Corrective outcome and transverse stability after orthognathic surgery using a surgery-first approach in mandibular prognathism with and without facial asymmetry

OBJECTIVES

The aim of this study was to evaluate corrective outcome and transverse stability after orthognathic surgery via a surgery-first approach (SFA) in mandibular prognathism with and without facial asymmetry using 3-dimensional analysis.

STUDY DESIGN

Twenty-nine patients who received mandibular setback surgery using SFA were divided into 2 groups according to the menton deviation (4 mm): symmetry group (n = 17) and asymmetry group (n = 12). Using computed tomography images obtained before (T0), immediately after (T1), and 6 months after (T2) surgery, time-dependent changes in variables related to facial asymmetry, including maxillary height, ramal length, frontal and lateral ramal inclination, mandibular body length, and mandibular body height, were evaluated.

RESULTS

Immediately after surgery, the asymmetry group showed significantly decreased discrepancies between the longer and non-longer sides for all variables (P < .05); there were no significant differences in discrepancies between the 2 groups. During the postoperative period, no significant changes in discrepancies were found in any variable in either group. Compared with T0, the asymmetry group showed significantly decreased discrepancies in ramal length, frontal and lateral ramal inclination, and mandibular body length at T2.

CONCLUSIONS

Variables related to facial asymmetry showed significant improvement after surgical-orthodontic treatment using SFA, and corrected outcomes showed good postoperative stability in both the symmetry and asymmetry groups.

Prevalence of Malocclusion in Permanent Dentition of Iranian Population: A Review Article

BACKGROUND

The aim of this study was systematic review and meta-analysis of prevalence in current and relevant literature about this developmental disorder to present the profile of malocclusion in Iran.

METHODS

This review study was carried out with systematically identified and critically assessed studies reporting malocclusion prevalence among Iranian population in permanent dentition. National and international databases were searched for articles about prevalence of malocclusion by Angle classification in different regions of Iran from 1994 to 2015. After applying inclusion and exclusion criteria, the quality of articles was checked by professional checklist. Data extraction and meta-analysis was performed. A random-effect model was employed. Publication bias was checked.

RESULTS

Of 2768 articles, 21 cases were included. The pooled prevalence of malocclusion was about 87% (95% CI: 78.3-92.2) in Iranian population; however, the prevalence of malocclusion across individual studies varied considerably (ranging from 23.7% to 99.7%). Prevalence of normal occlusion, class I, II and III malocclusion were reported as 13.3% (CI 95%: 7.8-21.7), 50.7% (CI 95%: 42.9-58.4), 21% (CI 95%: 17.5-25.1), 5.5% (CI 95%: 3-10); respectively. Maximum prevalence of malocclusion was in the East of Iran.

CONCLUSION

The results showed a high prevalence of malocclusion in Iranian population. The baseline information could be appropriately utilized for the future planning to meet the orthodontic treatment need among the Iranian population.

Immunohistochemical analysis of IL-1 Receptor 1 in the discs of patients with temporomandibular joint dysfunction

Objective Temporomandibular joint dysfunction (TMD) may affect a patient's quality of life, and one of the etiologies can be anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDWoR). Interleukin 1 Receptor 1 (IL-1R1) is a membrane receptor that plays an important role on initiating immune and inflammatory response by binding the agonists ligands of IL-1 alpha and IL-1 beta. Therefore, the aim of this study was to evaluate, through immunohistochemical analysis, the association of IL-1R1 with TMD. Methods Thirty-nine human disc samples were collected and composed three different groups: ADDwR (n = 19), ADDwoR (n = 12), and control group (n = 8). The samples were immunostained with IL-1R1 antibody and evaluated on both quantity and intensity of staining. Results There was a statistically significant difference (p < 0.05) between the control and test groups for both quantity and intensity of staining. Conclusion IL1-R1 was associated with ADDwR and ADDwoR in TMD discs of humans.

Comparative efficacy of Er,Cr:YSGG and Er:YAG lasers for etching of composite for orthodontic bracket bonding

Several techniques have been proposed to obtain a durable bond, and the efficacy of these techniques is assessed by measuring parameters such as bond strength. Laser has provided a bond strength as high as that of acid etching in vitro and has simpler use with shorter clinical time compared to acid etching. This study aimed to compare the efficacy of Er:YAG and Er,Cr:YSGG lasers for etching and bonding of composite to orthodontic brackets. No previous study has evaluated the effect of these particular types of laser. A total of 70 composite blocks were randomly divided into five groups (n = 14): group 1, etching with phosphoric acid for 20 s; group 2, Er:YAG laser irradiation with 2 W power for 10 s; group 3, Er:YAG laser with 3 W power for 10 s; group 4, Er,Cr:YSGG laser with 2 W power for 10 s; group 5, Er,Cr:YSGG laser with 3 W power for 10 s. Metal brackets were then bonded to composites, and after 5000 thermal cycles, they were subjected to shear bond strength test in a universal testing machine after 24 h of water storage. One sample of each group was evaluated under a scanning electron microscope (SEM) to assess changes in composite surface after etching. The adhesive remnant index (ARI) was calculated under a stereomicroscope. Data were statistically analyzed. The mean and standard deviation of shear bond strength were 18.65 ± 3.36, 19.68 ± 5.34, 21.31 ± 4.03, 17.38 ± 6.94, and 16.45 ± 4.26 MPa in groups 1-5, respectively. The ARI scores showed that the bond failure mode in all groups was mainly mixed. The groups were not significantly different in terms of shear bond strength. Er:YAG and Er,Cr:YSGG lasers with the mentioned parameters yield optimal shear bond strength and can be used as an alternative to acid etching for bracket bond to composite.

A comparison of different sealants preventing demineralization around brackets

AIM

Aim of the study was to compare how six different sealants resisted thermal, mechanical, and chemical loading in vitro.

MATERIALS AND METHODS

In all, 120 extracted human, nondecayed molars were divided into six groups (20 samples each) and embedded in resin blocks. The buccal surfaces of the tooth samples were polished and divided into three areas. Area A contained the product to be analyzed, area B was covered with colorless nail varnish (negative control), and area C remained untreated (positive control). The samples were stored in 0.1% thymol solution. To simulate a 3-month thermomechanical load, the samples were subjected to thermal cycling and a cleaning device. After 7 days incubation in a ten Cate demineralization solution (pH value: 4.6), the samples were dissected using a band saw and the lesion depths and demineralization areas were evaluated and compared microscopically.

RESULTS

The tooth surfaces treated with PRO SEAL® showed no demineralization. Mean lesion depths of 108.1, 119.9, 154.9, 149.2, and 184.5 μm were found with Alpha-Glaze®, Seal&Protect®, Tiefenfluorid®, Protecto®, and Fluor Protector, respectively. There was a significant difference between PRO SEAL® and the other products (p > 0.0001). There was no significant difference between the other products.

CONCLUSION

PRO SEAL® resisted thermal, mechanical, and chemical loading in vitro, providing protection against white spot lesions.

