Comparison of maxillary anterior tooth movement between Invisalign and fixed appliances.

INTRODUCTION: This research project aimed to compare the number of maxillary incisors and canine movement between Invisalign and fixed orthodontic appliances using artificial intelligence and identify any limitations of Invisalign. METHODS: Sixty patients (Invisalign, n = 30; braces, n = 30) were randomly selected from the Ohio State University Graduate Orthodontic Clinic archive. Peer Assessment Rating (PAR) analysis was used to indicate the severity of the patients in both groups. To analyze the incisors and canine movement, specific landmarks were identified on incisors and canines using an artificial intelligence framework, two-stage mesh deep learning. Total average tooth movement in the maxilla and individual (incisors and canine) tooth movement in 6 directions (buccolingual, mesiodistal, vertical, tipping, torque, rotation) were then analyzed at a significance level of α = 0.05. RESULTS: Based on the posttreatment Peer Assessment Rating scores, the quality of finished patients in both groups was similar. In maxillary incisors and canines, there was a significant difference in movement between Invisalign and conventional appliances for all 6 movement directions (P <0.05). The greatest differences were with rotation and tipping of the maxillary canine, along with incisor and canine torque. The smallest statistical differences observed for incisors and canines were crown translational tooth movement in the mesiodistal and buccolingual directions. CONCLUSIONS: When comparing fixed orthodontic appliances to Invisalign, patients treated with fixed appliances were found to have significantly more maxillary tooth movement in all directions, especially with rotation and tipping of the maxillary canine.

Outcomes of a contemporary credentialing and privileging program in a dental school.

The current credentialing and privileging (C&P) climate has evolved due to a risk reduction/management awareness of increased institutional legal liability. This recognition affects dental colleges and has caused the implementation of C&P processes. Contemporary best practices for methods, processes, and structure are reported here. Data reported from the process show how and what clinicians' red flags were discovered during the process. Conclusions include the following: C&P is a significant process to introduce in terms of institutional resources and commitment. This process includes increased clinician and administrative burden that needs to have a governor. Attention to experiences of other institutions can reduce but not eliminate challenges from the clinician and some administrators. A primary data-based verification process administered by a credentialing specialist can make the process valid and workable.

Quantitative evaluation of training method in placing miniscrews in orthodontic graduate program.

BACKGROUND: The purpose of this study was to assess the effectiveness of training residents in an orthodontic program in the placement of miniscrews by using cone beam computed tomography (CBCT) images. A total of 90 miniscrews were placed in 15 pig mandibles over a 3-year period by 15 first-year orthodontic residents. Miniscrews were divided into three groups (Control group: no radiographs; 2D group: placement with 2D radiographs; CBCT group: placement with CBCT). Proximity of the miniscrew to the neighboring root was measured. The miniscrew success rate was examined in the graduate clinic from 2015 to 2021. RESULTS: The percentage of root contact for each group was: 36.7% (11/30), 20.0% (6/30), 0% (0/30), for the Control, 2D, and CBCT groups, respectively. The CBCT group was significantly different from the Control and 2D groups (p < 0.05). For root proximity, the miniscrews were significantly closer to the roots in the Control (p < 0.001) and 2D (p < 0.001) groups compared with the CBCT group. No significant difference was observed between the Control and 2D groups (p = 0.80). There was no significant difference among the years in the miniscrew success rate. CONCLUSIONS: Training the residents in an orthodontic graduate program using CBCT may be helpful to avoid root damage and to decrease the miniscrew failure rate.

Rehearsal's effect on long-term recall and comprehension of orthodontic informed consent.

