Foramen tympanicum or foramen of Huschke: anatomical cone beam CT study.

OBJECTIVE: The foramen of Huschke (foramen tympanicum) represents a developmental defect in the antero-inferior aspect of the bony external auditory meatus. The foramen is located at the antero-inferior aspect of the external auditory canal, posteromedial to the temporomandibular joint. The aim of this study is to define the prevalence and location of the foramen of Huschke. METHODS: We retrospectively examined 207 cone beam CT (CBCT) studies (414 ears). We used flat panel detector (FPD)-based CBCT (New Tom FP; Quantitative Radiology, Verona, Italy) for imaging in our department. We noted the location of the foramen tympanicum and calculated its prevalence as a percentage. RESULTS: We found a foramen tympanicum in 37 (17.9%) of 207 patients. This was unilateral in 24 patients (11.6%) and bilateral in 13 patients (6.3%). Mean axial diameter was 5 mm and mean sagittal diameter was 2 mm. CONCLUSION: The foramen tympanicum is an uncommon disorder and is well demonstrated on CBCT. This is the first study to detect the foramen tympanicum using FPD-based CBCT.

The frequency of bifid mandibular condyle in a Turkish patient population.

OBJECTIVE: The objective of this study was to investigate the frequency and pattern of bifid mandibular condyles (BMCs). METHODS: A retrospective study was performed using panoramic radiographs from 10 200 patients undergoing dental treatment in the Department of Oral and Maxillofacial Radiology (Erzurum, Turkey) between 1996 and 2008. RESULTS: Of the 10 200 patients, 32 (0.3%) had BMCs, of whom 17 were female (53.1%) and 15 were male (46.9%). The age range of the patients with BMCs was 5 to 71 years (mean age 30.0+/-0.40). Of these 32 patients, 24 (75.0%) had unilateral and 8 (25.0%) had bilateral BMCs, none of the patients had a history of trauma. No symptoms associated with bifid condyles were observed in any of the patients with BMCs. CONCLUSIONS: It is possible that BMC is a more frequent condition than is commonly perceived. However, because of the minimal symptoms associated with this condition, the authors believe that it will remain an incidental finding upon routine radiographic examination, rather than a clinical observation. Nevertheless, in symptomatic cases or in cases where surgical treatment is planned, panoramic radiographs should be supplemented with CT.

Comparison of the sensitivity for detecting foreign bodies among conventional plain radiography, computed tomography and ultrasonography.

OBJECTIVE: The purpose of this study was to compare the sensitivity for detecting foreign bodies among conventional plain radiography, CT and ultrasonography in in vitro models. METHODS: Seven different materials were selected as foreign bodies with dimensions of approximately 1 x 1 x 0.1 cm. These materials were metal, glass, wood, stone, acrylic, graphite and Bakelite. These foreign bodies were placed into a sheep's head between the corpus mandible and muscle, in the tongue and in the maxillary sinus. Conventional plain radiography, CT and ultrasonography imaging methods were compared to investigate their sensitivity for detecting these foreign bodies. RESULTS: Metal, glass and stone can be detected with all the visualization techniques used in the study in all of the zones. In contrast to this, foreign bodies with low radiopacity, which could be detected in air with CT, became less visible or almost invisible in muscle tissue and between bone and muscle tissue. The performance of ultrasonography for visualizing foreign bodies with low radiopacity is relatively better than CT. CONCLUSIONS: Ultrasonography detects and localizes superficial foreign bodies with low radiopacity in the tissues of the body more effectively than CT and conventional plain radiography. However, CT is a more effective technique for visualization of foreign bodies in air than ultrasound and conventional plain radiography.

Reliability of mandibular cortical index and mandibular bone mineral density in the detection of osteoporotic women.

