoing orthodontic treatment. Materials and methods A cross-sectional observational study was conducted on 129 patients who were divided into three groups: group 1, controls (n=18); group 2, patients who underwent FOT without GE (n=89); and group 3, patients who underwent FOT with GE (n=22). The gingival index (GI), periodontal index (PI), and inflammatory biomarkers such as interleukin 6 (IL-6), transforming growth factor-beta 1 (TGF-β1), tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase 9 (MMP-9), and prostaglandin E2 (PGE2) were estimated by enzyme-linked immunosorbent assay (ELISA) analysis at baseline (T0) and after one year of orthodontic treatment (T1). Results GE was observed in 22 (19.81%) of the 111 patients who were undergoing orthodontic treatment. No statistically significant differences were observed between the groups for GI, PI, and biomarkers at T0 (p>0.05), whereas there was a statistically significant increase in the levels of inflammatory biomarkers, GI, and PI in group 3, followed by group 2, compared to group 1 (p<0.05). Group 3 showed the greatest increase in the biomarker levels from T0 to T1 (IL-6, 3.66±1.91 pg/mL; TGF-β1, 7.52±3.85 pg/mL; TNF-α, 16.96±3.82 pg/mL; MMP-9, 30.72±7.07 pg/mL; PGE2, 78.29±20.53 pg/mL). GI and PI were strong predictors of GE, whereas biomarkers were weak predictors. Conclusion GE in patients with FOT was significantly associated with an increase in GI and PI due to insufficient oral hygiene, leading to increased levels of inflammatory biomarkers in the GCF.

Awareness, attitudes and cost among patients for dental implants in teeth replacement

Dental implants are increasingly viewed as a preferred treatment option for tooth replacement, yet gaps remain in patient knowledge, attitudes, and cost perceptions. This cross-sectional, in vitro study surveyed 150 adults aged 20-60 to assess their awareness, attitudes, and perceived costs of dental implants. Results show that while 70% of patients are aware of implants, only 30% understand the procedure. Though 60% expressed interest in implants, 45% perceived them as too expensive. Positive attitudes correlated with greater awareness, highlighting the need for enhanced education on the benefits and financial options associated with implants.

Comparative Experimental Evaluation of Orthodontic Appliances for Maxillary Arch Expansion

Background/Objectives: The orthodontic treatment of posterior crossbite using appliances for gradual maxillary expansion is crucial to ensure proper transversal jaw relationships as much as occlusal functionality. The aim of this study was to analyze forces and torques generated by different appliances for maxillary expansion. Methods: Measurements were conducted for the Wilson® 3D® Quadhelix (WQH) and Wilson® 3D® Multi-Action Palatal Appliance (WPA) across various sizes and compared to the Remanium® Quadhelix (RQH). Activations were set to 8 mm for the WQH and RQH and 6 and 8 mm for the WPA. Rotations and root torque were simulated via an activation of 10° for arches. A total of eight test series were conducted. Results: The WPA displayed the highest force and torque values for all movements, far surpassing recommended guideline values (expansion 8.5->15.0 N/46.3-86.5 Nmm, rotation 3.1-6.1 N/40.7-61.4 Nmm, torque 3.9-5.1 N/22.4-29.7 Nmm), and the WQH displayed the lowest values (expansion 2.7-12.6 N/11.1-39.6 Nmm, rotation 0.1-1.7 N/23.0-32.2 Nmm, torque 0.9-2.9 N/3.4-10.5 Nmm). Appliances with the smallest transverse dimensions exhibited the highest force and torque maxima. Conclusions: This study underscores the importance of understanding biomechanical principles in orthodontics for minimizing unintended tooth movements, providing detailed insights into the force systems of appliances acting in the transverse plane, and establishing a foundation for future clinical investigations to validate these in vitro findings.

Effect of malocclusion severity on oral health and its correlation with socioeconomical status in Iranian adolescents

BACKGROUND

This study aimed to assess the effect of malocclusion severity according to the Index of Treatment Need (IOTN) on oral health (dental caries and gingivitis), and its correlation with socioeconomic status (SES) in Iranian adolescents.

METHODS

This descriptive cross-sectional study was conducted on adolescents between 10 and 16 years in Tehran city, who underwent clinical dental examination. The Dental Health Component (DHC) of the IOTN was used to assess the severity of malocclusion. The DMFT index was calculated to assess dental caries, and the gingival index (GI) was calculated for gingival health assessment. For oral hygiene assessment, the Oral Hygiene Index-Simplified (OHI-S) was calculated, and a questionnaire was used.

RESULTS

Totally, 306 adolescents participated in this study. The frequency of IOTN grades was 88 (28.8%), 89 (26.1%) ,49 (16%), 60 (19.6%), and 29 (9.5%) for grades 1 to 5, respectively. The multinomial logistic regression showed that by an increase in OHI-S score, the odds of having IOTN grade 4 compared to grade 1 increased. Postgraduate parental level of education decreased the odds of having IOTN grade 4 compared to grade 1. Furthermore, there was an inverse correlation between oral hygiene practice and the odds of having IOTN grade 5 compared to grade 1.

CONCLUSIONS

Malocclusion may hinder oral hygiene practice, and resultantly increase plaque accumulation. This risk may be amplified in children with lower SES, highlighting the need for preventive and educational oral health programs.

[Strategies for prevention and treatment of vascular and nerve injuries in mandibular anterior implant surgery]

Important anatomical structures such as mandibular incisive canal, tongue foramen, and mouth floor vessels may be damaged during implant surgery in the mandibular anterior region, which may lead to mouth floor hematoma, asphyxia, pain, paresthesia and other symptoms. In severe cases, this can be life-threatening. The insufficient alveolar bone space and the anatomical variation of blood vessels and nerves in the mandibular anterior region increase the risk of blood vessel and nerve injury during implant surgery. In case of vascular injury, airway control and hemostasis should be performed, and in case of nerve injury, implant removal and early medical treatment should be performed. To avoid vascular and nerve injury during implant surgery in the mandibular anterior region, it is necessary to be familiar with the anatomical structure, take cone-beam computed tomography, design properly before surgery, and use digital technology during surgery to achieve accurate implant placement. This article summarizes the anatomical structure of the mandibular anterior region, discusses the prevention strategies of vascular and nerve injuries in this region, and discusses the treatment methods after the occurrence of vascular and nerve injuries, to provide clinical reference.

Effectiveness of 2 Lip Taping Techniques in Infants With Bilateral Cleft Lip and Palate: A Randomized Clinical Trial

OBJECTIVES

This trial was designed to test the efficacy of 2 lip taping methods in modifying the maxillary arch dimensions (MADs) of infants with bilateral cleft lip and palate (BCLP) before lip repair surgery.

DESIGN

Parallel-group randomized clinical trial.

SETTING

The trial was conducted at 3 centers in Baghdad city.

PARTICIPANTS

Thirty-six nonsyndromic infants with BCLP.

INTERVENTION

The eligible infants were randomly assigned to either the first experimental group that received a conventional horizontal tape (3 M Steri strip-1/4 inch) or the second experimental group that received a custom-made tape made of Steri strips and orthodontic extra oral elastics. All of the included infants in both groups had rubber base impressions taken for them at the start of treatment (T1) and right before surgical lip repair (T2). A desktop scanner was used to scan each of the generated models, creating digital models that could be used for outcome evaluation.

MAIN OUTCOMES MEASURES

Virtual MAD measurements were performed by a blinded assessor on the generated digital models both before (T1) and after (T2) treatment.

RESULTS

At T2, both groups showed statistically significant changes in all measured MADs, with a mean difference ranging from 1.36 to 2.95 mm for the conventional taping group and from 1.46 to 7.96 mm for the custom-made one. The comparison of the 2 groups revealed both statistically and clinically significant differences with a P value <.05. The custom-made taping demonstrated more constriction in maxillary arch in terms of changes, which could provide easier surgical manipulation for the cleft parts.

CONCLUSION

Lip taping appears to be an efficient technique for modifying the MADs in infants with BCLP.

Evaluation of anterior teeth crown-root morphology and alveolar bone structure in patients with closed deep overbite using cone beam computed tomography

This retrospective study used cone-beam computed tomography to investigated the crown-root morphology and alveolar bone structure in incisors region in subjects with closed deep overbite and comparison the difference between gender and age. The CBCT images for 40 subjects (group C) with Angle II division 2 were selected from patients of the HeFei Stomatological Hospital from November 2023 to March 2024.20 individual normal occlusion subjects (group A),20 patients with Angle II division 1(group B) were included. The crown-root ratio of the maxillary and mandibular anterior teeth, crown-root angle and alveolar bone structure were measured on the CBCT images, the data were statistically analyzed. In addition to mandibular lateral incisor, the crown-root ratio of maxillary and mandibular anterior teeth in the Class II division 2 group was higher than that in the individual normal occlusion group and the Class II division 1 (P < 0. 05). The crown-root angle of maxillary anterior teeth in the Class II division 2 group was smaller than that in the individual normal occlusion group and the Class II division 1 (P < 0. 05). The alveolar bone thickness of the maxillary central incisor was comparatively smaller, while the alveolar bone height was relatively higher in the Class II division 2 group. Age and gender were associated with change in root lengths and crown-root angle for the Class II division 2 group (P < 0. 05). Patients with closed deep overbite malocclusion exhibit a significant difference compared to the controls for most measurements. The patients presenting with Class II division 2 malocclusion exhibit excessive inward positioning of the anterior teeth, resulting in evident crown-root angle, a large crown-root ratio, and minimal labial alveolar bone. In order to keep the tooth movement within the safe range of alveolar bone movement, it is necessary to strictly control the torque and use appropriate orthodontic force to reduce the risk of bone fenestration, bone dehiscence, gingival recession and root resorption.

