A support vector machine-based algorithm to identify bisphosphonate-related osteonecrosis throughout the mandibular bone by using cone beam computerized tomography images.

OBJECTIVE: This study aimed to develop an algorithm to distinguish the patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ) from healthy controls using CBCT images by evaluating both trabecular and cortical bone changes through the whole body of the mandibular bone. METHODS: Patient data set was created from axial CBCT images of 7 BRONJ patients (28 slices) and 8 healthy controls (27 slices). The healthy bone of healthy controls, bone sclerosis of BRONJ patients, bone necrosis of BRONJ patients, and normal appearing bone of BRONJ patients (NBP) were labeled on CBCT images by three maxillofacial radiologists. Proposed algorithm had preparation and background cancellation, mandibular bone segmentation and centerline determination, spatial transformation of gray values, and classification steps. RESULTS: Significant differences between the statistical moments (mean, variance, skewness, kurtosis, standard error, median, mode and coefficient of variance) of healthy and diseased (bone sclerosis and necrosis) groups were observed (p = 0.000, p < 0.05). Also, variations were noted between healthy controls and NBP of BRONJ patients (p = 0.000, p < 0.05).The statistical moments were utilized to develop the algorithm which has resulted with accuracy of 0.999, sensitivity of 0.998, specificity of 0.998, precision of 1, recall of 0.998, AUC of 1, and F1 score of 0.999 in identification of BRONJ patients from healthy ones. CONCLUSION: The proposed algorithm differentiated the mandibular bones of the healthy and the BRONJ patients with high accuracy in the present test sample.

Brush Biopsy Sample Quality: Preliminary Investigation of a Metal Brush Prototype

Objective: To qualitatively investigate whether a prototype brush composed of metal bristles collects oral epithelial cells effectively for cytological evaluation of oral mucosal lesions. Material and Methods: Twenty patients with suspicious oral mucosal lesions were enrolled. Patients were asked to gargle with saline and to deposit the oral rinse into specimen cup. Then, oral mucosal cell samples were collected using a metal oral brush, via sweeping motion. Punch biopsy was performed for histological examination. All samples were evaluated with liquid based cytology (LBC) according to the cellularity, the depth of the epithelial layer, cellular integrity by an oral pathologist. Results: Oral rinse provided samples with 100% cellular integrity and cellularity, mostly from the intermediary layers. With metal brush, both inadequate cellularity and cellular integrity was observed in 25% of the cases. Cellular integrity was adequate in 65%, cellularity was adequate in 45% of the lesions. Samples were dominantly from the intermediary layers, but in one case, metal brush collected cells from the parabasal layer. Conclusion: The narrow spiral pitch and width of metal bristles may have resisted to release the cellular samples collected. With adjustment of the spiral pitch and diameter of metal brush bristles, its' efficacy could be enhanced.

Characterization​ and ​analysis of ​m​otion ​m​echanism​ of electroactive​ chitosan-based actuator.

In order to analyze the bending mechanism of the electroactive​ chitosan-based actuator, different amounts of poly(diallyldimethylammonium chloride) (PDAD) were incorporated in chitosan solution. The effects of PDAD concentration on electromechanical performance of chitosan actuator were investigated under various excitation voltages. With the incorporation of PDAD into chitosan solution, crosslinked chitosan film acts as an actuator showing a considerable displacement behavior. However it can be noted that higher incorporation of PDAD into chitosan solution decreased the performance of the actuators. Thermal, viscoelastic, and crystallographic properties of the chitosan films were examined by thermogravimetric analysis, dynamic mechanical analysis, and X-ray diffraction analysis, respectively. The effect of incorporation of PDAD in chitosan-based film on morphological properties of chitosan film was determined by scanning electron microscopy. It was observed that the films involving PDAD have larger pore size than the PDAD free film.