OBJECTIVES: Measuring the bone mineral density (BMD) of the femur and lumbar vertebrae has been the traditional method for determining osteoporosis in women. In this study, we tried to determine the relationships between mandibular dual-energy X-ray absorptiometry (m-DXA) values obtained with a new methodology, mandibular cortical index (MCI), total BMD values of the femur and lumbar vertebrae in 80 women with osteoporosis determined by DXA in conformity with T-score thresholds, as defined by the World Health Organization (WHO). METHODS: m-DXA and panoramic radiography were performed on 80 women with osteoporosis. m-DXA was calculated by manual analysis of DXA scans. MCI was determined by the appearance of the mandibles on panoramic radiographs. DXA measurements of the skeletal BMD (femur and lumbar vertebras) and MCI values were also calculated. Correlations between these variables were assessed. RESULTS: Although there were no correlations between skeletal BMD (total BMD values of the femur and lumbar vertebras) and mandibular measurements (mDXA and MCI), we found that there was a significant correlation between the skeletal BMDs (r = 0.355, P = 0.001). CONCLUSIONS: It is concluded that no significant correlations were found between the mandibular and non-mandibular measures in women with osteoporosis.

Dental panoramic radiography in the diagnosis of osteoporosis.

Osteoporosis is common in the elderly and the dentist is often the only healthcare professional that they visit regularly. Since dental panoramic radiographs (DPRs) are widely used for routine examinations when planning treatment, this study evaluated whether the presence of osteoporosis might be apparent in a population of patients who underwent DPR. The mandibular cortical index (MCI) and a new method of measuring the mandibular radiographic density (m-RD), which used DPR that incorporated an aluminium step-wedge, were compared with the total vertebral bone mineral density (v-BMD) of the lumbar vertebrae measured using dual energy X-ray absorptiometry (DXA) in 25 osteoporotic women. Although there was only a weak correlation between m-RD and v-BMD, significant correlation was found between MCI and v-BMD. Since both m-RD and MCI were related to vBMD, dental radiographic density and MCI may be useful in clinical dental practice to identify osteoporotic women with previously undetected low BMD.

Evaluation of the mandible as an alternative autogenous bone source for oral and maxillofacial reconstruction.

The objective of this study was to quantify the amount of bone graft material present in the different regions of the mandible while avoiding the inferior alveolar neurovascular bundle, mental foramen and tooth injury. The study was carried out on 16 samples of dry, cadaverous skull. The dimensions of the anterior part of ascending ramus, mandibular symphysis and mandibular body in these samples were evaluated. The osteotomy lines in the anterior part of the ascending ramus were made in front of the mandibular canal from the mandibular notch to 3 mm posterior of the root of the third molar. The osteotomy line in the mandibular body was made just medial to the external oblique ridge from the ascending ramus to approximately 3 mm posterior to the mental foramen. Vertical osteotomy lines were then made from the cut ends of the first osteotomy down to the lower border of the mandible. The osteotomy lines in the mandibular symphysis were performed on the mandible with 5-mm safety margins caudal to the expected position of the mandibular dentition, anterior to the position of the mental foramen, and cephalad to the inferior border of the mandible. It was determined that the dimensions of the anterior part of the ascending ramus were 37.60 mm x 33.17 mm x 22.48 mm x 9.15 mm, and the thickest part of the graft material was 12.23 mm. The average horizontal length of the mandibular body bone was 35.10 mm, and the average vertical length was 19.13 mm. The dimensions of the bone graft obtained from the mandibular symphysis were 45.36 mm x 10.31 mm, and the average thickness was 9.63 mm. Based on the results of this study, it is apparent that the different regions of the mandible can reliably be selected as the harvest site in a variety of oral and maxillofacial reconstructive procedures.

Radiographic study of mandibular nutrient canals.

This study was undertaken to determine the correlation between the presence of nutrient canals in the mandibular anterior region and sex, age, edentulous mandible, periodontal disease, and high blood pressure. The periapical roentgenograms taken from the mandibular anterior region of 1040 patients were examined. According to the data obtained from the present study, the occurrence of nutrient canals in the mandibular anterior region seemed related to age, edentulous mandible, periodontal problems, and high blood pressure. However, no relation to sex was found.