Comparison of GUMMETAL® and stainless steel alloy during canine retraction: A pilot split-mouth randomized controlled trial

OBJECTIVES

A TiNb alloy wire (GUMMETAL® [GM], Toyota Central R&D Labs, Inc., Nagakute, Japan) was recently developed with unique properties for orthodontic applications. This pilot split-mouth randomized controlled trial compared maxillary canine retraction during space closure using sliding mechanics on GM vs. stainless steel (SS) archwires.

METHODS

Subjects who met the inclusion criteria were treated with fixed appliances and maxillary first-premolar extractions between September 2020 and March 2022. After leveling and aligning, maxillary archwires, fabricated by crimping together segments of 0.016×0.022" GM and SS archwires, were placed and canine retraction initiated using nickel-titanium coil springs. Digital models of the maxillary arch were superimposed at 0, 4, 8 and 12 weeks and the amount of canine movement (mm), rate of movement (mm/month), and 3-dimensional changes (rotational, vertical extrusion, tip) were measured and compared statistically.

RESULTS

Of the 12 subjects recruited, only six completed the study with a median age of 15.8 years (12.0-17.4 years). At 12 weeks, the median canine retraction was 3.41mm (IQR: 2.10, 4.76) with GM versus 3.71mm (IQR: 1.62, 6.45) with SS. The retraction rate was 1.14mm/month (IQR: 0.69, 1.59) with GM, versus 1.24mm/month (IQR: 0.54, 2.15) with SS. The median rotational, vertical and tip changes of the canine were 7.90̊, 0.59mm and 6.15̊ with GM, and 7.25̊, 0.29mm and 2.05̊ with SS. Intergroup differences with all measurements were not statistically significant.

CONCLUSION

No significant differences were found between GM and SS during maxillary canine retraction. GM demonstrated clinical potential for space closure mechanics, however, future larger studies are needed.

Maxillary Protraction: A Bibliometric Analysis

OBJECTIVES

The aim of this analysis was to investigate the historical development, current status, and research hot spots related to maxillary protraction in the treatment of maxillary hypoplasia.

METHODS

The term "TS = maxillary protraction" was used to search for articles in the Web of Science Core Collection at the library of Capital Medical University. The results were analysed using CiteSpace6.2.R1 software, including the examination of annual publication trends and analysis of author, country, institution, and keywords.

RESULTS

A total of 483 papers were included in this study. The annual publications showed an overall increasing trend. The top 5 authors with the most published papers were Lorenzo Franchi, Tiziano Baccetti, Seung-Hak Baek, Paola Cozza, and U Hagg. The top 5 countries with the highest publication counts were the US, Turkey, South Korea, Italy, and China. The top 5 institutions in terms of the number of published papers were the University of Florence, the University of Michigan, Kyung Hee University, Seoul National University, and Gazi University. The top 3 journals with the most citations were the American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, and the European Journal of Orthodontics. Furthermore, "Maxillary protraction," "Class III malocclusion," and "Maxillary expansion" were the most common keywords.

CONCLUSIONS

The effective age range for maxillary protraction has been expanded with the introduction of skeletal anchorage and the combination of maxillary expansion and protraction. Skeletal anchorage offers significant advantages over dental anchorage, but there is a need for further research to further substantiate its stability and safety. In recent years, the positive effects of maxillary protraction on the nasopharyngeal area have been well established, but its impact on the oropharyngeal area remains a topic of debate. Therefore, it is crucial to conduct further investigations into the effects of maxillary protraction on the oropharyngeal area and explore the factors that influence different outcomes.

Reliability of the novel cleft lip and palate smile esthetic index (CLP-SEI)

BACKGROUND/OBJECTIVES

The aim of this research was to determine the reliability of a novel index for the assessment of smile esthetics in patients with cleft lip and/or palate (CL ± P) at the end of their multidisciplinary treatment, for use in clinical and academic settings.

MATERIALS AND METHODS

Five orthodontists, five periodontologists, five general practitioners, five dental students, and five laypeople rated the smiles of 10 patients with CL ± P twice at a 2 weeks interval. The rating scale consisted of four main categories: 1. nasolabial esthetics, 2. gingival esthetics, 3. dental esthetics, and 4. overall esthetics. A total of 15 parameters were rated. Intra- and inter-rater agreements were calculated using SPSS.

RESULTS

The inter-rater agreement varied between good and excellent whereby the orthodontists, periodontists, general practitioners, dental students, and laypeople obtained agreement scores of 0.86, 0.92, 0.84, 0.90, and 0.89, respectively. The intra-rater agreement was good with agreement scores of 0.78, 0.84, 0.84, 0.80, and 0.79, respectively.

LIMITATIONS

Smile esthetics were rated on static pictures, not in real life or by video recordings in a young adult population.

CONCLUSIONS/IMPLICATIONS

The cleft lip and palate smile esthetic index is a reliable tool for the assessment of smile esthetics in patients with CL ± P.

Hard and soft tissue shape variation and changes in Class II division 1 malocclusion during orthodontic treatment: a geometric morphometric analysis

BACKGROUND

This study aims to determine the hard and soft tissue shape variation and its changes in Class II division 1 malocclusion before and after orthodontic treatment using Geometric Morphometric Analysis.

METHODS

This retrospective study included 141 pre-treatment and near-end treatment lateral cephalometric radiographs of Class II division 1 malocclusion patients aged 16-40 years with a skeletal II pattern (ANB > 4o). 32 landmarks in Cartesian coordinates were created and identified using MorphoJ software to establish a shape analysis.

RESULTS

The vertical dimensions (hypodivergent to hyperdivergent facial profiles) showed the largest variation in the general shape of hard and soft tissue, followed by the anteroposterior dimensions (mild to severe skeletal II patterns). Variations of lip shape (long to short), lip protuberance (everted to inverted), and nasolabial angle (obtuse to acute) were present. Orthodontic treatment affected the shape of the hard and soft tissue significantly (p < 0.0001). T2 showed significant uprighting of upper incisors (17.5o) and lower incisors (3.7o), improved NLA (8o), an increase in upper lip thickness (1.5 mm), and a reduction in lower lip thickness (0.7 mm) (p < 0.05).

CONCLUSION

Vertical and anteroposterior shape variations were found. Orthodontic treatment had an impact on both hard and soft tissue shapes. Hence, understanding both the hard and soft tissue shape variations and the orthodontic treatment changes is crucial for an accurate diagnosis and treatment plan to achieve a successful outcome and excellent patient satisfaction.

Periodontal health status, oral microbiome, white-spot lesions and oral health related to quality of life-clear aligners versus fixed appliances: A systematic review, meta-analysis and meta-regression

Objective

: Assess and evaluate the different indicators of oral health-related quality of life (OHRQoL) among patients treated with clear aligners (CAs) versus those treated with conventional fixed orthodontics (FAs).

Methods

: An electronic search was performed on the database is Web of Science, Scopus, and Embase databases. Randomized and non-randomized control trials, cross-sectional, prospective cohort and retrospective trials were included. Quality was assessed with risk of bias tool and risk of bias in non-randomised studies. Meta-analyses were performed with random effects models, estimating the standardized and non-standardized mean differences, odds ratio and risk ratio as the measure of effect. The effect on time was determined using a meta-regression model.

Results

: Thirty one articles were included in the qualitative synthesis and 17 in the meta-analysis. CAs had a significantly lower negative impact on QoL, with an "important" effect size, while the influence of time was not significant. Periodontal indicators plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing show significantly better values in patients treated with CAs, with moderate to large effect sizes. PI and GI have a significant tendency to improve over time. In microbiological indicators, CAs present a lower biofilm mass without differences in the percentage of patients with high counts of Streptococcus mutans and Lactobacilli bacteria. The risk of white spot lesion onset is ten times lower in carriers of CAs.

Conclusions

: Patients wearing CAs show better periodontal indicators, less risk of white spot development, less biofilm mass and a better QoL than patients with FAs.

Comparison of pain intensity and impacts on oral health-related quality of life between orthodontic patients treated with clear aligners and fixed appliances: a systematic review and meta-analysis

OBJECTIVE

This study aimed to compare the pain intensity and impacts on oral health-related quality of life (OHRQoL) between orthodontic patients treated with clear aligners (CAs) and fixed appliances (FAs).

METHODS

A systematic search was conducted up to December 2022 using PubMed, Web of Science, Cochrane Central Register of Controlled Trials, and Embase. Randomized controlled trials (RCTs) and prospective non-randomized controlled trials (non-RCTs) comparing pain intensity or OHRQoL between patients treated with CAs and FAs were included. The risk of bias (RoB) of individual studies was evaluated using the Cochrane RoB tool 2.0 and ROBINS-I tool for RCTs and non-RCTs, respectively. Further, meta-analyses were separately conducted for each included study using the total oral health impact profile (OHIP)-14 and visual analog scale (VAS) scores to evaluate OHRQoL and pain intensity, respectively.

RESULTS

Overall, 12 studies (5 RCTs and 7 non-RCTs) were included in the study. Subgroup analyses conducted according to the total OHIP-14 scores revealed that patients treated with CAs had higher OHRQoL at 1 week, 1 month, and 6 months of the treatment. Meanwhile, subgroup analyses conducted according to the VAS scores revealed that pain levels were lower in the CA group only at 3 and 4 days of the treatment.

