Evaluation of Bone Mineral Changes in Panoramic Radiographs of Hypothyroid and Hyperthyroid Patients Using Fractal Dimension Analysis.

Objective Hyperthyroidism and hypothyroidism are endocrinopathies that cause a decrease in bone mineral density. The aim of this study is to investigate possible bone changes in the mandible caused by hyperthyroidism and hypothyroidism using fractal analysis (FA) on panoramic radiographs. Material and Methods Panoramic radiographs of a total of 180 patients, including 120 patient groups (60 hyperthyroid, 60 hypothyroid) and 60 healthy control groups, were used. Five regions of interests (ROI) were determined from panoramic radiographs and FA was performed. ROI1: geometric midpoint of mandibular notch and mandibular foramen, ROI2: geometric midpoint of mandibular angle, ROI3: anterior of mental foramen, ROI4: basal cortical area from distal mental foramen to distal root of first molar, ROI5: geometric center of mandibular foramen and mandibular ramus. Results While a significant difference was observed between the patient and control groups regarding ROI1 and ROI2 (p < 0.05); there was no significant difference between the groups in relation to ROI3, ROI4, and ROI5. All FA values were lower in the hyperthyroid group than in the hypothyroid group. Conclusion Fractal analysis proves to be an effective method for early detection of bone mass changes. In the present study, it was concluded that while the mandibular cortical bone was intact, trabecular rich regions were affected by osteoporosis caused by thyroid hormones. Necessary precautions should be taken against the risk of osteoporosis in patients with thyroid hormone disorders.

Evaluation of the validity of mental foramen USG measurements by comparison with CBCT and determination of blood flow.

OBJECTIVES: To examine mental foramen (MF) morphology and morphometry in comparison with ultrasonography (USG) and cone-beam computed tomography (CBCT), and to determine the relationship between mental artery blood flow parameters and age, gender, dental status, alveolar crest height, mandibular cortical index (MCI) with USG. METHODS: A total of 120 MF and mental arteries of 60 patients (21 males and 39 females), including 20 patients in each group, aged 18-39, 40-59, and 60 years and above, were evaluated. The horizontal and vertical diameter of the MF and the distance between it and the alveolar crest were evaluated with USG and CBCT. In addition, mental artery blood flow parameters were examined by USG. RESULTS: When the horizontal diameter values of MF were compared in USG and CBCT measurements; the diameter was significantly lower in the measurements obtained by USG (p < 0.05). It was observed that there were no mental arteries whose blood flow could not be recorded, 31 (25.8%) had strong blood flow and 89 (74.2%) had weak blood flow. No significant correlation was observed between gender and blood flow parameters (p > 0.05). CONCLUSIONS: Considering that CBCT images are used as gold standard in our study, it may be said that USG is not as reliable as CBCT in evaluating the MF dimensions in the maxillofacial region. Nevertheless, USG is a suitable technique for determining the visualizing and blood flow of the MF.