INTRODUCTION: The purpose of this study was to determine if written rehearsal of informed consent improved 6-month recall and comprehension compared with the current best practices. METHODS: A consultation was provided and subjects read the modified informed consent document. They were randomized to group A (received the core and up to 4 custom elements of treatment, wrote what each image displayed) or group B (presentation of the 18 elements with core elements chunked at the end followed by up to 4 custom elements). Interviews recording knowledge recall/comprehension occurred immediately and after months later. RESULTS: Overall, no significant differences in baseline or 6-month follow-up scores were found between groups. Initially, group A outperformed group B in some core domains. There were no significant differences between groups in the change of scores from initial to follow-up. Follow-up scores were significantly lower than baseline scores (P <0.05). Higher initial scores were associated with larger drops at follow-up. A decrease in knowledge >20% was common. CONCLUSIONS: Overall the methods are comparable at baseline and 6-months. Initial content retention was roughly 60+%, with 6%-9% deterioration. For areas of treatment methods, risk, discomfort, and resorption at 6-months, the current processes failed the patient and left the practitioner vulnerable to risk management issues. Results support the rehearsal method with immediate feedback for misunderstandings as the preferred method for informed consent.

Comparison of 2 Invisalign tray generations using the Peer Assessment Rating index.

INTRODUCTION: This study aimed to establish if there is a significant difference in effectiveness between 2 generations of Invisalign trays in terms of Peer Assessment Rating (PAR) score reduction for finished patients from a graduate orthodontic clinic. METHODS: Forty-five pretreatment and posttreatment patients treated with the previous Invisalign material and 49 pretreatment and posttreatment patients treated with SmartTrack material were scored using the Peer Assessment Rating (PAR) index. Both groups were controlled for initial weighted PAR score, age, gender, and treatment time. The 2 generations were compared in regard to absolute reduction, percent reduction, and great improvement in PAR score. RESULTS: The mean absolute reduction in weighted PAR score between the groups was not statistically significant (P = 0.526). The mean percent reduction in weighted PAR score between the groups was not statistically significant (P = 0.210). The proportion of great improvement between the groups was not significant (P = 0.526). Only 6 of the 8 components of occlusion had enough variation to be modeled. An absolute reduction in unweighted PAR score was not significantly different between the groups for maxillary anterior alignment, overjet, or mandibular anterior alignment (P = 0.996, 1.000, and 0.114, respectively). Percent reduction in unweighted PAR score was not significantly different between the 2 groups for an anteroposterior, overbite, or transverse (P = 1.000, 1.000, and 1.000, respectively) relationships. CONCLUSIONS: Our study indicates that both generations of Invisalign aligners improved the malocclusion to a similar degree according to the PAR index. Patient-centric benefits of SmartTrack aligner should also be considered by the provider.

Rehearsal's effect on recall and comprehension of orthodontic informed consent.

INTRODUCTION: Proper informed consent allows patients to take an active role in their own treatment decisions, and enhanced compliance might improve treatment outcomes. The objective of this research was to determine if handwritten rehearsal of core and custom consent items would increase short-term recall and comprehension. METHODS: A total of 90 patient-parent pairs were randomly assigned to 2 groups. After case presentation, each subject was provided 10 minutes to read a modified informed consent document. Group A received visual printouts containing the 4 core elements (root resorption, decalcification, pain, and relapse/retention) likely to be encountered by all patients and up to 4 custom elements (eg, impacted teeth, orthognathic surgery, or other case-specific treatment issues). Subjects identified and wrote what the image depicted and how it could affect treatment. Group B viewed a slideshow presentation on all 18 consent elements arranged from general to specific. All participants were interviewed, and each provided their sociodemographic data, as well as completed literacy, health literacy, and state anxiety questionnaires. The groups were compared for recall and comprehension through an analysis of covariance. RESULTS: The rehearsal intervention significantly improved recall and comprehension of the core elements (P = 0.001). Rehearsal also improved custom recall and comprehension, but not significantly. Group B performed significantly better on treatment questions (P = 0.001). Overall, as anxiety increased, correct responses decreased. CONCLUSIONS: The rehearsal group improved recall and comprehension of the core and custom elements of informed consent and proved a more efficient method than an audiovisual presentation to provide informed consent. It also improved meeting legal obligations.