CONCLUSIONS

Patients treated with clear aligners had higher OHRQoL than those treated with fixed appliances during orthodontic treatment. However, OHRQoL appeared to be similar between the two groups at the end of the treatment. Moreover, patients treated with clear aligners experienced lesser pain than those treated with fixed appliances on the third and fourth day after the initial treatment. The difference in pain intensity between the two treatment modalities was not noted at other time points.

Tomographic analysis of relationship of mandibular morphology and third molars eruption

BACKGROUND

Lower third molars (L3M) are the last teeth to erupt in the oral cavity. Uneruption of these teeth still raises questions about its causes, in the literature (1) genetic factors, (2) dental lamina activity and, mainly, (3) insufficient growth and development of the bone bases are included. While the lack of space theory influenced by mandibular morphology and size of L3M was argued to be the main reason for L3M impaction, there is a limitation in the literature in examining such association using more accurate tomographic analysis obtained from CBCT. This work aimed to evaluate the relationship between mandibular morphology and the eruption of L3M.

METHODS

In this regard, 85 Cone Beam Computed Tomographies (CBCT), with 147 L3M, were selected from the archives of the Department of Surgery, Stomatology, Pathology and Radiology, Bauru School of Dentistry, obtained using an Accuitomo® Morita device and using the Dolphin Imaging 11.9 software. L3M eruption was related to linear measurements of jaw length (Co-Gn), retromolar space dimension (D2R), mesiodistal width of the L3M crowns, mandibular first molars (L1M) and mandibular canines (LC) and the angle mandibular (Ar-Go-Me). Independent samples t-test, chi-square tests and logistic regression were performed adopting a significance level of 5%.

RESULTS

The average mandible length of 116.446 mm + 6.415 mm, retromolar space of 11.634 mm + 2.385 mm, mesiodistal size of the L3M of 10.054 mm + 0.941 mm, sum of the mesiodistal widths of the L1M and LC of 15.564 mm + 1.218 mm and mandibular angle of 127.23° + 6.109. There was no statistically significant association between these factors and the eruption.

CONCLUSION

With the results obtained in this study, we conclude that the length and angle of the mandible, teeth size and dimension of the retromolar space are not associated with the L3M eruption.

Impact of Mechanical Strain and Nicotinamide on RUNX2-Deficient Osteoblast Mimicking Cleidocranial Dysplasia

Cleidocranial dysplasia (CCD) is a rare genetic defect caused by a heterozygous mutation of runt-related transcription factor 2 (RUNX2), which is important for osteoblast and skeletal development. RUNX2-deficiency causes extra- and intra-oral malformations that often require orthodontic treatment. Nicotinamide (NAM) affects bone remodelling processes. As these are crucial for orthodontic therapy, NAM could improve orthodontic treatment in CCD patients. This study investigates the effect of NAM in control and RUNX2-deficient osteoblasts under mechanical strain mimicking orthodontic treatment. First, the optimal NAM concentration and the differences in the expression profile of control and RUNX2-deficient osteoblasts were determined. Subsequently, osteoblasts were exposed to tensile and compressive strain with and without NAM, and the expression of genes critically involved in bone remodelling was investigated. NAM increased the expression of bone remodelling genes. RUNX2-deficient osteoblasts expressed more receptor activator of NFkB ligand (RANKL) and interleukin-6 (IL6), but less colony-stimulating factor-1 (CSF1). Most of the positive effects of NAM on bone remodelling genes were impaired by mechanical loading. In conclusion, NAM stimulated osteoblast differentiation by increasing the expression of RUNX2 and regulated the expression of osteoclastogenic factors. However, the positive effects of NAM on bone metabolism were impaired by mechanical loading and RUNX2 deficiency.

Vitamin C mesotherapy versus diode laser for the esthetic management of physiologic gingival hyperpigmentation: a randomized clinical trial

BACKGROUND

Physiologic gingival hyperpigmentation is a common esthetic concern that affects individuals of various ethnicities, and can have a significant impact on individual's self-confidence and overall quality of life. Thus, this study aimed to clinically assess the effectiveness of intra-mucosal injection of vitamin C versus 980 nm diode laser for the management of physiologic gingival hyperpigmentation.

METHODS

Twenty-six healthy non-smoker individuals with physiologic gingival hyperpigmentation were randomly assigned to two groups. Group I received intra-mucosal injection of vitamin C (L-Ascorbic acid 1000 mg/5 ml), and group II was managed using diode laser (980 nm, 1.5 W, continuous wave mode). Clinical evaluation of pigmentation intensity and distribution was performed preoperatively, and at 1, 2 and 3 months postoperatively using two different color assessment indices; Dummett-Gupta Oral Pigmentation Index (DOPI), and Gingival Pigmentation Index (GPI). Additionally, the study assessed pain intensity and patients' satisfaction.

RESULTS

Pigmentation scores decreased significantly between pre-operative visit and different follow-up visits for both treatment modalities (p < 0.0001*). When compared to the vitamin C mesotherapy group, the laser group demonstrated significantly lower gingival pigmentation scores (p < 0.0001*). However, both treatment modalities were equally satisfying for the patients.

CONCLUSIONS

Vitamin C mesotherapy and diode laser are both effective in the management of physiologic gingival hyperpigmentation. While diode laser yields better and earlier results, vitamin C mesotherapy offers a cost-effective, safe and minimally invasive approach that is equally satisfying for the patients seeking esthetic enhancements.

TRIAL REGISTRATION

The study was registered on ClinicalTrials.gov (NCT05608057) on (01/11/2022).

Comparative analysis of periodontal pain and quality of life in patients with fixed multibracket appliances and aligners (Invisalign®): longitudinal clinical study

BACKGROUNDS

The aim of this longitudinal clinical study is to analyse and compare according to location, degree and type, the pain presented by patients during their first year of treatment, as well as the quality of oral life after the placement of two types of orthodontic appliances: conventional brackets and removable Invisalign ® aligners.

METHODS

The sample consisted of 140 patients grouped into 2 study groups of 70 patients each. The first group (brackets group- BG), with fixed multibracket appliances, using the MBT technique and a 0.022" slot. The second group (invisaling group- IG), in treatment with removable aligners (IG), using the Invisalign ® system. They were providen with a questionnare where they had to record the degree (mild, moderate or intense), the type and location of the pain monthly during the first year of treatment. The second form was the Spanish version of the OHIP-14, oral quality of life questionnaire, which was provided the twelfth month after the start of treatment.

RESULTS

In both groups, we found that the most frequent location of pain occurred during the first phase: mandibular for the IG group and maxillary in the BG group. Throughout the whole analysis, the intensity was mild-moderate with lower values in the conventional brackets' group. The BG group reported acute pain while the IG group reported sensitive pain during the first month; later both reported sensitive pain.

CONCLUSIONS

There are differences in terms of periodontal pain in its degree, location, and type according to the different orthodontic techniques used.

TRIAL REGISTRATION

The study was approved by the bioethics committee of the University of Salamanca (USAL_20/516).

Fluoridated orthodontic adhesives: Implications of release and recharge and their impact on shear bond strength in demineralized tooth surfaces

Background

This study measured fluoride release from a light-cured orthodontic adhesive resin (Vega type) at three time intervals (one day, one week, and one month), investigated the rechargeability of the resin, and assessed its impact on shear bond strength in demineralized tooth surfaces.

Methods

This study used 30 recently extracted upper premolar teeth to explore the effects of fluoride release over specific time intervals. The teeth underwent demineralization and were categorized into groups based on time intervals: one day, one week, and one month. Subgroups within each interval underwent fluoride recharging through fluoride varnish application. Fluoride release and shear bond strength were assessed after etching with phosphoric acid gel, applying the orthodontic adhesive, and curing. The samples were stored in deionized water. Fluoride quantification used a selective electrode, while shear bond strength assessment employed a universal testing machine. Finally, statistical analysis of the data was performed using SPSS 22.

Results

The study found that after one month, the adhesive had the highest fluoride release and shear bond strength mean values. There were significant differences in fluoride release and shear bond strength between the various groups studied.

Conclusion

The application of fluoride varnish around the orthodontic bracket resulted in a positive effect on the shear bond strength of the bracket.

Changes in Upper Airway Anatomy Following Orthodontic Treatment for Malocclusion: A Comparative Retrospective Study in 96 Patients

BACKGROUND This retrospective study aimed to compare pharyngeal anatomical changes measured in cephalometric images before and after treatment for malocclusion Class I, II, and III in 96 patients undergoing orthodontic treatment. MATERIAL AND METHODS A total of 96 patients who underwent fixed orthodontic treatment were included in the study. The patients were divided into 3 groups according to the malocclusion (32 people in each group). The upper airway data in the lateral cephalometric images of the patients were retrospectively analyzed before starting fixed orthodontic treatment and the upper airway data taken after the end of the fixed orthodontic treatment. RESULTS According to the findings, all the upper airway data in individuals in Class I (Skeletal Class I malocclusion) group and most of the upper airway data in Class II (Skeletal Class II malocclusion) groups increased after orthodontic treatment compared to before treatment (P<0.05). Most of the upper airway data in Class III (Skeletal Class III malocclusion) group individuals decreased after orthodontic treatment compared to before treatment (P<0.05). CONCLUSIONS Orthodontic treatment should be chosen considering that an increase may be observed in individuals with Class I and Class II malocclusion. Similarly, in individuals with Class III malocclusion, orthodontic treatment can be chosen considering that there will be a decrease in the upper airways. By determining the effects of fixed orthodontic treatment on the airways, airway problems experienced at an early age can be prevented.

