Objectives: This study aimed to examine the outcome and stability of the anterior open bite treatment with clear aligners. Methods: Fifty-two adult anterior open bite patients who underwent nonextraction clear aligner treatment were enrolled. All cases were retained with upper and lower fixed and vacuum-formed retainers. Eleven cephalometric measurements at pretreatment (T1), end-of-active-treatment (T2), and at least 1-year post-treatment (T3) were evaluated. The changes during the treatment and retention period were calculated. Results: Mean end-of-treatment (T2) overbite was 1.1 ± 0.7 mm. The mean change in overbite during treatment was 3.3 ± 1.5 mm. Mean retention (T3) overbite was 1.3 ± 0.9 mm, with a mean increase in overbite of 0.2 ± 0.5 mm (P = 0.59) during the retention period. None of the eleven cephalometric measurements showed significant change during the retention period. Conclusions: Anterior open bite was successfully corrected in all the patients (n = 52) with clear aligners. When retained with upper and lower fixed retainers and upper and lower vacuum-formed retainers, there was no significant change in cephalometric measurements during retention period. Treatment stability could not be predicted using cephalometric measurements at pre-treatment, the change of cephalometric variables during treatment, retention time, or previous orthodontic treatment.

Introduction: This study was designed to analyze the cephalometric changes in adult Class III malocclusion treated with clear aligner therapy. Methods: In this retrospective study, thirty-six Class III adult patients treated with clear aligner therapy in private practice and a graduate orthodontic clinic were included in this study. Inclusion criteria included patients aged 18 years and older, Class III molar relationship that is end-on or greater, at least one anterior tooth that is in crossbite or incisors in an edge-to-edge bite, and complete records (initial and final lateral cephalograms) that are clear and traceable. Twenty-two cephalometric measurements were measured and analyzed by two calibrated judges. Results were categorized by skeletal vertical, skeletal anterior-posterior, dental vertical, and dental anterior-posterior. Descriptive analysis for mean, standard deviation, range, and percent was completed for demographic information, a paired T test to determine pretreatment and posttreatment cephalometric differences was performed, and a chi-square test for proportions was conducted. Results: No vertical changes were noted in upper and lower molar positions, and the upper incisor inclinations were maintained. On the other hand, lower incisors retroclined on average 5.6 degrees and retracted 1.78 mm. There was no change in the mandibular plane angle across different vertical pattern groups (normodivergent/hypodivergent/hyperdivergent patients). The only cephalometric variable that was statistically significant between different vertical pattern growers was the overbite. Conclusions: Adult patients with Class III malocclusion treated with clear aligners have good vertical control with no increase in mandibular plane angle and anterior face height. Clear aligner therapy is also good at maintaining vertical control for hyperdivergent patients. Finally, adult Class III dental camouflage treatment was resolved primarily through maintaining upper incisor inclination and lower incisor retroclination.

Introduction: Non-syndromic cleft lip with or without cleft palate (NCL±P) is characterized by a multifactorial etiology with both genetic and environmental factors playing a role in its embryonic development. Recent genetic studies have identified susceptibility loci and genetic variations in several genes that were associated with the risk of developing NCL±P. The purpose of this study was to investigate the association of MSX1, BMP4, TGFβ3, and GSK3β gene variants with NCL±P in a casecontrol data set from Karaikal, India. Methods: The case sample consisted of 331 individuals who were diagnosed with CL (bi/unilateral cleft lip), CLP (bi/unilateral cleft lip and palate), or CP (cleft palate). The control sample consisted of 156 individuals from the same location who were not affected with an orofacial cleft and had a negative family history of NCL±P. Genotype proportions and allele frequencies were determined and compared. Results: We tested differences in proportions of genotypes and allele frequencies in four gene variants. No statistically significant differences were found in single nucleotide polymorphisms (SNPs) of MSX1 rs3821949 and BMP4 rs17563. However, when comparing frequencies of TGFβ3 alleles in bilateral NCL±P cases vs controls, there was a close-to-significant difference at p = 0.069165 found. When frequencies of GSK3β alleles in female NCL±P cases vs female controls were compared, the difference was marginally statistically significant at p = 0.058246. Conclusions: Out of four SNPs studied in this Indian population, a possible association with NCL±P was found for GSK-3β rs13314595 and for TGFβ3 rs3917201. It was previously observed that variants of susceptibility genes may occur only in some cleft populations. Therefore, it is important to perform genetic studies in local populations. Knowledge of the presence of certain SNPs is essential if risk calculations or prevention measures are considered.

