Development of Cu application using dual-energy computed tomography for detecting medication-related osteonecrosis of the jaw.

INTRODUCTION: The present study developed an application using dual-energy computed tomography (DECT) focused on Cu for detecting medication-related osteonecrosis of the jaw (MRONJ). MATERIALS AND METHODS: First, we performed two types of phantom studies using a Cu wire syringe and pig mandible with Cu wire to detect Cu on DECT. Second, DECT examinations of 44 patients with MRONJ were performed to compare lesion and normal bone sites using single-energy CT, DECT-virtual non-calcium (VNCa), and DECT-Cu applications. Quantitative analyses of VNCa CT and CT values were performed, and a cut-off value was calculated using receiver operating characteristic analysis. Third, we compared the Cu content in the MRONJ and normal bone groups using inductively coupled plasma atomic emission spectroscopy (ICP-AES). RESULTS: The material-specific differences in attenuation between the two different energies enabled the accurate separation of Cu from Ca in phantom studies. The sensitivity and specificity for single-energy CT, DECT-VNCa, and DECT-Cu applications were 97.7% and 2.3%, 86.4% and 81.8%, and 88.6% and 97.7%, respectively. Thus, VNCa CT values obtained on DECT-Cu application images showed the highest area under the curve value and maximal diagnostic efficacy in differentiating lesion sites from normal bone sites. On ICP-AES analyses, the Cu content was significantly higher in the MRONJ group than in the normal bone group. CONCLUSION: DECT-Cu application demonstrated better diagnostic performance in detecting MRONJ compared with single-energy CT or DECT-VNCa.

Photodynamic therapy with verteporfin accelerates apoptotic bleb formation in human ameloblastoma.

OBJECTIVE: Although benign, ameloblastoma is a locally aggressive lesion in some patients and the development of additional treatments is needed. Verteporfin (VP) is a photosensitizer exhibiting considerable photocytotoxicity in various tumor cells. We aimed to investigate the effects of verteporfin photodynamic therapy (VP PDT) on ameloblastoma. METHODS: Eighteen patients who underwent surgery for ameloblastoma were randomly selected. We performed an immunohistochemical assessment to investigate the expression of low-density lipoprotein receptor (LDLR) and Yes-associated protein (YAP), targets of VP, in human ameloblastoma tissues and cultured human ameloblastoma cell line (HAM1). The effect of VP PDT on cell proliferation and apoptosis in HAM1 was analyzed. RESULTS: The expression of LDLR and YAP were detected in human ameloblastoma tissues and HAM1. LDLR expression was significantly higher in patients who had previously undergone surgery than in patients who were receiving it for the first time. The cytotoxic effect of the combination of low-concentration VP administration and laser irradiation was comparable to high-concentration VP administration with and without laser irradiation. The addition of laser irradiation to VP administration significantly accelerated apoptotic bleb formation compared with VP administration alone. CONCLUSION: VP PDT has the potential to become an additional treatment for large-sized ameloblastoma.

Expression of JCAD and EGFR in Perineurial Cell-Cell Junctions of Human Inferior Alveolar Nerve.

Although perineurium has an important role in maintenance of the blood-nerve barrier, understanding of perineurial cell-cell junctions is insufficient. The aim of this study was to analyze the expression of junctional cadherin 5 associated (JCAD) and epidermal growth factor receptor (EGFR) in the perineurium of the human inferior alveolar nerve (IAN) and investigate their roles in perineurial cell-cell junctions using cultured human perineurial cells (HPNCs). In human IAN, JCAD was strongly expressed in endoneurial microvessels. JCAD and EGFR were expressed at various intensities in the perineurium. In HPNCs, JCAD was clearly expressed at cell-cell junctions. EGFR inhibitor AG1478 treatment changed cell morphology and the ratio of JCAD-positive cell-cell contacts of HPNCs. Therefore, JCAD and EGFR may have a role in the regulation of perineurial cell-cell junctions.

Referral to Pain Specialists for Treatment of Intractable Mandibular Pain Caused by Osteonecrosis of the Jaw: A Case Series Report.

Pain is a problematic symptom in patients with osteonecrosis of the jaws (ONJ). Effective pain management in patients with advanced ONJ still remains an unresolved issue. This case series report presents three patients who were referred to the pain clinic for treatment of intractable pain caused by ONJ. Two patients received mandibular nerve blocks and achieved pain relief. After referral to the pain clinic, these two patients underwent segmental mandibulectomy for ONJ. In the third patient, the effect of pain control was limited. Appropriate cooperation between the oral and maxillofacial surgeon and the pain specialist is essential for pain management in patients with advanced ONJ who experience intense pain.