Correlation Between Maxillary Anterior Teeth and Common Facial Measurements

Background

The symmetry between maxillary anterior teeth and the face holds significant importance. This study assessed and analyzed the relationship between facial parameters and anterior teeth in the maxillary arch of male and female subjects. Specifically, individual width and combined width (CW) measurements of the maxillary anterior teeth were investigated.

Methods

This study involved a total of 150 dentate Yemeni subjects (74 men and 76 women), whose ages ranged from 18 years old to 30 years old. A maxillary cast was created, and two digital photographs of the face of each subject were taken and analyzed. Digital calipers and AutoCAD were used to gather measurement data of the dental parameters (intercanthal distance [ICD], interpupillary distance [IPD], interalar width [IAW], intercommissural width [ICW], and bizygomatic width [BZW]) and facial parameters (profile distance).

Results

Significant correlations were found for the following: IPD and width of six maxillary anterior teeth of each of the study subjects; ICD and their central incisors; and BZW and their canine width measurements. In contrast, IAW and ICW were not correlated with all tooth measurements. Linear regression findings showed that the CW measurement of the four incisors was significantly correlated with all facial parameter measurements, excluding the ICW and IAW in females and the IAW, ICW, and profile distance in males.

Conclusion

The IPD and ICD of males and females may be used to determine their CW measurements. The BZW and IPD of males can be used to take precise anthropological measurements of the width of the central canines and incisors. Meanwhile, the IPD distance of females can be used to assess the central and lateral incisor widths.

Implant-supported canine retraction using different reactivation intervals of elastomeric chains: A CBCT-based split-mouth randomized controlled trial

INTRODUCTION

Orthodontists attempt to maximize treatment efficiency regarding time, tooth position and adverse effects. A new approach, not yet explored, is the activation frequency.

OBJECTIVE

The aim of this split-mouth randomized controlled trial was to evaluate the effect of reactivation intervals on the efficiency of tooth movement.

METHODS

Thirty eight patients having a Class I malocclusion with bimaxillary dentoalveolar protrusion or severe crowding, Class II with mandibular deficiency or Class III, requiring first premolar extraction and canine retraction were recruited. Elastomeric chains producing 150g were replaced every two, four, six or eight weeks. There were 36, 37, 36, and 36 quadrants randomly allocated to these groups, respectively. The canine retraction rate was the primary outcome. Canine tipping, rotation, and root resorption and pain were the secondary outcomes. Only the outcome assessors were blinded to group assignment.

RESULTS

The average total movement for the 6 months was 5.14, 5.31, 2.79 and 3.85 mm for the two-week, four-week, six-week and eight-week reactivation intervals, respectively. Root resorption was significantly higher in the two-week and four-week groups. No adverse events were observed.

CONCLUSION

The canine retraction rate, tipping, rotation and pain were similar in 2, 4, 6 and 8-week activation intervals groups. Longer reactivation intervals show less root resorption. The trial protocol was not pre-registered. The study was self-funded.

Damon technique for orthodontic treatment of a patient with temporomandibular joint dysfunction

The Damon system is an effective, less-invasive treatment that provides orthodontic dentists with an adequate biomechanical process, offering a reduction in treatment time; patients with temporomandibular dysfunction present even greater complexity in their clinical picture, relying on clinical and radiographic differential diagnoses to facilitate a good prognosis. The objective was to apply the orthodontic treatment (Damon technique) to stabilize patients with temporomandibular dysfunction. The patient with premature loss of the first lower molars (36 and 46) experienced pathological alterations in the temporomandibular joints (TMJs) (bilaterally). The diagnosis was reached using the clinical history of temporomandibular joint disorders (diagnostic criteria) axis II: moderate pain (VAS) in muscles, moderate stress (Hamilton 51/60), lateral and panoramic cephalic radiographs, magnetic resonance imaging of bilateral TMJ, cephalometry, photographs, and models. Treatment with the Damon system is recommended to recover optimal functional occlusion in a short period, followed by referral for oral rehabilitation as an adjunct to the treatment plan. The verticalization of the second molars, maximum optimal intercuspidation, appropriate overbite and overjet, and pain control in the TMJ were evaluated. Stabilization of the disc condyle complex by eliminating interference and premature points of contact providing cervical/cranio/mandibular balance.

Three-dimensional evaluation of maxillary sinus volume, skeletal and dentoalveolar maxillary anterior region, in unilateral palatally impacted maxillary canine (Cross-sectional study)

OBJECTIVES

Three-dimensional evaluation of maxillary sinus volume using VR mesh and correlate it with the volume of maxillary canine, lateral incisor, and dentoalveolar and skeletal dimensions in both impacted and non-impacted sites.

MATERIALS AND METHODS

In a retrospective cross-sectional study, cone beam computed tomography scans of 100 patients with unilateral palatally impacted maxillary canine were analyzed. Canine, lateral incisor, and maxillary sinus volumes on the impaction and non-impaction sides were measured using DICOM files, with three-dimensional softwares (MIMICS) and VR mesh to accomplish this assessment.

RESULTS

There were no significant differences in canine and lateral incisors volumes between male and female patients in the impacted side at (p > 0.05) while the maxillary sinuses volume revealed a statistical difference (P = 0.022) between male (12642 ± 810) and female (12481 ± 650) patients in the impacted side. A strong positive correlation was found between canine and lateral incisor volume for male patients in the non-impacted (r = 0.420**, P = 0.008) and impacted sides (r = 0.334*, P = 0.038).

CONCLUSIONS

There were no significant differences in the canine volume, the height of the anterior alveolar ridge (AARHMLI), and anterior dentoalveolar (ADAHMLI) of maxillary lateral incisors in the impacted/non-impacted side, but it showed a statistically significant difference for the lateral incisors volume in the impacted and non-impacted sides for male and female patients. The maxillary sinus volumes revealed a statistical difference between males and females in impacted and non-impacted sides.

Prevalence of canine impaction in the western province of Saudi Arabia: A cross-sectional survey

BACKGROUND/AIM

Canine tooth impaction could have a negative influence on the stomatognathic system and could make it difficult for clinicians to manage malocclusions. The aim of this retrospective study was to investigate the prevalence of canine impaction, which could be a cause of malocclusion, in the population in the western province of Saudi Arabia.

METHODS

A retrospective analysis of digital orthopantomograms (OPGs) of 400 patients aged 12-40 years, who are citizens of Saudi Arabia residing in the western province and who presented for treatment at the dental clinics of Batterjee Medical College, Jeddah, Saudi Arabia were included. The OPGs and dental records of these patients were reviewed for canine impaction and were categorized based on age, gender, and type of impaction.

RESULTS

The prevalence of patients that exhibited canine impaction was found to be 4%. Males had a significantly higher percentage of prevalence than females (P < 0.016), and impaction was significantly higher among patients aged below 18 years (P < 0.001). Moreover, the most commonly observed impaction was mandibular canine impaction (87.5%).

CONCLUSIONS

Prevention of malocclusion and maintenance of a normal dentition (better aesthetics and chewing) necessitates early detection of impacted canines.

Cyclic shear fatigue of orthodontic brackets bonded to enamel using self-adhering flowable composites

Background

Self-adhering composites are claimed to bond to teeth without prior acid etching and bonding steps. This study aimed to evaluate the cyclic shear fatigue (CSF) of metal orthodontic brackets bonded to enamel using self-adhering flowable composites (Constic and VertiseTM Flow) in comparison with that of total-etch and self-etch adhesives.

Materials and methods

Twenty-five human premolars comprising 100 surfaces were randomly divided into four groups (n = 25): total-etch, self-etch, Constic, and VertiseTM Flow. A total of 10 surfaces were used per group for baseline static shear bond strength (SSBS) evaluation and 15 surfaces for CSF evaluation. Each tooth was treated with the four bonding agents. Both SSBS and CSF were evaluated using a universal testing machine. For CSF, the staircase method was used with an initial pulling load equivalent to 60% of the SSBS of each group for 1000 cycles or until failure. The adhesive remaining index (ARI) was evaluated for surviving samples using a stereomicroscope.

Statistical analysis

A one-way ANOVA with Tukey's post hoc test was used to analyze the CSF data, and a chi-square test was used to analyze the ARI.

Results

The total-etch adhesive showed significantly higher CSF values than that of the other groups (p < 0.001). Both total-etch (10.78 ± 0.31 MPa) and self-etch (6.75 ± 0.91 MPa) adhesives showed significantly higher CSF than did Constic (1.94 ± 0.31 MPa) and VertiseTM Flow (2.01 ± 0.25 MPa), (p < 0.001). The ARI indicated that more resin remnants were observed with the total-etch and self-etch adhesives than those with the self-adhering flowable composites. However, no significant differences were observed among groups (p > 0.05).

