Introduction: The purpose of this study is to compare dental and skeletal differences between Class I and Class II sides and their contributions to the degree of asymmetric molar relationship in Class II subdivision malocclusions using CBCT. Methods: One hundred and eight patients presenting with Angle Class II subdivision malocclusions (mean age =21.05 years) were assessed with 3-dimensional cone-beam computed tomography scans. Paired t-tests were used to compare linear skeletal, angular and dental measurement differences between Class I and Class II sides. Correlations of linear skeletal, angular and dental measurement differences between Class I and Class II sides were made against the Asymmetric Molar Relationship measurement. Differences between Class I and Class II sides were correlated to the degree of skeletal asymmetry, as defined by defined as menton deviation from mid-sagittal plane. Results: Maxillary first molar position was more mesially positioned on the Class II side and the mandibular first molar position was more distally positioned on the Class II side. No significant skeletal differences were found between Class I and Class II sides. Asymmetric Molar Relationship was correlated with a more mesially positioned maxillary first molar position and distally positioned mandibular first molar position on the Class II side. There were no significant skeletal differences that were correlated significantly with the Asymmetric Molar Relationship. Conclusion: In a sample of one hundred and eight patients exhibiting Class II subdivision malocclusion with and without skeletal asymmetry, the Class I and Class II sides display differences that are mainly dentoalveolar in nature. The degree of molar relationship asymmetry was correlated with a more a mesially positioned maxillary molar and a more distally positioned mandibular molar on the Class II side. There were no significant skeletal differences between Class I and Class II sides and no significant skeletal contributions to molar asymmetry.

Introduction: The purpose of this study was to investigate variance in prevalence and severity of short root anomaly (SRA) in patients seeking orthodontic treatment, stratified by ethnicity and sex. Materials and Methods: In this retrospective cross-sectional study, we evaluated 896 patients who had initial cone-beam computed tomographies (CBCTs) taken from July 1, 2014 to May 30, 2019. Panoramic radiographs and images from the CBCTs of each patient were extracted and placed in a database. The crown-to-root ratio of maxillary central incisors, lateral incisors, canines, and all pre-molars were evaluated to determine the presence, severity and associations of SRA. A Chi-square test and ordered logistic regression were used. Results: SRA was seen in 10.04% of the sample (90 patients). The maxillary central incisors are the most frequently and bilaterally affected. The severity of SRA among those with SRA showed statistically significant differences between the ethnic groups. Associations been SRA and Hispanic patients were found to be significant when evaluated by ordered logistic regression (P

Objective: The purpose of the present study is to develop prognostic models for surgical need and treatment success for class III malocclusions. Material and Methods: This is a retrospective cohort study that evaluated treatment outcomes of consecutively treated patients at UCSF from Jan 1st 2007-Jan 1st 2012 and UoP from May 1st, 2014 – May 1st 2019. Receiver operator curves were used to develop prognostic models for surgical need and treatment success for class III malocclusions. Predictor variables were selected a priori (Class III-WITS, U1-PP, IMPA). The prognostic models were validated first using a UCSF validation cohort to show consistency with in one program, and then using consecutively treated patients at UoP from May 1st, 2014 – May 1st 2019 as a second validation group as an outside program. Results: Derivation model for surgical need of class III malocclusion showed high sensitivity (81.8%); high specificity (94.3%), high positive predictive value (81.8%), high negative predictive value (94.3%), and the model correctly classified 91.3% of the subjects. UCSF validation model for surgical need of class III malocclusion showed moderate sensitivity (63.6%), high specificity (91.4%), high positive predictive value (70.0%), high negative predictive value (88.9%), and the model correctly classified 84.8% of the subjects. UoP validation model for surgical need of class III malocclusion showed moderate sensitivity (46.7%), high specificity (97.4%), high positive predictive value (77.8%), high negative predictive value (90.4%), and the model correctly classified 89.1% of the subjects. Derivation model for treatment success of Class III malocclusions showed moderate sensitivity (46.7%); high specificity (85.2%), moderate positive predictive value (63.6%), high negative predictive value (74.2%), and the model correctly classified 71.4% of the subjects. UCSF validation model for treatment success of Class III malocclusions showed low sensitivity (35.0%), moderate specificity (69.6%), moderate positive predictive value (50.0%), moderate negative predictive value (55.2%), and the model correctly classified 53.5% of the subjects. UoP validation model for treatment success of Class III malocclusions showed low sensitivity (16.1%), high specificity (87.5%), moderate positive predictive value (41.7%), moderate negative predictive value (65.3%), and the model correctly classified 62.1% of the subjects. Conclusion: WITS, U1-PP and IMPA were significant predictors of orthognathic surgical need in the derivation group, but only WITS predicted surgical need in the validation groups of Class III Malocclusions. Regarding treatment success, in the derivation group, only U1-PP was significantly associated with treatment success, while no variables were significantly associated with treatment success in the validation groups. Overall, the prognostic models developed in this study are more robust regarding predictions of Class III surgical need, as opposed to treatment success as defined by the ABO Cast and Radiograph examination.

