Evaluation of the relationship between tympanic plate morphology and degenerative bone changes of condyle and articular eminence.

INTRODUCTION: This study aimed to evaluate the relationship between tympanic plate morphology and degeneration of temporomandibular joint (TMJ) condyle and articular eminence (AE). MATERIAL AND METHODS: Cone beam computed tomography images of 700 patients (345 males, 355 females) were evaluated. The prevalence and location of tympanic plate pneumatization (TPP) and foramen tympanicum (FT) were recorded. Sagittal scans of the TMJs were classified according to the degenerative bone changes of condyle and AE (flattening, osteophytes, erosion, sclerosis, and subcortical cysts). RESULTS: TPP was found in 106 of 700 patients (15.2%) while FT was found in 165 (23.2%) of the patients. TPP and FT were bilateral in 52 (49.1%) patients and 46 (27.9%) patients, respectively. The mean axial diameter of FT was 2.53mm and the mean sagittal diameter was 2.52mm. The most common degenerative changes for condyle and AE were flattening. CONCLUSION: To know these structures is important for surgical operations in the region of TMJ and ear to prevent complications. CBCT is useful to evaluate these anatomical landmarks and the relationship between them and the degenerative bone changes of condyle and AE.

Evaluation of the effects of hemoglobinopathies on the mandible with fractal dimension analysis.

AIMS: The aim of this study was to evaluate the mandibular bone changes on panoramic radiographs of thalassemia and sickle cell anemia (SCA) patients using fractal dimension (FD) analysis and to compare the findings obtained from healthy individuals. MATERIALS AND METHODS: A total of 90 panoramic radiographs (from 30 patients with thalassemia, 30 patients with SCA and 30 healthy individuals) were assessed to measure FD, mandibular cortical width (MCW), panoramic mandibular index (PMI) in the mandible. Three region of interests (ROI) of angulus, corpus, and interdental bone were created. FD was calculated using ImageJ program. RESULTS: In thalassemia group, the mean value of FD was 1.11, 1.03, and 1.02 in interdental bone, corpus, and angulus, respectively. In SCA group, the mean value of FD was 1.10, 1.05, and 1 in interdental bone, corpus, and angulus, respectively. In control group, the mean value of FD was 1.09, 1.04, and 1 in interdental bone, corpus, and angulus, respectively. FD value of interdental bone are significantly higher in thalassemia group than control group. FD values of corpus and angulus values did not show a significant difference between the groups. CONCLUSIONS: Fractal analysis may be used and recommended for evaluation of the bone changes induced by hemoglobinopathies.

Effects of first permanent molar extraction on space changes observed in the dental arch using data mining method.

AIM: The high incidence of caries in first permanent molars (FPMs) makes premature extraction of these teeth common. The extraction of the permanent teeth results in various changes in the dental arch. The aim of this study was to evaluate space closure, the eruption of second permanent molars (SPMs), and changes in dental arch after extraction of the FPMs. MATERIALS AND METHODS: Eruption of 83 SPMs was recorded and radiographically developmental stage of these SPMs in the pre-extraction panoramic radiograph was assessed. Space was measured between the distal surface of the second premolar and the mesial surface of SPM. RESULTS: Out of 55 patients, 28 (50.9%) were males and 27 (49.1%) were females. Thirty-seven (44.6%) of 83 teeth belonged to category 1, 17 (20.5%) teeth belonged to category 2, and 5 (6.02%) teeth belonged to category 3. Although category 4 was not found, 24 (28.9%) teeth were observed to be in category 5. Out of all SPMs, 10.8% represented the ''ideal'' stage of Demirjian's dental development, stage E. CONCLUSION: In patients who had the FPMs extracted before the eruption of the SPM, it is important with regards to the patients' comfort and health to review the patient regularly and to determine any need for orthodontic treatment.

Comparison of the applicability of Demirjian and Willems methods for dental age estimation in children from the Thrace region, Turkey.

OBJECTIVES: Dental age (DA) estimation is frequently used in the fields of orthodontics, paediatric dentistry and forensic science. DA estimation methods use radiology, and are reliable and non-destructive according to the literature. The Demirjian method is currently the most frequently used method, but recently, the Willems method was reported to have given results that were more accurate for some regions. The aim of this study was to detect and compare the accuracy of DA estimation methods for children and adolescents from the Thrace region, Turkey. The mean difference between the chronological age (CA) and the DA was selected as the primary outcome measure, and the difference range according to sex and age group was selected as the secondary outcome. MATERIALS AND METHODS: Panoramic radiographs (n=766) from a Thrace region population (380 males and 386 females) ranging in age from 6 to 14.99 years old were evaluated. DA was calculated using both the Demirjian and the Willems methods. RESULTS: The mean CA of the subjects was 11.39±2.34 years (males=11.08±2.42 years and females=11.70±2.23 years). The mean difference values between the CA and the DA (CA-DA) using the Demirjian method and the Willems method were -0.87 and -0.17 for females, respectively, and -1.04 and -0.40 for males, respectively. For the different age groups, the differences between the CA and the DA calculated using the Demirjian method (CA-DA) ranged from -0.53 to -1.46 years for males and from -0.19 to -1.20 years for females, while the mean differences between the CA and the DA calculated by the Willems method (CA-DA) ranged from -0.19 to -0.50 years for males and from 0.20 to -0.49 years for females. CONCLUSION: The results suggest that the Willems method produced more accurate results for almost all age groups of both sexes, and it is better suited for children from the Thrace region of Turkey, than the Demirjian method.