Measurement and analysis of condylar morphology and thickness of the roof of the glenoid fossa in patients with unilateral second molar scissor bite

Objective The objective of this study was to measure and analyze the joint space, condylar morphology, and thickness of the roof of the glenoid fossa (RGF) in patients with unilateral second molar scissor bite using cone beam CT (CBCT). Methods A total of 80 patients were included in this study. Forty patients with a normal posterior occlusal relationship, who attended the Department of Orthodontics at the First Hospital of Shanxi Medical University from December 2021 to August 2023, were selected as the control group. The experimental group consisted of 40 patients with unilateral second molar scissor bite during the same period. All patients underwent CBCT scanning, and the resulting images were analyzed using the NNT viewer software in multiplanar reconstruction (MPR). Axial, coronal, and sagittal adjustments were made for each patient. Results In the control group, the right and left joint spaces (PS, SS, AS), the height of the upper part of the condyle, and the depth of the glenoid fossa did not show statistically significant differences (P > 0.05). When comparing bilateral condylar morphology and joint space in the experimental group, it was found that the posterior joint space on the scissor bite side was greater than that on the normal occlusion side, while the anterior joint space on the scissor bite side was smaller than that on the normal occlusal side. Additionally, the height of the upper condyle and the depth of the glenoid fossa on the scissor bite side were greater than that on the normal occlusal side, with statistically significant differences (P < 0.05). However, there were no statistically significant differences in SS, internal and external joint diameter, as well as anterior and posterior diameters (P > 0.05). The comparison of the minimum thickness of the roof of the glenoid fossa in both the sagittal and coronal directions between the patients in the experimental group and the control group showed no statistically significant difference (P > 0.05). Furthermore, the asymmetry index of the supracondylar height in the control group was significantly smaller than that in the experimental group, displaying a statistically significant difference (P < 0.05). The differences in the asymmetry indices of the anterior and posterior diameters of the condyle, as well as the inner and outer diameters, were not statistically significant (P > 0.05). When analyzing the position of the condyle in the sagittal direction of the glenoid fossa in the patients of the control group, it was observed that the majority were in the anterior and medial positions, with only 10% and 5% being in the posterior position. However, the analysis of the condyle position in the sagittal direction of the glenoid fossa in the experimental group revealed statistically significant differences (P < 0.05), with the condyle position on the scissor bite side being more anterior. Conclusion Unilateral second molar scissor bite can result in anterior displacement of the condyle, greater height of the condyle superiorly as well as the depth of the glenoid fossa.

Assessment of Condylar Changes in Patients with Degenerative Joint Disease of the TMJ After Stabilizing Splint Therapy: A Retrospective CBCT Study

BACKGROUND/OBJECTIVES

Degenerative joint disease (DJD) of the TMJ can impact patients' quality of life and complicate orthodontic treatment. Stabilizing splints are a common conservative treatment in managing TMDs symptoms, although their long-term effects on condylar morphology are poorly studied. This study aimed to assess the impact of stabilizing splints on condyle morphology using cone-beam computed tomography (CBCT) in patients with various stages of DJD. Forty-two condyles with pre- (T1) and post- (T2) splint therapy scans were analyzed.

METHODS

CBCT scans were sectioned into sagittal and coronal slices for condyle classification and measurement. T1 and T2 CBCTs were superimposed before linear and area measurements at different poles.

RESULTS

Our results indicate that condyles in the normal group remain unchanged after splint therapy. The majority of subjects in the degenerative groups remained in the same classification group: six out of fourteen degenerative-active patients became degenerative-repair, while three out of twenty-two degenerative-repair patients progressed to degenerative-active. There is no significant remodeling of condylar width pre- and post-splint therapy. On average, there is more bone deposition than reduction in condylar height after splint therapy, although individual variation exists.

CONCLUSIONS

Stabilizing splints offer a low-risk intervention for managing DJD and may contribute to favorable adaptive changes in the condyles.

Weight changes during the initial phase of orthodontic treatment with clear aligners versus fixed appliances: a pilot prospective cohort study

OBJECTIVE

The aim was to assess adult patients' weight changes during the initial phase of orthodontic treatment (OT) with clear aligner therapy (CAT) versus fixed bracket systems (FBS).

METHODS

This pilot prospective cohort study included systemically-healthy adults who were treated with CAT or FBS. Participants with eating disorders and/or undergoing dietary programs were excluded. Weight was assessed using a calibrated digital scale at the start of OT (T1), 6-8 weeks (T2), and 12-16 weeks (T3) after starting OT. A questionnaire was used to record demographic variables, diet and exercise habits, self-reported compliance and discomfort during OT, and use of analgesics. Repeated measures analysis of variance was used to assess the association between treatment type (FBS versus CT) and time-period (T1, T2, T3) on participants' weight while adjusting for baseline covariates such as age, gender, height, and weight.

RESULTS

Forty-two participants (CAT group: 22 and FBS group: 20) were analysed. In the CAT group, there was a slight initial mean weight gain of 0.2 Kg (~ 0.4 pounds) (T2-T1), and 0.8 Kg (~ 1.7 pounds) overall mean weight loss between T1 and T3. For the FBS group, there was a slight initial weight loss of 0.3 Kg (~ 0.7 pounds) (T2-T1) and no overall change between T1 and T3. Treatment type (CAT versus FBS) was not significantly associated with weight changes during the initial phase of OT.

CONCLUSIONS

There were no significant differences in the weight changes during the initial phase of OT with CAT compared with FBS.

CLINICAL RELEVANCE

Clear aligner therapy should not be advertised as a weight loss strategy.

Orthodontic management of severe inversely impacted maxillary central incisors: a case series

Background

Abnormal positioning and dislocation of the central incisor can disturb tooth eruption. Generally, inversely impacted maxillary central incisors do not erupt naturally. Performing traction and applied extrusion of an inversely impacted maxillary central incisor with a high inclination angle of the crown is challenging. This study aimed to examine the possibility of orthodontic treatment for severely inversely impacted maxillary central incisors in a series of case studies.

Methods

The inclination angle of the tooth crown, curvature of the tooth root, and length of the formed tooth root were measured using radiography. The teeth were then fenestrated and traction was applied using a lingual arch appliance with elastics.

Results

The average crown axis inclination was 113°, the degree of root curvature was 97.3°, and the root formation was 36.1%. Although the crown axis inclination and root curvature were severe, all the incisors were aligned in the correct position as vital teeth through surgical and orthodontic treatments.

Conclusions

Traction should be performed in the early period of incisor development when root formation is not progressing, regardless of the tooth angle.

Can Orthodontic Adhesive Systems Inhibit the Formation and Development of White Spot Lesions During Fixed Orthodontic Treatment? A Systematic Review

PURPOSE

This study aims to assess whether orthodontic bonding systems prevent orthodontic-induced white spot lesions (OIWSLs), exploring efficacy and identifying associated factors through a comprehensive systematic review of existing evidence.

MATERIALS AND METHODS

The study complied to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two evaluators screened records, and data were extracted on orthodontic bonding systems, outcomes, and participant characteristics from PubMed/MEDLINE, Cochrane Library, and EM Premium. The search equation focused on white spot lesions and orthodontic bonding. Only in-vivo studies and clinical trials on humans were included, while in-vitro studies were excluded. The risk of bias was assessed using Cochrane's RoB2 tool for RCTs and ROBINS-I tool for non-randomized studies, evaluating key domains related to bias.

RESULTS

The systematic review, including 12 articles with 550 participants and 2,000 teeth, revealed that bonding with nanoparticles of nCaF2-primer and amorphous calcium phosphate-containing adhesives effectively reduced WSLs. In contrast, one-step adhesive without primer (GC Ortho Connect™) was associated with higher and more severe WSLs. Fluoride-releasing primers (Opal Seal™ and Clearfil™) did not exhibit an advantage in demineralization reduction. The inclusion of TiO2 nanoparticles in two studies yielded conflicting results on antibacterial effects.

DISCUSSION

Various nanoparticles incorporated into adhesives or primers exhibit promise in preventing white spot lesions in fixed orthodontic treatment. However, the used evaluation methods, such as clinical examinations or advanced imaging, significantly impact result interpretation. The effectiveness of orthodontic adhesives in preventing WSLs should balance between biocompatibility, bond strength and demineralization control tailored to patient-specific needs.

Tomographic diagnosis of alveolar bone coverage impact in orthodontic planning: cross-sectional study

INTRODUCTION

Alveolar bone coverage can be diagnosed through cone beam computed tomography (CBCT) and this information can prevent orthodontic tooth movement beyond the biological limit.

OBJECTIVE

This study evaluated the impact of the bone coverage (BC) diagnosis by CBCT in the orthodontists' planning.

METHODS

One hundred fifty-nine Brazilian orthodontists suggested treatment plans for six patients at two different times, using two sequential questionnaires. The first questionnaire consisted of extra and intra-oral photographs, one panoramic radiograph; one lateral cephalometric radiograph with Steiner and Tweed analysis, and the patient chief complaint. The second questionnaire included the same presentations of cases with tomographic images and the radiologist's report. The McNemar test assessed the difference between the first and the second treatment plans.

RESULTS

In all six cases, most participants changed the treatment plan after evaluating the CBCT images and the radiologist's report (93.7% in case 5, 78.6% in case 4, 74.2% in case 3, 69.8% in case 6, 66% in case 2 and 61% in case 1; p≤0.01).

CONCLUSION

The evaluation of bone coverage through CBCT images has a substantial impact on the orthodontic diagnosis and planning of the Brazilian orthodontists.

The Mechanical and Clinical Properties of Customized Orthodontic Bracket Systems-A Comprehensive Review

The rise of computer-aided design and computer-aided manufacturing (CAD/CAM) and 3D printing technologies in orthodontics has revolutionized the development of customized labial and lingual bracket systems with a variety of materials, which offer potential advantages over traditional orthodontic brackets. To highlight the current state of knowledge regarding the mechanical and clinical properties of CAD/CAM and 3D-printed custom bracket systems, we conducted a comprehensive search across the PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases to identify relevant articles published before April 2024. Mechanical (including fracture toughness, hardness, modulus of elasticity, frictional resistance, slot accuracy, torque transmission, and shear bond strength) and clinical (including treatment efficiency and duration, cost, and comfort) properties were compared between traditional and customized orthodontic bracket systems in the current review. Our findings suggest that customized brackets have the potential to increase bracket slot precision, reduce treatment time, and offer cost-efficiency. However, it is worth noting that the advantages and disadvantages of customized bracket systems vary depending on the bracket material and the manufacturing methods, warranting comprehensively controlled investigations in the future.

