Introduction: Transverse occlusal plane (TOP) should be parallel to the true horizontal lines of the face (ie, the interpupillary line [IP] and commissural line [CL]). This study aimed to investigate the opinions of laypersons, orthodontists, and oral and maxillofacial surgeons about the impact of imbalanced IP and CL on facial attractiveness. Methods: We used a symmetrical face image as the reference. Then, using Photoshop software, we constructed the following 6 photographs: TOP roll relative to CL and IP (3 & DEG; and 6 & DEG;) with parallelism of CL and IP, CL roll relative to TOP and IP (3 & DEG; and 6 & DEG;) with parallelism of TOP and IP, TOP and CL roll relative to IP (3 & DEG; and 6 & DEG;). Consequently, the participants rated the photographs on the basis of their attractiveness. Kruskal-Wallis and Mann-Whitney U tests were used to compare the ratings. Results: One hundred thirtyone laypersons, 22 orthodontists, and 20 surgeons participated in this study. It was found that 51.1% of laypersons, 86.4% of orthodontists, and 70% of surgeons selected the reference photograph as the most beautiful, followed by the photograph with a 3 & DEG; roll of CL relative to TOP, with parallelism of TOP and IP (29% of laypersons, 31.8% of orthodontists, and 35% of surgeons). Conclusions: Most participants selected the reference photograph as the most beautiful and realized a roll in the horizontal planes up to 3 & DEG;. The parallelism of the esthetic line of dentition relative to interpupillary is preferred over its parallelism relative to CL. (Am J Orthod Dentofacial Orthop 2023;164:386-94)
Background: Exams are an inseparable part of education, and they are the main tool to evaluate the results of educational process. If based on scientific rules, exams can show the level of achievement to educational goals. Objectives: This study aimed to evaluate the quality of orthodontic exams in Shahid Beheshti Dental School, Iran. Methods: In this cross-sectional study, the quality of all written and multiple-choice questions (MCQ) exams of orthodontic department in 2014 - 2015 were evaluated in terms of content validity, structural rules, discrimination index, difficulty index, and taxonomy. To collect the data, the Millman checklist, content analysis table, and standard formula were used. SPSS software version 21 was used to analyze the data. T-test, chi square, and independent sample test were used for statistical analysis. Results: Our results showed that 86.55% of exams were in MCQ form and 13.5% in written form. Content validity was considered in 94.8% of exams. Standard structural rules were observed in 93.61% of questions. Discriminative index and difficulty index were estimated to be 41.6 and 68.8%, respectively. Also, 43.7% of questions were categorized as taxonomy I, 44.38% as taxonomy II, and 11.58% as taxonomy III. Conclusions: Exams held in Shahid Beheshti Dental School in the 2014 - 2015 academic year were acceptable considering their content validity, structural rules, and difficulty index. However, their discrimination index was low, and they were in poor conditions in terms of taxonomy.
INTRODUCTION:This study aimed to evaluate the ability of dental clinicians to predict posttreatment dental arch forms in patients with malocclusion with the aid of 3D imaging and digital software in comparison with a conventional method. METHODS:Pretreatment and posttreatment dental plaster casts of 100 patients (200 maxillary models and 200 mandibular models) were selected. Three orthodontists selected the best-fitted archwires among 5 commercially available preformed nickel-titanium archwires using 2 methods. In the conventional method, they fit the archwires to pretreatment casts, and in the digital method, they fit the scanned wire to a 3D digital model, using Ortho-Aid, a locally developed 3D software, using clinical bracket points as reference for wire fitness. The predicted posttreatment archwire in each method was compared with the best-fit archwire on the actual posttreatment model of each patient in both methods, and the level of agreement was calculated. The interobserver agreement between the 3 orthodontists in each method was evaluated using intraclass correlation coefficient and the Dahlberg formula. RESULTS:Orthodontists predicted the final treatment outcome in 50% of cases using the conventional method and 58% using the digital method. However, the range of method error was significantly higher in the conventional method (0.425-3.853 mm for the conventional vs 0.451-0.584 mm for the digital). CONCLUSIONS:Although the clinicians' ability to predict the final dental arch form after orthodontic treatment and the agreement between clinicians increased by the use of digital equipment, orthodontists can predict the final arch form in about 60% of patients.
