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.

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.

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.

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.

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.

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.

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.

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.

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.

Comparison of cone-beam computed tomography with multislice computed tomography in detection of small osseous condylar defects.

INTRODUCTION: Previous studies have indicated that orthodontic-grade cone-beam computed tomography (CBCT) images are limited when displaying small defects at the mandibular condyles for diagnosis. In this study, we investigated whether this limitation was inherent to CBCT by comparing CBCT with multislice computed tomography (CT), and whether image segmentation and color mapping could overcome this limitation. METHODS: Nine fresh pig heads (18 condyles, 36 medial and lateral condylar regions) were used. Small osseous defects (diameter and depth, 1.5 mm) were created at the medial and lateral regions of the condyles shown by gutta percha markers. After the overlying soft tissues were restored, the pig heads underwent orthodontic-grade CBCT scans (0.4-mm voxel size; i-CAT; Imaging Sciences International, Hatfield, Pa) and medical-grade CT scans (0.625-mm voxel size; LightSpeed; GE, Little Chalfont, Buckinghamshire, United Kingdom). Subsequently, 2 calibrated and blinded raters diagnosed the defect numbers in each condylar region from CBCT and CT images using Dolphin 3D software (Patterson Supply, St Paul, Minn) without image segmentation, and then 1 week later with the proprietary image segmentation and color mapping tools of Dolphin 3D. Condylar polyvinyl siloxane impressions were collected and evaluated by the same raters to obtain physical diagnoses. Rediagnoses were made on randomly selected subsamples to assess reliability. Using the physical diagnoses as references, the accuracy of imaging diagnosis was assessed and statistically compared among the varied imaging and analysis methods. RESULTS: Image diagnoses of all imaging and analysis methods showed good or excellent intrarater and interrater reliability values, except for those of the segmented CBCT images, which were substantially lower. The numbers of overdiagnoses and underdiagnoses per condylar region were not significantly different among the varied imaging and analysis methods (Wilcoxon tests, P >0.05), but classification functions demonstrated substantially lower sensitivity and accuracy with CBCT than with CT. Logistic regression also showed that CT had a significantly higher probability (odds ratio, 2.4) than CBCT in reaching the correct diagnosis, whereas use of the image segmentation and color mapping tool proprietary to Dolphin 3D did not improve the diagnostic accuracy from CBCT images. CONCLUSIONS: Even at a lower voxel size than medical CT images, orthodontic-grade CBCT images of mandibular condyles may be inherently less reliable and less accurate for the diagnosis of small condylar defects.

Effect of minocycline on induced glial activation by experimental tooth movement.

INTRODUCTION: Orthodontic tooth movement causes pain to a patient. Glial cells are nonneuronal cells in the central nervous system and are implicated in various types of pain. In this study, we assessed glial activation responses after experimental tooth movement using immunocytochemical detection of anti-CD11b (OX42) and glial fibrillary acidic protein immunoreactivity to illustrate the microglial and astrocytes response, respectively. In addition, the effect of minocycline in reducing pain during tooth movement was also investigated. METHODS: Fifty-five Sprague Dawley rats with and without administration of minocycline after 1, 3, 5, 7, and 14 days (n = 5, for each) of tooth movement were used. Immunohistochemistry for microglia (OX42) and astrocyte (glial fibrillary acidic protein) were performed at the medullary dorsal horn (trigeminal subnucleus caudalis). Three-dimensional quantitative analysis was performed with a confocal fluorescence microscope and a software program. RESULTS: There was a significant increase in the OX42 and glial fibrillary acidic protein immunoreactivity in response to tooth movement in the medullary dorsal horn. Furthermore, systematic administration of minocycline, a selective inhibitor of microglial activation, significantly attenuated the nociceptive c-Fos expression in the medullary dorsal horn that was induced by experimental tooth movement. CONCLUSIONS: These data indicate the possible importance of microglial activation in the development of orthodontic pain. This is also the first report on the systematic application of minocycline.