Maxillary lateral incisor agenesis; a retrospective cross-sectional study

Objective

This study aims to estimate the prevalence of congenitally missing lateral incisors in a sample of 2662 dental patients in Palestine.

Methods

A total of 2662 digital panoramic radiographs were retrospectively examined for the presence of congenitally missing permanent lateral incisors. The radiographs were obtained from the archival records of patients attending a local dental center at the city of Nablus in Palestine.

Results

The prevalence of missing lateral incisors among the examined population (n = 2662) was found to be 1.91%. Unilateral agenesis accounted for 66.6% of the total cases that showed at least one missing lateral incisor. Around 79% of the unilateral cases were on the left side while 21% were on the right side. Bilateral agenesis accounted for 33.3% of 34 cases that had at least one congenitally missing permanent maxillary lateral incisor.

Conclusion

The prevalence of missing maxillary lateral incisors in this study population was 1.91%) which was within the range reported in different populations.

Effectiveness of en masse versus two-step retraction: a systematic review and meta-analysis

Background

This review aims to compare the effectiveness of en masse and two-step retraction methods during orthodontic space closure regarding anchorage preservation and anterior segment retraction and to assess their effect on the duration of treatment and root resorption.

Methods

An electronic search for potentially eligible randomized controlled trials and prospective controlled trials was performed in five electronic databases up to July 2017. The process of study selection, data extraction, and quality assessment was performed by two reviewers independently. A narrative review is presented in addition to a quantitative synthesis of the pooled results where possible. The Cochrane risk of bias tool and the Newcastle-Ottawa Scale were used for the methodological quality assessment of the included studies.

Results

Eight studies were included in the qualitative synthesis in this review. Four studies were included in the quantitative synthesis. En masse/miniscrew combination showed a statistically significant standard mean difference regarding anchorage preservation − 2.55 mm (95% CI − 2.99 to − 2.11) and the amount of upper incisor retraction − 0.38 mm (95% CI − 0.70 to − 0.06) when compared to a two-step/conventional anchorage combination. Qualitative synthesis suggested that en masse retraction requires less time than two-step retraction with no difference in the amount of root resorption.

Conclusions

Both en masse and two-step retraction methods are effective during the space closure phase. The en masse/miniscrew combination is superior to the two-step/conventional anchorage combination with regard to anchorage preservation and amount of retraction. Limited evidence suggests that anchorage reinforcement with a headgear produces similar results with both retraction methods. Limited evidence also suggests that en masse retraction may require less time and that no significant differences exist in the amount of root resorption between the two methods.

Electronic supplementary material

The online version of this article (10.1186/s40510-017-0196-7) contains supplementary material, which is available to authorized users.

In vitro Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Different Adhesives

Background:

There is necessary of dry operating field for bonding of orthodontic brackets. The presence of moisture can alter the bond strength. Hence, the aim of the present study was to evaluate the shear bond strength of orthodontic brackets with different adhesives.

Materials and Methods:

In this in vitro study, a total of 100 orthodontically extracted premolars with sound crown structure were divided into 4 equal groups of different primers. Bonding on the buccal surface of all teeth was done after acid etching with upper premolar brackets using different primers followed by light curing. Shear bond strength was evaluated with or without salivary contamination with both adhesives. A shear force for deboning the bracket was done with universal testing machine. The debonded specimens were examined at ×10 magnification to check site of bond failure and remaining adhesive on tooth using adhesive remnant index (ARI). The obtained data were statistically evaluated using SPSS 20 for Windows (SPSS Inc., Chicago, IL, USA) using ANOVA, Kolmogorov–Smirnov, and Levene's test at the statistical significance of P < 0.05.

Results:

Transbond Plus showed higher shear bond strength of 8.92 MPa under dry and 5.65 MPa with saliva contamination over Transbond XT of 7.24 MPa under dry and 2.43 MPa with saliva contamination, respectively. Higher ARI score was found without contamination in both adhesives.

Conclusion:

Transbond Plus hydrophilic resin had good shear bond strength under both dry and contamination condition compared to hydrophobic Transbond XT resin material.

Assessment of oral findings of dental patients who screen high and no risk for obstructive sleep apnea (OSA) reporting to a dental college - A cross sectional study

To assess the oral findings of patients who screen high and no risk for obstructive sleep apnea (OSA) reporting to outpatient department of a dental college. Methods: Patients coming to dental Out Patient Department (OPD) were screened using STOP questionnaire and were categorized into high (n=130) and no risk (n=130) OSA groups. BANG (body mass index, age, neck circumference and gender) was recorded for both the OSA risk group patients. Following this oral and general examination was performed using predetermined criteria for temporomandibular disorder (TMD), Angle’s Class of Malocclusion, maxillary arch constriction, facial profile, Mallampati score for uvula, tongue size, depth of palatal vault and periodontitis. Chi-squared statistics was applied to know the significant difference among the two groups. Multivariate logistic regression model was run by including the significant variables. Results: 94 females and 166 males were present in the study with a mean age of 43.67±11.89 in both the risk groups. All the variables except Angle’s class of malocclusion and periodontitis showed significant difference among high and no risk OSA groups. Logistic regression confirmed that neck circumference, Class 3 or 4 Mallampati score, large tongue and deep palatal vault were commonly observed among high risk OSA group and were independent risk factors for developing high risk of OSA. Conclusion: Neck circumference>40cm, large tongue, Class 3 or 4 Mallampati score and deep palatal vault were found to be independent predictors of developing high risk of OSA. Dentist can play a vital role in screening such patients as he comes in close vicinity of oral cavity and thus can refer the patients to sleep physician to promote interdisciplinary approach.

Assessment of the effect of maxillary protraction appliance on pharyngeal airway dimensions in relation to changes in tongue posture

BACKGROUND

Literature is controversial in regard with alterations in pharyngeal airway dimensions subsequent to maxillary protraction. The correlation between maxillary protraction and sagittal airway dimension was investigated in association with tongue and soft palate position in skeletal Class III children. The results were compared with those of an untreated Class III and a Class I malocclusion control group.

MATERIALS AND METHODS

In this cross-sectional study pre- and post-treatment cephalometric radiographs of 19 Class III patients (6 males, 13 females; mean age, 7.93 ± 0.96 years) treated with facemask were analyzed. The correlation between treatment changes in craniofacial morphology and those in the upper airway, tongue, and soft palate was evaluated. These results were compared with those of a group of 16 Class I malocclusion patients (1 male, 15 females; mean age, 7.31 ± 0.7 years) and a group of 15 untreated Class III patients (4 males and 11 females; mean age, 7.46 ± 0.1 years). A paired t-test, the Shapiro-Wilk test and Mann-Whitney U-test was used. The level of significance was established as P < 0.05.

RESULTS

Nasopharyngeal airway measurements PNS-ad1 and PNS-ad2 significantly increased by 2 mm and 2.1 mm, respectively. Statistical analysis revealed that maxillary protraction had a positive relationship with PNS-ad1 and PNS-ad2.

CONCLUSION

Nasopharyngeal airway dimensions can be improved in the short term with maxillary protraction in skeletal Class III children.