Facial soft tissue characteristics of patients with different types of malocclusion

BACKGROUND

This study aimed to investigate the facial soft tissue characteristics of patients with different types of malocclusion.

METHODS

The 3dMD scanning data of patients with malocclusion admitted to our hospital from January 2018 to April 2022 were analyzed retrospectively. Forty-seven patients with Class I malocclusion, 43 patients with Class II malocclusion and 44 patients with Class III malocclusion were selected. All patients underwent 3dMD scans prior to orthodontic treatment. Then the differences in the 3D morphological parameters of the facial soft tissues were compared between different sexes and different types of malocclusion. Spearman's correlation was further used to analyze the correlation between each parameter and the classification of malocclusion.

RESULTS

In the Class I group and Class II group, there were no significant differences in the 3D morphometric parameters of malocclusion patients of different sexes (P > 0.05). There were significant differences between Al (R)-AL (L), Ac (R)-Ac (L), Prn-Ac (L), n-Prn-Sn, and Al (R)-Al (L)/Ac (L)-Ah (L) values among the three groups of patients. Spearman correlation analysis showed that Ac (R)-Ac (L) and Al (R)-Al (L)/Ac (R)-Ac (L) were correlated with the type of malocclusion.

CONCLUSION

Differences in facial soft tissues exist in patients with Class I, II, and III malocclusion. 3dMD technique may be helpful in developing an effective treatment plan prior to orthodontic treatment.

Mandibular morphology in schizophrenia patients compared with non-psychiatric controls using digital panoramic radiography: a retrospective cross-sectional study from Istanbul, Türkiye

BACKGROUND

Schizophrenia is a chronic severe mental disorder characterized by impairment in cognition, emotion, perception, and other aspects of behavior. In light of the association of craniofacial dysmorphology with schizophrenia, mandibular morphology may provide clues about the role of neurodevelopment in the pathophysiology of schizophrenia. This retrospective cross-sectional study aimed to compare the mandibular morphology of patients with schizophrenia with controls using digital panoramic radiography (DPR).

METHODS

302 recorded diagnostic panoramic images obtained from 143 schizophrenia patients (98 males, 45 females), and 159 controls (73 males, 86 females), aged 18-45 years, were evaluated. Seven mandibular measurements consisting of ramus height, condylar height, gonial angle, antegonial angle, antegonial notch depth, ramal notch depth and bigonial width were measured from the DPRs in a double-blinded manner. Bivariate comparisons were carried out using the Independent t-test and Mann-Whitney U test. Logistic regression analysis was used for multivariate comparisons.

RESULTS

Linear measurements were higher while angular measurements were lower in schizophrenia patients. Regression analyses indicated that female patients had greater ramus height (OR = 1.243; P = 0.001), condylar height (OR = 1.463; P = 0.048) and bigonial width (OR = 1.082; P < 0.001); male patients had greater ramus heights (OR = 1.216; P = 0.001) and bigonial width (OR = 1.076; P < 0.001) as well as lower antegonial angle (OR = 0.908; P = 0.012) compared to their respective controls.

CONCLUSION

Quantitative differences in mandibular morphology in schizophrenia patients versus controls deserve attention and corroborate with the concept of abnormal neurodevelopment in schizophrenia.

Nasal profile changes after orthodontic tooth extraction in Class II, Division 1 malocclusion patients: A retrospective study

INTRODUCTION

This study aimed to investigate changes in the facial soft-tissue profile, especially the nose, following fixed orthodontic treatment, with or without tooth extraction, in individuals diagnosed with dental Class II malocclusion.

MATERIALS AND METHODS

Cephalometric images of 81 individuals with dental Class II malocclusion who underwent fixed orthodontic treatment were assessed before and after treatment. The participants were categorized into three groups: non-extraction; upper first premolar extraction; and four first premolar extractions. The parameters measured were: upper lip height, upper lip to E-plane, lower lip to E-plane, lower lip height, nasolabial angle, nasomental angle, facial convexity, lower anterior face height, soft-tissue facial convexity, nasal tip angle, nasal bridge length, N'-nasal bridge point, nasal bone length, nasal bone angle, nasal depth, columella convexity, and nose height.

RESULTS

Within the upper two extraction group, there were significant increases at the start and end periods in nasolabial angle (P = 0.023), nasal depth Pr to Ac (P = 0.027), and nasal depth Pr to N-Prn (P = 0.040); and decreases in columella convexity (P = 0.010), upper lip to E-plane (P = 0.009), and nasomental angle (P = 0.009). There were significant results in comparisons between measurements based on the extraction status in the mean nasolabial angle (P = 0.011), mean columella convexity (P = 0.028), and mean lower lip to E-plane (P = 0.045).

CONCLUSION

Orthodontic treatment involving tooth extraction may potentially affect the nasolabial angle and nasal depth. During treatment planning, it is crucial to consider the potential changes that may occur to the nose and any alterations that may be needed to achieve the desired esthetic outcome.

A Critical Review on the Factors Affecting the Bond Strength of Direct Restorative Material Alternatives to Amalgam

This article comprehensively reviews the performance of simplified direct restorative materials that have the potential to be an alternative to amalgam. Following an understanding of the material structures and clinical performances, this review provides an analysis of the bonding mechanisms and influential factors on the bond strength. These factors include substrate-related variations, involving primary vs. permanent dentin, sound- vs. caries-affected/demineralized dentin comparisons and surface-related factors and pretreatments. Special attention is given to the factors changing the substrate surface, such as different contaminants, remedy methods after contamination and different conditioning methods related to the materials. Variations in sample preparation and bond strength test parameters are also evaluated for the analysis of the outcomes. This review aims to provide an overview of the factors involved in the application procedure of direct restorations together with in vitro testing variations to guide the selection of suitable materials by understanding strengths and shortcomings.

Investigating the dynamic relationship of sleep-disordered breathing, orthodontic treatment needs, and dental esthetics in the general population

BACKGROUND

Sleep-disordered breathing (SDB) is characterized by upper airway dysfunction and is linked to severe health issues. Individuals with SDB have distinct craniofacial morphology for which orthodontists are most suitable for the management due to their dental expertise.

AIM

This study aims to discern key differences in dental parameters between individuals with and without SDB.

METHODS

The present study is a cross-sectional observational study conducted for 12 months. Out of 70 participants, 35 were placed in the SDB group as per the Berlin questionnaire (BQ) and 35 in the control aged 18-22 years. Criteria excluded individuals with preexisting illnesses, missing teeth, tonsillectomy, orthodontic or jaw surgeries, cleft lip/palate, or craniofacial anomalies. Dental assessments included interdental width, palatal vault depth and shape, molar relation, overjet, and overbite. In addition, self-perceived orthodontic treatment needs were evaluated as a secondary measure.

RESULTS

In the SDB group, interdental distances were significantly reduced in the canine, first premolars, second premolars, and molar regions by 2, 3, 4, and 1.8 mm, respectively. A noticeable V-shaped arch was observed. Overjet and overbite increased by 42.85% and 31.42%, respectively, with Class 1 malocclusion more prevalent than Class 2. The Berlin questionnaire identified 54.3% as high-risk SDB. The Index of Orthodontic Treatment Need-Esthetic Component (IOTN-AC) revealed that 68.6% of snoring participants required orthodontic treatment.

CONCLUSION

Individuals with SDB exhibit a constricted maxilla and reduced interdental measurements, indicating a moderate risk. The Berlin questionnaire proves valuable in assessing SDB severity. Moreover, individuals displaying signs of SDB often present a high prevalence of orthodontic treatment needs, as indicated by the IOTN-AC.

Determinants of Cormack–Lehane grading for glottic exposure in microlaryngeal surgery in Middle Delta Egyptian patients

Background

Laryngoscopy is a diagnostic procedure utilized in critical care to examine and visualize the larynx through the diversion of upper airway structures. Its primary functions are airway management and tracheal intubation. The objective of this study was to detect the predictors of laryngeal exposure during microlaryngeal surgery (MLS).

Methods

An analytical cross-sectional study was conducted on a consecutive sample of 100 patients presenting laryngeal lesions that were trans-orally microsurgeries to treat various glottic diseases (biopsies revealed 68% benign lesions such as vocal fold polyps, cysts, and nodules, and 32% glottic masses) and prepared for MLS.

Results

This study included 100 patients presenting laryngeal lesions from both sexes with the age of 47.0 ± 14.7 years, in multivariate logistic regression analysis, all these parameters were significant predictors for Cormack–Lehane and Italian Grading (P < 0.05). Body mass index (BMI) (OR = 3.449, 95% CI = 2.463–8.187), mandibular protrusion test (OR = 2.981, 95% CI = 1.922–4.044), mento-sternal length (OR = 3.722, 95% CI = 1.980–7.794), and atlanto-occipital joint (AOJ) extension (OR = 1.572, 95% CI = 1.865–4.263). Cormack–Lehane and Italian Grading was significantly associated with BMI, mandibular protrusion test, Mallampati Index, mento-thyroid, mento-sternal length, and AOJ extension, it increased with BMI of > 35, with more protruded mandible (class C), higher Mallampati Index (class III) and shorter mento-sternal distance (≤ 12.5 cm).

Conclusions

During microlaryngeal surgery, BMI, mandibular protrusion test, Mallampati Index, mento sternal and AOJ extension were significant predictors of Cormack–Lehane and Italian Grading which makes it easier for laryngeal exposure.

Poly-Ether-Ether-Ketone versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 2: periodontal health and microbial biofilm assessment

BACKGROUND

Retainers have the potential to detrimentally impact periodontal health and contribute to tooth decay.