Objective: For the assessment of primary arch form, different methods have been used including qualitative classifications, inter-canine and inter-molar widths and quantitative and numerical methods using mathematical models. The purpose of this study was to compare the validity and reliability of Cast Analyzer X Iranian software with those of Curve Expert Professional version 1.1 for arch form construction based on mathematical models. Methods: This diagnostic, in vitro study was performed on 18 sets of dental casts with normal Class I occlusion. The clinical buccal points (bracket attachment sites)(CBPs) were marked on each tooth and their spatial coordinates were digitized using a three-dimensional (3D) laser scanning system. These coordinates were entered in Cast Analyzer X and Curve Expert software programs. Arch forms were constructed by the software programs using Brown’s beta function, Noroozi’s beta function and fourth order polynomial equation. The root mean square (RMS) of the distance from a reference point to their corresponding points on the curve was calculated. The RMS values in the two software programs were compared. Results: The RMS values in Brown’s beta function, Noroozi’s beta function and fourth order polynomial equation were significantly different in the Cast Analyzer X software (p<0.001) and the fourth order polynomial equation had the lowest RMS. The difference in RMS values between the two software programs was not clinically considerable and was 0.45 and 0.68 mm for the fourth order polynomial equation and Brown’s beta function, respectively. Conclusion: Considering the RMS values, the fourth order polynomial equation is the most suitable analysis for describing normal dental arch forms best fitted with the CBPs. Although the difference between the two software programs was statistically significant, this difference was not clinically noticeable. The RMS value was lower in Cast Analyzer X and consequently the fitting of curves with the landmarks (CBP) was better in the Iranian software.
OBJECTIVES:To compare archwire selection on dental casts with archwire selection using a three-dimensional (3D) software program (OrthoAid) and assess agreement between clinicians.MATERIALS AND METHODS:The best-fitting archwires were selected for dental casts of 100 patients with malocclusion using two approaches by three orthodontists. The first method was to visually determine the fitness of five preformed nickel titanium archwires to the arch form on a dental cast (subjective method). The second method was archwire selection on a virtual image of the same cast by means of 3D software (objective method). Agreement between selections performed by the orthodontists was calculated using Kappa statistics. The accuracy of fit of the archwires to the curves fitted to the arch form was also calculated or reversely assessed by means of the root mean square (RMS) for both methods using the Dahlberg formula.RESULTS:The mean RMS of the distances between the patient arch forms and the archwires for the subjective method was 1.163-1.366 mm. The agreement of selections between orthodontists was 42%-58% (Kappa ranged from .074 to .382). Using the 3D software (objective method), the mean RMS decreased to 0.966-1.171 mm, and agreement increased to 47% to 84% (Kappa ranged from .444 to .747).CONCLUSIONS:The use of 3D computer software for archwire selection in patients with malocclusion provided better adaptation and interexaminer reliability.
Background: New tools have been introduced for tooth inclination measurement and assessment of its changes over time. This study aimed to measure the change in inclination of teeth after the periods of 2 and 4 years in adolescents with normal occlusion using three-dimensional (3D) software. Materials and Methods: This retrospective longitudinal study was conducted on 54 pairs of dental casts of 24 adolescents between 9 and 13 years of age with normal occlusion. The inclination of teeth was determined by 3D measurements using OrthoAid software. After scanning the casts via stereophotogrammetric scanner, the mean and standard deviation of inclination of teeth were calculated at three time points. Change in these values was calculated after 2 and 4 years. The effect of sex, duration of follow-up, and the jaw (maxilla/mandible) on change of inclination was analyzed using the Mann–Whitney and Wilcoxon tests. P < 0.05 was considered statistically significant. Results: Incisor teeth torque was positive in the maxilla (9.72 ± 8) and mandible (4.22 ± 6.09), but it was negative for the canine (–7.73 ± 6.3 for maxilla and –9.9 ± 5.22 for mandible), premolar (–10.35 ± 6.84 for maxilla and –26.51 ± 9.94 for mandible), and molar teeth (–13.23 ± 6.22 for maxilla and –39.78 ± 9.5 for mandible) in both jaws. Maxillary lateral incisor in boys showed the greatest change of inclination in both 2 and 4 years (about 7°) and the mandibular canine tooth in girls showed the least change of inclination in 4 years (4°). Conclusion: Sex significantly affected the changes in the inclination of teeth throughout the period of study. The variation of changes in torque was considerable, and no consistent pattern was defined.
