Preliminary Performance of the Advanced Dental Admission Test (ADAT): Association Between ADAT Scores and Other Variables for Applicants to Residency Programs at a U.S. Dental School

Historically, dental residency programs have used numerical assessment criteria to evaluate and identify qualified candidates for admission. Recent elimination of such assessment tools has undermined many programs’ holistic evaluation process. The Advanced Dental Admission Test (ADAT) was developed and recently piloted in hopes of addressing this issue. The aim of this study was to evaluate the preliminary performance and validity of the ADAT by exploring the association between ADAT scores and other variables for a sample of applicants to residency programs. The WebAdMIT admissions database was used to identify the test scores and educational and demographic information of 92 individuals who completed the pilot ADAT and were seeking a 2017 postgraduate specialty position at Indiana University School of Dentistry. The results showed that the ADAT had strong to weak correlations with certain applicant variables (p<0.05). No significant differences were found for age, race, school location, or country of origin. However, males performed better than females (p<0.05), and non-Hispanics performed better than Hispanics (p<0.01). ADAT component scores were also higher for individuals with a history of research activity (p<0.05). This study found that significant associations existed between the ADAT and indices typically associated with competitive applicants. These findings suggest that the ADAT may serve as a useful numerical assessment instrument, with the potential to identify high-performing candidates. Furthermore, the ADAT seemed to be a plausible option for programs seeking to incorporate a quantitative assessment instrument as part of a holistic candidate selection process

Facial Soft-Tissue Asymmetry in 3D Cone Beam Computed Tomography Images of Children with Surgically Corrected Unilateral Clefts

Cleft lip with or without cleft palate (CL/P) is a relatively common craniofacial malformation involving bony and soft-tissue disruptions of the nasolabial and dentoalveolar regions. The combination of CL/P and subsequent craniofacial surgeries to close the cleft and improve appearance of the cutaneous upper lip and nose can cause scarring and muscle pull, possibly resulting in soft-tissue depth asymmetries across the face. We tested the hypothesis that tissue depths in children with unilateral CL/P exhibit differences in symmetry across the sides of the face. Twenty-eight tissue depths were measured on cone-beam computed tomography images of children with unilateral CL/P (n = 55), aged 7 to 17 years, using Dolphin software (version 11.5). Significant differences in tissue depth symmetry were found around the cutaneous upper lip and nose in patients with unilateral CL/P

Orthodontic Soft Tissue Parameters: A Comparison of CBCT and 3dMD

poster abstractObjectives: Orthodontists rely heavily on soft tissue analysis to determine esthetics and treatment stability. Although the reliability of three dimensional photography (3dMD) and cone beam computed tomography (CBCT) is established, little data exists comparing the soft tissue measurements between these two imaging modalities. The aim of this retrospective study is to compare the equivalence of soft tissue measurements between the 3dMD imaging system and the segmented skin surface derived from i-CAT CBCT. Methods: Seventy preexisting 3dMD extraoral photographs and CBCT scans taken within minutes of each other for the same subjects were superimposed using 3dMD Vultus software on soft tissue. Images were registered according to hard tissue planes in three dimensions. Following reliability studies, 28 soft tissue measurements were selected and recorded on both imaging modalities. The measures were then compared between the two images to analyze their equivalence. Intraclass correlation coefficients (all ICCs >.8) and Bland-Altman plots were used to assess the inter- / intra-examiner repeatability and agreement. Summary statistics were calculated for all measurements. To demonstrate equivalence of the two methods, the difference needed a 95% confidence interval contained entirely within the equivalence limits defined by repeatability results (twice the within-subject standard deviation of CBCT). Results: Statistically significant differences were reported for the following measurements: vermilion height (Ls-Li), mouth width (CH[R]–CH[L]), total facial width (Tr[R] – Tr[L]), mouth symmetry (Ch[R] to Sup. Facial Plane), ST Lip Thickness (LI to mand CI), and eye symmetry (Exoc R & L to Sup. Facial Plane). Conclusions: There are areas of non-equivalence between the two imaging methods. Differences are clinically acceptable from the orthodontic point of view