Conclusions

Total-etch and self-etch adhesives showed satisfactory bond strengths for orthodontic treatment. However, Constic and VertiseTM Flow self-adhering flowable composites may not be clinically sufficient for bonding metallic orthodontic brackets to enamel.

Correlation Between Horizontal and Vertical Skeletal Components in Dental Malocclusions Among the Jazan Population

INTRODUCTION

The dentoskeletal morphology of various malocclusions has been analyzed in cephalometric studies. It is important to understand the vertical and horizontal components of orthodontic treatment. To provide accurate treatment, an orthodontist needs to understand the facial types of an individual. This study aims to evaluate a correlation between vertical and horizontal components of skeletal and dental malocclusion by assessing cephalometric radiographs of the population of Jazan province.

METHODS

The cephalometric radiographs of 267 eligible participants were assessed digitally. Fourteen skeletal and dental parameters were used to evaluate the association. Reliability was checked with the intra-class coefficient. Statistical analyses included descriptive statistics and Spearman's rho test. Statistical significance was set at P ≤ 0.05.

RESULTS

Correlations were found between anterior facial height (AFH), posterior facial height (PFH), FH ratio (Jarabak ratio), upper incisor to NA (U1-NA), lower incisor to NB (L1-NB), and upper incisor to the palatal plane (U1/PP). In dental class I, AFH (N-Me) had a strong positive correlation with L1-NB (0.300), U1/PP (0.164), and L1/MP (0.215). In dental class II, AFH negatively correlated with U1-NA (-0.735) and positively correlated with L1-NB (0.292), L1/MP (0.085), and U1-NA. PFH (S-Go) positively correlated with L1-NB (0.525) in class I but negatively correlated in class II. However, a negative relation was observed between all the vertical and horizontal components in class III.

CONCLUSION

This study suggests potential associations between vertical and horizontal components in developing skeletal and dental discrepancies.

Coupling biomechanical models of implants with biodegradation models: A case study for biodegradable mandibular bone fixation plates

In fracture fixation, biodegradable implant materials are an interesting alternative to conventional non-biodegradable materials as the latter often require a second implant removal surgery to avoid long-term complications. In this study, we present an in silico strategy to design/study biodegradable metal implants focusing on mandibular fracture fixation plates of WE43 (Mg alloy). The in silico strategy is composed of an orchestrated interaction between three separate computational models. The first model simulates the mass loss of the degradable implant based on the chemistry of Mg biodegradation. A second model estimates the loading on the jaw plate in the physiological environment, incorporating a phenomenological dynamic bone regeneration process. The third model characterizes the mechanical behavior of the jaw plate and the influence of material degradation on the mechanical behavior. A sensitivity analysis was performed on parameters related to choices regarding numerical implementation and parameter dependencies were implemented to guarantee robust and correct results. Different clinical scenarios were tested, related to the amount of screws used to fix the plate. The results showed a lower initial strength when more screw holes were left open, as well as a faster decrease over time in strength due to the increased area available for surface degradation. The obtained degradation results were found to be in accordance with previously reported data of in vivo studies with biodegradable plates. The combination of these three models allows for the design of patient-specific biodegradable fixation implants able to deliver the desired mechanical behavior tuned to the bone regeneration process.

Classification of dental implant systems using cloud-based deep learning algorithm: an experimental study

BACKGROUND

This study aimed to evaluate the accuracy and clinical usability of implant system classification using automated machine learning on a Google Cloud platform.

METHODS

Four dental implant systems were selected: Osstem TSIII, Osstem USII, Biomet 3i Os-seotite External, and Dentsply Sirona Xive. A total of 4,800 periapical radiographs (1,200 for each implant system) were collected and labeled based on electronic medical records. Regions of interest were manually cropped to 400×800 pixels, and all images were uploaded to Google Cloud storage. Approximately 80% of the images were used for training, 10% for validation, and 10% for testing. Google automated machine learning (AutoML) Vision automatically executed a neural architecture search technology to apply an appropriate algorithm to the uploaded data. A single-label image classification model was trained using AutoML. The performance of the mod-el was evaluated in terms of accuracy, precision, recall, specificity, and F1 score.

RESULTS

The accuracy, precision, recall, specificity, and F1 score of the AutoML Vision model were 0.981, 0.963, 0.961, 0.985, and 0.962, respectively. Osstem TSIII had an accuracy of 100%. Osstem USII and 3i Osseotite External were most often confused in the confusion matrix.

CONCLUSION

Deep learning-based AutoML on a cloud platform showed high accuracy in the classification of dental implant systems as a fine-tuned convolutional neural network. Higher-quality images from various implant systems will be required to improve the performance and clinical usability of the model.

Dual nanocarrier of chlorhexidine and fluconazole: Physicochemical characterization and effects on microcosm biofilms and oral keratinocytes

OBJECTIVES

This study assembled and characterized a dual nanocarrier of chlorhexidine (CHX) and fluconazole (FLZ), and evaluated its antibiofilm and cytotoxic effects.

METHODS

CHX and FLZ were added to iron oxide nanoparticles (IONPs) previously coated by chitosan (CS) and characterized by physical-chemical analyses. Biofilms from human saliva supplemented with Candida species were grown (72 h) on glass discs and treated (24 h) with IONPs-CS carrying CHX (at 39, 78, or 156 µg/mL) and FLZ (at 156, 312, or 624 µg/mL) in three growing associations. IONPs and CS alone, and 156 µg/mL CHX + 624 µg/mL FLZ (CHX156-FLZ624) were tested as controls. Next, microbiological analyses were performed. The viability of human oral keratinocytes (NOKsi lineage) was also determined (MTT reduction assay). Data were submitted to ANOVA or Kruskal-Wallis, followed by Fisher's LSD or Tukey's tests (α=0.05).

RESULTS

Nanocarriers with spherical-like shape and diameter around 6 nm were assembled, without compromising the crystalline property and stability of IONPs. Nanocarrier at the highest concentrations was the most effective in reducing colony-forming units of Streptococcus mutans, Lactobacillus spp., Candida albicans, and Candida glabrata. The other carriers and CHX156-FLZ624 showed similar antibiofilm effects, and significantly reduced lactic acid production (p<0.001). Also, a dose-dependent cytotoxic effect against oral keratinocytes was observed for the dual nanocarrier. IONPs-CS-CHX-FLZ and CHX-FLZ significantly reduced keratinocyte viability at CHX and FLZ concentrations ≥7.8 and 31.25 µg/mL, respectively (p<0.05).

CONCLUSION

The nanotherapy developed outperformed the effect of the combination CHX-FLZ on microcosm biofilms, without increasing the cytotoxic effect of the antimicrobials administered.

CLINICAL SIGNIFICANCE

The dual nanocarrier is a promising topically-applied therapy for the management of oral candidiasis considering that its higher antibiofilm effects allow the use of lower concentrations of antimicrobials than those found in commercial products.

A survey of white spot lesion prevention and resolution in the US dental school curricula

PURPOSE/OBJECTIVES

White spot lesions (WSLs) are opaque white lesions on smooth tooth surfaces as a result of demineralization. Proven methods of prevention and resolution of these lesions are available yet the incidence rate, especially in orthodontic patients, is still high. Perhaps the way dental schools are educating students on the topic is insufficient. The purpose of this study was to determine if and how predoctoral dental students are taught about the prevention and resolution of WSLs.

METHODS

An electronic survey was developed and sent out to each of the 66 accredited dental schools in the United States and Puerto Rico. The survey consisted of 13 questions and inquired about whether the school includes instruction of WSLs in its predoctoral curriculum. If the school indicated instruction WSLs was in the predoctoral curriculum, further questions were asked pertaining to the content and method of the instruction. Demographic data was also gathered from each institution.

RESULTS

Twenty-eight of the 66 schools responded for a 42% response rate. Eighty-two percent of schools indicated they were teaching about prevention of WSLs, while 50% indicated they were teaching about resolution, or treatment, of WSLs. The most commonly taught methods were patient education, over-the-counter fluoride mouthrinse, toothpaste, or gel, and high fluoride content toothpaste.

CONCLUSION

The majority of responding dental schools are at least including some instruction of WSLs in the predoctoral curriculum. Many of the known prevention and treatment measures available, however, are not routinely taught.

Translucency characteristics of permanent maxillary central incisor in Indian population: An analytical cross-sectional study

Background

Understanding the optical characteristics, especially the translucency patterns (TPs) in teeth can assist clinicians in creating biomimetic restorations.

Aim

This study assessed the differences in enamel TPs and the area of translucency (AOT) in the most dominant teeth of an individual's smile according to their age and gender.

Materials and Methods

This cross-sectional study was conducted on 140 consented individuals. Based on the age, there were four groups with 35 subjects in each. The digital imaging method is used to classify and differentiate different TPs. The AOT was measured with the assistance of ImageJ 1.51j8 software.

Statistical Analysis Used

One-way ANOVA with a post hoc test was used to test the statistical significance difference among the various age groups, and an independent t-test was used to test the variations between genders.