Shear Bond Strength of Rebonded Ceramic Brackets Using Four Different Methods of Adhesive Removal

OBJECTIVES

Rebonding of isolated brackets is an economic option that can be conducted using available in-office or commercial recycling methods. Nowadays, lasers are known as an efficient modality for composite removal, but there is not much information available about using lasers for removal of adhesive remnants from the ceramic bracket base.

MATERIALS AND METHODS

Fifty human premolar teeth were divided into five groups. Samples in all groups were bonded to ceramic brackets. Brackets in four groups were debonded and the remaining adhesive was removed by Er:YAG laser, Er;Cr:YSGG laser, sandblasting or direct flame. After removing adhesives from the tooth surfaces by carbide bur, the recycled brackets were bonded again. in the control group, new ceramic brackets were bonded. Finally, all brackets were debonded by universal testing machine and their shear bond strength (SBS) was measured. The adhesive remnant index (ARI) was calculated under a stereomicroscope at ×10 magnification. Data were analyzed using oneway ANOVA and Tukey's test.

RESULTS

SRS values showed no significant difference among the five groups (P=0.568). The highest SRS was noted in the control group (7.46±1.4 MPa), followed by Er:YAG laser group (7.40±1.24 Mpa) and the lowest was noted in the flame group (6.32±2.3 Mpa). ARI scores indicated that most of the adhesive remained on the tooth surface in all groups.

CONCLUSIONS

Recycling of ceramic brackets with Er:YAG laser is an efficient in-office method which causes the least damage to the bracket base. However, all methods of bracket recycling showed acceptable SBS.

Microphotographic Assessment of Enamel Surface using Self-Etching Primer and Conventional Phosphoric Acid: An In vitro Study

INTRODUCTION

Conventional acid-etching method irreversibly removes several microns of enamel surface and also involves many steps. Hence, a simplified technique that minimizes enamel loss, improves adhesion procedures, prevents saliva contamination, and saves chair time, thereby producing clinically useful bond strength, would be valuable.

AIM

To assess and compare the bonding mechanism of a self-etching primer (SEP) to that of phosphoric acid on enamel of the human permanent teeth by a scanning electron microscope (SEM).

MATERIALS AND METHODS

Thirty freshly extracted premolars were randomly divided into two groups of fifteen teeth each - the control group I (phosphoric acid) and experimental group II (self-etching primer). Brackets were bonded using Transbond XT adhesive on the buccal surfaces of the teeth after etching and priming according to their respective protocols. The teeth were then sectioned and the samples were subjected to a protocol of demineralization cycles. After complete dissolution of dental tissues, the specimens were gold sputter coated and evaluated under SEM.

RESULTS

A characteristically uniform etch pattern was seen in the resin samples of the phosphoric acid/Transbond XT primer group, which revealed increased roughness and resin tags penetrating the demineralized enamel surface, whereas with Transbond Plus SEP, a regular resin tag distribution was observed which showed less magnitude when compared with the control group.

CONCLUSION

From the study, it was concluded that Transbond Plus SEP produced an etch pattern which was more conservative than conventional phosphoric acid system.

Comparison of Tumor Necrosis Factor-α Concentrations in Gingival Crevicular Fluid between Self-Ligating and Preadjusted Edgewise Appliances in the Early Leveling Stage of Orthodontic Treatment

Introduction:

Tumor necrosis factor-α (TNF-α) is an important proinflammatory cytokine that regulates the early phase of inflammation reaction during orthodontic tooth movement. The aim of the present study was to compare TNF-α concentrations in the gingival crevicular fluid (GCF) between preadjusted edgewise appliance (PEA) and self-ligating (SL) systems during the early leveling stage of orthodontic treatment.

Materials and Methods:

Eighteen patients (aged 15–35 years) who participated in this study were divided into two experimental groups (PEA and SL) and control group (without orthodontic treatment). The GCF was taken at five sites in the maxilla anterior teeth from each participant just before bracket bonding and at 1, 24, and 168 h after the initiation of tooth movement. Cytokine levels were determined through ELISA.

Results:

The concentration of TNF-α was significantly higher in the experimental groups than in the control group at 24 h after force application. TNF-α levels were significantly decreased at 168 h after force application in the PEA group. Meanwhile, in the SL group, the level of TNF-α at 168 h was still increased, although there was no statistically significant difference.

Conclusion:

TNF-α concentration was increased at 1 h and 24 h after orthodontic force application in both the PEA and SL groups. In the PEA group, TNF-α concentration was significantly decreased at 168 h, meanwhile in the SL group, this value remained increased at this time point. The differences in TNF-α concentration between the PEA and SL groups may be caused by their different types of brackets, wires, and ligation methods.

Sleeve Push Technique: A Novel Method of Space Gaining

Space gaining is frequently required in orthodontics. Multiple loops were initially used for space gaining and alignment. The most common used mechanics for space gaining is the use of nickel-titanium open coil springs. The disadvantage of nickel-titanium coil spring is that they cannot be used until the arches are well aligned to receive the stiffer stainless steel wires. Therefore, a new method of gaining space during initial alignment and leveling has been developed and named as sleeve push technique (SPT). The nickel-titanium wires, i.e. 0.012 inches and 0.014 inches along with archwire sleeve (protective tubing) can be used in a modified way to gain space along with alignment. This method helps in gaining space right from day 1 of treatment. The archwire sleeve and nickel-titanium wire in this new SPT act as a mutually synergistic combination and provide the orthodontist with a completely new technique for space opening.

Evaluation of Antimicrobial Properties of Conventional Poly(Methyl Methacrylate) Denture Base Resin Materials Containing Hydrothermally Synthesised Anatase TiO2 Nanotubes against Cariogenic Bacteria and Candida albicans

The purpose of this study was to investigate the antimicrobial properties of a conventional poly methyl methacrylate (PMMA) modified with hydrothermally synthesised titanium dioxide nanotubes (TNTs). Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentrations (MFC) for planktonic cells of the TiO₂ nanotubes solution against Lactobacillus acidophilus, Streptococcus mutans and Candida albicans were determined. The powder of conventional acrylic resin was modified using 2.5% and 5% by weight synthesised titanium dioxide (TiO₂) nanotubes, and rectangular-shaped specimens (10 mm × 10 mm × 3 mm) were fabricated. The antimicrobial properties of ultraviolet (UV) and non-UV irradiated modified, and non-modified acrylic resins were evaluated using the estimation of planktonic cell count and biofilm formation of the three microorganisms mentioned above. The data were analysed by one-way analysis of variance (ANOVA), followed by a post-hoc Tukey's test at a significance level of 5%. MIC, for Streptococcus. mutans, Lactobacillus. acidophilus, and Candida. albicans, MBC for S. mutans and L. acidophilus and MFC for Candida. albicans were obtained more than 2100 µg/mL. The results of this study indicated a significant reduction in both planktonic cell count and biofilm formation of modified UV-activated acrylic specimens compared with the control group (p = 0.00). According to the results of the current study, it can be concluded that PMMA/TiO₂ nanotube composite can be considered as a promising new material for antimicrobial approaches.

