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Introduction: Near infrared imaging (NIRI) uses non-ionizing radiation in the near-infrared spectrum to differentially scatter light off tooth surfaces. This generates images that allow for interproximal caries detection, which have been proposed as an alternative to radiographic detection. The new iTero Element 5D intraoral scanner (Align Technology) has integrated NIRI capture and viewing technology but has not been specifically studied in a pediatric population. Therefore, the goal of this study was to assess clinicians’ abilities to detect and characterize caries in pediatric patients using this instrument. Methods: Bitewing (BW) radiographs and a NIRIenabled intraoral scan were captured on 17 pediatric patients, and a total of 344 surfaces were then analyzed. The data was randomized and graded by five calibrated clinicians individually. A follow up round of grading was also done in which NIRI and BW datasets were combined and provided for the same patient together. Results: The reliability of lesion characterization (i.e., grade) amongst examiners was generally poor to fair in both systems, while the reliability of caries detection was moderate for BW (κ=0.4774) and NIRI (κ=0.4001). NIRI had an overall accuracy of 87.79%, a high specificity of 96.07%, and low sensitivity of 23.98%. The overall reliability of characterization of the combined dataset was moderate (κ=0.4957), while for detection was substantial (κ=0.6463). Conclusions: When using either BW or NIRI analysis, reliability was relatively poor, and clinicians were more likely to correctly identify a healthy tooth surface when compared to a carious surface. There was a small difference in error rate between BW and NIRI systems that is unlikely to be clinically significant. When NIRI and BW data was combined, agreement among clinicians for both lesion characterization and detection increased significantly. Overall, NIRI appears to be relatively comparable to BW as a diagnostic test, although both tests have significant limitations that are important to recognize.

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.

Indiana University-Purdue University Indianapolis (IUPUI) / A study was made to ascertain the effect of heat treatment, at a time-temperature ratio of three minutes at 900 F., on orthodontic 18-8 and Elgiloy steel wire with respect to the followings a) the ability of a vertical loop to resist permanent deformation when subjected to a tensile load; b) the effect of heat treatment on ductility of a steel orthodontic wire; c) the effect of heat treatment on the warpage of a orthodontic wire which has previously been formed. A standardized nine millimeter vertical loop was incorporated in the wire. Weights in increments of 100 grams were suspended from one end of the wire while the other end was firmly held in a vice. Permanent deformation as a result of a given load was determined by the amount of permanent opening of the vertical loop. The force just necessary to produce a permanent opening of the vertical loop is defined as the proportional limit. The ability of Elgiloy to resist permanent deformation due to heat treatment is enhanced as much as 66 percent. On the other hand, Elgiloy heat treatment produces the undesirable side effect of reducing ductility i.e., as high as 77 percent reduction in ductility following heat treatment. Therefore a Elgiloy steel wire cannot be altered in shape to any great extent after heat treatment. Eighteen-eight type 304 steel wire, when subjected to the same treatment, shows an increased ability to resist permanent deformation i.e. a 39 percent increase in proportional limit following heat treatment. It is significant that ductility, as determined by the cold bend test, is not significantly affected by heat treating 18-8 steel wire. The latter phenomena supports the claim of many investigators that 18-8 steel is not capable of a true heat treating transformation and therefore any improvements in elastic properties as a result of heat treatment can be considered to be due to a stress-relieving process. Ductility, as determined by the cold bend test, was found to be a highly variable property. Large variations in ductility were even found in the same feet-length of wire. Both 18-8 and Elgiloy steel wire exhibit this phenomena. Following heat treatment of Elgiloy a reduction in the variability of ductility was noted in all the wires tested. The effect of heat treatment on warpage of a previously shaped orthodontic steel wire was studied by incorporating a right angle bend in the center of a four inch section of wire. After a three week storage at a constant temperature of 98.6m to simulate mouth conditions, the angles were again measured. Any alteration in degrees from the right angle was considered to be indicative of warpage. Heat treated wires were compared to non-heat treated. Heat treatment appears to increase warpage in orthodontic steel wires; however, because of large variations no conclusive results were obtained with respect to this problem.

Indiana University-Purdue University Indianapolis (IUPUI) / The object of this study was the determination of the amount of force exerted by some of the simpler widely-used orthodontic appliances. More specifically, interest was centered on the rate of force delivery, as well as upon the nature of the stresses induced in the various parts of the wires. By using experimentally determined values of the modulus of elasticity and the appliance dimensions the forces and corresponding deflections of these simpler orthodontic structures may be calculated. Theoretical force determinations according to the methods employed in the science of strength of materials were made on the following appliance forms: the finger spring; the simply supported wire; the semicircular wire form; and the U-Shaped arch. Force values and corresponding displacement measurements were made on samples of various sizes of round and rectangular wires. Comparison of these measurements with the calculated values indicated very good agreement.

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this study was to assess the suitability of a pain model that utilizes the application of force between teeth as the noxious stimulus. Also, the time course of pain threshold alterations in patients subjected to orthodontic treatment was explored. A simple pressure algometer utilizing strain gages was produced to apply and measure the force required to reach the pain threshold of incisor teeth (central-lateral pairs) for three consecutive days. Fifteen orthodontic patients were used (nine females, six males) with incisors in good alignment and with interproximal contact. Each patient was used for both control and experimental measurements in each arch. Baseline pain threshold measurements were taken on the first day and individual orthodontic springs placed on the experimental side. The control side was the adjacent central-lateral incisor pair on the other side of the arch where no spring was placed. Additional measurements were taken the second and third day in each quadrant. A great variability in pain response between patients was evident. Significantly lower pain threshold levels were observed a day after the initial spring activation followed by an increase in the pain threshold the second day after spring activation. In the mandibular arch, the treatment by day interaction was significant, with the experimental side pain threshold substantially lower than control on the second and third day. Pain thresholds in males were significantly higher only in the maxilla, although there was a tendency for lower pain sensitivity in males for both arches. An apparent crossover of sensitivity between arch sides was observed in this study. The present model was shown to be suitable to study pain thresholds associated with orthodontic forces, and the pressure algometer was able to quantify pain threshold with objective measurements. The model could be used clinically to screen patients with low pretreatment pain thresholds so modifications of treatment mechanics or pharmacologic means could be used to allay patient pain.