The case for tying specialty status to completion of dental residency: Dental education's stake.

BACKGROUND: The American Dental Association's (ADA) specialty recognition process has long been the gold standard in dentistry. Specialty advertising regulations have been challenged as inconsistent with commercial speech rights of dentists wishing to advertise as specialists in areas not recognized as ADA specialties. Commission of Dental Accreditation-approved postdoctoral education exists to support this process using standard-based education, continuous quality review and accountability. PURPOSE: In 2017, a federal court declared Texas dental specialty advertising rules unconstitutional noting the state did not present evidence demonstrating the public was being misled. A state dental association commissioned a professional survey to assess state residents' understanding of the term "specialist" in dental advertising. METHODS: Telephone interviews conducted with 812, 18+-year-old Ohio residents focused on advertising related to dental implants and TMJ disorders (not recognized specialties) and orthodontics and oral surgery (recognized specialties). RESULTS: Respondents indicated they would be inclined to think a dentist who advertised as a specialist had completed an accredited dental residency program and was more qualified to perform specialty care than a general dentist. Respondents also indicated that they would be less likely to choose a dentist who advertised as a specialist who did not have accredited residency training. CONCLUSIONS: Tying specialty status to completion of a residency program accredited by an agency recognized by the U.S. Department of Education is important to the public's expectations and has implications for dental education.

Diagnostic testing of cervical vertebral maturation staging: An independent assessment.

INTRODUCTION: The reliability of the cervical vertebral maturation (CVM) method has been questioned. The objective of this research was to evaluate the diagnostic reliability of the CVM method to diagnose the mandibular growth spurt using longitudinal records from an alternative database (Iowa Facial Growth Study [IFGS]) using established diagnostic testing methods. METHODS: Cephalometric films from 43 subjects (males = 20, females = 23) with Class I or Class II skeletal pattern from the IFGS were scanned, digitized, and adjusted for magnification. At least 5 consecutive, annual films were digitized. For each subject, mandibular length (Co-Gn) was measured for each film, and the growth increment between films was calculated. The largest growth increment was the growth spurt. For each subject, the film displaying CVM stage 3 was identified by a blinded examiner viewing the films in random order. Interrater and intrarater repeatability for Co-Gn (intraclass correlation) and CVM staging (weighted kappa) were calculated. Diagnostic tests, including sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were carried out. The present data were compared with data previously derived from samples of the University of Michigan, Oregon, and Burlington Growth studies (UMGS, OGS, and BGS, respectively). A multilevel logistic regression analysis was also run with the mandibular growth peak as the response variable. RESULTS: Interrater repeatability for mandibular measurements (intraclass correlation coefficient [ICC] = 0.91) and CVM staging (k = 0.88) were excellent. Intrarater repeatability for mandibular measurements (ICC = 0.98) and CVM staging (kw = 0.55) were excellent to moderate. The UMGS data demonstrated higher sensitivity with comparable specificity. Accuracy was largely similar. Their PPV and NPV had larger ranges. The OGS and BGS data, compared with the IFGS data, showed that our sensitivity and PPVs were higher, that their specificity was higher, and that the NPV and accuracy were very similar. The regression analysis was applied to age groups 10-11 years through 13-14 years. Only chronological age was significant (P = 0.04). CONCLUSIONS: Agreement between CVM stage 3 and the maximum mandibular growth spurt is inconsistent. The diagnostic capability of CVM for the mandibular growth spurt is questionable.

The effect of dental and background facial attractiveness on facial attractiveness and perceived integrity and social and intellectual qualities.