Orthodontic informed consent considering information load and serial position effect.

INTRODUCTION: Previous research has demonstrated that current methods of informed consent are relatively ineffective as shown by poor recall and comprehension by adolescent patients and their parents. The purpose of this study was to determine whether adding a short videotape presentation reiterating the issues related to informed consent to a modified informed consent document that emphasizes a limited number of core and patient-specific custom "chunks" at the beginning of an informed consent presentation improved the recall and comprehension of the risks, benefits, and alternatives of orthodontic treatment. A second objective was to evaluate the current related data for recommendable practices. METHODS: Seventy patient-parent pairs were randomly divided into 2 groups. The intervention group (group A) patients and parents together reviewed a customized slide show and a short videotape presentation describing the key risks of orthodontic treatment. Group B followed the same protocol without viewing the videotape. All patients and parents were interviewed independently by research assistants using an established measurement tool with open-ended questions. Interviews were transcribed and scored for the appropriateness of responses using a previously established codebook. Lastly, the patients and parents were given 2 reading literacy tests, 1 related to health and 1 with general content followed by the self-administered demographic and psychological state questionnaires. RESULTS: There were no significant differences between the groups for sociodemographic variables. There were no significant differences between the groups for overall recall and comprehension; recall and comprehension for the domains of treatment, risk, and responsibility; and recall and comprehension for core, general, and custom items. The positional effects were limited in impact. When compared with previous studies, these data further demonstrate the benefit of improved readability and audiovisual supplementation with the addition of "chunking." CONCLUSIONS: There is no benefit to adding a short video to the previously established improved readability and audiovisual supplementation. There is a significant benefit of improved readability and audiovisual slide supplementation with the addition of "chunking" over traditional informed consent methods in terms of patient improvement in overall comprehension, treatment recall, and treatment comprehension. The treatment domain is the most affected.

Contribution of malocclusion and female facial attractiveness to smile esthetics evaluated by eye tracking.

INTRODUCTION: There is disagreement in the literature concerning the importance of the mouth in overall facial attractiveness. Eye tracking provides an objective method to evaluate what people see. The objective of this study was to determine whether dental and facial attractiveness alters viewers' visual attention in terms of which area of the face (eyes, nose, mouth, chin, ears, or other) is viewed first, viewed the greatest number of times, and viewed for the greatest total time (duration) using eye tracking. METHODS: Seventy-six viewers underwent 1 eye tracking session. Of these, 53 were white (49% female, 51% male). Their ages ranged from 18 to 29 years, with a mean of 19.8 years, and none were dental professionals. After being positioned and calibrated, they were shown 24 unique female composite images, each image shown twice for reliability. These images reflected a repaired unilateral cleft lip or 3 grades of dental attractiveness similar to those of grades 1 (near ideal), 7 (borderline treatment need), and 10 (definite treatment need) as assessed in the aesthetic component of the Index of Orthodontic Treatment Need (AC-IOTN). The images were then embedded in faces of 3 levels of attractiveness: attractive, average, and unattractive. During viewing, data were collected for the first location, frequency, and duration of each viewer's gaze. RESULTS: Observer reliability ranged from 0.58 to 0.92 (intraclass correlation coefficients) but was less than 0.07 (interrater) for the chin, which was eliminated from the study. Likewise, reliability for the area of first fixation was kappa less than 0.10 for both intrarater and interrater reliabilities; the area of first fixation was also removed from the data analysis. Repeated-measures analysis of variance showed a significant effect (P <0.001) for level of attractiveness by malocclusion by area of the face. For both number of fixations and duration of fixations, the eyes overwhelmingly were most salient, with the mouth receiving the second most visual attention. At times, the mouth and the eyes were statistically indistinguishable in viewers' gazes of fixation and duration. As the dental attractiveness decreased, the visual attention increased on the mouth, approaching that of the eyes. AC-IOTN grade 10 gained the most attention, followed by both AC-IOTN grade 7 and the cleft. AC-IOTN grade 1 received the least amount of visual attention. Also, lower dental attractiveness (AC-IOTN 7 and AC-IOTN 10) received more visual attention as facial attractiveness increased. CONCLUSIONS: Eye tracking indicates that dental attractiveness can alter the level of visual attention depending on the female models' facial attractiveness when viewed by laypersons.