Given the recent implementation of Invisalign First for early interceptive orthodontic treatment, a limited number of orthodontists have had experience with this treatment modality and there currently are no published studies on the topic. The present study aims to use a qualitative survey to identify common themes in providers’ perceptions of Invisalign First as a new treatment option for early interceptive orthodontics. Twenty-three orthodontists in the private practice sector voluntarily participated in an open-ended survey via email. The results of the survey indicate the following common themes in regards to benefits of Invisalign First: fewer emergencies, patient comfort, patient experience, patient happiness, ability to correct multiple things at once, and arch development. Some of the commonly cited drawbacks of Invisalign First are the following: attachment bonding issues, poor retention, and cost. Overall, all participants except for two (of twenty three) will continue to offer Invisalign First in some capacity. Seventeen participants spoke favorably of the treatment modality and would recommend Invisalign First to other providers. The results of this study provide a framework from which a more robust survey can be constructed. The intent of the future study is to gather and synthesize orthodontists’ perceptions based on experience with Invisalign First in a way that readers can constructively evaluate the potential for this treatment modality in their orthodontic practices.

Introduction: Orthodontics has clinical benefits, however, the psychosocial outcomes are not well understood. These soft benefits are often classified as aesthetic, functional, and psychosocial, however, there is limited work understanding these outcomes as reported directly from the patient. By better understanding the patient’s perspectives, we can continually refine our clinical model to be patient-centric and more appropriately manage the patient’s expectations and experiences. Materials and Methods: This is a cross-sectional qualitative study of 20 parents of 24 children ages 8-11 years. Participants were remotely interviewed using a semi-structured chronologically based line of questioning to elucidate their perceived outcomes of early orthodontic treatment or phase one. A content thematic analysis using a framework approach was used to analyze the resulting data. Results: The thematic analysis uncovered four major themes and associated subthemes as follows (1) dental health including functional changes, aesthetic improvement, and improved cleansability; (2) opportunity cost: meaning harnessing growth for lasting change, avoidance of future orthodontic treatment, avoidance of future dental treatment, and supervision of growth; (3) social outcomes: encompassing external perception and acceptance, self-perception, parental perception, and reduced dental anxiety; and (4) behavioral changes: including the correction of bad habits, development of good oral hygiene, and an increase in responsibility of the patient. Conclusions:This study highlights the depth of psychosocial benefit perceived by patients undergoing early orthodontic treatment, with the main outcome being functional improvement, followed by an advantage to treatment at a young age, and an improvement in aesthetics. Patients did not recognize an increase in self-perception which is contrary to outcomes previously found in other age groups.

Introduction: Socioeconomically disadvantaged children have limited access to orthodontic services not only because of their families’ competing needs for limited resources, but also because of the limited availability of orthodontists in their communities and a shortage of orthodontists who are willing to treat patients enrolled in Medicaid. We will systematically explore the hypothesis that an early interceptive treatment protocol using removable appliances provides the same treatment outcome but better cost-effectiveness than a traditional fixed-appliance protocol. Methods: Interim data on a prospective study with patients being treated either in private practice with rational fixed Phase I orthodontic treatment (n=11) or in a community clinic with removable interceptive orthodontic treatment (n=10). Initial and post treatment study models were acquired along with pretreatment PAR and clinical photos. PAR and ICON scores were assessed on all initial and final casts. Cost effective analyses were performed comparing the two treatment groups as well as comparing the removable group to no treatment. Sensitivity analyses were performed to assess the robustness of our data while manipulating certain treatment outcome variables. Results: For the fixed group the average PAR score at T2 was 7.6 with a 68% reduction from T1 to T2, while the ICON average score was 16.2 with a 67% reduction. In the removable group the average PAR score at T2 was 13.4 with a lesser reduction from T1 to T2 than the fixed group at 48% (p=0.20), while the ICON average score was 25.3 with a significantly lower reduction of 39% when compare to the fixed group (p=0.037). Cost effectiveness analyses showed that the removable appliance treatment protocol was cost effective when compared to no treatment but not cost effective when compared to 3 the traditional fixed Phase I treatment using the studies measured probabilities of success. Conclusion: The removable appliance protocol used at the Fruitvale community clinic can effectively reduce the severity of malocclusions. However, in order for this treatment to be cost effective when compared to a traditional fixed Phase I protocol it needs to demonstrate consistent clinical results and minimize the probability of “No Improvement”.