INTRODUCTION: The purposes of this study were to assess the role of dental attractiveness in background facial attractiveness and to evaluate how facial and dental attractiveness influenced raters' opinions of the integrity, social attractiveness, and intellectual attractiveness of the models. METHODS: Photographs of male and female individuals rated by peers as unattractive, average, and attractive were combined with oral images of 4 different levels of dental attractiveness (Index of Orthodontic Treatment Need [IOTN] 1, 5, 7, and 10). Sixty-seven participants meeting the inclusion criteria were recruited as raters. Raters viewed closed-lip smile and open-lip, posed smile of 24 models and rated them for facial attractiveness and integrity and multiple social/intellectual attractiveness dimensions using a Visual Analog Scale. RESULTS: Intrarater reliability was fair to excellent. Analysis of variance showed significant 3-way interactions (P < 0.0001=aim 1; P < 0.005=aim 2) for model sex, facial attractiveness, and dental attractiveness. The contribution of dental attractiveness to facial attractiveness was not fixed or linear, but dependent on dental attractiveness level, background facial attractiveness, and model sex. For both sexes, dental impact on facial attractiveness was neutral or negative when teeth were less than ideal, beginning at IOTN 5 for all background facial attractiveness levels. The impact of dental attractiveness on integrity and social and intellectual attractiveness was also dependent on dental attractiveness level, background facial attractiveness, and model sex. Dental attractiveness can make dramatic differences in Average and Attractive male individuals. CONCLUSIONS: The impact of dental attractiveness on facial attractiveness and integrity and social and intellectual attractiveness was dependent on dental attractiveness level, background facial attractiveness, and model sex. The effect of dental esthetics on facial attractiveness was neutral or negative for both male and female individuals when there was a need for treatment (IOTN 5 or higher) for all levels of facial attractiveness. For both male and female models, lower dental esthetics had a greater effect on more attractive faces. Judgments about integrity and social and intellectual attractiveness were strongly affected by dental esthetics, and these effects were more dramatic and consistent for male faces.

Associations of pretreatment parameters with changes during orthodontic treatment.

OBJECTIVES: To examine whether pretreatment conditions of a patient can determine alveolar bone changes after orthodontic treatment. SETTING AND SAMPLE POPULATION: Cone beam computed tomography (CBCT) images were obtained from 44 patients (17 male and 27 female, 14.02 ± 1.29 years). MATERIAL AND METHODS: Buccal bone height (BBH), buccal bone thickness (BBT), and molar angulation (MA) of right and left maxillary molars and intermolar distance (ID) were measured using the CBCT images obtained before and after orthodontic treatment using conventional brackets and self-ligating conventional brackets. RESULTS: There was a significant change only in BBH after treatment. All posttreatment parameters had significant positive correlations with the corresponding pretreatment parameters (r2  = 0.376-0.719, P < 0.001). Most of the changes had significant negative correlations with the corresponding pretreatment parameter (r2  = 0.054-0.249, P < 0.03). The results were not significantly influenced by the different bracket types. CONCLUSION: The current findings suggest that the CBCT-based morphological information about dentition and oral bone conditions of patients can provide a better pretreatment plan to estimate the results of orthodontic treatment.

Clinical Integration in a Dental School Clinic Through an Enhanced Patient Intake Process.

Dental care in the U.S. is based on a general practice model of care delivery that can be enhanced by the integration of the dentists and allied dental professionals. There are 25 U.S. dental schools with associated dental hygiene programs, presenting distinctive opportunities for educating the dental health care team. Integrated educational clinical experiences are believed to positively influence teamwork and quality of care that parallels the authentic general practice environment. Lean management, developed by Toyota and used in a variety of types of organizations including health care, provides a distinctive blend of engineering principles and operations management to enhance business and operations processes. A fundamental principle of Lean management is the elimination of waste and preservation of only those value-added components of a process. The faculty and staff of The Ohio State University College of Dentistry, trained in Lean process improvement, applied techniques to enhance and integrate an inefficient patient intake (admissions) process. The aim of this initiative was to improve patient throughput in the patient intake process and to provide dental and dental hygiene students with enhanced educational experiences from improved clinical integration. These goals were achieved through streamlining patient flow and relocating major phases of the process. Although new patient retention and cancellation/no-show rates remained mostly unchanged, this enhancement project resulted in improved access to care, improved continuity of care, expanded scope of dental services offered, improved patient satisfaction, and enhanced dental and dental hygiene student collaboration and teamwork. These outcomes suggest that process improvement initiatives can serve as valuable opportunities for integration of the dental health care team.