The potential of statistical shape modelling for geometric morphometric analysis of human teeth in archaeological research

This paper introduces statistical shape modelling (SSM) for use in osteoarchaeology research. SSM is a full field, multi-material analytical technique, and is presented as a supplementary geometric morphometric (GM) tool. Lower mandibular canines from two archaeological populations and one modern population were sampled, digitised using micro-CT, aligned, registered to a baseline and statistically modelled using principal component analysis (PCA). Sample material properties were incorporated as a binary enamel/dentin parameter. Results were assessed qualitatively and quantitatively using anatomical landmarks. Finally, the technique’s application was demonstrated for inter-sample comparison through analysis of the principal component (PC) weights. It was found that SSM could provide high detail qualitative and quantitative insight with respect to archaeological inter- and intra-sample variability. This technique has value for archaeological, biomechanical and forensic applications including identification, finite element analysis (FEA) and reconstruction from partial datasets.

Facial Anthropometric Evaluation of Unilateral Cleft Lip and Palate Patients: Infancy Through Adolescence

INTRODUCTION

Craniofacial anthropometric studies measure the differences in humans' craniofacial dimensions. The aim of this study was to determine facial anthropometric dimensions of newborn to 12-year-old girls with nonsyndromic unilateral cleft lip and palate (UCLP).

METHODS

In this cross-sectional analytical study, data was collected from 65 infant to 12-year old girls with UCLP. Digital frontal and profile facial photographs were transferred to a computer and desired anthropometric landmarks were traced on each image. Fifteen anthropometric parameters were measured which were the angles of facial, nasofacial, nasomental, Z, nasolabial, inclination of nasal base and labial fissure, nasal deviation, mentocervical, facial convexity and also ratios of nasal prominence relative to nasal height, middle to lower facial third, upper lip to lower lip height, columellar length relative to upper lip, and incisal show relative to incisal width. Pearson coefficient and linear regression were used for statistical analysis.

RESULTS

Upper lip to lower lip height ratio and angles of nasofacial, nasolabial, and facial convexity decreased with the age of the patients. In contrast, nasomental angle and the ratios of columellar length to upper lip length, middle facial height to lower facial height, and incisal show relative to incisal width increased. Other parameters studied did not appear to have any significant correlation with age.

CONCLUSION

In the girls with UCLP, various craniofacial dimensions have different growth rates with some parts growing slower than others. Some of the parameters studied were significantly correlated with age, thus growth-related curves and equations were obtained and presented.

In vitro Assessment of Influence of Various Bleaching Protocols on the Strength of Ceramic Orthodontic Brackets bonded to Bleached Tooth Surface: A Comparative Study

INTRODUCTION

Esthetics is one of the common issues because of which patients consult dental orthodontic treatment. Two ways of tooth bleaching are available these days, which includes in-office bleach and home bleach. Various bleaching protocols are available these days for treating the tooth surfaces. Hence, we planned the present study for investigating the impact of various intracoronal bleaching protocols on shear bond strength of ceramic brackets bonded to tooth surface after bleaching.

MATERIALS AND METHODS

The present study included assessment of 100 extracted maxillary central incisors with the integrated buccal surface. A resin block was made and individual teeth were embedded in each block. Root canal therapy procedure was performed in all the teeth, after which 2 mm short of tooth apex up to the level of cementoenamel junction, removal of the root canal filling was done. All the samples were broadly divided into four study groups with 25 samples in each group. Bleaching procedure was carried in all the samples intracoronally followed by testing of shear bond strength using universal force testing machine. Following the modified adhesive remnant index (AI), assessment of remaining adhesive on the brackets was done. All the results were compiled and analyzed by Statistical Package for the Social Sciences (SPSS) software version 17.0.

RESULTS

In the control group, mean shear bond strength was found to be 17.9 MPa. While comparing the carbamide peroxide (CP) group with sodium perborate study group, we observed a statistically significant difference. Nonsignificant results were obtained while comparing the shear bond strength in between sodium perborate group and hydrogen peroxide (HP) group.

CONCLUSION

Intracoronal bleaching does affect the shear bond strength of ceramic brackets. Sodium perborate bleaching influences shear bond strength more strongly than other bleaching agents such as CP and HP.

CLINICAL SIGNIFICANCE

In patients undergoing orthodontic treatment, HP is a preferred agent where bleaching has to be followed by orthodontic bonding to the tooth surface.

Effect of temporomandibular joint articular disc repositioning on anterior open-bite malocclusion: An orthodontic-surgical approach

An anterior open bite is a challenge to orthodontic treatment; it has a multifactorial etiology and a wide range of intervention options. Temporomandibular joint (TMJ) disorders are a risk factor for the development of malocclusions such as the anterior open bite, especially in patients who have TMJ osteoarthritis with disc displacement. Articular disc repositioning surgery is an available option for treating this pathology, and it contributes to maintaining the condyles in a more stable position. The aim of this article was to report the case of a 20-year-old woman diagnosed with anterior open bite and TMJ osteoarthritis with bilateral disc displacement. The patient received both orthodontic treatment and TMJ disc repositioning surgery. Cone-beam computed tomography was used to create 3-dimensional models of the condyles with regional superposition, and assessment of bone remodeling was performed at different time intervals. Complete orthodontic and surgical treatment time was approximately 12 months. The results provided a stable correction of the patient's anterior open bite with a 2-year follow-up and favorable bone remodeling of the condyles due to functional improvement of the TMJ.

The Influence of Class II Division 2 Malocclusions on the Harmony of the Human Face Profile

BACKGROUND Persons with class II division 2 malocclusion are characterized by a very specific dento-skeletal and soft-tissue profile (a profile in which a protruding nose and chin, retruding lips, concave and shortened lower third of the face, and gummy smile are dominant), which is the opposite of the currently modern profiles (convex profile of protruding lips and small chin). The aim of this research was to determine the differences in parameters of harmonies of facial profiles between persons with class II division 2 malocclusions and class I, and to establish the significance of those differences. MATERIAL AND METHODS For this study, 50 patients with class II division 2 malocclusions and 50 patients with class I were selected; profile photos were recorded and a photometric analysis was done: a type of profile according to Schwarz, the shape of a nose, the prominence of chin, biometrical field, the position of lips in relation to the tangent Sn-Pg, S-line (Steiner), E-line (Riketts) and a facial angle according to Arnett. RESULTS The significant differences in profiles of persons with class II division 2 compared to class I were: position and prominence of the chin, the position of the lower and upper lip in relation to the S-line, and smaller value of a facial angle in relation to persons with class I. CONCLUSIONS The differences seen in skeletal profiles were not associated with significant differences in the profiled facial contours of the examined groups. The compensatory role of the fullness of soft tissues of the lips is probably the reason why there were not significant deviations in all the examined parameters.