OBJECTIVES

To investigate periodontal health and bacterial biofilm related to Poly-Ether-Ether-Ketone (PEEK) fixed retainers as compared to Dead-soft coaxial fixed retainer (DSC).

TRIAL DESIGN

A two-arm parallel groups single-centre randomized clinical trial.

METHODS

The trial included patients whose orthodontic treatment was completed and required retainers. Participants were randomly assigned into two retainer groups: PEEK retainers, prepared by computer-aided design and manufacturing into 0.8 mm wire form, and DSC retainers. The objectives included assessing periodontal health through plaque accumulation index (PI), bleeding on probing (BOP), periodontal pocket depth (PPD), gingival index (GI), calculus index (CI), and alveolar bone height (ABH) assessment. Biofilm assessment involved bacteriological screening of aerobic, facultative anaerobic, mutans streptococci, and lactobacilli. The periodontal indices and microbiological screening as well as were assessed at the debonding stage (T0), 1-month (T1), 3-month (T3), and 6-month (T6) after the commencement of the trial, except for the ABH, which was recorded using periapical radiograph at T0 and T6.

BLINDING

Single blinding of participants in addition to the bacteriological specialist.

RESULTS

Initially, the trial enrolled 46 participants, aged between 12 and 28 years, and were randomly assigned to two groups, with 23 participants in each group. Subsequently, one participant withdrew from the trial, resulting in a total of 45 participants whose data were analysed. Assessment of the periodontal indices, excluding the CI (P = .480), revealed statistically but not clinically significant differences between groups after 6-month of retention (P = .016 of PI, P = .020 of BOP, P = .05 of PPD, and P = .01 of GI). There was slight plaque accumulation, normal PPD (approximately 1 mm), healthy to mild gingivitis with a GI of less than 1 and BOP was around 10%. Concerning the ABH, there was a noticeable reduction in its score after 6 months, particularly in the PEEK group, although the difference was not statistically significant (P = .102). Furthermore, the bacteriological viable count did not show any significant difference between the groups during the recall visits.

HARMS

There have been no reported negative consequences.

LIMITATIONS

Blinding the assessor of periodontal indices was not feasible due to the nature of the intervention. The trial follow-up duration was limited.

CONCLUSIONS

Both the PEEK and DSC retainers have comparable impacts on periodontal health and bacterial accumulation and composition during the retention period.

TRIAL REGISTRATION

NCT05557136.

Impact of Maxillomandibular Sagittal Variations on Upper Airway Dimensions: A Retrospective Cross-sectional CBCT Evaluation

AIM

This study aimed to analyze the upper airway dimensions in adult patients with different anteroposterior (sagittal) skeletal malocclusions (class I, II, and III) using cone beam computed tomography (CBCT) imaging.

MATERIALS AND METHODS

This retrospective cross-sectional study involved 90 CBCT records from adult subjects who were categorized into three skeletal groups based on their ANB values: Class I (n = 30), class II (n = 30), and class III (n = 30) and were evaluated. The following upper airway measurements were considered: oropharyngeal airway volume, hypopharyngeal airway volume, pharyngeal airway volume, oropharyngeal airway length, hypopharyngeal airway length, pharyngeal airway length, the most constricted site of the pharyngeal airway, and the most constricted cross-sectional area (MIN-CSA) of the pharyngeal airway. Additionally, the volume of the intraoral airway was determined. Pearson's correlation test was employed to evaluate the relationship between age and upper airway dimensions.

RESULTS

Significant differences in upper airway volume were found among skeletal groups in the hypopharyngeal (p = 0.034) and pharyngeal (p = 0.004) regions, with class III patients showing larger volumes compared to class II. Oropharyngeal (p = 0.044) and pharyngeal (p = 0.011) lengths were shorter in class III than in class I. In contrast, the narrowest cross-sectional area of the pharyngeal airway was larger in class III compared to class II (p = 0.003) and class I (p = 0.032). Class III patients had a significantly greater intraoral space volume than class II patients (p = 0.036).

CONCLUSIONS

The present study found significant differences in upper airway dimensions among adults with varying maxillomandibular sagittal relationships. Class III patients had larger hypopharyngeal and pharyngeal volumes, but shorter oropharyngeal and pharyngeal lengths compared to other classes. The narrowest pharyngeal area was larger in class III, with gender and age also influencing airway dimensions.

CLINICAL SIGNIFICANCE

These findings underscore the need to consider skeletal relationships, gender, and age in airway assessments. Accordingly, these factors can help clinicians better understand the correlation between airway dimensions and jaw position for accurate diagnosis and treatment planning of orthodontic and surgical interventions. How to cite this article: Aldhorae K, Ishaq R, Alhaidary S, et al. Impact of Maxillomandibular Sagittal Variations on Upper Airway Dimensions: A Retrospective Cross-sectional CBCT Evaluation. J Contemp Dent Pract 2024;25(10):955-962.

Improvements of facial profile and smile aesthetic using temporary anchorage devices and botulinum toxin: a case report

The severe gummy smile and a skeletal class II profile pose challenges in treatment. This case report outlines an effective alternative for addressing these problems in a patient with skeletal class II division 2, class II molar relationship, retroclination of upper incisors, and lip protrusion. Treatment objectives included normalizing the overjet and overbite, improving the gummy smile, and establishing a satisfactory occlusion. A three-dimensional simulation was performed to consult with the patient, assess possible results, and predict treatment biomechanics. The treatment involved the use of two zygomatic and one inter-radicular temporary anchorage devices, along with botulinum toxin. After the 2-year follow-up, a satisfactory dental occlusion, aesthetic improvement, and adequate function were achieved. This approach offers a viable alternative to orthognathic surgery for adults with skeletal class II malocclusion and a severe gummy smile due to hypermobile lip.

Craniofacial features and incisor position design of esthetics population after orthodontic treatment

OBJECTIVES

This study aims to provide craniofacial features and incisor position prediction models among esthetics population after orthodontic treatment.

METHODS

A total of 338 patients with esthetic profiles were selected from 1 055 post-orthodontic adults based on inclusion and exclusion criteria and scored by five dental students. Mean values of cephalometric measurement were demonstrated with gender and sagittal skeletal pattern (ANB) differences assessed by generalized estimating equation. Correlations among age, skeletal, and soft tissue variables in different genders were determined. Multivariate analysis was used to assess the influence of skeletal and soft tissue variables on orthodontic incisor position.

RESULTS

Within the esthetic cohort after orthodontic treatment, gender differences existed in cranial and mandibular length, mandibular rotation, protrusion of pogonion, inclination of maxillary incisors, upper lip thickness, lower 1/3 face height, and nose protrusion. However, in class Ⅰ malocclusion, the development of the chin showed no significance, whereas the protrusion of the lower lip significantly differed between genders, with less protrusion in males. In males, the protrusion of lip and chin varied among groups, with thinner basic upper lip thickness of class Ⅱ than class Ⅰ and greater lower lip height of class Ⅲ than class Ⅰ. In females, the protrusion and height of the upper lip and chin varied in groups, with thicker basic upper lip thickness of class Ⅲ than class Ⅰ. Upper lip thickness, female basic upper lip thickness, and female lower lip height were correlated with age. The protrusion of the upper lip was mainly correlated with posterior cranial base, mandibular body length, ANB in male and SNA, ANB, sagittal maxillary length, mandibular rotation, and protrusion of pogonion in female. The protrusion of the lower lip in males was mainly correlated with ramus height, mandibular rotation, protrusion of pogonion in male and ANB, mandibular rotation, and protrusion of pogonion in females. After employing skeletal variables to fit dental parameters, optimal results were achieved in male IMPA (adjusted R2=0.712) and female G Vert-U1 (adjusted R2=0.795). After employing skeletal and soft tissue variables simultaneously, optimal results were achieved in male and female G Vert-U1, which was mainly influenced by the protrusion of the chin and nasal base in males (adjusted R2=0.836) and the protrusion of the nasal base as well as ANB in females (adjusted R2=0.842).

CONCLUSIONS

This study demonstrated the craniofacial features of esthetics population after orthodontic treatment and revealed the correlation of gender, age, skeleton, and soft tissues to provide reliable prediction models for aesthetic orthodontic incisor position.

Effect of Two Different Penetration Depths of Micro-osteoperforation on the Rate of Orthodontic Tooth Movement: A Prospective Clinical Study

Objective

The objective is to evaluate the effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement over 60 days. In addition, the amount of pain and discomfort caused by the MOP was evaluated.

Materials and Methods

A total of 22 patients (18-30 years) who need fixed orthodontic treatment were recruited and randomly assigned into two groups. Randomization for determination of the experimental side and depth of perforations was done using sealed envelopes. On each patient, the other side of the mouth worked as control side with no MOPs. Patients in group 1 (MOP-5) received 3MOPs on the buccal surface of the alveolar bone each at 5 mm depth, whereas patients in group 2 (MOP-7) received 3MOPs on the buccal surface of the alveolar bone each at 7 mm depth. The amount of canine retraction was measured every 30 days at two intervals on both sides of the mouth. Pain perception was measured after 1 h, 24 h, 72 h, 7 days, and 28 days of procedure. MOP-related pain was measured using a visual analog scale. The level of statistical significance was P ≤ 0.05.

Results

The result of the intra-examiner reliability using intraclass correlation coefficient more than 0.97 (P < 0.001), indicating excellent repeatability and reliability of the measurements. The baseline characteristics between groups were similar (P > 0.05). Both the groups demonstrated a significantly higher canine movement than the control group. No significant difference was seen between the MOP-5 and MOP-7 groups (P > 0.05) in terms of canine retraction. Mild-to-moderate pain was experienced only in the first 24 h of the procedure.

Conclusion

Three MOPs with a depth of 5 mm can be performed as an effective method to increase the rate of tooth movement. However, increasing the depth of perforation beyond 5 mm does not additionally enhance tooth movement.

Incorporating nanosilver with glass ionomer cement-A literature review

OBJECTIVES

The objectives of this study were to retrieve and review studies that incorporated nanosilver with GIC and summarise the evidence regarding the properties of nanosilver-modified GIC.