Background and purpose: In recent years, questions regarding the genetic and environmental factors affecting variation in human craniofacial morphology have received increasing attention. Medical and clinical genetic research using family studies has proven foundational for our understanding of which genes affect craniofacial variation. On the other hand, cephalometricbased studies showed a relationship between the cranial base and midface characteristics among individuals with different skeletal pattern of malocclusion. The purpose of our pilot study was to analyze specific variants of facial genes that were suggested to be associated with cranial base width and depth in Class II and Class I malocclusions. Methods: Patient data (extraoral photographs, intraoral photographs, and iCAT CBCT images obtained as part of patients’ routine orthodontic examinations) was collected for patients who had come to the Orthodontic Clinic, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, CA, from July 2019 to July 2021. For 72 patients who met the inclusion criteria for Class I or Class II groups in our study, saliva samples were collected, and DNA was isolated and analyzed using rtPCR genotyping for the following single-nucleotide gene polymorphisms (SNPs): rs79272428 (A>G), rs17106852 (A>G), rs12786942 (A>T) and rs6555969 (C>T). Results: We observed differences between Class I and Class II malocclusions in genotype proportions and allele frequencies in gene variants rs6555969 (C>T) and rs12786942. Genotype 4 CT (rs6555969) was found in a higher frequency in the Class I group generally and in the phenotypic Cluster 1. There were no differences observed for other gene variants studied. Regarding the cranial base characteristics, Asian patients had shorter and more acute cranial base. In Hispanic patients, there was a significant difference (P<0.005) between Class I and Class II patients regarding the cranial base width. Conclusions: The aim of our study was to determine genotypic differences between Class I and Class II malocclusion groups and to study genotypic associations with phenotypic clusters. We showed genotypic and phenotypic cluster differences between Class I and Class II groups. These differences were not statistically significant, probably, due to a small size of the studied groups. However, in this pilot study, we found trends, on which we will focus in our future study using a larger sample.

Background and Purpose. Orthodontic treatment helps to ensure proper function of teeth and to create healthy smiles. To this aim, the orthodontist’s goal is establishment of an esthetic harmony between soft and hard tissues of the face. Dimensions of facial width and height are crucial for accurate diagnosis and formulation of an efficient treatment plan. A knowledge of genetic determinants of these dimensions in Class II patients will deepen our understanding of etiology of skeletal Class II malocclusions and would make it possible to personalize a patient’s treatment plan. The purpose of our pilot study was to analyze, if specific variants of PAX 3, PAX 5, PAX 7 and PAX 9 genes are associated with Class II malocclusion but not with Class I malocclusion or vice versa. Methods. Patient data (extraoral photographs, intraoral photographs, and iCAT CBCT images obtained as part of patients’ routine orthodontic examinations) was collected for patients who had come to the Orthodontic Clinic, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, CA, from July 2019 to July 2021. For 72 patients who met the inclusion criteria for Class I or Class II groups in our study, saliva samples were collected, and DNA was isolated and analyzed using rtPCR genotyping for PAX 3 SNP: rs974448, PAX 5 SNP: rs7031673, PAX 7 SNP: rs4920520 and PAX 9 SNP: rs8004560. 4 Results. Genotype A5G5 (rs7031673, PAX5) was high in Class I generally, but also in phenotypic Cluster 1 and Cluster 9. Genotype G5G5 (rs7031673, PAX5) was high in Class II generally, but also in phenotypic Cluster 8 and Cluster 10. Allele G5 was more frequent in Class II than in Class I. Genotype A7A7 (rs4920520, PAX7) was high in Class II generally. It was absent in phenotypic Cluster 1 and Cluster 9, present in phenotypic Cluster 8 and Cluster 10. Genotype A9G9 (rs8004560, PAX9) was higher in Cluster 8 than in Cluster 10 (and also higher than in Clusters 1 and 9). Allele A9 was more frequent in Class II than in Class I. Conclusions. The aim of this study was to determine genotypic differences between Class I and Class II malocclusion groups and to study genotypic associations with phenotypic clusters. We showed genotypic and phenotypic cluster differences between Class I and Class II groups. We report several genotypes tentatively identified by genotypic analysis and found in association with certain phenotypic clusters. None of these differences proved to be statistically significant, probably, due to a small size of the studied groups. However, in this pilot study, we found trends, on which we will focus in our future study using a larger sample.