Results

The outcome of this study showed that the AOT was the highest for the 50 and above age group as compared to other age groups (P = 0.003). Although there were variations in the TPs between the two genders, the AOT showed no significant difference.

Conclusion

The area of incisal third translucency in the upper central incisors varied between different age groups. However, gender had no influence in the area of incisal translucency. Wide variations in the TPs were seen based on age and gender.

The Correlation between Mandibular Arch Shape and Vertical Skeletal Pattern

Background and Objectives: The aim of this study was to evaluate the correlation between the mandibular arch shape and the vertical skeletal pattern in growing patients. Materials and Methods: A total of 73 Caucasian patients (33 males and 40 females; mean age 9.4) were retrospectively enrolled from a pool of patients treated in chronological order at the Department of Orthodontics, University of Foggia, Italy, from April 2018 to December 2021. Each patient received a laterolateral radiograph and a digital scan of the dental arch. Eight cephalometric parameters (lower gonial angle, intermaxillary angle, divergence angle, Wits index, Jarabak ratio, OP-MP angle, PP-OP angle, and ANB) and five dental measurements (posterior mandibular arch width, anterior mandibular arch width, mandibular occlusal angle, posterior width on distobuccal molar cusps, and molar angle) were analyzed and then compared. A Spearman's rho correlation test between the cephalometric measurements and the dental measurements was performed. Statistical significance was set at p < 0.05. Results: A negative statistically significant correlation was found between the Jarabak ratio and the intermolar angle; a statistically significant correlation was also observed between the Wits index, the posterior mandibular width, and the occlusal mandibular angle; the ANB angle and the occlusal mandibular angle; the intermaxillary angle (PP-PM) and the mandibular occlusal angle, posterior mandibular width on the disto-vestibular cusp, and the intermolar angle; and the OP-MP angle and mandibular occlusal angle and the posterior mandibular width on the disto-vestibular cusp. Conclusions: The mandibular arch form may be related to certain predisposing features in craniofacial morphology, such as jaw divergence, the Jarabak ratio, and the intermaxillary angle.

Evaluation of the flexural strength of orthodontic acrylic resin incorporated with propolis nanoparticles: an in vitro study

AIM

Nanopropolis has become the subject of interest in medicine and dentistry as a natural product due to its outstanding properties, particularly antimicrobial activity. This study aimed at investigating the effect of nanopropolis on flexural strength of polymethyl methacrylate (PMMA).

Finite element analysis of sagittal screw expander appliance in the treatment of anterior maxillary hypoplasia

The skeletal anterior crossbite is a common malocclusion in clinic. However, there have been no reports on the maxillary sagittal expansion to correct the premaxillary hypoplasia, which greatly influences the facial morphology and masticatory function, using finite element analysis. In the present study, a three-dimensional finite element model of craniomaxillofacial complex with maxillary sagittal hypoplasia is constructed and the treatment for premaxillary hypoplasia by the sagittal screw expander appliance is simulated. The hypoplasia of the left premaxilla is more serious than that of the right and thus the size of the left part of premaxillary expander baseplate is designed to be larger than that of the right part and the loading is applied at 10° leftward to the sagittal plane and 30° forward and downward to the maxillary occlusal plane. The displacements or equivalent stress distributions of the maxilla, teeth and their periodontal ligaments, are analyzed under the loads of 5.0 N, 10.0 N, 15.0 N, and 20.0 N. Consequently, as the load increases, the displacements or equivalent stresses of the maxilla, teeth and their periodontal ligaments all increase. Almost the whole premaxilla markedly move forward, downward, and leftward while other areas in the craniomaxillofacial complex remain almost static or have little displacement. The equivalent stress concentration zone of the maxilla mainly occurs around and in front of the incisive foramina. The displacements of left premaxilla are generally greater than those of the right under the loading forces. The maximum equivalent stress on the teeth and their periodontal ligaments are 2.34E-02 MPa and 2.98E-03 MPa, respectively. Taken together, the sagittal screw expander appliance can effectively open the premaxillary suture to promote the growth of the premaxilla. An asymmetrical design of sagittal screw expander appliance achieves the asymmetric expansion of the premaxilla to correct the uneven hypoplasia and obtains the more symmetrical aesthetic presentation. This study might provide a solid basis and theoretical guidance for the clinical application of sagittal screw expander appliance in the efficient, accurate, and personalized treatment of premaxillary hypoplasia.

How Effective Are Non-Frictional Techniques Compared to Sliding Techniques in the Retraction of Upper Anterior Teeth When Using Buccal Fixed-Appliance Therapy? A Systematic Review

Methods for retracting the anterior teeth are divided into frictional methods and non-frictional methods. However, evidence regarding the superiority of one technique over the other is still lacking in the available literature. Therefore, we aimed to evaluate the current evidence regarding the effectiveness of frictional methods of anterior teeth retraction compared to the non-frictional ones. The extracted data included the mechanism of application of the retraction force and its intensity, the observation period, follow-up records, and outcome measures. Ten studies were included in this review; the results did not favor a specific technique regarding the rate of orthodontic tooth movement and loss of anchorage during canine retraction, although a preference was shown for the sliding technique in the rate of en-masse retraction (0.74 versus 0.39 mm/month) and the anchorage control during the retraction of the incisors (0.5 versus 0.1 mm/month). The control of the incisor's torque during the en-masse retraction was higher when frictionless techniques were used (-12° versus -7°). Regarding the rate of orthodontic tooth movement, the non-frictional technique is characterized by a high sensitivity to the quality of the design, and the sliding technique was generally effective. As for controlling the torque of the incisors, the preference is for the non-frictional technique. Overall, there is a need to conduct more studies with an appropriate design.

Evaluation of the mandibular condyles trabecular structure in patients with severe class III pattern: a computed tomography (CT) fractal analysis study

Class III malocclusion is a combination of dental and skeletal disorders that causes discrepancies in occlusion. Malocclusion can affect the structure of the Temporomandibular joint (TMJ) resulting in many problems, one of which is affecting the internal structure of the bone. This study aimed to examine the morphological features of class III patients' trabecular structure of the mandibular condyle in comparison with normal class I individuals using fractal analysis (FA). To study the internal structure of the mandibular condyle bone, Computed Tomography (CT) scans of 45 severe class III patients (age: 16-46) who were the candidates for orthognathic surgery were selected and matched by age and sex with 45 normal class I individuals. The trabecular bone structure of the left and right mandibular condyles in three CT planes of the study group and control group were evaluated employing the FA. The result of the present study indicated that the fractal dimensions (FD) values of class III patients were lower than those of the normal class I individuals in axial (class I: 1.31 ± 0.02, class III: 1.28 ± 0.02), sagittal (class I: 1.25 ± 0.03, class III: 1.19 ± 0.08), and coronal (class I: 1.5 ± 0.06, class III: 1.45 ± 0.07) planes (P < 0.001). There were no significant differences between the FD values of the males and females. The intra-group evaluation revealed that there was no correlation between age and FD values. No evidence of laterality was found regarding the FD values of the right and left condyles. Given the noticeable differences between the FD values, it can be implied that severe class III malocclusion may affect the trabecular pattern of the cancellous bone of the mandibular condyle compared to class I individuals. Therefore, due to the altered trabecular structure, clinicians should be cautious when planning treatments for these patients.

Influence of lip position on esthetics perception with respect to profile divergence using silhouette images

BACKGROUND

The aim of the study was to determine the facial divergence and lip position combinations that are most and least preferred, and to investigate whether age or gender has an impact on these preferences.

METHODS

The current investigation was carried out on a sample of 1077 individuals who were not experts in the field (253 men and 824 females). The research employed black silhouette photographs of profiles featuring different lip locations and profile divergences. The recruitment of participants was conducted in order to assess the attractiveness of the profiles, employing a Likert scale. The various positions of the lips and variations in facial profiles were thoroughly categorized. Results were analyzed using the Chi-square test.

RESULTS

The findings of the research demonstrated that aesthetic perceptions displayed diversity when considering different lip locations and profile divergences. It was shown that neutral lip positions were predominantly favored, accounting for approximately 40.2% of the total frequencies in the anterior diverging group. It is noteworthy to highlight the aesthetically pleasing features exhibited by those with the most prominent lip position, occurring at a frequency of 10.9% in straight-diverging group. In the posterior divergent group, the most protruded lip position, showed very attractive aesthetics with frequency (7.1%). Gender, age, region, and level of education had significant influence on aesthetic perception.

CONCLUSIONS

The variety of aesthetic preferences is influenced by the location of the lips and the divergence of the facial profile, resulting in different outcomes within the categories of anterior, straight, and posterior divergence. Clinicians are advised to customize the treatment regimen in order to correspond with the unique desires and preferences of the patient.