MATERIALS AND METHODS

Two independent researchers performed a literature search using the keywords (nanosilver OR nano-silver OR (nano silver) OR (silver nanoparticles)) AND (GIC OR (glass ionomer cement) OR (glass ionomer cements)) in PubMed, Web of Science and ScienceDirect.

RESULTS

A total of 368 articles were identified. After removing duplicate results, titles and abstracts were screened for eligibility. Full texts of publications that investigated the manufacture and properties of nanosilver-modified GIC were retrieved and analysed. Finally, 21 studies were included.

CONCLUSIONS

All of the studies reviewed in this investigation included the incorporation of nanosilver in GIC. The proportions of nanosilver added into GIC varied from 0.05 % to 50 %. Thirteen studies investigated the antimicrobial properties of nanosilver-modified GIC; all studies supported that adding nanosilver enhanced antimicrobial effectiveness. Nineteen studies reported the mechanical properties including compressive strength, flexure strength, tensile strength, and microhardness of nanosilver-modified GIC; but the results were inconclusive. Four studies tested the bonding strength of nanosilver-modified GIC to dentine and found that adding nanosilver would not influence the bonding property of GIC. Some studies explored fluoride release level, colour stability, and cytotoxicity of nanosilver-modified GIC; but the results were all inconclusive.

CLINICAL SIGNIFICANCE

This literature review is the first study to retrieve and summarise the findings and evidence regarding nanosilver-modified GIC research. It can provide clinicians with clinically relevant information about novel GIC materials that can be used in their treatment decisions.

Effects of mechanical loading on matrix homeostasis and differentiation potential of periodontal ligament cells: A scoping review

Various mechanical loadings, including mechanical stress, orthodontics forces, and masticatory force, affect the functions of periodontal ligament cells. Regulation of periodontal tissue destruction, formation, and differentiation functions are crucial processes for periodontal regeneration therapy. Numerous studies have reported that different types of mechanical loading play a role in maintaining periodontal tissue matrix homeostasis, and osteogenic differentiation of the periodontal ligament cells. This scoping review aims to evaluate the studies regarding the effects of various mechanical loadings on the secretion of extracellular matrix (ECM) components, regulation of the balance between formation and destruction of periodontal tissue matrix, osteogenic differentiation, and multiple differentiation functions of the periodontal ligament. An electronic search for this review has been conducted on two databases; MEDLINE via PubMed and SCOPUS. Study selection criteria included original research written in English that reported the effects of different mechanical loadings on matrix homeostasis and differentiation potential of periodontal ligament cells. The final 204 articles were mainly included in the present scoping review. Mechanical forces of the appropriate magnitude, duration, and pattern have a positive influence on the secretion of ECM components such as collagen, as well as regulate the secretion of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases. Additionally, these forces regulate a balance between osteoblastic and osteoclast differentiation. Conversely, incorrect mechanical loadings can lead to abnormal formation and destruction of both soft and hard tissue. This review provides additional insight into how mechanical loadings impact ECM homeostasis and multiple differentiation functions of periodontal ligament cells (PDLCs), thus making it valuable for regenerative periodontal treatment. In combination with advancing technologies, the utilization of ECM components, application of different aspects of mechanical force, and differentiation potential of PDLCs could bring potential benefits to future periodontal regeneration therapy.

Prevalence and Etiology of Maxillary Midline Diastema among University Students, Hodeidah Governorate, Yemen: A Cross-sectional Study

AIM

This study assessed the prevalence and etiological factors of maxillary midline diastema (MMD) in students attending different colleges and universities in Al-Hodeidah governorate, Yemen.

PARTICIPANTS AND METHODS

A total of 1,661 participants from different universities in Al-Hodeidah governorate were assessed, analyzed, and screened for the presence or absence of MMD. Only 246 had positive MMD and were divided five age-groups. Maxillary midline diastema width was assessed, and three groups were established: groups I (0.5-1 mm), II (1.1-2 mm), and III (over 2 mm). Associations of MMD with gender, family history, and etiology of MMD were documented. The data were recorded and statistically analyzed.

RESULTS

Out of the total students from different colleges, 1,107 were males (66.6%). The 19-20-year age-group was the largest (712; 42.9%), and 264 participants had positive MMD (15.9%). A significant difference in MMD was found between genders (p = 0.002), but no significant differences were found among different age-groups (p = 0.511). Highly attached labial frenum attachment was the most frequent cause of MMD. Males were larger in number and had higher percentages for all different causes, and a significant difference was observed between genders in terms of highly attached labial frenum and generalized spacing parameters (p = 0.004, 0.009). The Chi-squared test showed significant differences in family history and presence of MMD between genders (p = 0.016). Large MMD widths were recorded in groups I, II, and III (1.00, 1.5, and 2.1 mm, respectively), which were together 108 (83.1%), 60 (87.0%), and 16 (53.3%), respectively.

CONCLUSION

The prevalence of MMD can be considered high in the participants and slightly higher in males. Among the causative factors of MMD, a highly attached labial frenum was the most common cause. Group II recorded the highest number of participants with large MMD widths, followed by group I.

CLINICAL SIGNIFICANCE

Addressing the prevalence and causes of MMD can result in proper planning to minimize further esthetic appearances and functional complications. How to cite this article: Al-Zazai HSAA, Al-Haddad K, Al-Harazi G, et al. Prevalence and Etiology of Maxillary Midline Diastema among University Students, Hodeidah Governorate, Yemen: A Cross-sectional Study. J Contemp Dent Pract 2024;25(10):968-975.

Differences in the Buccolingual Inclinations of Premolars Among Class II Division I Subjects With Different Vertical Facial Patterns

BACKGROUND

 Understanding the attributes of vertical patterns is essential for delivering optimal orthodontic care. Cone-beam computed tomography (CBCT) represents a valuable resource for assessing the buccolingual inclination of the teeth. The present research delves into examining the buccolingual inclination of premolars in nongrowing individuals exhibiting diverse vertical facial patterns.

METHODS

CBCT scans of 66 adult patients (31 males and 35 females), mean age 31.6 years (SD = 6.4 years), exhibiting class II division I maxillomandibular relationships, were employed. Participants were categorized into three groups based on linear and angular measurements: normodivergent group (n = 22), hypodivergent group (n = 22), and hyperdivergent group (n = 22). The independent samples t-test and Mann-Whitney U test were conducted to investigate statistical differences in the buccolingual inclination of the premolars among the three vertical patterns.

RESULTS

 Statistically significant differences between the three groups were observed in the buccolingual inclinations of both maxillary and mandibular first and second premolars (p < 0.05). The upper right first premolars exhibited a significantly increased buccal inclination in the normodivergent group compared to the hypodivergent group (p < 0.05). In contrast, the two groups had no notable differences in the inclination of the remaining premolars. The upper right and left first premolars exhibited a significantly increased buccal inclination in the hyperdivergent group compared to the hypodivergent group (p < 0.05). In contrast, there were no notable differences in the inclination of the remaining premolars between the two groups. The lower left first premolars exhibited a significantly increased lingual inclination in the hyperdivergent group compared to the normodivergent group (p < 0.05). In contrast, the two groups had no notable differences in the inclination of the remaining premolars. The upper right second premolars exhibited a significantly increased buccal inclination, and the lower left second premolars exhibited greater lingual inclination in the normodivergent group than in the hypodivergent group (p < 0.05). In contrast, there were no notable differences in the inclination of the remaining premolars between the two groups. The upper right and left second premolars exhibited a significantly increased buccal inclination, and the lower left second premolars exhibited greater lingual inclination in the hyperdivergent group than in the hypodivergent group (p < 0.05). In contrast, there were no notable differences in the inclination of the lower right second premolars between the two groups. There were no notable differences in the inclination of the second premolars between the hyperdivergent and normodivergent groups.

CONCLUSIONS

 In individuals presenting with class II relationships, the buccolingual inclinations of the first and second premolars exhibit similarities and variations across distinct facial patterns. As such, it is imperative for orthodontic practitioners to exercise meticulous consideration of these nuances throughout treatment.

Evaluating the efficacy of platelet-rich plasma on orthodontic tooth movement rate: A systematic review and meta-analysis

BACKGROUND

The main objective of this study was to evaluate the effect of autologous platelet-rich plasma (PRP) on acceleration of the orthodontic tooth movement and assess the evidence based on the available literature.

METHODS

The trial was registered and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic databases including PubMed, Cochrane, Scopus, Central Register of Controlled Trials, and Google Scholar were searched for randomized controlled studies of PRP on the rate of tooth movement. The search was restricted to articles published in English between January 2000 to 31 December 2023. The search was completed by two reviewers independently and the risk of bias was evaluated using the Cochrane Risk of Bias tool (RoB 2.0) and meta-analysis was performed. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was done to determine the certainty of evidence.

RESULTS

Thirteen studies were included in the systematic review and 10 were included in the quantitative analysis. A random-effects model for meta-analysis of seven studies evaluating the rate of canine retraction revealed a statistically significant increase in the rate of orthodontic tooth movement of 0.38 mm/month in 1 month (121 patients; 95% confidence interval [CI] 0.27-0.49; I2 = 35%; P < 0.001) which decreased to 0.09mm/month in the fourth month (80 patients; 95% CI 0.02-0.17; I2 = 0%; P < 0.02). Three studies that considered en masse retraction revealed a mean difference of 0.36mm over 3 months (40 patients; 95% CI -0.23 to 0.94; I2 = 74%; P < 0.23).

CONCLUSIONS

The study suggests that PRP application can accelerate tooth movement, but its effects decreased over 4 months. The results should be interpreted cautiously due to the study's inherent limitations.

A Novel Approach for Improving Midface Aesthetics: A Pilot Study

Background

Asian individuals often seek solutions to address midface depression and enhance nasal alar base morphology to achieve Western facial aesthetics. Current treatment options, including injections and invasive procedures, have limited efficacy and safety. To address these challenges, we introduced the "modified A-10 surgery," which integrates the Point A-Koji method, titanium plates, and artificial dermis insertion.