Abstract CROWN SIZE COMPARISONS IN PATIENTS WITH PALATALLY DISPLACED CANINES By Joseph L. Eliason, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2015 Thesis Director: Steven J. Lindauer, D.M.D., M.Dent.Sc. Professor and Chair, Department of Orthodontics There has been significant debate over the past decades regarding the etiology of palatally displaced canines. Theorized risk factors include agenesis or malformation of the lateral incisors, incisor retroclination, transverse deficiency, or genetic predisposition. The purpose of this study is to compare the linear and volumetric measurements of canines and lateral incisors to determine how tooth size relates to canine impaction. Cone-beam CT images for 40 patients with unilateral palatally displaced canines were utilized to measure the linear dimensions and total crown volume of canines and lateral incisors and to compare those teeth on the impaction side with their isomers on the non-impaction side. Results showed that unilateral palatally impacted maxillary canine crowns were slightly, but statistically significantly wider and larger in volume than their non-impacted isomers. Lateral incisor crowns adjacent to impacted canines were significantly shorter than those adjacent to non-impacted canines.

Introduction: In order to properly diagnose and treatment plan, an orthodontist needs to be knowledgeable about the changes that occur to the maxillary and mandibular dental arches throughout growth. The purpose of this study is to provide an analysis of morphological shape differences seen in the maxillary and mandibular dental arches individually, as well as together, from birth to 3 years of age. Methods: Dental casts from the Iowa Infant Growth study ranging from 2 months to age 4 were photographed in the occlusal plane. The images were landmarked with 3 standard landmarks and 10 sliding semi-landmarks along the curvature of the maxillary and mandibular arches. TpsRelW was used to slide the semi-landmarks and superimpose the date to facilitate shape analysis. MorphoJ was used to determine the degree to which size influences dental arch shape. Once the effects of allometry had been removed, a principal component analysis was run on the residuals to display major features of shape variation in the dataset. Finally, a two block partial least squares analysis was run to determine the degree to which the maxillary and mandibular arches were integrated throughout early growth. Results: Allometry accounts for 9.63% of symmetric shape variation in the maxilla, while it accounts for 56% of symmetric shape variation in the mandible. Asymmetric shape variation is independent of allometry as it only affects 0.34% of the maxillary and 1.46% of the mandibular shape variation. Principal component one accounts for over 60% of all shape variation seen in maxillary and mandibular residuals. Principal component one of symmetric residuals results in a longer, wider dental arch or a shorter, narrower one. Principal component one of asymmetric residuals results in a dental arch with one posterior side being longer and wider while the contralateral side is shorter and narrower. The first three time points (2 months- 1 year) do not display significant integration between the maxillary and mandibular arches. Integration increases with age, displaying significant integration at the last three time points, with the most integration being displayed at 2.5 years. Conclusions: Allometry affects some of the symmetric shape variation in the maxilla, but over half of the symmetric shape variation in the mandible. The asymmetric components are independent of allometry. Integration of the maxillary and mandibular arches increase with age from 2 months to 3 years, peaking at a time point of 2.5 years.

