Mandibular cortical index evaluation in masked and unmasked panoramic radiographs.

OBJECTIVES: The first aim of this study was to evaluate intra- and interobserver agreement in evaluating the mandibular cortical index (MCI) in masked and unmasked panoramic radiographs. The second aim was to evaluate the effect of previous experience of MCI classification on the observers' performance. METHODS: Three observers separately evaluated MCI, twice in masked and twice in unmasked panoramic radiographs, with 2 week intervals. The observations were repeated more than 9 months later. The second and third observers were inexperienced in evaluating MCI. Weighted kappa statistics were used to evaluate the inter- and intraobserver agreement. RESULTS: In the first session of the study, the kappa values for intraobserver agreements in masked panoramic radiographs were between 0.565 and 0.789; in unmasked panoramic radiographs, they were between 0.420 and 0.732. The kappa values for interobserver agreement were between 0.131 and 0.392 in masked radiographs and between 0.043 and 0.225 in unmasked radiographs. In the second session of the study, the kappa values for intraobserver agreements in masked panoramic radiographs were between 0.586 and 0.786. The kappa values for intraobserver agreements in unmasked panoramic radiographs were between 0.558 and 0.781. The kappa values for interobserver agreement were between 0.146 and 0.510 in masked radiographs and between 0.174 and 0.568 in unmasked radiographs. CONCLUSIONS: Masking has no effect on the evaluation of panoramic radiographs for MCI. Previous experience causes higher intraobserver agreement. Intra- and interobserver agreement increases along with the increased experience in MCI evaluations.

Investigation of elongated styloid process prevalence in patients with torus palatinus.

The aim of the current study was to determine the presence of styloid process elongation (SPE) detected on panoramic radiographs in patients with torus palatinus (TP). Between December 2005 and November 2007, a total of 149 patients with TP are investigated for routine dental examination in the outpatient clinic. Any patient who had disorders related to calcium and phosphorus metabolism was excluded. All medical data were obtained from the files. Twenty (15%) subjects demonstrated SPE at least one side. These patients consisted of 15 women (14.3% of all women) and five men (17.8% of all men). In our previous report performed in normal population at the same region, the prevalence had been found to be 7.7% in 698 dental patients. Although the number of the patients is different in both studies, there is a marked difference in terms of the SPE prevalence between the two reports. This prevalence difference might be related to concomitant disorder.

The prevalence of carotid artery calcification on the panoramic radiographs of end-stage renal disease patients with peritoneal dialysis: do incidental findings provide life-saving information?

This study investigated the presence of carotid artery calcifications (CACs) on panoramic radiographs (PRs) in end-stage renal disease (ESRD) patients treated with peritoneal dialysis (PD), and analysed the relationship between CAC prevalence and PD duration. A random sample of 110 PRs were collected from ESRD patients (15 with questionable CACs were subsequently excluded). CACs were found in 26 (27.4%) patients; 10 males (23.3% of all males) and 16 females (30.8% of all females). The overall mean PD period was 4.0 +/- 3.2 years. There was a significant difference in PD period between patients with and without CACs (5.3 +/- 3.1 years versus 3.5 +/- 3.1 years, respectively). To our knowledge, this study has the highest CAC prevalence, is the first to be carried out in ESRD patients being treated with PD and has the largest sample of ESRD patients (n = 95). We believe dentists should carefully evaluate patients' PRs for evidence of CACs, enabling these incidental findings to provide life-saving information.

Mandibular metastasis in a patient with pulmonary adenocarcinoma.

Metastatic tumour spread to the mandible is quite rare. We report a case of distant metastasis of pulmonary adenocarcinoma in the mandibular bone. The patient had pain in his left mandibular premolar-molar area caused by a mandibular metastasis from a previously undiagnosed pulmonary adenocarcinoma.

The differences in panoramic mandibular indices and fractal dimension between patients with and without spinal osteoporosis.

OBJECTIVES: The aims of this study were to evaluate the relationship between osteoporosis, oral signs, body mass index and age; and to assess the possibility of using these parameters as an indicator of post-menopausal osteoporosis. The oral signs were panoramic-based mandibular indices, such as cortical width, cortical index, panoramic mandibular index and mandibular crest resorption degree; the number of teeth and fractal dimension analysis. METHODS: Forty-eight post-menopausal women between the ages of 40 years and 64 years were evaluated. Mandibular indices and the number of mandibular teeth were measured and evaluated from panoramic radiographs and fractal dimension was calculated from the direct digital periapical radiographs of the mandibular premolar-molar region in box-counting method. Weight, height, menopausal status and age of the patients were recorded by questionnaire. Bone mineral densities of the patients were measured with dual energy X-ray absorptiometry. RESULTS: In this study there were no statistically significant differences between the osteoporotic and non-osteoporotic patients for cortical width, panoramic mandibular index, alveolar crest resorption degree, fractal dimension and the number of mandibular teeth, but there was a difference for cortical index. Binary logistic regression analyses demonstrated that age (P = 0.015) was an important risk factor for osteoporosis. CONCLUSION: The results of this study demonstrated that osteoporotic patients were more likely to have altered inferior cortex morphology than non-osteoporotic patients and age is an important risk factor for osteoporosis.

Fractal dimension and lacunarity analysis of dental radiographs.

OBJECTIVE: As the occlusal forces transmitted to the jaw bones during mastication might be different in dentate and edentulous regions, there might be different radiographical trabecular bone texture in these regions. Image analysis procedures are promising techniques which are used to detect structural changes of bone texture on radiographs. In this study, the differences of fractal dimension (FD) and lacunarity measurements of radiographical trabecular bone between dentate and edentulous regions were investigated. METHODS: Direct digital radiographs of premolar-molar region were taken from 51 patients who were included in our study. Two rectangular regions of interest (ROIs) with the same dimensions (37x119 pixels) were created on these radiographs; one in the edentulous region and the other one in the dentate region. The ROIs were segmented as black and white areas. Box-counting fractal dimension and lacunarity of these regions were calculated. RESULTS: Paired samples t-test and Pearson correlation coefficients were calculated. It was found that there were differences between dentate and edentulous regions for FD and lacunarity (P=0.000). There is a negative correlation between FD and lacunarity (-0.643, P<0.01), positive correlation between dentate and edentulous regions and FD (0.819, P<0.01), and a negative correlation between lacunarity and dentate and edentulous regions (-0.541, P<0.01). CONCLUSIONS: The differences of occlusal forces generated in dentate and edentulous regions during mastication cause some alterations in trabecular bone structure, and fractal dimension and lacunarity can reveal these alterations quantitatively.