Reliability and Validity of the OrthoMechanics Sequential Analyzer

poster abstractPurpose: The aim of this study was to evaluate the reliability and validity of newly developed software in the assessment of orthodontic tooth movement three dimensionally. Methods: The sample consisted of pre- and post- treatment computed tomography scans and plaster dental models of 20 orthodontic subjects treated with a hyrax expander as a part of their comprehensive orthodontic treatment. Dental arch measurements, including arch widths, tooth inclinations and angulations, were measured on the scans using InvivoDental 3D imaging software version 5.1. The plaster dental models were laser scanned, superimposed, and measurements were obtained digitally using the new software. Agreement between the digital models and the CT measurements was evaluated using intraclass correlation coefficients (ICCs), paired t-tests, and Bland-Altman plots. A p-value of ≤ 0.05 was considered statistically significant. Results: High agreement (ICC > 0.9), a non-significant paired t-test, and no indication of agreement discrepancies were observed for most of the measured parameters. Conclusions: The new software program offers a valid and reliable tool concerning dental arch measurements obtained from 3D laser scanned models. It could be considered a possible practical method that helps the orthodontist evaluate the treatment progress in a non-invasive manner and without unnecessary radiation exposure. Funding: Indiana University Purdue University - Office of the Vice Chancellor for Research & the Funding Opportunities for Research Commercialization and Economics Success (FORCES)

Endodontic management of an Infected Immature Tooth with Spontaneous Root Closure and Type II Dens Invaginatus: A Case Report

Apical periodontitis in an immature maxillary lateral incisor (#10) with arrested root development and a natural closure of the open apex in 22-year-old male was endodontically treated in a manner that conserved the existing hard tissue barrier (HTB). A dens invaginatus Oehlers II was also present. The patient reported no symptoms, but did recall an incident of dental trauma as a child. A 3D image showed the nature of the HTB closing the open foramen as well as the anatomy of the immature root with the dens invaginatus. Porosities were seen in the HTB and that is consistent with the histological “Swiss Cheese” appearance known to occur in apexification. Endodontic treatment was performed in a single-visit. Access to the root canal system (RCS) included penetration through the dens invaginatus. The canal was not mechanically cleaned, but only irrigated with sodium hypochlorite, ethylenediaminetetra-acetic acid (EDTA), chlorhexidine using the EndoVac® system. The barrier was maintained and covered with a 5mm layer of mineral trioxide aggregate (MTA). A sterile damp sponge was placed on the MTA. On the following visit the MTA had set, and an EndoSequence fiber post was placed in the canal and EndoSequence dual-cure core build-up material was used to close the access and restore the tooth. A clinical and radiographic follow-up, 30 months after the initial treatment revealed resolution of the radiolucency and apical trabecular bone deposition and the patient was asymptomatic

Effects of mandibular advancement appliances on the upper airway dimensions

poster abstractPurpose: The aim of this retrospective cephalometric study was to investigate dentoskeletal and airway dimensional changes in a group of orthodontic patients with deficient mandible using Herbst vs. MARA appliances. Methods: Pre-treatment and post-treatment lateral cephalometric radiographs of 34 subjects with deficient mandible (aged 9-22 years) were selected from the postgraduate orthodontic clinic archives. The cephalograms were classified into 2 groups . Group 1 (n=17) consisted of cephalograms from individuals treated with a Herbst appliance and group 2 (n=17) consisted of cephalograms from individuals treated with a MARA appliance. Each cephalogram was traced manually and the selected dentoskeletal and airway parameters were recorded for all subjects. Intraclass correlations (ICC) were performed on duplicate measures of 10 cephalograms to assess reliability. Paired t-tests were used to differences in the airway parameters from pre-treatment to post-treatment within groups. Statistical significance was set at P < 0.05. Results: ICC values were ˃0.90 for all measurements. Significant changes were recorded in ANB, N-S, ANS-PNS, Go-Gn, Overbite, Overjet, Co-ANS, Co-Gn, TFH, AFH, and LAFH for both Herbst and MARA groups. Airway parameters such as soft tissue thickness of the posterior pharyngeal wall (Ba-ad1 and Ba-ad2), anteroposterior dimension of bony nasopharynx (Ba-PNS, AA-PNS and AA-ptm), and width of the nasopharyngeal airway space (PNS-ppw1) showed statistically significant decreases in both groups. The Herbst group also showed statistically significant decrease in the sagittal depth of pharyngeal lumen at the nasopharynx and oropharynx (ptm-ad1, PNS-ad1, and PNS-ppw2) while the MARA group demonstrated a statistically significant decrease in the angle represents the anteroposterior dimension of the nasopharynx (AA-S-PNS). Conclusion: Using mandibular advancement appliance decrease significantly the upper airway dimensions. The amount of the change in the upper airway size was variable between Herbst and MARA appliances

Computational fluid dynamics analysis of the upper airway after rapid maxillary expansion: a case report