Objective: The aim of this study is to compare the adaptation of a straight wire between brackets positioned at the mid-lingual surface and those placed gingivally by using a three-dimensional simulation software. Methods: This cross-sectional study was performed using OrthoAid, an in-house software. The subjects were 36 adolescents with normal Class I occlusion. For each dental cast, two bracket positioning approaches, namely the middle and gingival, were examined. In the middle group, the reference points were placed on the mid-lingual surface of each tooth, while in the gingival group, the reference points were positioned lingually on the anterior teeth. A 4th degree polynomial was adopted, and the in-plane and off-plane root mean squares (RMSs) of the distances between the reference points and the fitted polynomial curve were calculated using the software. Statistical analysis was performed using the paired-samples t-test (alpha = 0.05). Results: The mean in-plane RMS of the polynomial curve to the bracket distance in the gingival group was significantly lower than that in the middle group (p < 0.001). The off-plane RMS was higher in the gingivally positioned brackets in the maxilla than in the middle group (p < 0.001). However, the off-plane RMS in mandible was not statistically significantly different between the two groups (p = 0.274). Conclusions: The results demonstrated that the gingival placement of lingual brackets on the anterior teeth could decrease the distance between a tooth and the straight wire.
OBJECTIVES We introduce a weighted method for superimposition of serial digital maxillary models based on the variable stability of rugae points. SETTING AND SAMPLE POPULATION Plaster maxillary models of 24 randomly selected 12-year-olds as well as their models at the age of 14 were obtained and scanned using a benchtop structured-light 3D scanner. METHODS The models were registered twice, once via the unweighted and again via the proposed weighted rugae superimposition method based on 12 rugae landmarks. For each superimposition, distances between the corresponding rugae points were measured and compared with reported displacements of rugae points in literature. RESULTS The unweighted superimposition produced no meaningful differences in terms of total displacements of registration landmarks, whereas the weighted method recognized the medial points of the third ruga as the most stable landmarks. Results of the weighted method also demonstrated statistically significant smaller changes for medial rugae points in almost every dimension compared to the lateral rugae points. These results comply with the growth patterns of maxilla and rugae point displacements reported in similar studies. CONCLUSION Considering the variable stability of rugae points during growth, the weighted rugae superimposition method results in more promising registrations on serial models. This method prioritizes registration landmarks based on clinical criteria of choice and is suitable for analysis of other structures such as tooth movements.
The aim of this study was to assess the dental arch curvature in subjects with normal occlusion in an Iranian population and propose a beta function formula to predict maxillary arch form using the mandibular intermolar widths (IMW) and intermolar depths (IMD). The materials used were study casts of 54 adolescents with normal occlusion and mean age of 14.1 years (25 males, 29 females, age range 12–16 years). Curve-fitting analyses were carried out and the curves passing through the facial-axis point of the canines, premolars, first molars, and the incisal edges of the anterior teeth were studied using a 3D laser scanner. Using the measured IMW and IMD of the dental arches at the maxillary and mandibular first molar region, a beta function formula proposed for predicting maxillary arch form. The accuracy of the proposed formula was assessed on 10 randomly selected dental casts. The mean (SD) of the maxillary and mandibular IMW and IMD were 57.92 (4.75), 54.19 (5.31), and 31.59 (2.90) and 28.10 (2.59) mm, respectively. There was no gender dimorphism (P > 0.05) for both variables (IMW, IMD). There was a strong positive association (n = 10, Pearson r = 0.98, P < 0.05) between the measured (actual) maxillary arch length and proposed arch length derived from generated formula. The goodness of fit (whole arch) for the proposed beta function formula, using adjusted r square measure and root mean square in 10 patients averaged 0.97 and 1.49 mm, respectively. The corresponding figures for the maxillary anterior arch (canine to canine) were 0.90 and 0.92 mm, respectively. The proposed beta function formula used for predicting maxillary arch form based on two mandibular measures (IMW, IMD) was found to have a high accuracy for maxillary arch prediction in the Iranian population and may be used as a guide to fabricate customized arch wires or as an aid in maxillary reconstructive surgery.
Introduction: The present study was aimed to assess the amount and direction of growth in cranial base, jaws, and soft tissue of airway structures by cephalometric analysis in 9–11-years-old Iranian girls and boys. Materials and Methods: Thirty-four Iranian children with normal occlusion and class I molar relationships were recruited, and 2 lateral cephalograms were obtained from 9 and 11-year-old children Cephalometric variables included variables defining cranial base length and angle, maxillomandibular length and height, dental relationship, head and cervical position, soft palate and tongue, vallecula and hyoid position, and pharyngeal dimension. Normal distribution was confirmed by Kolmogorov–Smirnov analysis (P>0.05). Paired t-test was used for assessing growth changes. P value was set at 0.05. Results: Anterior, posterior, and total cranial base length were increased significantly. The increase in total and upper anterior, total and lower posterior facial heights, ramus height, and palatal inclination were statistically significant. Maxillomandibular length increased significantly with insignificant change in their position. Dental relationship and head and cervical posture were stable. Oropharyngeal and nasopharyngeal anteroposterior dimension did not change. However, hypopharynx sagittal length increased significantly. Nasopharyngeal vertical dimension increased and hyoid moved anteriorly and inferiorly. Conclusion: The results of the present study showed that cranial base and jaws grow anteriorly and inferiorly while maintaining dental occlusion and head posture. Most of the airway structures grow simultaneously with craniofacial components.