Methods

The efficacy of the modified A-10 surgery was illustrated using a case study of a 22-year-old woman. Surgical planning was based on dental cone-beam computed tomography data, with lateral cephalometric radiographs used to determine the titanium plate dimensions. The surgery involved customized plate alignment, fixation, and artificial dermis insertion.

Results

The modified A-10 surgery substantially improved facial aesthetics and structural parameters. Facial convexity increased from 15.5 degrees to 23.2 degrees, enhancing the 3-dimensionality. The nasolabial angle shifted from 91.9 degrees to 110.2 degrees, achieving the desired mouth projection. Other measurements, such as the E-line to the lower lip and the distance from point A to the subnasal point, contributed to refined aesthetics. The nasal alar base thickness increased by 2.2 mm (19.5%), correcting the depression.

Conclusions

The modified A-10 surgery represents a minimally invasive and comprehensive solution for midface depression and nasal alar base enhancement. By combining the Point A-Koji method, titanium plates, and artificial dermis insertion, this surgery successfully achieved improved facial aesthetics and contours. The results validate its potential as a long-term solution, with implications for antiaging interventions and promising avenues for future research.

Effect of different mouthwash solutions on the surface morphology, nanohardness and flexural modulus of nickel-titanium orthodontic wire

Objective

This laboratory study aimed to evaluate the effect of different mouthwash solutions on the surface and mechanical properties of NiTi arch wire.

Methods

This experimental study was conducted at the Department of Preventive Dental Sciences, College of Dentistry, Princess Nourah bint Abdulrahman University, Saudi Arabia from September 2023 to November 2023. A 30 mm NiTi wires in length with 0.017 × 0.022" in dimensions were selected and equally divided into four groups: Control (G0) group wires were immersed in distilled water (DW); G1 wires were immersed in antiseptic mouthwash; G2 wires were immersed in fluoridated mouthwash; and G3 wires were immersed in therapeutic mouthwash. Surface morphology, nanohardness, and flexural modulus were evaluated at 24-hours, four weeks, and eight weeks' time points. Data were statistically analyzed using a two-way analysis of variance (P<0.05).

Results

The arch wires immersed in DW showed insignificant effects on surface roughness, nanohardness, and flexural modulus at different time points. However, all the experimental groups showed a significant effect of time and immersion solutions on the said properties (P<0.05). At the end of eight weeks, G3 showed the highest surface roughness (0.346 ± 0.032 µm) and the lowest nanohardness (1.350 ± 0.412 GPa) and flexural modulus (3.960 ± 0.140 MPa) compared to other study groups.

Conclusions

The efficiency of tooth realignment could be influenced by the detrimental influence of fluoride and hydrogen peroxide mouthwash solutions on superelastic NiTi arch wires.

Pretreatment of enamel with Riboflavin activated photodynamic therapy and Er, Cr: YSGG laser for bonding of orthodontic bracket with adhesive modified with cerium oxide nanoparticles

AIM

To assess the degree of conversion (DC) and shear bond strength (SBS) of experimental adhesive (EA) infused with and without 1 % Cerium oxide (CeO₂)-NPs on metallic bracket bonded to enamel conditioned with three different pretreatment regimes PDT-activated (Riboflavin) RF, ECY (Er, Cr: YSGG), and Phosphoric acid (PA).

MATERIAL AND METHOD

EA and EA modified with 1 % CeO₂-NPs were prepared. Characterization of CeO2NPs was assessed using a scanning electron microscope (SEM). Seventy-two premolars extracted due to periodontal or orthodontic reasons were disinfected. Samples were mounted and allocated into three groups according to enamel surface treatment before bracket bonding. Samples in Group 1 were pretreated with Traditional 37 % PA-gel; Specimens in Group 2 surface treated with RF-activated PDT, and samples in Group 3 were conditioned using ECY. Brackets were placed on conditioned surfaces and samples were aged and underwent SBS testing using UTM. ARI index was used to assess bond failure. DC was evaluated for both adhesives using FTIR. ANOVA and Tukey post hoc test were used to compare the means and standard deviation (SD) of SBS and DC in different experimental groups.

RESULTS

Enamel conditioned with PA and RF activated by PDT demonstrated comparable bond values with 1 % CeO2 infused in EA and EA (p>0.05).ARI analysis shows that enamel conditioned with PA and RF activated by PDT showed the majority of failure types between 1 and 2 irrespective of the type of adhesive. DC value in EA (73.28±8.37) was the highest and comparable to 1 % CeO2 infused in EA (66.48±6.81) CONCLUSION: RF-activated PDT can be used alternatively to 37 % PA for enamel conditioning when bonding metallic brackets. Infiltration of 1 % CeO2 NPs in EA improves SBS irrespective of the type of enamel conditioning. Infusion of 1 % CeO2 NPs in EA demonstrates no significant difference in DC compared to EA.

Sexual dimorphism in the permanent maxillary first molar in a population of Maharashtrian ancestry: A cross-sectional study

Introduction

Teeth, being the most stable tissues in the body, can serve as excellent sources in forensic investigations. Tooth size standards based on odontometric investigations can be used for sex determination. The aim of this study was to evaluate the existence of sexual dimorphism in the buccolingual and mesiodistal dimensions of permanent maxillary first molars in a population of Maharashtrian ancestry.

Materials and methods

This study was conducted on 200 subjects (100 males and 100 females) of the Maharashtrian population, in the age group of 18-25 years. The buccopalatal (BP) and mesiodistal (MD) diameters of the maxillary first molars were measured using digital vernier callipers on the study casts.

Results

Unpaired t-tests and paired t-tests were used to analyse the data. There was a statistically significant sexual dimorphism (P < 0.01) in the permanent maxillary first molar dimensions in the Maharashtrian population.

Conclusion

Sexual dimorphism in permanent maxillary first molars may serve as a supplementary tool in sex determination and also provide population-specific baseline data.

Improvement of the Facial and Dental Esthetics With Surgery-Only Approach

With the development and introduction of orthodontic techniques and surgical protocols, modern patient prototypes are emerging. This paves the way for new approaches to the treatment of dentomaxillofacial deformities. The aim of the authors' study is to determine the appropriate timing and procedure for orthognathic surgery and to obtain the best patient and physician-oriented results. It is stated that surgery first and surgery only approaches are protocols that increase the motivation for treatment, with esthetic improvement being the priority. In this case report, the treatment of the authors' patient, who complained of asymmetry and planned to have a prosthetic restoration after correction of the skeletal deformity, with only a surgical protocol, is described. Treatment of dentomaxillofacial deformities involves a comprehensive analysis of patient, orthodontist, and surgeon-specific variables. Within appropriate indications, only a surgical approach can be an ideal approach for patients and specialist physicians in a short time.

Varghese R, Sisodia M, Kumar Gupta N, Chandrakar A. Up-cycling the dental waste materials: Going green in dentistry

The depletion of natural resources due to the extensive use of various materials in dentistry is a growing concern. A significant contributor to this issue is the lack of recycling practices, leading to the continuous exploitation of these resources. This research aims to explore simple yet effective scientific techniques to up-cycle common dental materials while maintaining their properties. The focus of modern practices should align with the 3R's-Reduce, Reuse, and Recycle. In dental institutions and clinics, materials like dental plaster and dental stone, extensively used for pouring impressions, are completely discarded as waste. This study involves collecting these waste products and evaluating their properties for potential reuse. Additionally, endodontic materials such as stainless steel hand files and rotary Ni-Ti files, typically discarded, can be recycled in metallurgical departments and repurposed into custom-made cast posts and titanium posts, respectively. The wisdom tooth crush technique is explored for its application as autologous graft material in filling bone defects. Discarded alginate impressions, widely used in Prosthodontics, are heated and repurposed as a denture polishing agent and as a fertilizer in agriculture. Excess glass ionomer cement, a common restorative material, can be repurposed into polishing cones and powders, or used as a polishing agent with rubber cups and buffs. Modeling wax, predominantly used in occlusal rim fabrication, can be collected and purified, with 90% of it recoverable without compromising its properties. Finally, discarded dental burs can be repurposed to splint implant impression copings, aiding in the accurate transfer of orientation, a critical step in implant prosthodontics. This study advocates for the adoption of recycling practices in dental colleges and among practitioners to manage and reuse the waste generated in the field. By doing so, the treatment cost can be reduced by 30-40%, and natural resources can be conserved, contributing to the preservation of the Earth's resources.

Panoramic evaluation of external root resorption in mandibular molars during orthodontic treatment: a comparison between root-filled and vital teeth treated with fixed appliances or clear aligners

BACKGROUND

This investigation compared the extent of external apical root resorption (EARR) in root-filled teeth (RFT) and their contralateral vital pulp teeth (VPT) counterparts during orthodontic treatment (OT) with clear aligner (CA) treatment or fixed appliance (FA) treatment.

METHODS

Sixty-six patients with similar baseline American Board of Orthodontics (ABO) discrepancy index scores were divided into two groups: 37 patients (21 females, 16 males; mean age 17.45 ± 2.67 years) in the FA group, and 29 patients (18 females, 11 males; mean age 18.33 ± 1.96 years) in the CA group. Digital panoramic radiographs captured pre- and post-OT were used to measure tooth lengths and root surface measurements in mandibular molars. EARR in both RFT and contralateral VPT was evaluated pre- and post-OT. Statistical analysis employed paired t-tests, independent t-tests, and analysis of covariance (ANCOVA) (p < .05).

RESULTS

All teeth exhibited varying degrees of EARR following OT. FA treatment resulted in significantly longer treatment duration (p < .05) and greater EARR compared to CA treatment (p < .05). Moreover, statistically significant differences in EARR were observed within both groups between RFT and VPT (p < .05).

CONCLUSIONS

Comparison of pre- and post-OT radiographs revealed different degrees of EARR in all teeth. CA treatment resulted in less frequent and less severe EARR compared to FA treatment. RFT demonstrated greater resistance to EARR than VPT in both treatment groups.

