Clinical Outcomes of 0.018-Inch and 0.022-Inch Bracket Slot Using the ABO Objective Grading System

Objective: To determine if there is a significant difference in the clinical outcomes of cases treated with 0.018-inch brackets vs 0.022-inch brackets according to the American Board of Orthodontics (ABO) Objective Grading System (OGS). Materials and Methods: Treatment time and the ABO-OGS standards in alignment/rotations, marginal ridges, buccolingual inclination, overjet, occlusal relationships, occlusal contacts, interproximal contacts, and root angulations were used to compare clinical outcomes between a series of 828 consecutively completed orthodontic cases (2005–2008) treated in a university graduate orthodontic clinic with 0.018-inch- and 0.022-inch-slot brackets. Results: A two-sample t-test showed a significantly shorter treatment time and lower ABO-OGS score in four categories (alignment/rotations, marginal ridges, overjet, and root angulations), as well as lower total ABO-OGS total score, with the 0.018-inch brackets. The ANCOVA—adjusting for covariants of discrepancy index, age, gender, and treatment time—showed that the 0.018-inch brackets scored significantly lower than the 0.022-inch brackets in both the alignment/rotations category and total ABO-OGS score. Conclusions: There were statistically, but not clinically, significant differences in treatment times and in total ABO-OGS scores in favor of 0.018-inch brackets as compared with the 0.022-inch brackets in a university graduate orthodontic clinic (2005–2008)

Phrasal phonology in Copperbelt Bemba

Copperbelt Bemba exhibits several rightward spreading tonal processes which are sensitive to prosodic phrase structure. The rightmost H tone in a word will undergo unbounded spreading if the word is final in a phonological phrase (phi). In an intonational phrase consisting of several single-word phi's, the rightmost H in the first word will spread through all following toneless phi's. From a rule-based perspective, this can only be accounted for by positing mutually feeding iterative rules, as a single H-tone spreading rule cannot account for the long-distance spreading. Rather, a second rule that spreads a H from the final mora of one word onto the initial mora of the following word is required, as a bridge to further unbounded spreading. Three phrase-sensitive OT constraints are proposed to account for H-tone spreading between words. One is of the domain-juncture variety, requiring the specification of two separate prosodic domains

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)

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

Mucosal Thickening of Maxillary Sinuses of CLP vs non-CLP patients

poster abstractObjectives: The objective of this retrospective radiographic study was to compare mucosal thickening of maxillary sinuses of patients with cleft lip and palate (CLP) vs. non-CLP. Methods: Following IRB approval, three-dimensional cone beam computerized tomographs (CBCT; i-CAT) of children with unilateral CLP and children without CLP (age and gender matched; 8-14yoa; n=15ea) were selected randomly from pre-existing orthodontic records. Following reliability studies, one investigator segmented both sinuses from each CBCT using Dolphin-3D Imaging software. The sinuses were separated coronally into .4mm slices anterioposteriorly. Bony sinuses and airspaces were outlined manually on each slice. Software calculated total sinus and airspace area. Areas were summed and multiplied by slice thickness to determine volume. Mucosal thickening was the difference between total sinus and airspace volumes. Percent mucosal thickening was calculated. Since no significant differences existed between cleft (left) and noncleft (right) sides of either patient group (p>.05), sinuses for each group were pooled (n=30 ea). Significant differences in total sinus, airspace, mucosal thickening volumes and % mucosal thickening were determined using paired t-tests, accepting p<0.05 as significant. Principal Component Analysis (PCA) scatterplots were used to determine patterns of multivariate variation based on group, age, and sex. MANOVA was used to confirm PCA findings. Reliability was determined using Intraclass Correlations (ICC). Results: Reliability was excellent (ICC>0.99). The CLP total sinus and airspace volume were significantly smaller and mucosal thickening and % mucosal thickening were significantly greater than non-CLP sinuses (all p<.024). PCA showed that 89.6% of sample variance was explained by PC axis 1 and 2 (group and age). Age group 8-9yrs showed more separation with 13-14yrs than with 10-12yrs. MANOVA confirmed a significant effect of sample (p=.001) and age (p=.007)

Determination of trace elements in the plants of Mt. Bozdag, Izmir, Turkey

The aim of this study was to determine the current level of atmospheric heavy metal content on the Bozdag Mountain of the Aegean Region, Turkey. Twenty nine different plants were selected to study their potential as biomonitors of trace elements such as Ni, Zn, Fe, Pb, Mn and Cd (μg g-1, dry weight). The samples were collected from two different altitudes of Mt. Bozdag. The concentrations of trace elements were determined by atomic absorption spectrometry. The mean concentrations determined at 1000 m altitude ranged from 0.025 to 1.609, 0.232 to 0.731, 0.578 to 5.983, 0.287 to 0.565 and 0.176 to 2.659 (μg g-1, dry weight), for Ni, Zn, Fe, Pb and Mn, respectively. At the altitude of 1600 m, the values ranged from 0.023 to 0.939, 0.258 to 1.254, 0.839 to 5.176, 0.301 to 1.341 and 0.405 to 3.351 (μg g-1, dry weight) for Ni, Zn, Fe, Pb and Mn, respectively. No Cd was detected at either altitude. Statistical significance was determined by the independent sample t-test and comparisons were made in order to determine if there were any differences between the averages of herbaceous and woody plants.

The Effect of Anterior Tooth Position on Trumpet Performance Quality

poster abstractObjective: Music teachers contend that the arrangement of anterior teeth affects trumpet performance by influencing the embouchure. Since there is little quantitative data to support this claim, the purpose of this study was to determine whether trumpet performance skills are associated with the malalignment of anterior teeth. Methods: Following IRB approval, 70 trumpet students (55M:15F; aged 20-38.9 yrs.) from 11 universities were consented to complete a survey concerning dental history and trumpet playing habits. The students were asked to play a scripted performance skill test (flexibility, range, endurance, and articulation exercises) on their instrument in a soundproof music practice room while being audio and video recorded. A threedimensional (3D) cone beam computerized tomograph (CBCT) was taken of each student the same day as the skill test. Following reliability studies, overjet, overbite, and degree of anterior tooth irregularity (Little’s Index) were measured on the 3D CBCT. Nonparametric correlations, accepting p0.8). Significant (p<0.05), but weak (r<0.30) associations were found only between Little’s Index of the mandibular anterior dentition and the performance skills: flexibility (exercises a, c and avg) and articulation (double tongue). No other associations were significant. Conclusions: University trumpet students with mandibular anterior teeth that are smoothly aligned have significantly better performance skills than those with misaligned mandibular anterior teeth; however, the association is weak

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