Computer programme to assess mandibular cortex morphology in cases of medication-related osteonecrosis of the jaw with osteoporosis or bone metastases

PURPOSE: The purpose of this study was to evaluate the morphology of the mandibular cortex in cases of medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis or bone metastases using a computer programme.MATERIALS AND METHODS: Fifty-four patients with MRONJ (35 with osteoporosis and 19 with bone metastases) were examined using panoramic radiography. The morphology of the mandibular cortex was evaluated using a computer programme that scanned the mandibular inferior cortex and automatically assessed the mandibular cortical index (MCI) according to the thickness and roughness of the mandibular cortex, as follows: normal (class 1), mildly to moderately eroded (class 2), or severely eroded (class 3). The MCI classifications of MRONJ patients with osteoporosis or bone metastases were evaluated with the Pearson chi-square test. In these analyses, a 5% significance level was used.RESULTS: The MCI of MRONJ patients with osteoporosis (class 1: 6, class 2: 15, class 3: 14) tended to be higher than that of patients with bone metastases (class 1: 14, class 2: 5, class 3: 0) (P=0.000).CONCLUSION: The use of a computer programme to assess mandibular cortex morphology may be an effective technique for the objective and quantitative evaluation of the MCI in MRONJ patients with osteoporosis or bone metastases.

Usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases

PURPOSE: To evaluate the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. MATERIALS AND METHODS: Ten patients with oral and maxillofacial diseases and 28 volunteers drawn from our student doctors were examined by shear wave elastography with a 14-MHz linear transducer using an Aplio 300 apparatus (Canon Medical Systems, Otawara, Japan). A statistical analysis of the shear elastic modulus (kPa) of healthy tissue (the sublingual gland, submandibular gland, anterior belly of the digastric muscle, and geniohyoid muscle) in the 28 volunteers was performed using 1-way repeated measures analysis of variance with the Tukey honest significant difference test. The maximum shear elastic modulus (kPa) of 8 patients with squamous cell carcinoma (SCC) and 2 patients with benign lesions was evaluated with the Mann-Whitney U test. The analysis used a 5% significance level. RESULTS: The mean shear elastic modulus of the sublingual gland (9.4±3.7 kPa) was lower than that of the geniohyoid muscle (19.2±9.2 kPa, P=.000) and the anterior belly of the digastric muscle (15.3±6.1 kPa, P=.004). The maximum shear elastic modulus of the SCCs (109.6±14.4 kPa) was higher than that of the benign lesions (46.4±26.8 kPa, P=.044). CONCLUSION: Our results demonstrated the usefulness of shear wave elastography in the diagnosis of oral and maxillofacial diseases. Shear wave elastography has the potential to be an effective technique for the objective and quantitative diagnosis of oral and maxillofacial diseases.