Comparative efficacy of pharmaceutical (Ibuprofen) and non-pharmaceutical (photobiomodulation, and chewing gum) interventions for pain reduction after elastomeric separator placement in orthodontic patients: a randomized clinical trial

This study compared the efficacy of pharmaceutical (ibuprofen) and non-pharmaceutical (photobiomodulation and chewing gum) interventions for pain reduction after elastomeric separator placement in orthodontic patients. This 3-arm, parallel-group randomized clinical trial was conducted on 90 orthodontic patients. The level of anxiety and pain threshold of patients were measured at baseline using the Pain Catastrophizing Scale (PCS) and an algometer, respectively. The patients were randomly assigned to three groups (n = 30; equal number of males and females). In the laser group, 940 nm diode laser (Epic X, Biolase, USA, 12.35 J/cm2 energy density and 300 mW power in continuous-wave mode., The cross-sectional area of the laser handpiece tip was 1.7 cm2.) was irradiated to the buccal and lingual surfaces for 35 s each, prior to placement of separators. In the gum group, the patients were asked to chew a piece of sugar-free gum immediately after the placement of separators and repeat every 8 h for 5 min for one week in case of pain. In the ibuprofen group, patients received 400 mg ibuprofen (Hakim Pharmaceuticals, Tehran, Iran) after the placement of separators and were asked to take one tablet every 8 h for one week in case of pain. The pain score was recorded using the Modified McGill Pain Questionnaire (MPQ). The normality of data distribution was analyzed by the Kolmogorov-Smirnov test. ANOVA was applied to compare age, and the Chi-square and Monte Carlo Chi-square tests were used to compare gender and patient responses to the questions among the groups. Repeated measures ANOVA was used to compare the pain score at different time points and among the three groups. All statistical analyses were conducted using SPSS version 19 (SPSS Inc., Chicago, IL, USA) at 0.05 level of significance. Data analysis in this study had an intention to treat approach. Although the pain score was slightly lower in ibuprofen and gum groups, the difference among the three groups was not statistically significant (P > 0.05). 'Repeated measures ANOVA showed no significant effect of method of pain reduction on pain score (F = 1.520, P = 0.225). Time had a significant effect on pain score (F = 20.310, P < 0.001). The interaction effect of time and pain reduction method on pain score was not significant (F = 0.737, P = 0.651). patients experienced a lower level of pain in the ibuprofen and chewing gum groups, the difference in pain score was not significant among the three groups (P = 0.225). patients experienced a higher level of pain at 12 and 24 hours after the placement of separators in all groups. Considering the comparably equal analgesic efficacy of this modalities, non-pharmaceutical interventions can be used for pain reduction of elastomeric separator. The study protocol was registered in the Iranian Registry of Clinical Trials (IRCT20210927052611N1). Date of registration 2022/03/14.

Investigation of the biocompatibility of various pulp capping materials on zebrafish model

Testing the biocompatibility of commercially available dental materials is a major challenge in dental material science. In the present study, the biocompatibility of four commercially available dental materials Mineral Trioxide Aggregate, Biodentine, Harvard BioCal-CAP and Oxford ActiveCal PC was investigated. The biocompatibility analysis was performed on zebrafish embryos and larvae using standard toxicity tests such as survivability and hatching rates. Comparative toxicity analysis of toxicity was performed by measuring apoptosis using acridine orange dye and whole mount immunofluorescence methods on zebrafish larvae exposed to the dental materials at different dilutions. Toxicity analysis showed a significant decrease in survival and hatching rates with increasing concentration of exposed materials. The results of the apoptosis assay with acridine orange showed greater biocompatibility of Biodentine, Oxford ActiveCal PC, Harvard BioCal-CAP and Biodentine compared to MTA, which was concentration dependent. Consequently, this study has shown that showed resin-modified calcium silicates are more biocompatible than traditional calcium silicates.

Evaluation of Incisor Position in a Sample of Orthodontic Patients

BACKGROUND

To achieve a successful result, the orthodontist must use a systematic approach to plan the orthodontic treatment. Defining the correct position of the upper and lower incisors and evaluating their relationship with intermaxillary discrepancy and facial divergence have been recognized as the starting point for the diagnostic decision regarding extractions and anchorage requirements. The aim of our study was to analyze the relationship between intermaxillary discrepancy (ANPg^), mandibular inclination (SN^GoGn), lip incompetence, and the positioning of the upper and lower incisors (UIPs and LIPs) in a group of orthodontic patients. This retrospective study included 290 lateral cephalograms in 122 males (42.1%) and 168 females (57.9%) aged 8 to 53 years (median 14; interquartile range IQR 12-17). Data were analyzed by means of one-way Analysis of Variance (ANOVA) and linear regression analysis.

RESULTS

This study showed a statistically significant increase in LIP values in patients with lip incompetence (p < 0.001). Moreover, the distribution of LIPs in groups with various SN^GoGn and ANPg^ angles was significantly different (p < 0.001). The regression analysis also showed a positive association between the LIP and SN^GoGn and between the LIP and ANPg^.

CONCLUSION

The LIP presented a statistically significant difference in patients with and without lip incompetence, which varied significantly in subjects with different sagittal malocclusions and vertical face patterns.

Biofilm formation of Streptococcus mutans, Streptococcus sanguinis, Staphylococcus epidermidis, Staphylococcus aureus, Lactobacillus casei, and Candida Albicans on 5 thermoform and 3D printed orthodontic clear aligner and retainer materials at 3 time points: an in vitro study

INTRODUCTION

Orthodontic clear aligners and retainers have numerous advantages that is making them ever increasingly popular. However, they might, similar to any other oral appliance, contribute to biofilm formation and finally dental caries or white spot lesions or gingival inflammations. The literature on biofilm formation on orthodontic clear appliances is very scarce and limited to a few microorganisms and materials. Therefore, this experimental study evaluated the biofilm formation on 5 thermoformed and 3D printed CAD/CAM orthodontic retainers in 3 intervals.

METHODS

In this in vitro study, 345 specimens (270 test discs and 45 negative controls) were created from fabricated retainers. Retainers included a 3D printed CAD/CAM material (Detax) and four thermoformed retainers [Erkodent (polyethylene terephthalate glycol [PETG]); EasyVac (polyethylene); DB (polyester based on terephthalic acid); and Clear Tech]. They were all 1 mm thick, and all completely fabricated, i.e., heated or printed. The discs were placed in 96-well plates. Microorganisms were cultured on 270 discs for 24 h (90 discs), 72 h (90 other discs), and 5 days or 120 h (90 other discs). Biofilm formation of the strains and negative controls was measured using the microtiter plate assay by ELISA reading. The microbes' ability to produce biofilm was categorized based on the comparison of average optical density (OD) of tests versus a cut-off point OD (ODc) calculated as the average of the OD of corresponding negative controls plus 3× its standard deviation: non-biofilm former [OD ≤ ODc], weak biofilm former [ODc < OD ≤ (2 × ODc)], moderate biofilm former [(2 × ODc) < OD ≤ (4 × ODc)], and strong biofilm former [(4 × ODc) < OD]. These were also converted to ranked scores between zero (no biofilm) and 3. The difference between ODs with control ODs were calculated. These were analyzed using 3-way ANOVA, 2-way ANOVA, and Tukey tests (α = 0.05, α = 0.008).

RESULTS

The 3-way ANOVA showed that the overall difference among the ΔODs of 5 retainers (all microorganisms and all intervals combined, n = 270) was not significant (F = 1.860, P = 0.119). Nevertheless, the difference among 3 intervals (F = 31.607, P = 0.0000) and the difference among the 6 microorganisms (F = 24.044, P = 0.0000) were significant. According to the Tukey test, the differences between the 1st interval with either of the other two intervals was significant (both P values = 0.000). There were significant differences between Candida albicans with all other organisms (all 5 P values = 0.0000). All other pairwise comparisons were insignificant (all 10 P values ≥ 0.1). After taking the averages of the 3 intervals, the order of the biofilm generation for different materials were as follows: Detax (average score: 1.56), Easyvac (1.67), Erkodent (1.78), Clear Tech (1.83), BD (2.28).

CONCLUSIONS

As far as these 6 microorganisms are of concern, there might not be a significant overall difference among the clear retainer materials tested in this study. A significant overall increase was observed between the first and third days, which later did not significantly increase more until day 5. The Candida albicans biofilm was more intense than the tested 5 bacteria, which themselves showed rather similar growth patterns to each other.

Influence of different types of mouthwashes on force decay of elastomeric chain recommended in SARS-COV-2 pandemic

OBJECTIVES

This study aimed to compare the force decay of the power-chain elastics after exposure to anti-coronavirus 2019 (COVID-19) antiseptic mouthwashes at different intervals.

METHODS

A total of 300 power-chain pieces were used from American Orthodontics (AO) and Dentaurum (D) brands. Each piece composed of five loops that were selected to simulate canine retraction distally. The samples were randomly grouped according to immersion in the tested mouthwashes 0.2% povidone-iodine (PVP-I), 1% hydrogen peroxide (H2O2), and 0.2% chlorhexidine (CHX) and cetylpyridinium chloride (CPC). The maximum tensile load failure testing (MTLT) was assessed at six time points (zero, one hour, 24 hours, 1, 2 and 4 weeks). Analysis of variance (ANOVA) and Tukey's post hoc tests were used to analyse the data, where P < 0.05.

RESULTS

Significant differences in MTLT of power-chain elastics used at different immersion intervals were observed. MTLT, in each tested group, decreased significantly as the immersion time increased with significant differences among the tested mouthwashes at each time point. H2O2 group displays a maximum force decay throughout the time intervals for both brands, in contrast to CPC group, which shows less degradation over time.

CONCLUSION

Both brands are decade over time during exposure to the tested mouthwashes. CPC mouthwashes is a good option to be described for orthodontic patient during COVID-19 pandemic, whereas H2O2 mouthwashes should be avoided.