An interpretable machine learning approach to study the relationship beetwen retrognathia and skull anatomy

Mandibular retrognathia (C2Rm) is one of the most common oral pathologies. Acquiring a better understanding of the points of impact of C2Rm on the entire skull is of major interest in the diagnosis, treatment, and management of this dysmorphism, but also permits us to contribute to the debate on the changes undergone by the shape of the skull during human evolution. However, conventional methods have some limits in meeting these challenges, insofar as they require defining in advance the structures to be studied, and identifying them using landmarks. In this context, our work aims to answer these questions using AI tools and, in particular, machine learning, with the objective of relaying these treatments automatically. We propose an innovative methodology coupling convolutional neural networks (CNNs) and interpretability algorithms. Applied to a set of radiographs classified into physiological versus pathological categories, our methodology made it possible to: discuss the structures impacted by retrognathia and already identified in literature; identify new structures of potential interest in medical terms; highlight the dynamic evolution of impacted structures according to the level of gravity of C2Rm; provide for insights into the evolution of human anatomy. Results were discussed in terms of the major interest of this approach in the field of orthodontics and, more generally, in the field of automated processing of medical images.

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment

Background

This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment.

Methods

This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha = 0.05).

Results

A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P < 0.001), which was correlated with the magnitude of retraction of upper and lower incisors (r = 0.6 - 0.8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0.001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0.001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r = 0.4 - 0.6).

Conclusion

According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions.

Shear Bond Strength of Metal and Ceramic Brackets Depending on Etching Protocol in Direct Bonding Technique

Successful orthodontic therapy, apart from a proper treatment plan, depends on optimal bracket-enamel adhesion. Among numerous factors affecting adhesion, the type of bracket and preparation of the tooth's surface are crucial. The aim of this study was to compare the shear bond strength (SBS) of metal and ceramic brackets to the enamel's surface using direct bonding. Forty extracted human premolars were divided into four groups according to the etching method (etch-and-rinse and self-etch) and bracket type. The SBS and adhesive remnant index (ARI) were determined. The ceramic brackets achieved the highest SBS values both in the self-etch (SE) and etch-and-rinse (ER) protocols. Higher SBS values for ceramic and metallic brackets were found in the ER protocol. In all tested groups, the achieved SBS value was satisfactory to withstand orthodontic and occlusal forces. There was no significant difference in the ARI score between study groups (p = 0.71). The fracture occurred between the bracket base and adhesive material in both types of brackets, which decreased the risk of enamel damage during debonding.

Evaluation of the Loss of Strength, Resistance, and Elasticity in the Different Types of Intraoral Orthodontic Elastics (IOE): A Systematic Review of the Literature of In Vitro Studies

BACKGROUND

Intraoral orthodontic elastics (IOE), typically referred to as rubber bands, are important tools for correcting malocclusion, and they are classified into latex and synthetic (elastomeric-based) elastics. They have different strengths and sizes, depending on their intended use, that provide clinicians with the ability to correct both anteroposterior and vertical discrepancies. Clinical use, together with saliva, alters the physical characteristics of both latex and synthetic elastics, causing declines in strength over time.

AIM

The aim of the study was to assess, through a systematic review of in vitro studies, the properties of intraoral elastics. The primary goal was to evaluate how IOEs behave in terms of tension strength and duration. The secondary goal was to investigate the force loss during the first hours of wear. The tertiary goal was to assess how these forces decayed.

MATERIALS AND METHODS

The following electronic databases were searched from December 2020 to April 2021: Medline Full Text, PubMed, Cochrane Clinical Trials Register, Science Direct, and Literature Review. Out of 8505 initial articles, 10 were selected for the systematic review.

RESULTS

The force-degradation property was found in all types of IOEs. The loss of strength was directly proportional to time, with the highest value during the first 3 h after extension, regardless of the elastic band size and manufacturer. The forces generated by the latex bands were higher than in those of the elastomeric-based elastics, but they did not consistently correspond to the loads specified by the manufacturers. The retention forces in the latex IOEs were significantly higher than those in the nonlatex bands, suggesting that elastomeric-based bands need to be changed more frequently and at regular intervals throughout a 24 h period.

CONCLUSION

This systematic review indicates that intraoral orthodontic elastics have the greatest loss of force during the first 3 h, that latex rubber bands have the highest strength during the first hour, that the forces generated are not always consistent with the manufacturer's specifications, and that nonlatex (elastomeric-based) IOEs need to be changed frequently and regularly during a 24-h cycle.

Effect of bleaching treatments on the adhesion of orthodontic brackets: a systematic review

BACKGROUND

Nowadays bleaching procedures have gained popularity in orthodontic patients. Peroxide and Carbamide acids are the common agents which are used in in-office and at home bleaching techniques. Consequently, the Bonding adhesion to the enamel can be influenced by the orthodontic phase and the residual peroxide might interfere with the polymerization and the adhesion of the brackets. Frequent debonding of the brackets from teeth after the bleaching procedure could cause the lengthening of the therapy and promote irregularities on enamel surface derived from an additional bonding phase of the brackets. The aim of this systematic review is to appraise the influence regarding the effect of the bleaching procedure on the bond strength of orthodontic brackets.

METHODS

An electronic database search was performed. Search terms included: bleaching, brackets, adhesion; data were extracted and summarized. Risk of bias was assessed using the Chocrane risk of bias tool, adapted for in vitro studies.

RESULTS

A total of 8689 articles were screened and 11 studies met the inclusion criteria of this systematic review. 1000 teeth of human and bovine origin were analyzed for the shear bond strength (SBS) of stainless and ceramic brackets after the bleaching treatments. All the authors divided the groups in different subgroups with different bleaching agents and in different concentration. The SBS value allowed to demonstrate the necessity to delay the bonding of the brackets for two weeks after a bleaching treatment and its improvement when tooth mousse or antioxidants agents are used.

CONCLUSIONS

The SBS values and the delay of the bonding procedure must be considered in dental practice and clinical strategies are necessary in order to avoid drawbacks which could cause the debonding of the brackets after bleaching due to the alterations of the dental substrate, thus interfering with the orthodontic treatments.

Effect of Erbium:YAG Laser Recycling on Mechanical Characteristics of Retrieved Orthodontic Mini-screws

Introduction: This study aimed to evaluate the influence of two recycling methods on the mechanical and surface characteristics of orthodontic mini-screws. Methods: Thirty-six retrieved mini-screws were randomly classified into two equal groups. In the first group (laser recycled group (LG)), the Er:YAG laser (2940 nm, 5.5 W, 275 mJ, perpendicular to the mini-screws at a distance of 7-10 mm, 25 s) was used to recycle mini-screws. In the second group (phosphoric acid and sodium hypochlorite recycled group (ASG)), the mini-screws were kept in 37% phosphoric acid gel (10 minutes) and then placed in 5.25% sodium hypochlorite for 30 minutes. Eighteen new mini-screws were selected as the control group (CG). Maximum insertion torque (MIT), maximum removal torque (MRT), and fracture torque (FT) of all mini-screws were measured. A sample from each group was examined for the surface changes of the mini-screw and tissue remnants under a scanning electron microscope (SEM). Results: The mean MIT was significantly higher in both LG and ASG groups than the CG (P<0.001 and P=0.002, respectively). However, no significant difference was shown between the LG and ASG groups. The mean values of MRT and FT showed no significant difference between the groups. The amount of tissue remnants in the ASG group was significantly higher than that in the LG group. The evidence of porosity and corrosion was observed on the ASG mini-screw surface, and there was an increase in roughness on the LG mini-screw surface. Conclusion: The Er:YAG laser recycling of mini-screws is a proper method causing minimum damage to the screw surface.

Maxillary canine position of patients with non-syndromic craniofacial disorder: a retrospective evaluation of panoramic radiographs

BACKGROUND

The study evaluates the position and displacement tendency of unerupted maxillary canines in orthodontic patients with non-syndromic craniofacial disorders (CD) compared to a control (C) group.

METHODS

Canine position and displacement tendency were evaluated using panoramic radiographs (PAN) examined with parameters such as sector classification (sectors 1-5) and inclination angles (α and β). The displacement tendency was defined as the positioning of the tip in sectors 1 or 2, as well as its combination with increased angles (α > 30° and β > 39°). In addition, the correlation of the tooth position and agenesis, cleft side, and sex was assessed.

RESULTS

A total of 116 pre-treatment PAN, divided into the CD group (n = 50; mean age 8.32 ± 2.27 years) and the C group (n = 66; mean age 10.80 ± 2.82 years), were evaluated in this study. The sector classification showed no displacement tendency in both groups. Inclination angles α/β showed a statistically significant higher displacement tendency (p = 0.01) of the CD group (n = 5) on the right side, compared to healthy subjects (n = 1). Male CD patients had a statistically significant higher displacement tendency on the right side (p = 0.03). A statistically significant correlation between cleft and non-cleft-side (p = 0.03) was found.

CONCLUSION

Patients with CD showed a statistically significant higher displacement tendency of the maxillary canine affected by the cleft side. The inclination angle was found to be the better predictor compared to the sector classification which should be considered in the orthodontic treatment planning.

Accuracy and Retention of Molding Plates Used for Infants with Cleft Lip and Palate Fabricated from Different Materials: A Cross-Sectional Clinical Study

OBJECTIVES

The study aimed to comparatively assess the accuracy and retention of molding plates made of polyethylene terephthalate modified with glycol (PET-G) and polymethyl methacrylate (PMMA) materials, while also investigating the effect of adhesive addition on retention.

DESIGN

A cross-sectional clinical study.