Introduction: Prevalence of childhood obesity is at an all-time high. The effect of childhood obesity on dental development and eruption is a widespread topic today in the dental field. Several cross-sectional studies over the past decade have found an association between advanced dental development and eruption and childhood obesity. The purpose of this study is to examine the longitudinal relationship between childhood Body Mass Index (BMI), and the development of the permanent dentition. Methods: 76 subjects from a longitudinal dataset (Iowa Facial Growth Study 1946-1960) were selected to examine the relationship between BMI and dental development during childhood. Periapical and lateral cephalometric radiographs were used to provide a dental maturity score for each subject using the Demirjian et al. (1973) method at three separate time points (age 4, 8, and 12). BMI was calculated using subjects’ height and weight at each time point. Results: Children with higher BMI’s at all three time points (4, 8 and 12) tended to have advanced dental development compared to children who were of normal weight status. Children who were considered underweight (< 5th BMI percentile) were more likely to be dentally delayed. BMI at age 4 was predictive of dental development status at age 8 and 12. Conclusion: Our results add to the growing body of evidence that childhood obesity is associated with advanced dental development. This is important in the dental and orthodontic fields, as early eruption has been hypothesized to be associated with increased dental caries, crowding, and malocclusions.

Class II malocclusion in non-growing individuals is treated in one of two ways - masking or surgery. If the dentoskeletal discrepancy is great enough, masking usually involves extraction of two maxillary premolars and subsequent incisor retraction and closure of overjet. This is the option of choice for patients without profile concerns, or who have medical or financial concerns. However, this treatment modality can sometimes result in less-than-ideal results. In the present study, we sought to understand what factors may influence the outcomes of this type of treatment. 65 subjects were included in this study. The total sample was divided into good and compromised finish categories based on objective criteria of overbite, overjet, and AP position of the maxillary canines. The good finish group was further subdivided into two groups, acceptable and excellent finishes. Several variables were measured on each subject's initial and final casts and compared between groups to determine whether any were associated with a particular finish group. At the initial time point, a mesial displacement of the maxillary right first molar by 3.35mm or less was found to correspond significantly to an excellent finish. This may indicate that if an individual presents with molars that are Class II by 3 mm or less, the prognosis is better than if that same individual had a greater Class II discrepancy. None of the other variables for the initial time point were found to be significantly different, suggesting that treatment mechanics, rather than a pre-existing occlusal factor, plays a predominant role in treatment outcome. At the final time point, we found that the maxillary arch length and tooth-size arch-length discrepancy were greater in the compromised group, indicative of excess spacing in this group at the end of treatment. Based on the other findings of this study, we attribute this result to differences in the mechanics used by individual practitioners. This hypothesis is further supported by our findings that none of the variables measuring patient compliance were found to be different between the good and compromised group. In the future, studies examining the particular mechanics used, and compliance where applicable, in this population will yield valuable insights into this area of patient research.

Introduction: The purpose of this study was to evaluate the amount of external apical root resorption (EARR) secondary to orthodontic treatment in patients with Short Root Anomaly (SRA) using Cone Beam Computed Tomography (CBCT) at the University of the Pacific Orthodontic Clinic. Material and Methods: In this retrospective study, CBCTs of forty-eight SRA patients who underwent orthodontic treatment were selected from the graduate orthodontic clinic. CBCTs before and after treatment were analyzed to measure root length changes on the upper central and lateral incisors. Results: Differences between the two methods of assessing SRA severity occurred between categorizing mild and moderate SRA subjects with the quantitative method resulting in more moderate cases and visual method determining more mild cases. Root resorption changes ranged from 0.92-1.3 mm for all incisors. Between the Non-Hispanic and Hispanic group, there was no statistical significance for all tooth length changes. There is a statistically significant difference in the root resorption of SRA teeth and non-SRA teeth (0.55mm). Conclusions: Post orthodontic treatment SRA teeth exhibited less linear changes than non SRA teeth and no differences were found between non-Hispanic and Hispanic upper incisors.