The Effects of Primary Canine Loss on Permanent Lower Dental Midline Stability.

Purpose: The purpose of this study was to compare changes in the lower dental midline position after premature unilateral loss of a primary mandibular canine with dental midline position after normal primary mandibular canine exfoliation. Methods: Dental casts were identified from growth studies at the University of Iowa and the University of Toronto. Two groups of dental casts were identified: (1) premature unilateral loss; and (2) normal asymmetric exfoliation of a single primary mandibular canine. The first set of casts displaying unilateral primary canine loss (time one) and the second set of casts displaying full permanent dentition (time two) were collected. The palatal rugae and palatal raphe were used to construct a median palatal plane (MPP). Dental midline position at each time point was measured from the MPP. Results: A total of 56 cases (15 premature, 41 normal) were identified. The mean lower dental midline changes from time one to time two for the premature and normal loss groups were 1.32±0.83 mm and 0.97±0.91 mm, respectively. This difference was not statistically significant regarding group (P=0.62), gender (P=0.91), or the interaction effect of group and gender (P=0.85). Conclusions: There was no significant difference in midline shift between the 15 individuals with premature unilateral primary canine loss and the 41 individuals with normal, asymmetric unilateral loss of a primary canine.

Development and Implementation of a Uniform Dental School-Wide Electronic Treatment Consenting Process for Patients.

One approach to enhancing quality care outcomes and patient safety is through effective implementation of clinical risk reduction strategies. Clinical risk identification at The Ohio State University College of Dentistry revealed lack of a standardized informed consenting process for patients. The purpose of this project was to develop and implement a uniform college-wide informed consenting process. An operating procedure was also developed. The resulting consenting documents used a uniform approach in which clinics could use a basic readable and processable informed consent template. The template was edited for appropriate content suitable for an electronic health record. Implementing an operating procedure along with associated contemporary uniform electronic informed consent forms was realized through efforts of a core team with informed consenting experience. The core team developed the template and the majority of all documents before editing all division-based consents. This method relied on growing expertise and momentum. Outcomes of chart audits following implementation of the new electronic informed consent forms showed a transitory increase in missing consent forms. Subsequently, the number of missing consent forms decreased to near pre-implementation levels. Patient refunds related to missing informed consent issues dropped, and patient satisfaction remained high throughout the project. Other institutions can use this project as a guide for developing their own uniform consent forms and process.

Objective assessment of the contribution of dental esthetics and facial attractiveness in men via eye tracking.