ABSTRACT Introduction: Medical imaging continues to play an increasing role in health care and is an integral part of medicine and dentistry. Recent technological advancements have led to the development of fully automated landmark identification (ALI) systems capable of tracing Cone-Beam Computed Tomography (CBCT). The purpose of this study was to evaluate the accuracy and reliability of an ALI system as a tool for automatic landmark location compared to human judges. Methods: One hundred subjects’ CBCT volumes from multiple imaging centers were traced by two human judges who were calibrated and had an ICC close to 1. Fifty-three landmarks were identified in the x, y, and z coordinate planes using Checkpoint Software (Stratovan Corporation, Davis, CA). The ground truth was created by calculating the mean values of the x, y, and z coordinates for each landmark across both judges’ landmark identification. To evaluate the accuracy of ALI, the mean absolute error at each coordinate and mean error distance (mm) between the human landmark identification (ground truth) and the ALI were determined, and a successful detection rate (SDR) was calculated. Results: Overall, the ALI system was as successful at landmarking as the human judges with the exception of a few landmarks. The mean error distance for all 53 landmarks was 4.04 mm ± 6.5. Forty-nine out of 53 landmarks were located within a mean error of 4mm when the average for the coordinates of human judges was considered as a ground truth. Conclusion: Across all three coordinate planes, 96% of the landmarks had a mean absolute error of less than 4mm when compared to the ground truth. The ALI was more precise than humans when identifying landmarks on the same image at different times. This study demonstrates the promise of ALI in aiding orthodontists with landmark identification on CBCTs in the future.

WORK-RELATED MUSCULOSKELETAL DISORDERS AMONG DENTISTS AND ORTHODONTISTS A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. by Natalie R. La Rochelle Thesis Director: Dr. Eser Tüfekçi, D.D.S., M.S., Ph.D., M.S.H.A. Professor, Department of Orthodontics Virginia Commonwealth University Richmond, Virginia May 2017 The practice of dentistry is physically demanding due to static and dynamic postures sustained daily throughout careers. Previous literature suggests that work-related musculoskeletal disorders (WMSD) are not solely the result of work habits, but also due to the individual, his or her physical makeup, genetics, and personal lifestyle. A 33-question survey was distributed to 1000 general dentists and 2300 orthodontists. The overall prevalence of work-related musculoskeletal disorders was greater among dentists and most often reported as self-limiting. Dentists were three times more likely than orthodontists to report WMSD; females were twice as likely to report WMSD than males; those who sought alternative medical remedies were two times more likely to have WMSD; and practitioners 6-10 years in practice were least likely to report WMSD. Dentists reported sitting in static positions longer than orthodontists; and those with WMSD indicated exercising, stretching, and seeking alternative health remedies more than dentists without WMSD.

Introduction: Orthodontists increasingly rely on digital models in clinical practice. The ability of modern scanners to articulate digital models must be scientifically evaluated. Methods:Twenty five digital articulated models were produced from four digital scanners in five experimental groups. The resulting inter-arch measurements were compared to the gold standard. An acceptable range of 0.5mm more or less than the gold standard was used for evaluation. Results: iTero® and iTero® Element yielded all acceptable inter-arch measurements. The 3M™ True Definition and Ortho Insight 3D® with Regisil® bite registration produced four of six acceptable inter-arch measurements. The Ortho Insight 3D® with Coprwax ™ bite registration yielded three of six acceptable inter-ach measurements. Conclusions: The iTero® and iTero® Element produced the most accurately articulated models. The 3M™ True Definition and Ortho Insight 3D® with Regisil® were the next most accurate. The Ortho Insight 3D® scanner with Coprwax ™ was the least accurate method tested.

The purpose of this study was to identify and compare preferences and perceptions of orthodontists and general dentists when restoring peg-shaped lateral incisors. The investigation sought to summarize these preferences with regard to treatment planning, tooth preparation and interdisciplinary communication. A pair of mailed and electronic surveys was distributed to 1,500 general dentists and orthodontists, respectively. The results indicated that general dentists perceived that general dentists held the primary decision-making responsibility, while orthodontists disagreed (P<0.0001). Orthodontists prioritized the treatment goals of Class I canine relationship and overbite/overjet more significantly than general dentists, whom valued tooth proportions more highly (P<0.0001). General dentists reported receiving significantly less input than orthodontists report seeking (P<0.0001).The consensus of both groups showed that the tooth should be positioned centered mesiodistally and guided by the gingival margins incisogingivally. Both groups agree that orthodontists must improve communication to improve treatment results.