Evaluation of condylar positions in patients with temporomandibular disorders: A cone-beam computed tomographic study

PURPOSE: This study was performed to compare the condylar position in patients with temporomandibular joint disorders (TMDs) and a normal group by using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: In the TMD group, 25 patients (5 men and 20 women) were randomly selected among the ones suffering from TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The control group consisted of 25 patients (8 men and 17 women) with normal temporomandibular joints (TMJs) who were referred to the radiology department in order to undergo CBCT scanning for implant treatment in the posterior maxilla. Linear measurements from the superior, anterior, and posterior joint spaces between the condyle and glenoid fossa were made through defined landmarks in the sagittal view. The inclination of articular eminence was also determined. RESULTS: The mean anterior joint space was 2.3 mm in the normal group and 2.8 mm in the TMD group, respectively. The results showed that there was a significant correlation between the superior and posterior joint spaces in both the normal and TMD groups, but it was only in the TMD group that the correlation coefficient among the dimensions of anterior and superior spaces was significant. There was a significant correlation between the inclination of articular eminence and the size of the superior and posterior spaces in the normal group. CONCLUSION: The average dimension of the anterior joint space was different between the two groups. CBCT could be considered a useful diagnostic imaging modality for TMD patients.

Spatial relationship between mandibular third molars and inferior alveolar nerve using a volume rendering software

Precise localization of the third molars in relation to the inferior alveolar nerve canal is critical from a clinical point of view and strongly affects the surgical treatment outcome. Recently, by using three-dimensional modeling software, the relationship of third molar root apices and inferior alveolar nerve canal can be better understood. In this study, the spatial relationship of two surgical sites of 19 impacted third molars with close relationship to the inferior alveolar nerve canal is described by using imaging data from a cone beam computed tomography system. This study aimed to investigate the ability of three-dimensional modeling of tooth-nerve relationship using the data imported to Amira 5.2.2 imaging software

[Age assessment of developmental stages of permanent mandibular teeth using the Demirjian method]

Age estimation of the children usually is assessed using tooth developmental stages in radiographs. The Demirjian's method is one of them. This study was done with the aim of assessment of the Demirjian's developmental age stages of the permanent mandibular teeth in panoramic radiographs of 6-13 years old patients attended to Radiology Department of Mashhad dental school. In this descriptive cross-sectional study, a sample of 310 orthopantomographs taken from 169 girls and 141 boys between 6 and 13 years old referred to Mashgshad dental school was selected. The chronological age of each child was calculated by subtracting her or his birth date from the date on which the radiograph had been obtained and the developmetal stages of each of the seven left mandibular permanent teeth were recorded using the Demirjian method. Independent-sample t test was applied for comparison of the mean age of different developmental stages in both genders. The mean chronological age of stage G of teeth 32 and 33, stage F of tooth 34 and stages D and F of tooth 35 was different between the two genders [P<0.05]. The mean chronological age of teeth 31, 36 and 37 in both sexes and in different developmental stages showed no statistically significant difference [P>0.05]. The mean ages of different developmental stages of permanent mandibular teeth using the Demirjian method were similar to former studies. Also, the stage of mandibular teeth development was higher in girls than boys with similar chornological ages

Periapical status and quality of root canal fillings and coronal restorations in Iranian population

This cross-sectional survey determined the dental prevalence of apical periodontitis [AP] in selected Iranian population, and evaluated the influence of the quality of root canal treatment [RCT] and their coronal restorations [CR] on the periapical status. A total of 1064 panoramic radiographies were evaluated by two observers during 2009. The quality of RCT i.e. length/density of root fillings and CR in addition to periapical status of endodontically treated teeth were recorded. Their interrelationship was analyzed by Chi-squared, logistic regression and Spearman's rho statistics. Hosmer and Lemeshow tests were used for assessing fitness of logistic regression model and one sample k-s test was used for evaluating of normality of the data. Our results showed that 527 teeth [52%] of the endodontically treated teeth presented with AP radiographically. The percentages of teeth which fulfilled the criteria of an acceptable RCT or CR radiographically were 42.3 and 62.5 respectively. Incidence of AP among teeth with acceptable RCT [29.1%] was significantly lower than those suffering from unacceptable RCT [68.8%] [P<0.001]. Moreover, adequate CR demonstrated a significantly better periapical status [58.6%] compared to teeth with inadequate CR [30.3%] [P<0.001]. The incidence of AP ranged from 25.6% [good qualities] to 79.5% [bad qualities] [P<0.001]. Cases with both unacceptable RCT/CR were 11 times more likely to have AP than cases with acceptable RCT/CR. The quality of RCT and CR were found to impact the periapical health of endodontically treated teeth. There are a significant high number of technically unacceptable endodontic and restorative treatments in Iran; therefore considerable efforts are needed to improve the standards of endodontic and restorative treatments