Analysis of image defects in digital intraoral radiography based on photostimulable phosphor plates.

OBJECTIVES: In digital intraoral radiography (DIR), images with defects caused by the digital process are sometimes produced. Hence, we analyzed DIR images with defects taken using the photostimulable phosphor (PSP) plate method and then classified these images based on the causes of the defect. The aim of this study was to classify defects in DIR using the PSP plate system, and to discuss the causes of each type of defect and the methods that can prevent their occurrence. METHODS: Images with defects due to the two PSP plate systems (Arcana and Arcana Mira) were selected and classified according to the defect. Image defects caused by geometrical techniques that occur in both the film and PSP plate methods were excluded from this study. Moreover, changes in the rate of occurrence of images with defects over time were analyzed in this study. RESULTS: The defects in images obtained by the PSP plate system were classified into six types, which were further divided into those caused by machine error or human error. Both types of error could influence the diagnostic performance. Machine error accidentally and rarely occurred; thus, the prevention of such errors is difficult. However, human error, especially errors caused by photo-induced discharge, could be prevented using appropriate measures. CONCLUSIONS: In DIR systems using the PSP plate method, human error should be prevented by education and training to improve operation.

Cross-sectional and longitudinal assessment of subchondral cysts in temporomandibular joints: Clinical and MRI study with a mean follow-up of 66 months.

PURPOSE: This observational study aimed to elucidate the pathophysiology of subchondral cysts (SC) in the temporomandibular joint (TMJ) and examine the results of conservative therapy administered to patients with SCs in the TMJ. METHODS: The study included 41 patients with SCs, extracted from 684 consecutive patients who underwent magnetic resonance imaging (MRI). The anatomical features of SCs and positional abnormalities of the articular disc were initially evaluated using MRI. A second MRI examination was performed for 28/41 patients at 40-107 months (mean, 66 months) after the first MRI. The joint space, anteroposterior width of the condylar head (WiC), articular eminence angle (AEA), and visual analog scale of jaw pain (VAS) were assessed alongside the MRI examinations. RESULTS: Most SCs were present in the anterosuperior and central condyle. Disc displacement was observed in 100% of 42 TMJs with SCs. Of the 29 joints in 28 patients, SCs in 19 joints resolved with time, whereas SCs in 10 joints persisted. A significant increase in the WiC and a significant decrease in AEA and VAS scores were observed on the second MRI scan. CONCLUSIONS: SCs tended to form in the anterosuperior and central parts of the condyle, where mechanical loading was likely to be applied. SCs are strongly associated with articular disc displacement. Two-thirds of SCs resolved over time, accompanied by resorption and osteophytic deformation of the condyle. SC might not be an indicator for the start of surgical treatment, and nonsurgical treatment could improve the clinical symptoms of patients with SCs.

Involvement of an FTO gene polymorphism in the temporomandibular joint osteoarthritis.

OBJECTIVES: The FTO gene has been reported as an obesity-associated gene and is also considered a risk gene for osteoarthritis (OA). However, its exact function is unclear, and there is conflicting evidence on the involvement of FTO polymorphisms in OA via obesity. The purpose of this study was to determine the effects of FTO polymorphism rs8044769 alleles on OA in the temporomandibular joint (TMJ), which is minimally affected by body weight. MATERIALS AND METHODS: A total of 324 TMJs (113 with OA and 211 without OA, serving as controls) from 162 Japanese patients with temporomandibular disorders and undergoing MRI examination were analyzed. Genotyping was conducted, and multivariate analysis was performed after adjusting for the effects of age, sex, body mass index, and TMJ disc abnormalities. RESULTS: Mean age, BMI, and sex did not differ between the TMJs with OA and the TMJs without OA, but a significant difference was found for positional and dynamic disc abnormalities (P < 0.05). The allele frequency of FTO polymorphisms also differed significantly between the TMJs with OA and the TMJs without OA (P = 0.011). Moreover, logistic regression analysis showed no significant association between BMI (P = 0.581) and the occurrence of TMJOA but also indicated that the CC allele of rs8044769 is a risk factor for TMJOA (P = 0.040). CONCLUSIONS: Our results show that rs8044769 in the FTO gene might be involved in TMJOA. CLINICAL RELEVANCE: The present study provides a basis for a deeper understanding of the mechanism underlying degenerative skeletal diseases and the more effective selection and development of treatment strategies based on the patients' genetic characteristics.

Distant metastasis from oral cavity-correlation between histopathology results and primary site.

