Objectives: To determine the treatment effects produced in Class II patients by the Carriere® Motion 3D™ appliance (CMA) followed by full fixed appliances (FFA). Materials and Methods: This retrospective study evaluated 34 adolescents at three time points: T1 (pretreatment), T2 (removal of CMA), and T3 (posttreatment). The comparison group comprised 22 untreated Class II subjects analyzed at T1 and T3. Serial cephalograms were traced and digitized, and 12 skeletal and 6 dentoalveolar measures were compared. Results: Phase I with CMA lasted 5.2 ± 2.8 months; phase II with FFA lasted 13.0 ± 4.2 months. CMA treatment restricted the forward movement of the maxilla at point A. There was minimal effect on the sagittal position of the chin at pogonion. The Wits appraisal improved toward Class I by 2.1 mm during the CMA phase but not during FFA. Lower anterior facial height increased twice as much in the treatment group as in controls. A clockwise rotation (3.9°) of the functional occlusal plane in the treatment group occurred during phase I; a substantial rebound (−3.6°) occurred during phase II. Overjet and overbite improved during treatment, as did molar relationship; the lower incisors proclined (4.2°). Conclusions: The CMA appliance is an efficient and effective way of correcting Class II malocclusion. The changes were mainly dentoalveolar in nature, but some skeletal changes also occurred, particularly in the sagittal position of the maxilla and in the vertical dimension.

WNT10A is a signaling molecule involved in tooth development, and WNT10A defects are associated with tooth agenesis. We characterized Wnt10a null mice generated by the knockout mouse project (KOMP) and six families with WNT10A mutations, including a novel p.Arg104Cys defect, in the absence of EDA,EDAR, or EDARADD variations. Wnt10a null mice exhibited supernumerary mandibular fourth molars, and smaller molars with abnormal cusp patterning and root taurodontism. Wnt10a−/− incisors showed distinctive apical–lingual wedge-shaped defects. These findings spurred us to closely examine the dental phenotypes of our WNT10A families. WNT10A heterozygotes exhibited molar root taurodontism and mild tooth agenesis (with incomplete penetrance) in their permanent dentitions. Individuals with two defective WNT10A alleles showed severe tooth agenesis and had fewer cusps on their molars. The misshapened molar crowns and roots were consistent with the Wnt10a null phenotype and were not previously associated with WNT10A defects. The missing teeth contrasted with the presence of supplemental teeth in the Wnt10a null mice and demonstrated mammalian species differences in the roles of Wnt signaling in early tooth development. We conclude that molar crown and root dysmorphologies are caused by WNT10A defects and that the severity of the tooth agenesis correlates with the number of defective WNT10A alleles.

Objectives: The aim of this study was to evaluate the reliability of 3-dimensional maxillary dental changes using two methods of digital model superimposition. Setting and Sample Population: The Department of Orthodontics of Bauru Dental School, University of São Paulo and University of Michigan Craniofacial Growth Center. Fifteen subjects with normal occlusion. Material & Methods: The sample was composed of digital study models of 15 normal occlusion subjects taken at 13 (T1), 18 (T2) and 60 years of age (T3). Using the software SlicerCMF 3.1, superimposition (registration) was conducted using 9 landmarks placed on the incisive papilla, second and third palatal rugae and 10 mm distal to the third palatal rugae. Two registration methods were compared: landmarks (LA) and regions of interest (ROI). Three-dimensional changes of landmarks on the buccal cusp tip of posterior teeth bilaterally and the incisal edge of the right central incisor were measured by three examiners. Intraclass correlation coefficients and Bland-Altman method evaluated intra- and inter-examiner agreements. Results: Good or excellent intra-examiner agreement was found for T1–T2 and T2–T3 measurements using both registration methods. Inter-examiner agreements were good to excellent for T1–T2 measurements and poor to fair for most T2–T3 measurements. Mean T1–T2 differences were less than 0.5 mm for most measurements. Conclusion: Maxillary digital dental models of patients with normal occlusion superimposed on palatal rugae showed an adequate reliability for a 5-year interval comparison using landmarks or regions of interest. Lower than acceptable reproducibility using both superimposition methods was found for a 40-year interval comparison.

By leveraging emerging technologies in augmented reality (AR) and virtual reality (VR), a Virtual Dental Library and AR virtual tooth identification test were developed at a U. S. dental school. The AR virtual tooth identification test is a vision‐ based AR application that uses three‐dimensional models of extracted human teeth as test items. The aims of this study were to investigate the validity of the AR virtual tooth identification test and evaluate the users' experience with the virtual testing method. The AR virtual tooth identification test scores were compared with real tooth identification tests, scores on three quizzes, final exam, and final grade for the course to assess its validity. In addition, a survey was used to assess students' perceptions of the AR tool. In 2018, all 109 first‐year dental students who had completed the dental anatomy course were invited to participate in the study. Of the 93 participants, 61 (56% of total students) were included in the correlation analysis (32 were excluded due to incomplete test answer sheets or missing criterion measures). All 93 could respond to the survey and provide comments. In the results, the AR virtual tooth identification test had a positive correlation with the real tooth identification test (r=0.410, p<0.01), a combined score of two real tooth identification tests (r=0.545, p<0.01), the final exam (r=0.489, p<0.01), and overall grade for the dental anatomy course (r=0.661, p<0.01). On the tests, the students had some difficulty in viewing and manipulating the images and experienced technical difficulties related to their smartphones, and their survey responses expressed little support for the AR tool. Nevertheless, this study demonstrated criterion validity of the AR virtual assessment tool for tooth identification.

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