Evaluation of cone-beam computed tomography in the diagnosis of simulated small osseous defects in the mandibular condyle.

INTRODUCTION: In this study, we investigated the impact of defect size and scan voxel size on the accuracy of cone-beam computed tomography (CBCT) diagnoses of simulated condylar defects and assessed the value of orthodontic CBCT images typically scanned at lower settings (0.4-mm voxel size and full-size field of view) in diagnosing condylar erosion defects. METHODS: Cylindrical holes simulating condylar defects with varied diameters (≤2, 2-3, and >3 mm) and depths (≤2 and >2 mm) were created in 22 fresh pig mandibular condyles, with defect number and size per condyle and quadrant randomly determined. With the soft tissues repositioned, 2 CBCT scans (voxel sizes, 0.4 and 0.2 mm) of the pig heads were obtained from an i-CAT unit (Imaging Science International, Hatfield, Pa). Reconstructed CBCT data were analyzed independently by 2 calibrated, blinded raters using Dolphin-3D (Dolphin Imaging and Management Solutions, Chatsworth, Calif) for defect identification and localization and defect diameter and depth measurements, which were compared with physical diagnoses obtained from polyvinyl siloxane impressions. RESULTS: Identification and localization of simulated defects demonstrated moderate interrater reliability and excellent specificity and sensitivity, except for extremely small defects (both diameter and depth ≤2 mm) viewed with 0.4-mm scans, which had a significantly lower sensitivity (67.3%). Geometric measurements of simulated defects demonstrated good but not excellent interrater reliability and submillimeter inaccuracy for all defects. Receiver operating characteristic analyses demonstrated that the overall accuracy of diagnosing simulated condylar defects based on CBCT geometric measurements was fair and good for the 0.4-mm and 0.2-mm voxel-size scans, respectively. With the prevalence of condylar erosion defects in the patients considered, the positive predictive values of diagnoses based on 0.5-mm size (diameter or depth) cutoff points were near 15% and 50% for asymptomatic and symptomatic temporomandibular joints, respectively; the negative predictive values were near 95% and 90%, respectively. CONCLUSIONS: When using orthodontic CBCT images for diagnosing condylar osseous defects, extremely small (<2 mm) defects can be difficult to detect; caution is also needed for the diagnostic accuracy of positive diagnoses, especially those from asymptomatic temporomandibular joints.

Cervical vertebral bone mineral density changes in adolescents during orthodontic treatment.

INTRODUCTION: The cervical vertebral maturation (CVM) stages have been used to estimate facial growth status. In this study, we examined whether cone-beam computed tomography images can be used to detect changes of CVM-related parameters and bone mineral density distribution in adolescents during orthodontic treatment. METHODS: Eighty-two cone-beam computed tomography images were obtained from 41 patients before (14.47 ± 1.42 years) and after (16.15 ± 1.38 years) orthodontic treatment. Two cervical vertebral bodies (C2 and C3) were digitally isolated from each image, and their volumes, means, and standard deviations of gray-level histograms were measured. The CVM stages and mandibular lengths were also estimated after converting the cone-beam computed tomography images. RESULTS: Significant changes for the examined variables were detected during the observation period (P ≤0.018) except for C3 vertebral body volume (P = 0.210). The changes of CVM stage had significant positive correlations with those of vertebral body volume (P ≤0.021). The change of the standard deviation of bone mineral density (variability) showed significant correlations with those of vertebral body volume and mandibular length for C2 (P ≤0.029). CONCLUSIONS: The means and variability of the gray levels account for bone mineral density and active remodeling, respectively. Our results indicate that bone mineral density distribution and the volume of the cervical vertebral body changed because of active bone remodeling during maturation.