BACKGROUND: Assessment of the upper airway volume, morphology, and mechanics is of great importance for the orthodontic patient. We hypothesize that upper airway dimensions have significant effects on the dynamics of the airway flow and that both the dimensions and mechanics of the upper airway are greatly affected by orthodontic and orthopedic procedures such as rapid maxillary expansion (RME). The aim of the current study was to assess the effect of RME on the airway flow rate and pattern by comparing the fluid dynamics results of pre- and post-treatment finite element models. METHODS: Customized pre- and post-treatment computational fluid dynamics models of the patient's upper airway were built for comparison based on three-dimensional computed tomogram. The inhalation process was simulated using a constant volume flow rate for both models, and the wall was set to be rigid and stationary. Laminar and turbulent analyses were applied. RESULTS: Comparisons between before and after RME airway volume measurements showed that increases were only detected in nasal cavity volume, nasopharynx volume, and the most constricted area of the airway. Pressure, velocity, and turbulent kinetic energy decreased after dental expansion for laminar and turbulent flow. Turbulent flow shows relatively larger velocity and pressure than laminar flow. CONCLUSIONS: RME showed positive effects that may help understand the key reasons behind relieving the symptom of breathing disorders in this patient. Turbulence occurs at both nasal and oropharynx areas, and it showed relatively larger pressure and velocity compared to laminar flow

Retrospective CBCT analysis of airway volume changes after bone-borne vs tooth-borne rapid maxillary expansion

Objectives: To compare changes in upper airway volume after maxillary expansion with bone- and tooth-borne appliances in adolescents and to evaluate the dentoskeletal effects of each expansion modality. Materials and Methods: This retrospective study included 36 adolescents who had bilateral maxillary crossbite and received bone-borne maxillary expansion (average age: 14.7 years) or tooth-borne maxillary expansion (average age: 14.4 years). Subjects had two cone beam computed tomography images acquired, one before expansion (T1) and a second after a 3-month retention period (T2). Images were oriented, and three-dimensional airway volume and dentoskeletal expansion were measured. Analysis of variance was used to test for differences between the two expansion methods for pretreatment, posttreatment, and prepost changes. Paired t-tests were used to test for significance of prepost changes within each method. Results: Both groups showed significant increase only in nasal cavity and nasopharynx volume (P < .05), but not oropharynx and maxillary sinus volumes. Intermolar and maxillary width increased significantly in both groups (P < .05); however, the buccal inclination of maxillary molars increased significantly only in the tooth-borne group (P < .05). There was no significant difference between tooth- and bone-borne expansion groups, except for the significantly larger increase in buccal inclination of the maxillary right first molar after tooth-borne expansion. Conclusions: In adolescents, both tooth- and bone-borne RME resulted in an increase in nasal cavity and nasopharynx volume, as well as expansion in maxillary intermolar and skeletal widths. However, only tooth-borne expanders caused significant buccal tipping of maxillary molars

A Three-Dimensional Analysis of Maxillary Sinus Congestion in Unilateral Cleft Lip and Palate

Cleft lip and palate (CLP) perturbs osseous and soft-tissue development of the nasolabial regions, often resulting in chronic maxillary sinusitis and mucosal thickening (MT) of the maxillary sinus. This preliminary study quantifies maxillary sinus MT in children with surgically repaired unilateral CLP. We hypothesize that maxillary sinus MT is increased in children with CLP relative to controls. We define "MT" as the difference between the entire maxillary sinus volume and airspace volume. Cone beam computed tomography (CBCT) images of 8-14 yr. old age- and sex-matched unilateral CLP patients (n = 10) and controls (n = 10) were obtained (IRB approval # 1210009813). Both maxillary sinus and airspace surface areas (SAs) were measured on each individual CBCT slice in coronal view. SA measurements were summed and multiplied by voxel size (0.4mm) to obtain a volume. Paired t-tests determined whether maxillary sinus volume, air volume, MT (i.e. maxillary sinus volume – airspace volume), and percentage of MT (i.e. MT/maxillary size x 100) differed. A p-value of ≤ 0.05 was considered significant. Intra-class correlation assessed reliability and was high (0.99). Significant differences were found for several measurements: Maxillary airspace (non-cleft side vs. right side control p-value = 0.002; cleft-side vs. left side control p-value = 0.004), MT (cleft-side vs. left side p-value = 0.009), and percentage of MT (non-cleft side vs. right side control p-value = 0.002, cleft-side vs. left side control p-value = 0.002). Maxillary airspace was decreased by 30% (non-cleft side) and by 33% (cleft side). Percentage of average MT was 40% (non-cleft side) and 42% (cleft side) of CLP patients, but only 9% (left and right side) in controls. Surgically repaired CLP patients exhibit decreased maxillary airspace and increased MT relative to controls. CLP deformities are associated with MT. 3D imaging is useful for quantitatively evaluating MT of the maxillary sinus