Comparison of the bony changes of TMJ in patients with and without TMD complaints using CBCT

Statement of the Problem: Temporomandibular joint disorders [TMD] may show a poor correlation between their clinical findings and radiological characteristics

Purpose: The aim of this study was to assess the osseous alterations of temporomandibular joint [TMJ] in symptomatic and asymptomatic subjects by employing cone beam computed tomography [CBCT] images

Materials and Method: In this study, CBCT images of 120 temporomandibular joints in 30 patients with TMJ disorder and 30 age- and sex-matched individuals without TMJ complaints were evaluated. Osteoarticular derangements of the joint were assessed by two experienced examiners. Data was statistically analyzed with SPSS software using chi-square test [p <0.05]

Results: Out of 120 CBCT images [60 in each group], at least one osseous change was observed in 90% and 86.7% joints in symptomatic and asymptomatic subjects, respectively. There were no significant differences between symptomatic and asymptomatic subjects regarding frequency of osteoarticular changes including flattening [73.3% vs. 75%], irregularity [36.7% vs. 48.3%], sclerosis [20% vs. 8.3%], cyst [3.3% vs. 3.3%], erosion [13.3% vs. 21.7%], hypoplasia [3.3% vs. 5%], ankylosis [1.7% vs. Zero], osteophyte [43.3% vs. 40%], decrease joint space [3.3% vs. 3.3%], and increase joint space [5% vs. 5%]. [p> 0.05]

Conclusion: By employing CBCT as a modern diagnostic imaging tool, findings of this study revealed that the frequency of various temporomandibular joint alterations on CBCT images is comparable in patients with and without TMD complaints, suggesting that some people with TMJ structural damage may not display clinical manifestations. Moreover, CBCT imaging might not be necessary for TMD patients and more attention should be given to clinical examination

Photogrammetric comparison of facial soft tissue profile before and after protraction facemask therapy in class III children [6-11 years old]

Statement of the Problem: Achieving a normal soft tissue facial profile is considered to be the main concern of class III patients and the goal of most class III treatments

Purpose: The purpose of this study was to investigate the effects of facemask treatment on profile with photogrammetric method

Materials and Method: Before [T0] and after [T1] treatment photograms of 40 class III patients profiles [20 male and 20 female individuals] treated with protraction face mask that met the inclusion criteria were digitized and analyzed using Aesthetic Analyzer software. Selected linear and angular measurements were performed for each patient and the changes were noted

Results: An increase in inferior facial height [p< 0.001] and inferior facial angle [p< 0.001] was observed. Nasal prominence and upper lip prominence also increased significantly [p< 0.001]. Advancement of sub nasal area was observed to be significant in females [p< 0.05] in contrast to males

Conclusion: Remarkable advancement in the middle face and consequent fullness in the soft-tissue profile can be achieved by using protraction face mask. The response to treatment is not different between males and females

Evaluating the stability of open bite treatments and its predictive factors in the retention phase during permanent dentition

Statement of the Problem: Orthodontists often find challenges in treating the anterior open bite and maintaining the results

Purpose: This retrospective study was aimed to evaluate the stability of corrected open bite in the retention phase during permanent dentition

Materials and Method: A total number of 37 patients, including 20 males and 17 females, with the mean age of 18 +/- 2.1 years at the beginning of the treatment were studied after correction of the anterior open bite. Overbites of the patients were measured from their lateral cephalograms before [T[1]], at the end [T[2]] and at least 3 years after the end of the treatment in the presence of their fixed retainers [T[3]].The mean overbite changes and the number of patients with open bite, due to treatment relapse, at T[3] were calculated. The relationship between the pre-treatment factors and the treatment relapse was assessed at T[1] and T[2]. Also the effects of treatment methods, extraction and adjunctive use of removable appliances on the post-treatment relapse were evaluated