Comparison of muscle response in patients treated with rigid and flexible fixed functional appliances

AIM

The present study was undertaken to evaluate and compare muscle activity after the treatment with rigid and flexible fixed functional appliance.

MATERIAL AND METHOD

The study was conducted on 14 skeletal Class II malocclusion patients in the age group of 13-17 years, divided into two groups comprising 7 patients in each group. Group I was treated with a rigid fixed functional appliance (MPA IV), and Group II was treated with a flexible fixed functional appliance (Churro Jumper). Masseter and anterior temporalis muscle activities were recorded using needle electromyography (EMG) at postural rest, saliva swallowing, and clenching during five intervals (T0 to T4) during fixed functional appliance treatment. Unpaired t-test, Mann-Whitney U, and Wilcoxon sign rank test were applied for statistical analysis, and a P value of <.05 was considered statistically significant.

RESULTS

Group I (MPA IV) showed a significant increase in EMG activity during postural rest position (P = 0.003, P = 0.001), swallowing (P = 0.013, P = 0.005), and clenching (P = 0.001, P = 0.002) in masseter and anterior temporalis muscle, respectively. Group II (Churro jumper) also showed a significant increase in EMG activity during postural rest position (P = 0.000, P = 0.000), swallowing (P = 0.001, P = 0.000), and clenching (P = 0.001, P = 0.000) in masseter and anterior temporalis muscle, respectively.

CONCLUSION

Both rigid (MPA IV) and flexible (Churro Jumper) fixed functional appliances caused a significant increase in EMG activity of masseter and anterior temporalis muscle during postural rest position, swallowing, and clenching in 6 months of the observation period, but the flexible appliance (Churro Jumper) showed more significant increase.

The effect of different clinical recycling methods on load deflection properties of super-elastic and thermal nickel-titanium orthodontic arch wires: A comparative assessment

INTRODUCTION

Repeated clinical use of arch wires requires sterilization and may result in alteration of the properties of the wires as they get subjected to corrosion and cold working. Therefore, the present study aimed to assess the effects of different clinical recycling methods on the load-deflection properties of super-elastic and thermal nickel-titanium orthodontic arch wires.

MATERIALS AND METHODS

A total of 50 0.014" round nickel-titanium orthodontic wires [Group I: super-elastic nickel-titanium (n = 25) and Group II: thermal nickel-titanium wires (n = 25)] were tested for changes in their load deflection properties after three different recycling methods, that is, dry heat sterilization, autoclave, and cold sterilization. For each group, five wires as received from the manufacturer were taken as control (T0), and the rest of the 20 wires were placed intra-orally for a duration of one cycle of clinical use (T1). Five wires out of these were subjected to 3-point bending tests, and the rest of the wires were subjected to different recycling methods. Load deflection properties of recycled wires were measured with an Instron universal testing machine. The results were tabulated, and the data were analyzed by analysis of variance (ANOVA) with the Tukey post hoc test.

RESULTS

Statistically, no significant difference was found in the super-elastic group between samples recycled by dry heat, autoclave, and cold sterilization when compared with as-received super-elastic NiTi up to 2.5 mm of deflection. A highly significant difference was found between as-received thermal NiTi group (83.51 ± 6.49 N/mm) and samples recycled by dry heat (53.73 ± 4.72 N/mm), autoclave (45.38 ± 4.37 N/mm), and cold sterilization (48.44 ± 3.12 N/mm) at 0.5 mm of deflection.

CONCLUSION

Among thermal NiTi, any of the sterilization methods could opt at all deflections. For super-elastic NiTi, at higher deflections or in cases of crowding of more than 2.5 mm, cold sterilization should be the method of choice, whereas any sterilization method can be used at deflections less than 2.5 mm.

Accidental ingestion of a fractured piece of orthodontic aligner: a case report

BACKGROUND

Ingestion and aspiration of orthodontic devices are rare occurrences, typically associated with components such as expansion keys, archwire segments, dislodged fixed appliances (including brackets, buccal tubes, and bands), as well as fractured metal or plastic appliances. This article describes the clinical diagnosis and treatment process of a case of accidental ingestion of a fractured piece of orthodontic aligner.

CASE PRESENTATION

A 31-year-old female under orthodontic treatment by aligners accidentally ingested a fractured piece of the aligner. The special difficulty of this case is that the transparent orthodontic aligner has a low radiopacity. At the beginning, no foreign body was found in the commonly used soft tissue window, causing difficulty in its location until greyscale was adjusted to lung window. The 2-centimeter fractured piece was taken out under anesthesia and endoscopic surgery.

CONCLUSION

Materials with low radiopacity should be read with a lower grayscale range. Fractured orthodontic appliances with low retention force should not continue to be worn until consultation with attending doctor.

Comprehensive evaluation of early shear bond strength and antimicrobial activity in orthodontic adhesives enhanced with salvadora persica oil

OBJECTIVES

This study investigates the mechanical properties and antimicrobial efficiency of orthodontic adhesive modified with Salvadora persica (SP) oil, including adhesive remnant index (ARI) and shear bond strength (SBS), specifically antimicrobial efficacy against Streptococcus mutans.

METHODS

Forty freshly extracted human premolars were recruited. They were classified into four groups according to the concentration of SP oil added to Heliosit orthodontic adhesive where the control group was with no adhesive modification, alongside three experimental groups, wherein SP oil was integrated into the adhesive at concentrations of 1%, 3%, and 5% weight/weight, respectively. The tooth buccal surface was etched by phosphoric acid gel (37%). The orthodontic brackets utilized were standard stainless steel edgewise 22". The brackets were bonded with Heliosit by Woodpecker LED light cure for 20 sec. The SBS was assessed using a universal testing machine, and ARI was inspected by a stereomicroscope at 20X magnification power. The antimicrobial activity against Streptococcus mutans was evaluated. The statistical analyses, analysis of variance (ANOVA), and Kruskal-Wallis and Duncan were performed where P ≤ 0.05.

RESULTS

The findings indicated that among the experimental groups, the 3% SP oil group exhibited the highest mean SBS value, following closely behind the control group. Conversely, the mean SBS was lowest for the SP group with a 5% concentration. However, ANOVA and Kruskal-Wallis tests revealed no significant differences between groups (P ≥ 0.275, 0.069), respectively. Antimicrobial tests demonstrated a concentration-dependent antibacterial effect, the 5% group exhibiting the highest efficacy.

CONCLUSION

Orthodontic adhesive modified with SP oil maintains favorable SBS while demonstrating antimicrobial effects against Streptococcus mutans.

Classification of cervical vertebral maturation stages with machine learning models: leveraging datasets with high inter- and intra-observer agreement

OBJECTIVES

This study aimed to assess the accuracy of machine learning (ML) models with feature selection technique in classifying cervical vertebral maturation stages (CVMS). Consensus-based datasets were used for models training and evaluation for their model generalization capabilities on unseen datasets.

METHODS

Three clinicians independently rated CVMS on 1380 lateral cephalograms, resulting in the creation of five datasets: two consensus-based datasets (Complete Agreement and Majority Voting), and three datasets based on a single rater's evaluations. Additionally, landmarks annotation of the second to fourth cervical vertebrae and patients' information underwent a feature selection process. These datasets were used to train various ML models and identify the top-performing model for each dataset. These models were subsequently tested on their generalization capabilities.

RESULTS

Features that considered significant in the consensus-based datasets were consistent with a CVMS guideline. The Support Vector Machine model on the Complete Agreement dataset achieved the highest accuracy (77.4%), followed by the Multi-Layer Perceptron model on the Majority Voting dataset (69.6%). Models from individual ratings showed lower accuracies (60.4-67.9%). The consensus-based training models also exhibited lower coefficient of variation (CV), indicating superior generalization capability compared to models from single raters.

CONCLUSION

ML models trained on consensus-based datasets for CVMS classification exhibited the highest accuracy, with significant features consistent with the original CVMS guidelines. These models also showed robust generalization capabilities, underscoring the importance of dataset quality.

Effects of facial forms and midline deviations and rolls on female facial beauty according to laypeople, orthodontists, and prosthodontists or restorative dentists

No study has examined the simultaneous effect of facial forms, midline deviations and midline angulations on facial beauty. Therefore, this comprehensive study aimed to evaluate these and many other hypotheses. This psychometric study was performed on 15,042 observations. A female frontal photograph was edited to 45 perceptometric images with controlled anatomical alteration: 3 facial forms (euryprosopic [brachyfacial], mesoprosopic [mesofacial], leptoprosopic [dolichofacial]), each having either 9 bidirectional midline deviations (0, 1, 2, 3, and 4 mm deviated to the left and right) or 7 bidirectional midline angular deviations (0°, 5°, 10°, and 15° deviated to the left and right). One of the photographs were repeated. These 46 images were esthetically judged by 327 participants (243 laypeople, 49 orthodontists, and 35 'prosthodontists or restorative dentists'). Hierarchical mixed-model multiple linear regressions and post hoc tests were adopted to evaluate the simultaneous impacts of the photomodel's facial forms, midline deviations to the right or left, and midline rolls to the right or left plus sex, age, experience, and dental specialty of the referees on their perception of facial beauty as well as the tolerable zones of midline alterations. These were also done separately for each specialty group, and also for each facial face. Ideal combinations of anatomic features were determined using repeated-measures ANOVAs. Differences between esthetic preferences of different groups in terms of each image were assessed using one-way ANOVAs and t-tests (α = 0.05, α = 0.008, α = 0.001). All 5 anatomical features significantly and independently influenced perception of facial beauty. The tolerance threshold for midline deviations was 1 mm deviations to the right and left sides. For midline rolls, the only tolerable form was the no-roll ('on') midline; the judges preferred right-oriented defects over left-sided ones. The most beautiful facial form was mesoprosopic, followed by leptoprosopic. Men perceived the female face slightly more attractive than did women. The viewers' specialty (or lack of it), their age, or their experience did not affect their esthetic preferences. Predictors of esthetic preferences were all 5 anatomical features plus views' sex, but not their dental specialty, age, or experience. Zones of acceptability and also the ideal range of anatomical features were determined.