Success of dental implants in patients with large bone defect and analysis of risk factors for implant failure: a non-randomized retrospective cohort study.

OBJECTIVES: This study aimed to retrospectively investigate the success and survival rates of dental implants used for dentomaxillary prostheses at our hospital and the risk factors associated with large bone defects. MATERIALS AND METHODS: A total of 138 external joint system implants used for dentomaxillary prostheses in 40 patients with large bone defects were included in this study. The alveolar bone at the site of implant insertion was evaluated using panoramic radiography and computed tomography. Various risk factors (demographic characteristics, dental status, and operative factors such as the employment of alveolar bone augmentation, the site, the length, and diameter of implants) for implant failure and complete implant loss were investigated using univariate and multivariate analyses. The associations between the variables and the success and survival rates of dental implants were analyzed using the multivariate Cox proportional hazard models. RESULTS: The 10-year overall success and survival rates were 81.3% and 88.4% in this study. Multivariable analysis showed that the male sex (HR 6.22), shorter implants (≤ 8.5 mm) (HR 5.21), and bone augmentation (HR 2.58) were independent predictors of success rate. Bone augmentation (HR 5.14) and narrow implants (≤ 3.3 mm) (HR 3.86) were independent predictors of the survival rate. CONCLUSION: Male sex, shorter or narrow implants, and bone augmentation were independent risk factors for dental implants used in dentomaxillary prostheses in patients with large bone defects. CLINICAL RELEVANCE: Clinicians should consider these risk factors and pay close attention to the management of these patients.

Association between pain severity and clinicohistopathologic findings in the mandibular canal and inferior alveolar nerve of patients with advanced mandibular osteoradionecrosis.

OBJECTIVE: Pain is one of the most problematic symptoms in patients with osteoradionecrosis of the jaws. This study investigated the associations between pain severity and morphologic alterations of the mandibular canal and inferior alveolar nerve, in respective computerized tomography images and resected specimens of mandibular osteoradionecrosis. STUDY DESIGN: We assessed 14 lesions in 13 patients who underwent segmental mandibulectomy for surgical debridement and simultaneous reconstruction with free fibula flap (1 patient exhibited bilateral lesions). The extent of the mandibular canal bone defect on preoperative coronal computerized tomography images and the number of inferior alveolar nerve fascicles in resected specimens were evaluated. Comparisons were made between the slight pain and extreme pain groups. In most of the patients in the extreme pain group, either mandibular canal bone defects were absent or entire circumferential defects were present; inferior alveolar nerve fascicles were either distinguishable or completely absent in the resected specimens. RESULTS: Although there was no statistically significant association between extreme pain and computerized tomography or histopathologic findings, the histopathologically indistinguishable inferior alveolar nerve fascicles was significantly associated with slight pain. CONCLUSIONS: The degree of degeneration of mandibular canal and inferior alveolar nerve may be associated with pain severity in patients with mandibular osteoradionecrosis.

Temporal Evaluation of Neurosensory Complications After Mandibular Third Molar Extraction: Current Problems for Diagnosis and Treatment.

OBJECTIVE: This retrospective study aimed to report the incidence of neurosensory complications after third molar extraction and also to identify current problems and discuss appropriate management of these complications. METHOD: Patients who underwent extraction of deeply impacted mandibular third molars under general anesthesia were included. The following epidemiological data were retrospectively gathered from medical charts: type of neurosensory complication, treatment for complication, and outcome. RESULTS: A total 369 mandibular third molars were extracted in 210 patients under general anesthesia during this study period. Thirty-one of the 369 teeth (8.4%) in 31 patients had neurosensory complications during the first postoperative week resulting from inferior alveolar nerve damage. Neurosensory complications lasting from 1 to 3 months postoperatively included 17 cases of hypoesthesia and 8 of dysesthesia in 19 patients. Five cases of hypoesthesia and 4 of dysesthesia in 5 patients persisted over 1 year postoperatively. Sixteen of 369 teeth (4.3%) in 16 patients had persistent neurosensory complications after third molar extraction under general anesthesia. Stellate ganglion block was performed in 4 patients. Early initiation of stellate ganglion block (within 2 weeks postoperatively) produced better outcomes than late stellate ganglion block (over 6 months postoperatively). CONCLUSION: Refractory neurosensory complications after third molar extraction often combine both hypoesthesia and dysesthesia. Current problems in diagnosis and treatment included delayed detection of dysesthesia and the lack of uniform timing of stellate ganglion block. In the future, routinely inquiring about dysesthesia and promptly providing affected patients with information about stellate ganglion block might produce better outcomes.