Effects of orthodontic treatment on human alveolar bone density distribution.

OBJECTIVES: The objective of this study was to examine if non-invasive clinical cone beam computed tomography (CBCT)-based degree of bone mineralization (DBM) measurement can be used to detect the different results from orthodontic treatment between the maxilla and mandible in human patients. MATERIALS AND METHODS: CBCT images were taken before and after orthodontic treatment from 43 patients (19 males and 24 females, 14.36 ± 1.50 years). A histogram of computed tomography (CT) attenuation value, which is equivalent to the DBM, was obtained from the alveolar cortical (AC), trabecular (AT), and enamel (E) regions of each image. Mean, standard deviation (SD), and coefficient of variation (COV) of the CT attenuation values were computed. The regional variations and percentage (%) differences between the E and alveolar regions of the CT attenuation parameters at the maxilla and mandible were analyzed before and after orthodontic treatment. RESULTS: The AC had higher mean and variability (SD and COV) than the AT before and after treatment (p < 0.001). The variability was higher in the mandibular AC than in the maxillar AC (p < 0.01) independent of orthodontic treatment. The percentage (%) difference of variability of CT attenuation values changed for both AT and AC in the maxilla after orthodontic treatment, while that changed for only the AT (p < 0.02), but not for AC, in the mandible (p > 0.16). CONCLUSIONS: The alveolar cortical region of the mandible responded differently to orthodontic treatment compared with other alveolar regions. CLINICAL RELEVANCE: The CBCT-based DBM analysis can be used clinically to assess alveolar bone quality changes induced by orthodontic treatment to improve treatment planning and result evaluation.

Etiologic factors for buccal and palatal maxillary canine impaction: a perspective based on cone-beam computed tomography analyses.

INTRODUCTION: The aim of this research was to identify the etiologic factors associated with palatally impacted canines and buccally impacted canines in a Chinese population by using the cone-beam computed tomography technique. METHODS: Pretreatment cone-beam computed tomography scans of 170 Chinese subjects with impacted maxillary canines and 170 age- and sex-matched subjects without impaction were used. Impacted canine subjects were divided into 2 groups: those with palatally impacted canines and those with buccally impacted canines. One rater analyzed the cone-beam computed tomography data for qualitative and quantitative variables of the teeth, dental arch, and skeletal components. The measurements were compared by using analytical statistical methods. RESULTS: The mesiodistal dimension of the lateral incisor was significantly smaller in the palatally impacted canine group than in the other group (by an average of 0.4-0.5 mm; analysis of variance [ANOVA], P <0.001). Both anterior maxillary dental (interpremolar) width and skeletal width (interjugal points) in the buccally impacted canine group were significantly smaller than in the palatally impacted canine and control groups (ANOVA, P <0.001), whereas the intermolar widths and posterior mandibular widths were similar among the groups. The groups with palatally impacted or buccally impacted canines had significantly increased prevalence values of peg-shaped lateral incisors and incisor impaction, respectively (chi-square or Fisher exact tests, P <0.001). After excluding subjects who also had lateral incisor anomalies, the prevalence values of supernumerary teeth, missing premolars, or third molars combined were not different among the impaction and control groups. The average mesiodistal location of the canine cusp tip was significantly different between the buccally impacted canines and the palatally impacted canines groups; it was distal and mesial to the lateral incisor long axis, respectively. CONCLUSIONS: In Chinese subjects, buccal canine impaction is mostly associated with anterior transverse (dental and skeletal) deficiency and incisor impaction, whereas palatal impaction is mostly associated with small or missing lateral incisors, consistent with the guidance theory. Likely, preimpaction migrations of the canines are mainly buccal for buccal impactions and excessively mesiopalatal for palatal impactions.