Results: The mean overbite change during the post-treatment period was -0.46 +/- 0.7 mm and six patients [16.2%] had relapse in the follow-up recall. Cephalometric Jaraback index showed statistically significant, but weak correlation with overbite changes after the treatment [p= 0.035; r= -0.353]. No significant difference was found between the extraction and non-extraction groups [p= 0.117] the use and the type of the removable appliances [p= 0.801]

Conclusion: Fixed retainers alone are insufficient for stabilizing the results of corrected open bite. The change of overbite in the retention phase could not be predicted from cephalometric measurements. Extraction and use of adjunctive removable appliance did not have any effect on the treatment relapse

Evaluating stress distribution pattern in periodontal ligament of maxillary incisors during intrusion assessed by the finite element method

Statement of the Problem: The use of miniscrews has expedited the true maxillary incisor intrusion and has minimized untoward side effects such as labial tipping

Purpose: The aim of this study was to assess the stress distribution in the periodontal ligament of maxillary incisors when addressed to different models of intrusion mechanics using miniscrews by employing finite element methods. The degree of relative and absolute intrusion of maxillary incisors in different conditions was also evaluated

Materials and Method: Finite element model of maxillary central incisor to first premolar was generated by assembling images obtained from a three-dimensional model of maxillary dentition. Four different conditions of intrusion mechanics were simulated with different placement sites of miniscrews as well as different points of force application. In each model, 25-g force was applied to maxillary incisors via miniscrews

Results: In all four models, increased stress values were identified in the apical region of lateral incisor. Proclination of maxillary incisors was also reported in all the four models. The minimum absolute intrusion was observed when the miniscrew was placed between the lateral incisor and canine and the force was applied at right angles to the archwire, which is very common in clinical practice

Conclusion: From the results yield by this study, it seems that the apical region of lateral incisor is the most susceptible region to root resorption during anterior intrusion. When the minimum flaring of maxillary incisors is required in clinical situations, it is suggested to place the miniscrew halfway between the roots of lateral incisor and canine with the force applied to the archwire between central and lateral incisor. In order to achieve maximum absolute intrusion, it is advised to place miniscrew between the roots of central and lateral incisors with the force applied at a right angle to the archwire between these two teeth

analytical study on an orthodontic index: index of complexity, outcome and need [ICON]

Statement of the Problem: The validity of the Index of Complexity, Outcome and Need [ICON] which is an orthodontic index developed and introduced in 2000 should be studied in different ethnic groups

Purpose: The aim of this study was to perform an analysis on the ICON and to verify whether this index is valid for assessing both the need and complexity of orthodontic treatment in Iran

Materials and Method: Five orthodontists were asked to score pre-treatment diagnostic records of 100 patients with a uniform distribution of different types of malocclusions determined by Dental Health Component of the Index of Treatment Need. A calibrated examiner also assessed the need for orthodontic treatment and complexity of the cases based on the ICON index as well as the Index of Orthodontic Treatment Need [IOTN]. 10 days later, 25% of the cases were re-scored by the panel of experts and the calibrated orthodontist

Results: The weighted kappa revealed the inter-examiner reliability of the experts to be 0.63 and 0.51 for the need and complexity components, respectively. ROC curve was used to assess the validity of the index. A new cut-off point was adjusted at 35 in lieu of 43 as the suggested cut-off point. This cut-off point showed the highest level of sensitivity and specificity in our society for orthodontic treatment need [0.77 and 0.78, respectively], but it failed to define definite ranges for the complexity of treatment

Conclusion: ICON is a valid index in assessing the need for treatment in Iran when the cut-off point is adjusted to 35. As for complexity of treatment, the index is not validated for our society. It seems that ICON is a well-suited substitute for the IOTN index

[Evaluation of fixed orthodontic patients' compliance in the clinic of Shiraz dental school: a cross-sectional study]