Introduction: Maintaining a patient's original arch form increases treatment stability. In this study, we assessed the agreement between subjective analyses of arch form and archwire selection by orthodontists and an objective method with Cast Analyzer Iranian X software (Khallaghane Mehr, Tehran, Iran). Methods: Thirty-six casts with normal occlusion were scanned with a laser. The software generated the best-fit curve using a fourth-degree polynomial equation to the clinical bracket points on the casts; then it selected the best preformed nickel-titanium archwire based on the root mean square calculation either objectively or semiobjectively. Three orthodontists selected the best-fit curve and archwire subjectively using the casts. To assess intraexaminer reliability, the same orthodontists reevaluated 10 casts after 2 weeks. To assess interexaminer reliability, the 3 orthodontists performed the analyses with the software and on the casts. Agreements were evaluated with the intraclass correlation coefficient and Dahlberg's formula. Results: The semiobjective method (visual selection of wire by orthodontists using the software) yielded the best results. The differences were clinically negligible between the objective (fully automated) and semiobjective methods (1.30 vs 1.36 mm). Conclusions: The objective method improved wire adaptation to the clinical bracket points. Agreement among orthodontists regarding wire selection will improve significantly when they are trained to use the software.
OBJECTIVE: The aim of the present study was to assess the diagnostic value of a laser scanner developed to determine the coordinates of clinical bracket points and to compare with the results of a coordinate measuring machine (CMM). METHODS: This diagnostic experimental study was conducted on maxillary and mandibular orthodontic study casts of 18 adults with normal Class I occlusion. First, the coordinates of the bracket points were measured on all casts by a CMM. Then, the three-dimensional coordinates (X, Y, Z) of the bracket points were measured on the same casts by a 3D laser scanner designed at Shahid Beheshti University, Tehran, Iran. The validity and reliability of each system were assessed by means of intraclass correlation coefficient (ICC) and Dahlberg's formula. RESULTS: The difference between the mean dimension and the actual value for the CMM was 0.0066 mm. (95% CI: 69.98340, 69.99140). The mean difference for the laser scanner was 0.107 ± 0.133 mm (95% CI: -0.002, 0.24). In each method, differences were not significant. The ICC comparing the two methods was 0.998 for the X coordinate, and 0.996 for the Y coordinate; the mean difference for coordinates recorded in the entire arch and for each tooth was 0.616 mm. CONCLUSION: The accuracy of clinical bracket point coordinates measured by the laser scanner was equal to that of CMM. The mean difference in measurements was within the range of operator errors.
Introduction: Hemifacial microsomia (HFM) is a birth defect involving craniofacial structures derived from the first and second branchial arches. Although it is a relatively uncommon malformation, it is the second most common craniofacial birth defect after cleft lip and palate (CL/P). Case Presentation: This is a case report about the successful orthodontic treatment of a patient with mild hemifacial microsomia (HFM), using a non-surgical orthopedic and orthodontic treatment approach. The aim of this approach was to make the best noninvasive modality to treat HFM. A 7-year-old boy with a mild HFM presented with a convex profile and slight chin deviation. Orthopedic treatment performed using a hybrid functional and high pulls headgear. Treatment continued by fixed orthodontic straight wire appliance to achieve perfect occlusion. Conclusions: Excellent esthetic and functional results achieved; total treatment duration was about 72 months.