Determination of the centre of resistance during en masse retraction combined with corticotomy: finite element analysis

OBJECTIVE

To determine the effect of corticotomy on the change in the centre of resistance of the six maxillary anterior teeth Materials and methods: Three-dimensional finite element models of the maxillary anterior teeth with and without corticotomy were constructed. Brackets (size 0.022 inch × 0.028 inch) were placed passively on all anterior teeth that were set at the centre of the labial surface in the mesio-distal dimension and 3 mm from the incisal edge to the bracket slot in the vertical direction. The power arm was set mesial of the canine bracket. For the model with corticotomy, the bone density was decreased from initial value at 5% to 25%. The point of force application was varied in order to locate the centre of resistance. The centre of resistance was located by measurement of the difference of the displacement between the apical and incisal edges. The position of force was varied by moving apically parallel to the occlusal plane to simulate tooth movement.

RESULTS

As the alveolar bone density decreased from initial value to 25%, the location of the centre of resistance moved apically from the bracket slot from 10.8 mm to 11.2 mm, respectively.

CONCLUSIONS

The change of alveolar bone density due to corticotomy was associated with the location of the centre of resistance. The location of the centre of resistance moved apically as the alveolar bone density decreased but it was not clinically noticeable.

Enamel Resistance to Demineralization After Bracket Debonding Using Fluoride Varnish

The aim of this study was to evaluate the elemental content and morphology of enamel subjected to demineralization cycles after bracket debonding, adhesive remnant removal, and application of a fluoride varnish. 125 bovine teeth were divided into five groups (n = 25): 1) Intact enamel; 2) Intact enamel + demineralization cycles (DC); 3) Enamel after adhesive removal; 4)Enamel after adhesive removal + DC; 5) Enamel after adhesive removal + Profluorid + DC. The weight percentages of calcium (Ca), phosphorous (P) and fluoride (F) were calculated using energy dispersive X-ray spectroscopy (EDX). Samples were observed under scanning electron microscopy (SEM). Data were analyzed using Kruskal-Wallis and Mann-Whitney test. The weight percentages of Ca and P in Group 1 were significantly higher than Groups 2, 4, and 5. The weight percentages of Ca and P in Group 2 were significantly higher than Groups 4 and 5. Group 3 presented significantly higher percentages of Ca and P than Group 4. Group 5 showed a significantly higher percentage of Ca than Group 4. The presence of F was detected in Group 5. SEM images showed more signs of demineralization in Group 4 than Group 5. Fluoride varnish application may protect enamel from demineralization after bracket debonding.

445-nm diode laser-assisted debonding of self-ligating ceramic brackets

Objectives:

This study determined the influence of irradiation on aesthetic ceramic brackets with a novel 445-nm diode laser prior to debonding on the bracket failure mode.

Materials and methods:

Thirty ceramic brackets (In-Ovation® C, GAC) were standard-bonded to the oral and buccal planed and polished enamel surfaces of 15 caries-free human 3

Results:

In the laser group, the ARI-score was statistically significantly reduced (p<0.05) at 10-fold and 20-fold magnifications compared to the conventional group, while enamel fractures were not found at any magnification in either group at T1. Enamel fractures and grinding marks were increasingly found in the conventional group by SEM at T2.

Conclusion:

Irradiation with the novel diode laser prior to debonding of ceramic brackets significantly changes bonding failure in terms of less remaining adhesive. This is of clinical importance as the risk of enamel fractures and chair time can be reduced.

The effect of canine disimpaction performed with temporary anchorage devices (TADs) before comprehensive orthodontic treatment to avoid root resorption of adjacent teeth

Objective:

The aim of this study was to evaluate the movement of impacted canines away from the roots of neighboring teeth before full-mouth bracket placement, performed by means of TADs to decrease undesired side effects on adjacent teeth.

Methods:

The study sample consisted of 34 palatally impacted canines, being 19 in the experimental group and 15 in the control group. In the experimental group, before placement of brackets, the impacted canine was erupted by means of miniscrews. In the control group, after initiation of comprehensive orthodontics, canine disimpaction was performed by means of a cantilever spring soldered to a palatal bar. At the end of treatment, volume of lateral incisors and canine root resorption were measured and compared by means of a CBCT-derived tridimensional model. Visual Analogue Scale (VAS) score, bleeding on probing (BOP) and gingival index (GI) were recorded. Clinical success rate was also calculated.

Results:

The volume of root resorption of lateral teeth in the control group was significantly greater than in the experimental group (p < 0.001). At the end of treatment, VAS score, GI and BOP were not significantly different between the two groups.

Conclusion:

Based on our results, it seems that disimpaction of canines and moving them to the arch can be done successfully carried out with minimal side effects by means of skeletal anchorage.

Reliability of overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) in the assessment of different vertical and sagittal dental malocclusions: a receiver operating characteristic (ROC) analysis

Introduction:

Differential diagnosis of skeletal and dental relationships is crucial for planning orthodontic treatment. Overbite depth indicator (ODI) and anteroposterior dysplasia indicator (APDI) had been introduced in the past for assessment of vertical and sagittal jaw relationships, respectively.

Objective:

The objectives of this study were to evaluate the reliability of ODI and APDI in overbite and Angle malocclusions, as well as assess their diagnostic reliability among males and females of different age groups.

Material and Methods:

This study was conducted using pretreatment dental casts and lateral cephalograms of 90 subjects. For ODI, subjects were divided into three groups based on overbite (normal overbite, open bite and deep bite). Likewise, the same subjects were divided for APDI into three groups, based on Angle's malocclusion classification (dental Class I, II and III malocclusions). Mann-Whitney U test was applied for comparison of study parameters regarding sex and different age groups. The mean values of ODI and APDI were compared among study groups by means of Kruskal-Wallis and post-hoc Dunnet T3 tests. The receiver operating characteristic (ROC) curve was applied to test diagnostic reliability.

Results:

Insignificant differences were found for ODI and APDI angles, particularly in regards to sex and age. Significant intergroup differences were found in different overbite groups and Angle's classification for ODI and APDI, respectively (p < 0.001). ROC showed 91% and 88% constancy with dental pattern in ODI and APDI, respectively.

Conclusions:

ODI can reliably differentiate deep bite versus normal overbite and deep bite versus open bite. APDI can reliably differentiate dental Class I, II and III malocclusions.

Effects of 445-nm Diode Laser-Assisted Debonding of Self-Ligating Ceramic Brackets on Shear Bond Strength

OBJECTIVE

The aim of this study was to measure the effect of irradiation with a novel 445-nm diode laser on the shear bond strength (SBS) of ceramic brackets before debonding.

MATERIALS AND METHODS

Thirty ceramic brackets (In-Ovation^® C, GAC) were bonded in standard manner to the planed and polished buccal enamel surfaces of 30 caries-free human third molars. Each tooth was randomly allocated to the laser or control group, with 15 samples per group. The brackets in the laser group were irradiated with the diode laser (SIROLaser Blue^®; Sirona) on three sides of the bracket bases for 5 sec each (lateral-coronal-lateral, a total of 15 sec) immediately before debonding. SBS values were measured for the laser group and control group. To assess the adhesive remnant index (ARI) and the degree of enamel fractures, micrographs of the enamel surface were taken with 10-fold magnification after debonding.