INTRODUCTION: Recently, greater emphasis has been placed on smile esthetics in dentistry. Eye tracking has been used to objectively evaluate attention to the dentition (mouth) in female models with different levels of dental esthetics quantified by the aesthetic component of the Index of Orthodontic Treatment Need (IOTN). This has not been accomplished in men. Our objective was to determine the visual attention to the mouth in men with different levels of dental esthetics (IOTN levels) and background facial attractiveness, for both male and female raters, using eye tracking. METHODS: Facial images of men rated as unattractive, average, and attractive were digitally manipulated and paired with validated oral images, IOTN levels 1 (no treatment need), 7 (borderline treatment need), and 10 (definite treatment need). Sixty-four raters meeting the inclusion criteria were included in the data analysis. Each rater was calibrated in the eye tracker and randomly viewed the composite images for 3 seconds, twice for reliability. RESULTS: Reliability was good or excellent (intraclass correlation coefficients, 0.6-0.9). Significant interactions were observed with factorial repeated-measures analysis of variance and the Tukey-Kramer method for density and duration of fixations in the interactions of model facial attractiveness by area of the face (P <0.0001, P <0.0001, respectively), dental esthetics (IOTN) by area of the face (P <0.0001, P <0.0001, respectively), and rater sex by area of the face (P = 0.0166, P = 0.0290, respectively). For area by facial attractiveness, the hierarchy of visual attention in unattractive and attractive models was eye, mouth, and nose, but for men of average attractiveness, it was mouth, eye, and nose. For dental esthetics by area, at IOTN 7, the mouth had significantly more visual attention than it did at IOTN 1 and significantly more than the nose. At IOTN 10, the mouth received significantly more attention than at IOTN 7 and surpassed the nose and eye. These findings were irrespective of facial attractiveness levels. For rater sex by area in visual density, women showed significantly more attention to the eyes than did men, and only men showed significantly more attention to the mouth over the nose. CONCLUSIONS: Visual attention to the mouth was the greatest in men of average facial attractiveness, irrespective of dental esthetics. In borderline dental esthetics (IOTN 7), the eye and mouth were statistically indistinguishable, but in the most unesthetic dental attractiveness level (IOTN 10), the mouth exceeded the eye. The most unesthetic malocclusion significantly attracted visual attention in men. Male and female raters showed differences in their visual attention to male faces. Laypersons gave significant visual attention to poor dental esthetics in men, irrespective of background attractiveness; this was counter to what was seen in women.

Comparison of digital intraoral scanners and alginate impressions: Time and patient satisfaction.

INTRODUCTION: Recent technological advances have made intraoral scans and digital models a possibility and a promising alternative to conventional alginate impressions. Several factors should be examined when considering an intraoral scanner, including patient acceptance and efficiency. The objectives of this study were to assess and compare patient satisfaction and time required between 2 intraoral scanners and conventional alginate impressions. METHODS: An initial pilot study was completed to create a valid and reliable survey instrument that would measure 3 areas of patient satisfaction with the impression experience. A visual analog scale survey was developed and administered to 180 orthodontic patients receiving 1 of 3 types of impressions: (1) iTero Element intraoral scan (Align Technologies, San Jose, Calif), n = 60; (2) TRIOS Color intraoral scan (3Shape, Copenhagen, Denmark), n = 60; and (3) conventional alginate impression (imprEssix Color Change; Dentsply Sirona, York, Pa), n = 60, and the time required to obtain the impressions was recorded. RESULTS: Reliability was evaluated with intraclass correlation coefficient values for 17 paired questionnaires, and all questions were found to be reliable (intraclass correlation coefficient, ≥0.65). For the main study, 180 subjects completed timed impressions and surveys. Data indicated that subjects receiving intraoral scans preferred the digital impressions, and subjects receiving alginate impressions were neutral regarding impression preference, and that efficiency varied based on the impression method. CONCLUSIONS: Intraoral scanners are accepted by orthodontic patients, and they have comparable efficiency with conventional impression methods depending on the type of scanner.

Comparison of changes in irregularity and transverse width with nickel-titanium and niobium-titanium-tantalum-zirconium archwires during initial orthodontic alignment in adolescents: A double-blind randomized clinical trial.

OBJECTIVES: The purpose of this prospective, double-blind, randomized clinical trial was to compare the clinical efficiency of nickel-titanium (NiTi) and niobium-titanium-tantalum-zirconium (TiNbTaZr) archwires during initial orthodontic alignment. MATERIALS AND METHODS: All subjects (ages between 12 and 20 years) underwent nonextraction treatment using 0.022-inch brackets. All patients were randomized into two groups for initial alignment with 0.016-inch NiTi archwires (n = 14), or with 0.016-inch TiNbTaZr archwires (n = 14). Digital scans were taken during the course of treatment and were used to compare the improvement in Little's Irregularity Index and the changes in intercanine and intermolar widths. RESULTS: There was approximately a 27% reduction in crowding during the first month with the use of 0.016-inch TiNbTaZr (Gummetal) wire, and an additional 25% decrease in crowding was observed during the next month. There was no significant difference between the two treatment groups in the decrease in irregularity over time ( P = .29). There was no significant difference between the two groups in the changes in intercanine and intermolar width ( P = .80). CONCLUSIONS: It can be concluded that Gummetal wires and conventional NiTi wires possess a similar ability to align teeth, and Gummetal wires have additional advantages over conventional NiTi, such as formability and use in patients with nickel allergy.