OBJECTIVES: Oral cancer is the eighth most common type of cancer worldwide and a significant contributor to the global burden caused by this disease. The principal parameters considered to influence prognosis, and thus treatment selection, are size and location of the primary tumor, as well as assessment of the presence and extent of lymph node and distant metastasis (DM). However, no known report regarding the relationship between the primary site and DM has been presented. For effective treatment selection and good prognosis, the correlation of DM with anatomic site and histopathology results of the primary malignancy is important. In the present study, we performed a systematic review of published reports in an effort to determine the relationship between the anatomic site of various types of oral cavity cancer and DM. METHODS: A systematic review of articles published until the end of 2018 was performed using PubMed/MEDLINE. RESULTS: A total of 150 studies were selected for this review. The percentage of all cases reported with DM was 6.3%, ranging from 0.6% to 33.1% in the individual studies. The rate of incidence of tongue occurrence was 9.3%. A frequent DM site was the lungs, with adenoid cystic carcinoma the most commonly involved histopathological factor. Malignant melanoma was most frequent (43.4%) in all histopathology findings, whereas there were no cases with an acinic cell carcinoma or cystadenocarcinoma. CONCLUSIONS: We found that the occurrence of DM from the primary site as well as rate of incidence was dependent on histopathological factors.

Diffuse large B-cell lymphoma of the mandible with periosteal reaction: a case report.

This report describes a rare case of a 63-year-old man with a lymphoma in the right mandibular ramus with periosteal reaction. Computed tomography (CT) images showed a soft tissue density (28 × 48 × 32 mm) around the right mandibular foramen. Bone-mode CT images showed diffuse bone destruction of the right mandibular ramus. Moreover, a periosteal reaction was seen on the lingual cortical bone of the right mandibular ramus. Histopathologic examination found a diffuse large B-cell lymphoma.

Electron beam radiotherapy for tongue cancer using an intra-oral cone.

To explain the adaptation technique using an intra-oral cone (IOC) for radiation therapy, and to determine the optimal schedule resulting in a high local control rate and an acceptable complication rate using direct electron beam radiation for the treatment of tongue cancer. Thirty patients with the tongue cancer (T1:T2:T3=16:11:3) were treated with 6-15 MeV electron radiation using an IOC. Twenty-six patients were treated with electron radiation using an IOC with or without an excisional biopsy. The other four patients were treated with a combination of the external beam radiation and electron radiation using the IOC. In order to formulate a safe and effective treatment program, we calculated the biologically effective dose (BED). The two- and five-year local control rates for all patients were 63% and 52%, respectively. The two- and five-year overall survival rates for all patients were 73% and 69%, respectively. Local control was achieved in 12 of 15 patients who were irradiated with a BED of 90.9 Gy(10) or more, whereas it was not achieved in nine of the 15 patients who were treated with less than a BED of 90.9 Gy(10) (p=0.03). The application of electron radiation using an IOC for the treatment of tongue cancer provides acceptable local control and adverse effect rates, especially for elderly patients considered to be high risk for complications from anesthesia. The optimum BED(10) value for the treatment of early tongue cancer using the IOC technique appears to be at least 90.9 Gy(10).

Diagnostic imaging findings for mandibular metastasis from gastric adenocarcinoma.

A case of metastatic adenocarcinoma from gastric cancer to the mandibular canine region is reported. Computerized tomography (CT) scanning revealed a small round enhanced inhomogeneous mass, indicating an osteolytic lesion on radiographic classification. Although chemotherapy and radiation therapy was performed, the mass increased, and a subsequent CT scan showed further calcifications within the tumor, indicating progression from an osteolytic to a mixed lesion.

Benign fibrous histiocytoma of the mandible.

A very rare case of benign fibrous histiocytoma of the mandible is presented. A 49-year-old woman was admitted because of left buccal swelling and pain. Panoramic radiograph showed well-demarcated soap-bubble appearance without sclerotic rim in the left mandibular bone. A yellowish-white and partly brown solid tumor was noted in the excised mandibular bone specimen. The tumor histologically consisted of spindle cells, in which areas showing a storiform pattern and other areas composed of histiocytic cells with erythrophagocytosis and foam cells were mixed. Immunohistochemically, the tumor cells were positive for vimentin, CD68, alpha-1-antichymotrypsin and alpha-1-antitrypsin. From these findings the tumor was diagnosed as a primary BFH of the mandible. No recurrence has been noted 2 years and 11 months after surgery.