RESULTS

The SBS values were significantly lower statistically in the laser group in comparison with the control group (p < 0.05). The ARI scores were also significantly lower statistically in the laser group in comparison with the control group (p < 0.05). No bracket fractures or enamel fractures occurred in either group after debonding.

CONCLUSIONS

Irradiation of ceramic brackets with the novel diode laser before debonding significantly reduces the SBS values. This is of clinical importance, as it means that the risk of damage to the teeth, bracket fractures, and the overall treatment time can be reduced.

Temporal brow lift vs internal browpexy in females undergoing upper blepharoplasty: Effects on lateral brow lifting

BACKGROUND

Lateral brow-lifting surgical procedures in conjunction with upper blepharoplasty may prevent secondary descent following upper blepharoplasty.

OBJECTIVE

To compare the results of internal browpexy (IBP) and temporal brow lift (TBL) in patients with dermatochalasis undergoing simultaneous upper blepharoplasty.

METHODS

This study was a single-center, parallel-group randomized controlled trial conducted on 32 female patients suitable for upper blepharoplasty. Patients were divided into two groups: the IBP group and the TBL group. The brow lift was measured using change in the distance between the ala nasi and lateral tail of the eyebrow as nasal ala to lateral brow (NALB) in millimeter (mm), and the vertical line between the lateral tail of eyebrow and horizontal line extending the lateral cantus as lateral brow plump line (LBPL) in mm before and after the surgery. The follow-up time was 6 months.

RESULTS

The mean ± SD age of patients was 55.93 ± 7.1 years and 53.94 ± 7.7 years in the TBL and IBP groups, respectively (P > .05). No significant change in mean LBPL at 6 months compared to baseline was observed in the TBL group (baseline: 15.7 ± 1.6 mm vs 6 month: 15.8 ± 1.3 mm; P = .602). In the IBP group, a significant increase in mean LBPL at 6 months compared to baseline was observed (baseline: 15.09 ± 2.13 mm vs 6 months: 17. 43 ± 2.68 mm; P < .001).

CONCLUSIONS

Internal browpexy combined with blepharoplasty could be considered the better procedure in patients with upper eyelid dermatochalasis in terms of long-lasting stability and lateral brow elevation.

Comparative analysis of impacted upper canines: Panoramic radiograph Vs Cone Beam Computed Tomography

Background

The use of CBCT exam in the study of IMC is not new. However, it’s still not known in what specific aspects CBCT exam shows a better result than then conventional exams. The aim of this study was to compare and conclude in what way the opinion regarding upper canine impaction differed when observing a panoramic image compared to the observation of a set of CBCT reconstructions.

Material and Methods

Twenty patients (10 males and 10 females) with a total of 28 impacted maxillary canines were identified from the database of the Department of Dentistry, Faculty of Medicine, University of Coimbra. For each canine, two different images were available: a panoramic image and a set of CBCT reconstructions. After a random distribution of both groups images, nine orthodontists completed a questionnaire where they were asked to evaluate ten different questions regarding canine impaction. Statistic analysis was performed using Cronbach’s alpha statistics, Kappa statistics and McNemar test, considering p<0,05 statistically significant.

Results

This study showed differences between the two images regarding tooth position. A statistical significant poor agreement was found between the two methods for the mesio-distal position of the apex (k=0,388, p<0,001) and for the labio-palatal tip cusp position (k=0,035, p=0,114). The adjacent root resorption showed a poor and very poor agreement between the two methods. Every other items were scored with an agreement between modalities ranging from moderate to strong.

Conclusions

The analyses of panoramic images versus CBCT images reconstructions provided different information regarding tooth position (especially concerning the mesio-distal apex position and the labio-palatal cusp position) but also in the assessment of root resorption. Further investigation should be done to determine in what cases CBCT exam has a clear advantage over conventional 2D exams, justifying its use.

Key words:Cone-Beam Computed Tomography, Orthodontics, Impacted Tooth, Root resorption.

Smile esthetics: Impact of variations in the vertical and horizontal dimensions of the maxillary lateral incisors

OBJECTIVE

The purpose of this study was to determine the perception of trained dental professionals and laypersons toward the esthetic impact of variations in the vertical position, width, and gingival height of the maxillary lateral incisor.

MATERIALS AND METHODS

The present study analyzed the perspective of smile photographs by dental professionals such as "fifty orthodontics and fifty general dental practitioners (GDPs)" as well as fifty laypersons, consisting of an equal number of male and female participants. Photographs edited to depict alteration of golden proportion, incisal length, and gingival height of lateral incisor. SPSS software was used to analyze the data and determine the significant difference within all the participants, at 0.05% level (95% confidence interval).

RESULTS

There was no significant difference in ranking between the genders. Golden proportion of 62%-67% were ranked the highest by orthodontists, whereas GDPs and laypersons preferred 67%. Regarding gingival display, corrected height of -0.5 and -1 mm received highest ranking from all the three groups. In case of lateral incisal length, -0.5 mm was ranked highest by laypersons, in contrast to -1 mm by orthodontists and GDPs.

CONCLUSION

Specific differences were observed in the ranking of smile esthetics by health-care professionals and laypersons. Golden proportion of 62% and 67% were ranked the highest by orthodontists, whereas GDPs and laypersons preferred 67%. Corrected gingival height of -0.5 and -1 mm received highest ranking from all the three groups. In case of lateral incisal length, -0.5 mm was ranked highest by laypersons, in contrast to -1 mm by orthodontists and GDPs.

Sustainability in Orthodontics: what can we do to save our planet?

The sustainability of the natural resources of our planet is a topic for worldwide debate. Mankind, during its evolution as a species, has not been greatly concerned about conserving the environment in which we live. Nowadays we are reaping the fruits of this neglect. Climatic changes and storms are good examples of this. We, humans, must re-think our attitudes in order to leave the planet in a healthy state to be used by our descendants. But thinking of orthodontics, what can we do as orthodontists? From this perspective, the authors of the present study aimed, in a clear and objective manner, to present simple and sustainable ways to proceed during our activity as orthodontists, in order to minimize the effects on nature, caused by man.

Facial profile and frontal changes after bimaxillary surgery in patients with mandibular prognathism

BACKGROUND/PURPOSE

Patients are always concerned about their postoperative appearance before surgery for facial deformity correction. The present study investigated the facial profile and frontal changes following two-jaw surgery.

METHODS

Forty patients who underwent two-jaw surgery were divided by the amount of mandibular setback (group I: ≤8 mm and group II: >8 mm). Cephalometric radiograms (lateral and frontal) were collected and analyzed at three intervals: preoperatively (T1), immediately postoperatively (T2), and final follow-up (T3). The following points were identified: cheek points (C1-C5), pronasale (Prn, tip of the nose), anterior nasal spine (ANS), subnasal (Sn), point A, labrale superius (Ls), incision superius (Is), labrale inferius (Li), incision inferius (Ii), point B, labiomental sulcus (Si), pogonion (Pog), soft tissue pogonion (PogS), ramus point (RP), and gonion (Go). The immediate postoperative changes (T21), final postoperative changes (T32), and final stability (T31) were calculated and analyzed.