Orthodontic patients' cooperation is a determining factor in treatment outcomes. The aim of this study was to evaluate the relationship between patient cooperation during orthodontic treatment with variables such as age, sex, life setting, treatment duration and functional and social discomfort experienced. Specimens were consisted of 100 orthodontic patients [36 males and 64 females] between 13-35 years old [average age: 22.57 +/- 1.69 years]. Patients' demographic traits, treatment duration and functional-social discomfort by the orthodontic treatment were evaluated using a questionnaire answered by the patients or their parents. The degree of patient cooperation was assessed by the modified cooperation questionnaire [Orthodontic Patient Cooperation Scale [OPCS] which was completed by an orthodontist. Data were analyzed using One-way ANOVA, T-test, intraclass correlation coefficient and Pearson Correlation. No significant difference was found between the cooperation of male and female patients [P=0.867] and also between the cooperation of the patients who lived in the urban and rural setting [P=0.613]. Treatment duration and compliance showed a low negative correlation which was not statistically significant [r=-0.155, P=0.127]. Functional-social discomfort and compliance showed a low negative correlation which was not statistically significant [r-0.118, P=0.244]. No significant correlations were found between the compliance and age [r=0.002, P=0.988]; and also the treatment duration and functional-social discomfort experienced [r=0.164,P=0.105]. Patient compliance appears to be a complex issue that cannot easily be predicted only by factors such as age, gender, life setting, treatment duration and functional-social discomfort experienced

Associations between normative and self-perceived orthodontic treatment needs in young-adult dental patients / 대한치과교정학회지

OBJECTIVE: Our aim was to determine the correlation between dental treatment need as assessed by the components of the index of orthodontic treatment need (IOTN) and a self-evaluation questionnaire in a population selected from the dental clinics of Shiraz, Iran. METHODS: The dental treatment needs of 240 participants (120 men and 120 women) were measured on the basis of the IOTN dental health component (IOTN-DHC), IOTN aesthetic component (IOTN-AC), IOTN AC determined by the examiner (IOTN-ACE), and a self-evaluation questionnaire (SEQ). The correlations between the treatment needs assessed by all the methods as well as the correlations of the treatment needs with age and gender were assessed using a Spearman's correlation coefficient (alpha = 0.01). RESULTS: All methods were significantly correlated (p 0.06). CONCLUSIONS: The correlations between the self-evaluation and the IOTN components in young adults were close to those reported in children, and IOTN-ACE was more reliable than IOTN-AC.

[Evaluation of simple method to predict the anterior and overall bolton discrepancy in a south Iranian population]

Bolton analysis is a good indicator to evaluate tooth size discrepancies but the ethnic variation of these values should be considered. Thus, the aim of this study was to determine the tooth ratios in different sexes and malocclusion groups in Iranian population and to compare these ratios with the data from the Bolton study. Also the best predictors of anterior and overall Bolton discrepancies were determined in this study. In this cross-sectional study, a total of 715 dental casts [526 female. 189 male] were recruited from department of orthodontics of Shiraz dental school and private offices of orthodontists. The samples were divided into three groups based on Angles Malocclusion groups. Then the greatest mesiodistal widths of all teeth were measured with digital caliper with accuracy of 0.01 mm and the anterior and overall ratios were calculated. Finally, the data were analyzed by Pearson Correlation, independent t-test and Kruskal-Wallis test, through SPSS software. The anterior ratio [78.74%] and the overall ratio [91.94%] showed no statistically significant differences according to sex and malocclusion groups in south Iranian population. The results revealed that the correlation coefficient of lateral ratio with anterior Bolton discrepancy was 0.544 and central ratio with anterior Bolton discrepancy was 0.536. Also the correlation coefficient of first premolar ratio with overall Bolton discrepancy was 0.440 and the second premolar ratio with overall Bolton discrepancy was 0.407. The anterior ratio for the whole population was statistically different from Bolton's, but no statistically significant difference was found for the overall ratio. In Iranian population, the best predictor of anterior Bolton discrepancy was lateral tooth and the best predictor of overall Bolton discrepancy was first premolar