PATIENTS/SETTING

The study included 30 infants diagnosed with non-syndromic cleft lip and palate (16 unilateral, 14 bilateral). Two molding plates were fabricated for each infant, and their accuracy and retention were evaluated. The data were analyzed using independent t-tests, Mann-Whitney U tests, and Wilcoxon rank tests.

MAIN OUTCOME MEASURES

Accuracy: The accuracy of the molding plates was assessed by measuring the virtual gap between the inner surface of the plates and their working cast using Exocad software. The accuracy was evaluated in different regions (anterior, middle, and posterior) and compared between PET-G and PMMA materials. Retention: The retention of the molding plates was measured using a digital force gauge, which recorded the force required to dislodge the plates from the infant's mouth. The retention was compared between PET-G and PMMA materials, as well as the effect of adhesive addition on retention. Overall adaptation; PET-G plates showed a significantly smaller gap (mean= 0.264 ±0.106) compared to PMMA (mean= 0.362 ±0.130). Region-specific adaptation: PET-G plates demonstrated better accuracy in all regions (means of anterior =0.246, middle =0.262, posterior =0.282 µm). Significant differences in accuracy were observed in the middle and posterior regions compared to PMMA. Retention assessment revealed that the PET-G groups (with or without adhesive) exhibited significantly higher retention compared to the PMMA groups (P<0.01).

CONCLUSION

PET-G plates demonstrated superior accuracy and retention compared to PMMA, with a significant difference observed in both accuracy and retention. Furthermore, the addition of denture adhesive had a positive effect on retention for both materials.

Efficacy of hypochlorous acid as an alternative oral antimicrobial agent on human gingival fibroblasts, Aggregatibacter actinomycetemcomitans, and Candida albicans biofilms in vitro

This study compared the cytotoxicity and antimicrobial activity of hypochlorous acid (HOCl) at 50 ppm and 200 ppm and 0.2% chlorhexidine (CHX) at various time intervals, in vitro. Cell viability and cytotoxicity of human gingival fibroblasts (HGF) were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and the lactate dehydrogenase assay. Antimicrobial effects on Aggregatibacter actinomycetemcomitans and Candida albicans were determined using the time-kill method. All solutions exhibited a significant impact on HGFs in a dose- and time-dependent manner. 50 ppm HOCl demonstrated the highest cell viability, followed by 200 ppm HOCl. Both HOCl solutions were less cytotoxic to HGFs than 0.2% CHX. 50 ppm and 200 ppm HOCl demonstrated stronger efficiencies than CHX against A. actinomycetemcomitans and C. albicans. The data suggest that HOCl solutions have potential as an alternative antiseptic to CHX due to their lower cytotoxicity and superior antimicrobial activity, but optimal dosage of HOCl requires further investigations.

Survival Rate of Dental Implants in the Cleft Area: A Cross-Sectional Retrospective Study

This study aimed to evaluate the survival rate of osseointegrated implants installed in the cleft area. An extensive data survey was conducted using the medical records of individuals who had implants installed in the cleft area between 1999 and 2020. The variables assessed were age, sex, implant follow-up time, implantation procedures, and rehabilitation with implant-supported prostheses. Data were analyzed in terms of implant survival time, correlating with the factors: age, sex, execution, or no-execution of bone regrafting, the time interval between secondary alveolar bone grafting and regrafting, the time interval between regrafting and implant installation, and the time interval between implant installation and provisional and definitive prosthesis. Data were analyzed with respect to implant survival. χ 2 and Student t tests were used with a 5% significance level. A total of 1295 medical records were analyzed, of which 688 reported implants in cleft areas (56.1% in females, 43.9% in males) with a success rate of 92.73% and a mean follow-up time of 53.2 (±45.0) months. There were no statistically significant differences in the correlation between the survival rate and sex ( P = 0.895, χ 2 test), between the implant survival rate and regrafted area ( P = 0.904, χ 2 test), or between the survival rate and patient age ( P = 0.246, Student t test). The survival rate of implants in the cleft area was 92.73%. Age, sex, and the need for regrafting did not influence the survival rate of implants installed in the cleft area. Clinical studies that evaluate the survival rate of implants installed in patients with cleft maxilla are of great relevance to the dental field.

Long-term vertical stability of horseshoe osteotomy for the correction of large vertical excess of the maxilla, a retrospective assessment in 15 patients

INTRODUCTION

Vertical stability after a Le Fort I (LF1) osteotomy with substantial upward movement can be compromised by the position and the volume of the inferior turbinate. A horseshoe (HS) osteotomy represents then an alternative as it preserves the hard palate and the intranasal volume. The aim of this study was to assess the vertical stability of the maxilla after HS osteotomy.

MATERIALS AND METHODS

Patients who underwent a HS osteotomy for the correction of long-face syndrome were retrospectively analyzed. The vertical stability was assessed on lateral cephalograms performed preoperatively (T0), immediately postoperatively (T1), and at the last follow-up (T2) by studying points C (the distal cusp of the first maxillary molar), point P (the prosthion, the lowest edge of the maxillary alveolus of the central incisor), and point I (the upper central incisor edge) in a coordinate system. Postoperative complications and aesthetics of the smile were also investigated.

RESULTS

Fifteen patients were included (7 females, 8 males, mean age 25.5 ± 9.8 yeras). The mean impaction ranged from 5 mm on point P to 6.1 mm on point C, with a maximal movement of 9.5 mm. A non-significant relapse of 0.8 ± 1.7, 0.6 ± 0.8, and 0.5 ± 1.8 mm was observed after a mean 20.7 months on point C, P, and I respectively. Smile parameters were significantly improved by the procedure, mainly regarding the correction of the gum smile.

CONCLUSION

HS osteotomy represents a good alternative to total LF1 osteotomy for substantial maxillary upward movement in long face syndrome deformities.

Evaluation of craniofacial anthropometry of children with β-thalassemia major in the eastern Anatolia: a case-control study

OBJECTIVE

The present study aims to compare β-thalassemia major patients and healthy individuals in terms of anthropometric characteristics and changes in craniofacial profile.

SUBJECTS AND METHOD

Craniofacial anthropometric measurements were performed on a total of 422 subjects (199 β-thalassemia major patients and 223 healthy individuals) by using a millimetric caliper and tape measure on 19 anthropometric parameters (8 horizontal, 10 vertical, and 1 head circumference) in cranial, facial, nasal, orolabial, and orbital zones.

RESULTS

The difference between the orbital, nasal, and orolabial zone parameters of healthy subjects and β-thalassemia major patients was found to be statistically significant (p < 0.05). There was no statistically significant difference between the groups in terms of head circumference in the cranial zone and total facial height in facial zone (n-gn) values (p˃0.05). In intragroup comparison between females and males with β-thalassemia, statistically significant differences were found in forehead width (ft-ft), forehead height (tr-gl), right eye width (R ex-ex), and upper lip height (sn-stm) (p < 0.05).

CONCLUSION

Understanding the craniofacial profile changes in β-thalassemia major patients and increasing our knowledge about the relationship between the course and severity of disease and the level of these changes would contribute to the advancements in diagnoses to be made in facial and jaw zones of these patients and in the treatment plans.

CLINICAL RELEVANCE

We believe that the analysis and results of the craniofacial anthropometric data obtained in the study will contribute to the diagnosis and treatment processes of patients with β-thalassemia major in areas of expertise such as craniofacial surgery, orthodontics, and hemato-oncology.

Separation effect, pain perception during functional activity and gingival inflammation of elastomeric and Kansal separators-a split mouth study

INTRODUCTION

An effective space opening for band placement with minimal pain and gingival inflammation is a prime requisite during fixed orthodontic procedures. The study aimed to compare the effectiveness of two types of separators, elastomeric and Kansal, in the amount of space opening, pain perception elicited, and gingival inflammation.

METHODS

A random split-mouth study was designed with 30 subjects undergoing fixed orthodontic treatment. Two different separators (Elastomer and Kansal) were placed alternatively on the left and right sides around the mesial and distal sides of the first molars in the mandibular arch of each subject. After 3 days, the amount of separation after 3 days was assessed with a leaf gauge on both mesial and distal sides. The subjective pain perception by visual analog Scale (VAS) at different points and during different functions for each of the 3 days was evaluated. A self-filled chart was utilized to be performed by the patients. Gingival index was used to assess the inflammatory changes.

RESULTS

The most significant amount of separation (0.28 mm) was found with elastomers on the mesial side and is statistically significant (p < 0.001) compared to the mesial side (0.18 mm). The Kansal separators produced equivalent separation on mesial (0.19 mm) and distal sites (0.17 mm). The highest pain score was found after 24 h with elastomeric separators (median-40) for chewing and biting and the least for sleep (median-30). There is a statistical difference of pain perception between elastomers and Kansal separators at different points for the given function (p < 0.001). Both the separators resulted in mild gingival index of score less than 1 (0.70 ± 0.65, 0.97 ± 0.720, and there was no statistically significant difference between the two types of separators.

CONCLUSION

Both the separators produced adequate separation after a minimum 3 days. Kansal produces minimum discomfort and pain compared to elastomeric separators. Mild gingival inflammation was observed with both the separators.