RESULTS

In T31, the cheek line showed significant advancements of 2.3 mm (group I) and 1.6 mm (group II). The soft:hard tissue ratios were significantly correlated: Prn:ANS (0.37:1), Prn:A (0.39:1), Sn:A (0.85:1), C3:A (0.82:1), Ls:Is (0.92:1), Li:Ii (0.91:1), Si:B (0.88:1), and PogS:Pog (group I, 0.78:1 and group II, 0.93:1). The intercondylion and intergonial widths of group II (T31) significantly increased 1.8 and 4 mm, respectively. Regarding the postoperative skeletal stability (T32), group I showed significant correlations between amounts of mandibular setback, but group II did not.

CONCLUSION

In the facial profile, the cheek line showed significant advancement postoperatively. The frontal mandibular transverse dimensions were significantly increased.

[Cephalometry efficacy in orthodontic treatment planning: correlations of cephalometric values and their changes in the course of treatment]

The aim of the study was to assess the efficacy of cephalometry in planning of orthodontic patients with teeth crowding (TC) and Angle Class I molar relationship (MR). Cephalometric values of 70 patients with TC and class I MR were analyzed before and after orthodontic treatment. Cephalometric study of correlations proved to be more relevant than comparing with mean values. In patients with TC and class I MR statistically significant were correlations with: facial profile (ÐN-A-B) and jaws relationship in anterio-posterior direction (ÐA-N-B); ÐN-A-B and type of maxillary growth (ÐPn-Mp, ÐB); ÐB and maxillary incisors inclination (Ðis-SpP); ÐPn-Mp and mandibular incisors inclination (Ðii-Mp). These correlations depend on age, anomaly severity and orthodontic strategy. Cephalometry proved to be effective tool for orthodontic treatment planning, prognosis and modelling.

Effect of Surface Treatment on Enamel Cracks After Orthodontic Bracket Debonding: Er,Cr:YSGG Laser-Etching Versus Acid-Etching

OBJECTIVES

This study sought to compare enamel cracks after orthodontic bracket debonding in the surfaces prepared with erbium, chromium: yttrium-scandium-galliumgarnet (Er,Cr:YSGG) laser and the conventional acid-etching technique.

MATERIALS AND METHODS

This in-vitro experimental study was conducted on 60 sound human premolars extracted for orthodontic purposes. The teeth were randomly divided into two groups (n=30). The teeth in group A were etched with 37% phosphoric acid gel, while the teeth in group B were subjected to Er,Cr:YSGG laser irradiation (gold handpiece, MZ8 tip, 50Hz, 4.5W, 60μs, 80% water and 60% air). Orthodontic brackets were bonded to the enamel surfaces and were then debonded in both groups. The samples were inspected under a stereomicroscope at ×38 magnification to assess the number and length of enamel cracks before bonding and after debonding. Independent-samples t-test was used to compare the frequency of enamel cracks in the two groups. Levene's test was applied to assess the equality of variances.

RESULTS

No significant difference was noted in the frequency or length of enamel cracks between the two groups after debonding (P>0.05).

CONCLUSIONS

Despite the same results of the frequency and length of enamel cracks in the two groups and by considering the side effects of acid-etching (demineralization and formation of white spot lesions), Er,Cr:YSGG laser may be used as an alternative to acid-etching for enamel surface preparation prior to bracket bonding.

[A change of paradigm in the treatment of Class II malocclusions in children and adolescents: the benefits of the Class II Corrector]

INTRODUCTION

The treatment of class II malocclusions is the core of our clinical activity. What elements can clinician rely on to offer their patients, whether children or adolescents, a treatment of their class II malocclusion that is not only effective but also the most appropriate for each individual case? Which schedule and what therapeutic device should be used?

MATERIALS AND METHODS

Evidence-based orthodontics, along with a search for the best data on two-phase treatments, were used to judge the validity of the main objectives sought when correcting a Class II malocclusion in children or adolescents, including treatment of mandibular retrognathy.

RESULTS

Published data show that the long-term effects of a first phase of treatment on the amount of mandibular growth are at best weak and clinically insignificant. This observation triggers a paradigm shift by refocusing patient treatment on the achievement of other therapeutic objectives. A new orthodontic appliance, the Clas II Corrector, is presented. Its advantages and its use are described and illustrated by means of clinical cases.

CONCLUSIONS

Class II Corrector allows distalization of maxillary lateral areas, effectively limits undesirable dentoalveolar compensations and facilitates the rehabilitation of orofacial functions. In addition to its clinical efficacy, patients appreciate its small footprint, ease of wearing, and lack of impact on phonation.

Effect of Sodium Fluoride Mouthwash on the Frictional Resistance of Orthodontic Wires

OBJECTIVES

The friction between the brackets and orthodontic wire during sliding mechanics inflicts difficulties such as decreasing the applied force and tooth movement and also the loss of anchorage. Therefore, many studies have focused on the factors that affect the friction. The purpose of this study was to assess the effect of 0.05% sodium fluoride mouthwash on the friction between orthodontic brackets and wire.

MATERIALS AND METHODS

Four types of orthodontic wires including rectangular standard stainless steel (SS), titanium molybdenum alloy (TMA), nickel-titanium (NiTi) and copper-nickel-titanium (Cu-NiTi) were selected. In each group, half of the samples were immersed in 0.05% sodium fluoride mouthwash and the others were immersed in artificial saliva for 10 hours. An elastomeric ligature was used for ligating the wires to brackets. The frictional test was performed in a universal testing machine at the speed of 10 mm/minute. Two-way ANOVA was used for statistical analysis of the friction rate.

RESULTS

The friction rate was significantly higher after immersion in 0.05% sodium fluoride mouthwash in comparison with artificial saliva (P=0.00). Cu-NiTi wire showed the highest friction value followed by TMA, NiTi and SS wires.

CONCLUSIONS

According to the results of the current study, 0.05% sodium fluoride mouthwash increased the frictional characteristics of all the evaluated orthodontic wires.

Effectiveness of high irradiance for short-time exposures on polymerization of composite under metal brackets

OBJECTIVE

To evaluate the effect of different curing modes available in a dental light-curing unit on degree of conversion (DC) of a composite photoactivated under a metal orthodontic bracket.

MATERIALS AND METHODS

The average irradiance and total energy delivered by three curing modes (standard, high, and extra power) of a multiwave LED unit (Valo Cordless, Ultradent Products, South Jordan, Utah) were measured using the longest time available for each mode (20, 4, and 3 seconds, respectively). Brackets (n = 3/group) were bonded to molar epoxy resin replicas using each curing mode. Mesiodistal sections, 0.5 mm thick, were assessed using an infrared spectrometer microscope. Spectra of composite beneath the brackets were sequentially collected using the mapping tool in near-infrared (NIR)-transmittance mode. Composite conversion was mapped between the mesial and distal edges of the bracket base using 400-μm steps for a total of 10 measurements per specimen. Data from irradiance and total energy were analyzed by one-way ANOVA, while data of DC were analyzed with two-way repeated measures ANOVA (α = 0.05).

