Oral Radiology

A case of venous malformation of the mandible Abstract Objective Vascular malformations occur more rarely in bones than in soft tissue, with 0.5–1.0% of all intraosseous tumors occurring in the mandible. We report a diagnostically challenging case of unilocular venous malformation of the mandible. Case report A 76-year-old man presented with a heterogeneous, unilocular, radiolucent lesion with a well-defined border. Panoramic radiography and computed tomography imaging revealed a continuous white line on the cortical bone at the inferior border of the left mandibular molar region. A spherical lesion with a well-defined border and a clear round region in the left mandible were revealed on magnetic resonance imaging. The lesion had the same signal intensity as muscles on T1-weighted imaging, a homogeneous high-intensity signal on short T1-inversion recovery imaging, and a well-defined low-signal intensity region surrounded by a high-intensity signal region on T2-weighted imaging. Pathological findings indicated that the lesion was a venous malformation. Discussion Although many studies have reported that venous malformations have a multilocular appearance, few have described the occurrence of unilocular lesions. Future investigations using magnetic resonance imaging and computed tomography are needed to increase the diagnostic accuracy for unilocular central vascular malformations of the jaw bone.

Schwannoma assumedly originating from the submandibular ganglion or glandular branches radiologically mimicking a submandibular gland tumor Abstract Schwannoma is a benign nerve sheath tumor composed of Schwann cells. Schwannomas originating from ganglia are rare, and schwannomas of the submandibular ganglion or glandular branches have not been reported to date. We present a case of a Japanese woman in her sixties with a submandibular schwannoma originating from the submandibular ganglion, mimicking a submandibular gland tumor on radiological findings. As the radiological findings were nonspecific, the key finding in the present case may be the characteristic location of the tumor suspended from the undersurface of the lingual nerve and situated above the deep portion of the submandibular gland.

Radiological features of synovial chondromatosis affecting the temporomandibular joint: report of three cases Abstract Synovial chondromatosis is a benign nodular cartilaginous proliferation that mainly occurs in large joints. The temporomandibular joint is considered to be rarely affected. Several cases of synovial chondromatosis of the temporomandibular joint have been reported with clinical and histological features. People with this disease may present with swelling, pain, intracapsular sounds, and limitation of mandibular movement. Radiographs are an important component in the diagnostic process for synovial chondromatosis. In this article, we report three cases of synovial chondromatosis occurring in the temporomandibular joint with a focus on the radiological features, including those on plain films, cone-beam computed tomography (CT) images, and conventional CT images. The three cases had totally different radiological features. The imaging differences were analyzed and compared to create combined diagnostic methods based on clinical features and examination techniques. The role of cone-beam CT examination in the diagnosis of the disease is discussed.

Effect of bisphosphonate treatment on the jawbone: an exploratory study using periapical and panoramic radiographic evaluation Abstract Objective This cross-sectional study aimed to explore potential jawbone changes secondary to bisphosphonate (BP) treatment of osteoporosis using digital panoramic and periapical radiography. Methods Thirty-nine women, previously examined with dual-energy X-ray absorptiometry, were radiographed by digital panoramic and/or periapical radiography. On periapical radiographs, trabecular bone structure and fractal dimension analyses of the mandibular first molar and edentulous regions were performed. On panoramic radiographs, the mandibular cortical width (MCW) was calculated, and trabecular bone structure and fractal dimension analyses of the trabecular bone in the alveolar and basal bones were performed. The results were compared between patients treated or not treated with BP using linear regression analysis to adjust for potential confounding factors. Results The analyses of periapical and panoramic radiological images showed no statistical differences in the jawbones between groups after bisphosphonate use for mean intervals of 4.3 and 5 years; respectively. Although the mandibular cortical width on panoramic radiography was correlated with BP use, it was not noted to be statistically significant. Conclusions The trabecular parts of the alveolar and basal bones and the MCW were not significantly altered by BP treatment in patients with osteoporosis over 4.3–5 years, as detected by digital periapical and panoramic radiography. The low dosages of bisphosphonates used in the treatment of osteoporosis may explain this lack of change in MCW. Dental radiographs should not be considered as a method to monitor BP-induced jaw bone alterations among osteoporotic patients.

Reproducibility of CBCT image analysis: a clinical study on intrapersonal and interpersonal errors in bone structure determination Abstract Objective For correct implant planning based on cone-beam computed tomography (CBCT), the bone contour must be accurately determined. Identification of the contour is difficult in bones with incomplete mineralization. In this clinical study, we investigated the intrapersonal and interpersonal reproducibilities of manual bone contour determination on CBCT images using a semi-automated computerized process. Methods The bone surface level in the area of the socket in 20 patients who had undergone tooth extraction from the upper jaw at 10 ± 1 weeks previously was determined on CBCT images. Two investigators with different levels of experience determined the bone structure initially (T0) and repeated the procedure after 3 months (T1). The bone structure marked on CBCT images was converted into a surface data set. The resulting data sets were superimposed on one another. In the analyses, the shortest distances between the datasets were identified and measured. The average deviations were statistically evaluated. Results The intrapersonal evaluation resulted in an average deviation of 0.18 mm across both investigators. The interpersonal analysis comparing the two investigators resulted in average deviations of 0.15 mm at T0 and 0.26 mm at T1. Significant differences were not found. Conclusions The low intrapersonal deviation indicates that the procedure has satisfactory reproducibility. All deviations were within the range of the selected resolution of the CBCT device. Application of a semi-automated procedure to detect the bone border in areas with incomplete mineralization is a predictable process. Trial registration The study was registered in the German Clinical Trials Register and the International Clinical Trials Registry Platform of the WHO: DRKS00004769, date of registration: 28 February 2013; and DRKS00005978, date of registration: 09 November 2015.