Evaluation of objective structured clinical examination for advanced orthodontic education 12 years after introduction.

INTRODUCTION: Advanced education programs in orthodontics must ensure student competency in clinical skills. An objective structure clinical examination has been used in 1 program for over a decade. The results were analyzed cross-sectionally and longitudinally to provide insights regarding the achievement of competency, student growth, question difficulty, question discrimination, and question predictive ability. METHODS: In this study, we analyzed 218 (82 first-year, 68 second-year, and 68 third-year classes) scores of each station from 85 orthodontic students. The grades originated from 13 stations and were collected anonymously for 12 consecutive years during the first 2 decades of the 2000s. The stations tested knowledge and skills regarding dental relationships, analyzing a cephalometric tracing, performing a diagnostic skill, identifying cephalometric points, bracket placement, placing first-order and second-order bends, forming a loop, placing accentuated third-order bends, identifying problems and planning mixed dentition treatment, identifying problems and planning adolescent dentition treatment, identifying problems and planning nongrowing skeletal treatment, superimposing cephalometric tracings, and interpreting cephalometric superimpositions. Results were evaluated using multivariate analysis of variance, chi-square tests, and latent growth analysis. RESULTS: The multivariate analysis of variance showed that all stations except 3 (analyzing a cephalometric tracing, forming a loop, and identifying cephalometric points) had significantly lower mean scores for the first-year student class than the second- and third-year classes (P <0.028); scores between the second- and third-year student classes were not significantly different (P >0.108). The chi-square analysis of the distribution of the number of noncompetent item responses decreased from the first to the second years (P <0.0003), from the second to the third years (P <0.0042), and from the first to the third years (P <0.00003). The latent growth analysis showed a wide range of difficulty and discrimination between questions. It also showed continuous growth for some areas and the ability of 6 questions to predict competency at greater than the 80% level. CONCLUSIONS: Objective structure clinical examinations can provide a method of evaluating student performance and curriculum impact over time, but cross-sectional and longitudinal analyses of the results may not be complementary. Significant learning appears to occur during all years of a 3-year program. Valuable questions were both easy and difficult, discriminating and not discriminating, and came from all domains: diagnostic, technical, and evaluation/synthesis.

Evaluation of Invisalign treatment effectiveness and efficiency compared with conventional fixed appliances using the Peer Assessment Rating index.

INTRODUCTION: The purpose of this retrospective case-control study was to compare the treatment effectiveness and efficiency of the Invisalign system with conventional fixed appliances in treating orthodontic patients with mild to moderate malocclusion in a graduate orthodontic clinic. METHODS: Using the peer assessment rating (PAR) index, we evaluated pretreatment and posttreatment records of 48 Invisalign patients and 48 fixed appliances patients. The 2 groups of patients were controlled for general characteristics and initial severity of malocclusion. We analyzed treatment outcome, duration, and improvement between the Invisalign and fixed appliances groups. RESULTS: The average pretreatment PAR scores (United Kingdom weighting) were 20.81 for Invisalign and 22.79 for fixed appliances (P = 1.0000). Posttreatment weighted PAR scores between Invisalign and fixed appliances were not statistically different (P = 0.7420). On average, the Invisalign patients finished 5.7 months faster than did those with fixed appliances (P = 0.0040). The weighted PAR score reduction with treatment was not statistically different between the Invisalign and fixed appliances groups (P = 0.4573). All patients in both groups had more than a 30% reduction in the PAR scores. Logistic regression analysis indicated that the odds of achieving "great improvement" in the Invisalign group were 0.329 times the odds of achieving "great improvement" in the fixed appliances group after controlling for age (P = 0.0150). CONCLUSIONS: Our data showed that both Invisalign and fixed appliances were able to improve the malocclusion. Invisalign patients finished treatment faster than did those with fixed appliances. However, it appears that Invisalign may not be as effective as fixed appliances in achieving "great improvement" in a malocclusion. This study might help clinicians to determine appropriate patients for Invisalign treatment.

