Effect of Second and Third Molar Eruption Stages on First Molar and Maxillary Arch Distalization With Modified Palatal Anchorage Plate and Beneslider: A 3D Finite Element Analysis.

AIM: To analyze the effects of the maxillary second molar and third molar eruption stages on the distalization of first molars with a modified palatal anchorage plate (MPAP) and Beneslider using three-dimensional (3D) finite element analysis. MATERIALS AND METHOD: Six finite element models (FEMs) of individual maxillary molar distalization and six FEM models of en-masse maxillary arch distalization (EMAD) at different stages of the maxillary molar eruption were created from cone-beam computed tomography (CBCT) images of the maxillary complex, and 3D displacements of the maxillary first and second molars were evaluated with MPAP and Beneslider. RESULTS: On individual molar distalization, Beneslider showed first molar distal translation during the second and third molar follicular stages, while MPAP showed distal tipping of the first molar. With EMAD, either of the appliances showed distal tipping of the first molars. There was palatal rolling and extrusion of the first molars. The second molar showed buccal drifting with intrusion, and the incisors showed palatal displacement along with extrusion. CONCLUSIONS: Second and third molar eruption stages had no adverse influence on first molar and en-masse maxillary arch distalization. Beneslider showed distal translation of the first molar, while distal tipping was seen with MPAP.

Development and psychometric validation of the orthodontic health literacy tool.

Introduction: Over the past few years, there has been increasing emphasis on context-specific health literacy. However, no such context-specific psychometric tools are available with regard to oral health literacy. The aim of this study was to develop and validate an Orthodontic Health Literacy Tool (Orth-HLT). Materials and Methods: After development of initial item pool, the items were assessed for content validity. The final tool consisted of 22 items in the four domains of functional, communicative, critical orthodontic health literacy, and orthodontic knowledge. Orth-HLT was administered to a convenience sample of 642 subjects. The data were subjected to exploratory and confirmatory factor analyses using IBM SPSS Version 20.0 software and IBM SPSS Amos 26.0, respectively. Pearson's correlation, independent samples t-test, and one-way analysis of variance were performed. Results: Orth-HLT demonstrated good face and content validity. The domain-specific internal consistency reliability values were optimal. Exploratory factor analysis on the items in all four domains resulted in a single factor solution. Four models were evaluated in the confirmatory factor analysis; the correlated factors model showed best model fit indices. Each domain of Orth-HLT showed moderate to strong positive correlation with Indian Oral Health Literacy Measure in Telugu indicating the convergent validity of the tool. Conclusion: Orth-HLT is the first context-specific oral health literacy tool and demonstrates strong psychometric properties, which could be used to evaluate orthodontic health literacy and articulate orthodontic health education materials in an informed manner.

Efficacy of Super Slick elastomeric modules in reducing friction during sliding: a comparative in vitro study.

AIM: To evaluate and compare the frictional resistance produced by Super Slick modules during sliding with four different types of brackets and four ligature types both in conventional and figure-of-8 ligation method with saliva as lubricant. MATERIALS AND METHODS: The frictional resistance was evaluated by using four different ligatures on 0.019" × 0.025" stainless steel (SS) archwires using four different brackets using an universal testing machine with unstimulated saliva as a lubricant. Mean and SD values were calculated. Data was statistically analyzed using analysis of variance ANOVA with post hoc test. RESULTS: The results showed that self-ligating brackets produced least frictional forces. Among all other tested combinations,Tefon-coated SS ligatures in ceramic with metal slot brackets produced least coefficient of static and kinetic friction and full ceramic brackets ligated with Super Slick elastomeric modules demonstrated the highest, with other combinations falling in between. CONCLUSION: Super Slick elastomeric modules, produced highest coefficient of both static and kinetic friction with the conventional and figure-of-8 ligation technique even in wet conditions using natural fresh human saliva. CLINICAL SIGNIFICANCE: Both static and kinetic frictional resistance play an important role during sliding mechanics. Various factors have been attributed for friction. However, bracket type, archwire material, type of ligature and method of ligation are important variables. Recently polymeric coated slick elastomeric modules were introduced with the claim that they produce very low frictional forces in wet condition. Contrary to the claim made by the manufacturers of Super Slick elastomeric modules, they produced highest coefficient of both static and kinetic friction with the conventional and figure-of-8 ligation technique.