RESULTS

The highest DC values were observed for standard power (mean 56%, P < .05), while no difference was observed between high (50%) and extra power (49%) modes. Regarding the site of measurement, higher DC was observed close to the bracket edges (52%, P < .05).

CONCLUSIONS

The use of high irradiance for a short time slightly reduced the DC. The small magnitude of reduction suggests that use of a high irradiance protocol is a clinically valid approach when bonding metal brackets.

Biosynthesis of Silver Nanoparticles on Orthodontic Elastomeric Modules: Evaluation of Mechanical and Antibacterial Properties

In the present study, silver nanoparticles (AgNPs) were synthesized in situ on orthodontic elastomeric modules (OEM) using silver nitrate salts as metal-ion precursors and extract of the plant Hetheroteca inuloides (H. inuloides) as bioreductant via a simple and eco-friendly method. The synthesized AgNPs were characterized by UV-visible spectroscopy; scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The surface plasmon resonance peak found at 472 nm confirmed the formation of AgNPs. SEM and TEM images reveal that the particles are quasi-spherical. The EDS analysis of the AgNPs confirmed the presence of elemental silver. The antibacterial properties of OEM with AgNPs were evaluated against the clinical isolates Streptococcus mutans, Lactobacillus casei, Staphylococcus aureus and Escherichia coli using agar diffusion tests. The physical properties were evaluated by a universal testing machine. OEM with AgNPs had shown inhibition halos for all microorganisms in comparison with OEM control. Physical properties increased with respect to the control group. The results suggest the potential of the material to combat dental biofilm and in turn decrease the incidence of demineralization in dental enamel, ensuring their performance in patients with orthodontic treatment.

Characterization and coating stability evaluation of nickel-titanium orthodontic esthetic wires: an in vivo study

The objective of this study was to compare coating dimensions and surface characteristics of two different esthetic covered nickel-titanium orthodontic rectangular archwires, as-received from the manufacturer and after oral exposure. The study was designed for comparative purposes. Both archwires, as-received from the manufacturer, were observed using a stereomicroscope to measure coating thickness and inner metallic dimensions. The wires were also exposed to oral environment in 11 orthodontic active patients for 21 days. After removing the samples, stereomicroscopy images were captured, coating loss was measured and its percentage was calculated. Three segments of each wire (one as-received and two after oral exposure) were observed using scanning electron microscopy for a qualitative analysis of the labial surface of the wires. The Lilliefors test and independent t-test were applied to verify normality of data and statistical differences between wires, respectively. The significance level adopted was 0.05. The results showed that the differences between the wires while comparing inner height and thickness were statistically significant (p < 0.0001). In average, the most recently launched wire presented a coating thickness twice that of the control wire, which was also a statistically significant difference. The coating loss percentage was also statistically different (p = 0.0346) when the latest launched wire (13.27%) was compared to the control (29.63%). In conclusion, the coating of the most recent wire was thicker and more uniform, whereas the control had a thinner coating on the edges. After oral exposure, both tested wires presented coating loss, but the most recently launched wire exhibited better results.

Dental Hygiene and Orthodontics: Effect of Ultrasonic Instrumentation on Bonding Efficacy of Different Lingual Orthodontic Brackets

Dental hygienists are often faced with patients wearing lingual orthodontic therapy, as ultrasonic instrumentation (UI) is crucial for oral health. As the application of external forces can lead to premature bonding failure, the aim of this study was to evaluate the effect of UI on shear bond strength (SBS) and on adhesive remnant index (ARI) of different lingual orthodontic brackets. 200 bovine incisors were divided into 10 groups. Four different lingual (STB, Ormco; TTR, Rocky Mountain Orthodontics; Idea, Leone; 2D, Forestadent) and vestibular control (Victory, 3M) brackets were bonded. UI was performed in half of specimens, whereas the other half did not receive any treatment. All groups were tested with a universal testing machine. SBS and ARI values were recorded. Statistical analysis was performed (significance: P = 0.05). TTR, Idea, and 2D lingual brackets significantly lowered SBS after UI, whereas for other braces no effect was recorded. Appliances with lower mesh area significantly reduced their adhesion capacity after UI. Moreover groups subjected to UI showed higher ARI scores than controls. UI lowered SBS of lingual appliances of small dimensions so particular care should be posed avoiding prolonged instrumentation around bracket base during plaque removal. Moreover, UI influenced also ARI scores.

Reducing posttreatment relapse in cleft lip palatal expansion using an injectable estrogen-nanodiamond hydrogel

Patients with cleft lip and/or palate (CLP), who undergo numerous medical interventions from infancy, can suffer from lifelong debilitation caused by underdeveloped maxillae. Conventional treatment approaches use maxillary expansion techniques to develop normal speech, achieve functional occlusion for nutrition intake, and improve esthetics. However, as patients with CLP congenitally lack bone in the cleft site with diminished capacity for bone formation in the expanded palate, more than 80% of the patient population experiences significant postexpansion relapse. While such relapse has been a long-standing battle in craniofacial care of patients, currently there are no available strategies to address this pervasive problem. Estrogen, 17β-estradiol (E2), is a powerful therapeutic agent that plays a critical role in bone homeostasis. However, E2's clinical application is less appreciated due to several limitations, including its pleiotropic effects and short half-life. Here, we developed a treatment strategy using an injectable system with photo-cross-linkable hydrogel (G) and nanodiamond (ND) technology to facilitate the targeted and sustained delivery of E2 to promote bone formation. In a preclinical expansion/relapse model, this functionalized E2/ND/G complex substantially reduced postexpansion relapse by nearly threefold through enhancements in sutural remodeling compared with unmodified E2 administration. The E2/ND/G group demonstrated greater bone volume by twofold and higher osteoblast number by threefold, compared with the control group. The E2/ND/G platform maximized the beneficial effects of E2 through its extended release with superior efficacy and safety at the local level. This broadly applicable E2 delivery platform shows promise as an adjuvant therapy in craniofacial care of patients.

Influence of the Smile Line on Smile Attractiveness in Short and Long Face Individuals

Objectives

The study assessed the impact of facial height on attractiveness of smile, in association with the maxillary gingival display. This research was performed by dental professionals and laypersons.

Materials and Methods

Frontal extraoral photographs were captured for both short and long faces. The photographs were modified using software for image-processing and three rater groups (orthodontists, dentists, and laypersons) evaluated the smile attractiveness, with 30 subjects in each group. Differences in ratings of the different smiles among the different experimental groups were examined using the Kruskal-Wallis test. The Mann–Whitney U test was performed for pairwise comparisons between the experimental groups.

Results

Dentists and laypeople were most likely to agree. For the short face, laypeople and dentists both rated the +2 mm gingival display smile as the most attractive smile whilst orthodontists ranked the 0 mm gingival display smile as the most attractive smile. For the long face, laypeople and dentists ranked the 0 mm gingival display smile as the most attractive smile, whilst orthodontists ranked the +2 mm gingival display as the most attractive.

Conclusion

Smile line of both short and long face subjects was found to influence the smile attractiveness rating by the three rater groups.