Preparation and Assessment of Antimicrobial Effect of Strontium and Copper Co-substituted Hydroxyapatite Nanoparticle-Incorporated Orthodontic Composite: A Preliminary In Vitro Study

Background and aims Enamel demineralization and white spot lesions (WSLs) during orthodontic treatment have always been a challenge to orthodontists. The advancement of nanotechnology has paved the way for the incorporation of bioactive compounds in orthodontic materials especially orthodontic composites for prevention and management of WSLs. The present study aims to prepare, characterize, and then incorporate copper and strontium doped nanohydroxyapatite into orthodontic composite material and test its antibacterial efficacy. Materials and methods The present in vitro study involved the preparation of the strontium and copper co-substituted hydroxyapatite (SrCuHA) nanoparticles (Nps) using the sol-gel method. The prepared Nps were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), and Fourier transform infrared spectroscopy (FTIR). The Nps were incorporated into a commercially available orthodontic composite. The antimicrobial properties of the SrCuHA Nps-incorporated composite were tested using the Agar well diffusion method against Staphylococcus aureus(S. aureus), Streptococcus mutans (S. mutans), and Escherichia coli (E. coli). Results The SrCuHA Nps were successfully prepared. EDAX, FTIR, and SEM analyses revealed the successful formation of the Nps. The SrCuHA-incorporated orthodontic composite at a higher concentration of 40 μl showed the maximum zone of inhibition (ZOI) against S. mutans. The control group showed the maximum ZOI against E. coli and the SrCuHA Nps-incorporated composite at 20 μl showed the maximum inhibition against S. aureus. Conclusion In the present study, successful preparation of SrCuHA Nps followed by incorporation in the orthodontic adhesive was done. The prepared nanoparticle was characterized and the SrCuHA Nps-incorporated orthodontic composite demonstrated comparable ZOI against S. mutans to the control.

The relationship of tooth crown dimensions between first molar and central incisor in maxilla

The purpose of this study was to investigate a correlation between the cusp dimensions of the first molar and mesiodistal crown diameters of the central incisors in the maxilla. The study materials were composed of dental casts from 29 modern Japanese female subjects with a mean age of 20 years and 8 months. The mesiodistal crown diameters of the maxillary central incisors were measured. The mesiodistal and bucco-lingual crown diameters and the cusp diameters of the maxillary first molars, such as the paracone, metacone, protocone, and hypocone, were also measured. The crown areas and indices of the first molars were calculated. The Spearman's single rank correlation coefficients between the mean values for the crown dimensions of the first molars and the mesiodistal crown diameters of the central incisors were calculated. The hypocone cusp diameter and the hypocone index were the largest compared to those of the paracone, protocone, and metacone cusps. The bucco-lingual diameter and hypocone cusp diameter of the first molars positively correlated with the mesiodistal crown diameters of the central incisors on the same sides. There were positive correlations between the hypocone index of the first molars and the mesiodistal crown diameters of the central incisors. Based on the results, if a large hypocone is observed in eruption of the maxillary first molars, it will be predictable that of the mesiodistal crown diameter of the maxillary central incisor large.

Impact of Clear Aligners on Oral Health and Oral Microbiome During Orthodontic Treatment

The demand for clear aligners has risen over the past decade because they satisfy patients' desire for less noticeable and more comfortable orthodontic appliances. Because clear aligners are increasingly used in orthodontics, there is a big push to learn more about the physiologic and microbial changes that occur during treatment. The present work highlighted further links between clear aligners and changes in oral health and the oral microbiome and provided plaque control methods for clear aligner trays. Existing literature revealed that clear aligners have no significant influence on the structure of the oral microbiome during orthodontic therapy. Clear aligner treatment demonstrated promising results in terms of controlling plaque index, gingival health, and the prevalence of white spot lesions. Nevertheless, grooves, ridges, microcracks, and abrasions on the aligner surface would provide a prime environment for bacterial adherence and the development of plaque biofilms. A combination of mechanical and chemical methods seems to be a successful approach for removing plaque biofilm from aligners whilst also preventing pigment adsorption.

Relationship of the Morphology and Size of Sella Turcica with Dental Anomalies and Skeletal Malocclusions

This study aimed to assess the relationship of the morphology and size of the sella turcica (ST) with dental anomalies and skeletal malocclusions. This cross-sectional study was conducted on records of fixed orthodontic patients treated between 2013 and 2022. Cephalometric analysis was performed to determine the anteroposterior and vertical skeletal patterns. Preoperative panoramic radiographs and lateral cephalograms, intraoral photographs, and primary dental casts of patients were used to detect dental anomalies. Gender, sagittal and vertical skeletal patterns, dental anomalies, and dimensions (length, depth, and diameter), and morphology of the ST were all recorded according to the lateral cephalograms of patients. Data were analyzed using independent t-test, one-way and two-way ANOVA, Chi-square test, and log rank test (alpha = 0.05). The depth and diameter of the ST had no significant correlation with gender (p > 0.05); however, the length of the ST was significantly longer in males than females (p < 0.05). The morphology of the ST had a significant correlation with gender (p < 0.05). The ST morphology had a significant correlation with the anteroposterior skeletal pattern, microdontia, and tooth impaction as well (p < 0.05). The present results revealed a significant correlation of the ST morphology with the anteroposterior skeletal pattern, microdontia, and tooth impaction.

Three-dimensional evaluation of the association between tongue position and upper airway morphology in adults: A cross-sectional study

Objective

This study aimed to evaluate the association between low tongue position (LTP) and the volume and dimensions of the nasopharyngeal, retropalatal, retroglossal, and hypopharyngeal segments of the upper airway.

Methods

A total of 194 subjects, including 91 males and 103 females were divided into a resting tongue position (RTP) group and a LTP group according to their tongue position. Subjects in the LTP group were divided into four subgroups (Q1, Q2, Q3, and Q4) according to the intraoral space volume. The 3D slicer software was used to measure the volume and minimum and average cross-sectional areas of each group. Airway differences between the RTP and LTP groups were analyzed to explore the association between tongue position and the upper airway.

Results

No significant differences were found in the airway dimensions between the RTP and LTP groups. For both retropalatal and retroglossal segments, the volume and average cross-sectional area were significantly greater in the patients with extremely low tongue position. Regression analysis showed that the retroglossal airway dimensions were positively correlated with the intraoral space volume and negatively correlated with A point-nasion-B point and palatal plane to mandibular plane. Males generally had larger retroglossal and hypopharyngeal airways than females.

Conclusions

Tongue position did not significantly influence upper airway volume or dimensions, except in the extremely LTP subgroup.

Evaluation of pain experienced by orthodontic patients following elastomeric separator insertion: A cross-sectional study

Objective

Pain following the insertion of separators and archwires varies with age, sex, race, ethnicity, threshold, and health status. This study aimed to evaluate the characteristics of pain in orthodontic patients after the insertion of elastomeric separators, its effects on daily life, and its association with age and sex in a population not previously studied in this regard.

Methods

A cross-sectional study of 130 patients undergoing orthodontic treatment included collecting data on demographics, pain experienced following the placement of separators, time of onset, duration, characteristics, change in dietary pattern or chewing side, intake of analgesics, and severity of pain on the Wong Baker's scale. The results are reported as counts and percentages. Associations between sex and age were evaluated using Pearson's chi-square test.

Results

Among the 130 patients, 56.2% were 9-20 years old, 63.8% experienced pain following the insertion of separators, 22.9% had their first episode of pain at 4 hours, 56.6% experienced intermittent pain, and 37.3% experienced discomfort; 18.1% males and 81.9% females experienced pain following the insertion of separators. Pearson's chi-square test showed a significant association between pain and sex (P = 0.04). Most patients (37.3%) reported "hurts little more" for pain intensity on Wong Baker's scale and 21.7% reported all four quadrants as sites of pain.

Conclusions

The pain experienced after separator insertion was associated with sex and age. Females experienced more pain than males and patients between the age range of 21 and 36 years suffered more pain during mastication than between 9 and 20 years old.

Treatment for Severe Class II Open Bite Using a Bonded Hyrax Expander, IZC Mini-Implants, and MEAW Technique in an Adolescent Patient

This case report describes the successful 3D treatment of a patient with a narrow maxilla and a severe class II open bite using a combination of a bonded hyrax expander, infrazygomatic crest mini-implants, and the multiloop edgewise arch-wire (MEAW) technique. A 14-year-old female with a thumb-sucking habit in childhood, presented with a severe open bite, a convex profile, and an obtuse nasolabial angle. Diagnosis revealed a skeletal Class II open bite with moderate crowding in the maxillary and mild crowding in the mandibular arch. Treatment objectives included eliminating the open bite, achieving normal overbite and overjet, and improving upper incisor visibility. Treatment involved the use of a bonded rapid palatal expansion device, mini-implants for maxillary intrusion, fixed appliances, vertical elastics, and a MEAW. Treatment results showed resolution of the open bite, improvement in overbite and overjet, achievement of Class I molar and canine relationships, and improved upper incisors visibility. Fixed appliances were used for the whole 22-month therapy period, and post-treatment records demonstrated that the treatment's objectives were met.