Background: Evaluation of the craniofacial bones is the oldest method to measure the facial proportion ratio in orthodontics.Objectives: The purpose of this study was to evaluate the effect of emboss enhancement on the reliability of landmark identification in digital lateral cephalometric images.Materials and Methods: Ten digital lateral cephalograms were selected from the archive of an oral and maxillofacial radiology center. Using DIGORA software, these images were saved in two formats; common images and 3D emboss images. On these images, 32 skeletal, dental, and soft tissue landmarks were marked at least twice with a 2-week interval by four observers (two radiologists and two orthodontists). In order to determine the position of the marked landmarks (in x and y coordinates), a software was designed. The statistical analysis was performed in SPSS software and the reliability of each observer was obtained by means of intraclass correlation coefficient (ICC).Results: In three skeletal landmarks [Orbit (Or), condyl top (Cond), and pogonion (Pog)], the enhancement caused significant reduction in the reliability, and in four skeletal [Anterior Nasal Spine (ANS), B, A, and Basion (Ba)], two dental (U1 root, L1 incisal), and one soft tissue landmark (Menton soft tissue), the enhancement increased the reliability of landmark detection between the two phases of the study. Totally, ICC of embossed images in both x and y coordinates were greater than the typical images, but the difference was not statistically significant. However, the effect of enhancement on the improvement of the reliability of landmark identification was higher in the x-axis than the y-axis.Conclusions: Using embossed images is only effective in increasing the reliability of detection in a few numbers of cephalometric landmarks.
Cephalometric norms of McNamara analysis have been studied in various populations due to their optimal efficiency. Dolphin cephalometric software greatly enhances the conduction of this analysis for orthodontic measurements. However, Dolphin is very expensive and cannot be afforded by many clinicians in developing countries. A suitable alternative software program in Farsi/English will greatly help Farsi speaking clinicians. The present study aimed to develop an affordable Iranian cephalometric analysis software program and compare it with Dolphin, the standard software available on the market for cephalometric analysis.In this diagnostic, descriptive study, 150 lateral cephalograms of normal occlusion individuals were selected in Mashhad and Qazvin, two major cities of Iran mainly populated with Fars ethnicity, the main Iranian ethnic group. After tracing the cephalograms, the McNamara analysis standards were measured both with Dolphin and the new software. The cephalometric software was designed using Microsoft Visual C++ program in Windows XP. Measurements made with the new software were compared with those of Dolphin software on both series of cephalograms. The validity and reliability were tested using intra-class correlation coefficient.Calculations showed a very high correlation between the results of the Iranian cephalometric analysis software and Dolphin. This confirms the validity and optimal efficacy of the newly designed software (ICC 0.570-1.0).According to our results, the newly designed software has acceptable validity and reliability and can be used for orthodontic diagnosis, treatment planning and assessment of treatment outcome.
BACKGROUND:This study sought to assess symphyseal morphology in adolescents with different mandibular growth patterns (MGPs) in order to see if a relation exists.MATERIALS AND METHODS:In this study the symphyseal parameters (height, depth, and ratio) of normal subjects were compared with four groups with malocclusion (cl III vertical, cl II vertical, cl III horizontal, and cl II horizontal). These groups (15 samples each) were matched (for sex and cervical maturation stage [CVMS]) based on their cephalograms and patient charts. Growth patterns were differentiated by seven vertical parameters and the Wylie analysis. After confirmation of normality of the groups and similarity of their variances the two-way analysis of variance (ANOVA) was used for analysis of data assessed by adjusted chi-square (P < 0.001). The comparison of cases with the normal group was performed by the Dunnett method. Intraclass Correlation Coefficient (ICC) was used for evaluation of intraobserver reliability.RESULTS:We found the symphyseal ratio to have a significant correlation with the MGP (P < 0.001). The symphyseal ratio (Height/Depth) was small in a mandible with vertical growth pattern Cl II or Cl III. Conversely, a horizontal growth pattern of a Cl II or Cl III mandible was associated with a larger ratio of the symphysis in comparison with the normal group. The symphyseal ratio was also found to be greater in females.CONCLUSION:The symphyseal ratio was found to be strongly associated with the MGP.
Introduction:: The role of nasal septum in development of the maxilla after birth remains to be a question. Study of monozygotic twins may elucidate the role of epigenetic factors in growth and development of craniofacial structures. Case Presentation:: Herein, we report a case of 16 year-old male monozygotic twins with Angle class III malocclusion and high angle facial pattern. One of them (patient M.H) had a history of mid-face trauma at the age of 6. Radiographic and clinical examinations revealed significant nasal septum deviation and the patient demonstrated nasal airway obstruction on the right side. The effects of this traumatic injury and the consequences of septal deviation were evident both clinically and radiographically at the age of 16. Increased airway resistance caused by septal deviation significantly affected the arch form and the configuration of the nose. The overall facial growth pattern is predetermined genetically but vertical dimension of the face may be more influenced by the environmental factors. Conclusions:: Patients should be carefully monitored after trauma to the nose and face and any deviation in the facial structure should be treated promptly in order to prevent asymmetries.