Role of facial attractiveness in patients with slight-to-borderline treatment need according to the Aesthetic Component of the Index of Orthodontic Treatment Need as judged by eye tracking.

INTRODUCTION: Previous eye-tracking research has demonstrated that laypersons view the range of dental attractiveness levels differently depending on facial attractiveness levels. How the borderline levels of dental attractiveness are viewed has not been evaluated in the context of facial attractiveness and compared with those with near-ideal esthetics or those in definite need of orthodontic treatment according to the Aesthetic Component of the Index of Orthodontic Treatment Need scale. Our objective was to determine the level of viewers' visual attention in its treatment need categories levels 3 to 7 for persons considered "attractive," "average," or "unattractive." METHODS: Facial images of persons at 3 facial attractiveness levels were combined with 5 levels of dental attractiveness (dentitions representing Aesthetic Component of the Index of Orthodontic Treatment Need levels 3-7) using imaging software to form 15 composite images. Each image was viewed twice by 66 lay participants using eye tracking. Both the fixation density (number of fixations per facial area) and the fixation duration (length of time for each facial area) were quantified for each image viewed. Repeated-measures analysis of variance was used to determine how fixation density and duration varied among the 6 facial interest areas (chin, ear, eye, mouth, nose, and other). RESULTS: Viewers demonstrated excellent to good reliability among the 6 interest areas (intraviewer reliability, 0.70-0.96; interviewer reliability, 0.56-0.93). Between Aesthetic Component of the Index of Orthodontic Treatment Need levels 3 and 7, viewers of all facial attractiveness levels showed an increase in attention to the mouth. However, only with the attractive models were significant differences in fixation density and duration found between borderline levels with female viewers. Female viewers paid attention to different areas of the face than did male viewers. CONCLUSIONS: The importance of dental attractiveness is amplified in facially attractive female models compared with average and unattractive female models between near-ideal and borderline-severe dentally unattractive levels.

Primary stability and viscoelastic displacement of mini-implant system under loading.

BACKGROUND: The objectives of the current study were to examine the effects of mini-implant diameters on 1) primary stability before bone properties are changed by active peri-implant bone remodeling and 2) the time-dependent displacement of mini-implant systems in bone under a functional radial loading and their associations with bone mineral density. METHODS: Twenty one, 8mm length mini-implants (7 each for 1.4mm, 1.6mm, and 2mm diameters) were placed in mandibular sections of human cadavers (4 males and 3 females, average 69.7 (SD 13.1) years of age). Displacement of the mini-implant in wet bone was assessed during initial and subsequent continuous radial loading of 2N in the mediolateral direction for 2h. Mean, standard deviation and coefficient of variation of peri-implant bone mineral density were obtained using histograms of cone-beam computed tomography attenuation values. The cortical thickness along with the miniscrew site was also measured. FINDINGS: The primary stability and displacement of mini-implants in bone were not significantly different between the 3 diameter groups (p>0.147, n=21). Moderate positive correlations of time-dependent viscoelastic displacement (creep) were found with bone mineral density variability independent of the mini-implant diameters (p>0.11). INTERPRETATION: The post-implantation displacements of mini-implant suggested that the orthodontic treatment loading can develop micromotion between the mini-implant and surrounding bone leading to reduction of its primary stability. Current findings also provide an insight that peri-implant bone mineral density variability plays an important role in controlling displacement of the mini-implant, which determine its stability during early and prolonged orthodontic treatment loading periods.