Sonographic diagnosis in the head and neck region: from an educational lecture presented at the 56th General Assembly and Annual Scientific Congress of the Japanese Society for Oral and Maxillofacial Radiology Abstract Sonography is a simple, inexpensive, and non-invasive diagnostic modality. Although tissues behind bony structures and deep tissues are not delineated, sonography can depict superficial soft tissues very clearly. In the head and neck region, however, it has not yet been used widely, as the anatomical structures are complicated, and considerable experience is needed both to perform an examination and to make a diagnosis. To perform examinations efficiently, operators must be familiar with the sonographic system in use, and take images at standard planes. To make a correct diagnosis, operators require knowledge of the sonographic anatomy on standard planes, representative sonographic signs and artifacts, and common diseases and their typical sonographic findings. In this paper, we have explained the sonographic anatomy on standard planes, and the sonographic findings of common diseases in the oral and maxillofacial region.

Radiological analysis of the sella turcica and its correlations with body mass index in a North Indian population Abstract Objectives The sella turcica is an important component situated in the mid-third of the cranial fossa. Knowledge about its normal morphologies and dimensions may play a crucial role in diagnosing underlying pathologies. The present study aimed to analyze the principal morphological shapes of the sella turcica, measure its linear dimensions, and determine whether any correlations exist between its dimensions and body mass index (BMI) in subjects in a North Indian population. Methods The study was conducted on 100 subjects (50 men; 50 women) who underwent cone-beam computed tomography scans at our Oral Medicine and Radiology Department. The subjects had an age range of 20–60 years. The morphology of the sella turcica was examined according to age and various measurements were taken to determine its size. Possible correlations between the dimensions of the sella turcica and BMI were evaluated by statistical analysis. Results In the present study, 69% of the subjects had a normal morphology. No uniform increases in length, width, and depth of the sella turcica were observed with aging. When Pearson correlation coefficients were calculated, no strong correlations were found between the dimensions of the sella turcica and BMI. A mild correlation was seen between the length and width of the sella turcica. Conclusion No significant correlations were found between the dimensions of the sella turcica and BMI in the present study. These findings may have arisen through the small sample size, and thus further studies with larger groups of subjects are warranted.

Comparison of cone-beam computed tomography with bitewing radiography for detection of periodontal bone loss and assessment of effects of different voxel resolutions: an in vitro study Abstract Objective The aim of the study was to compare intraoral radiographs and CBCT images for detection of horizontal periodontal bone loss, and to investigate the diagnostic effect of different voxel resolutions in CBCT imaging. Methods A total of 240 sites with horizontal bone loss were measured on the buccal, lingual, mesial, and distal surfaces of 60 posterior teeth in four maxillary and six mandibular bones obtained from cadavers (dry skulls). Direct measurements on the dry skulls were accepted as the gold standard values. Measurements on CBCT images at two different voxel resolutions (0.250 and 0.160 mm3) and intraoral bitewing radiographs were compared with one another and with the gold standard values. Results The measurements on the CBCT images at two voxel resolutions and bitewing radiographs did not differ significantly (p > 0.05) from the direct measurements on the dry skulls. No significant difference was found between the bitewing radiographs and CBCT images for measurements in the mesial and distal regions (p > 0.05). There was no significant difference between the measurements on the buccal and lingual surfaces at the two different voxel resolutions (p > 0.05). Conclusions CBCT scans are recommended for evaluation of buccal and lingual bone loss to avoid intraoral radiographs that exceed routine examination of interproximal alveolar bone loss. Furthermore, instead of basing the voxel size on the required CBCT scans, it is recommended to select the smallest possible field of view to reduce the dose of radiation.

Incidental findings during head and neck MRI screening in 1717 patients with temporomandibular disorders Abstract Objective Magnetic resonance imaging (MRI) plays an important role in the evaluation of temporomandibular disorders (TMDs). At our institution, we perform additional head and neck screening using head coils when performing MRI screening of the temporomandibular joint (TMJ) to detect lesions in areas other than the TMJ (lesions discovered by chance, or incidental findings; IFs) and to conduct a diagnosis of exclusion. The objective of this study was to determine the number and frequency of IFs detected during head and neck screening, according to sites and diseases. Materials and methods The study evaluated 1717 patients with clinically suspected TMDs who underwent MRI of the TMJ. IFs were assessed on horizontal sections of images of the craniofacial region obtained by the short tau inversion recovery imaging technique. Results The patients undergoing MRI of the TMJ comprised 433 males and 1284 females. Among the patients, at least one IF was detected on images in 461 patients. The most common IF site was the maxillary sinus. Based on diagnostic imaging, there were 21 IFs (1.2%) associated with TMD symptoms, or for which an association with TMD symptoms could not be ruled out. Conclusions Combination of conventional MRI imaging of the TMJ with craniofacial MRI screening may allow detection of lesions other than TMDs, thereby confirming the usefulness of MRI. Detection of IFs may require development of different therapeutic strategies than those for TMDs.