Objective:This retrospective study was conducted to reveal usability of surgical treatment in the cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) stage 2 with sequestrum.Patients and Methods:Study subjects included 18 patients having BRONJ stage 2 with sequestrum and 12 non-BRONJ patients with nearly equal clinical states of BRONJ stage 2. Patient characteristics, frequency of inciting factors of osteonecrosis, and treatment results were compared between BRONJ group and non-BRONJ groups. In addition, correlation between treatment methods (conservative therapy, sequestrum curettage, and sequestrectomy) and treatment results and correlation between the administration route of bisphosphonates (BPs) (oral or intravenous) and treatment results were examined statistically. The Student's t-test and Fisher's exact test were performed for statistical analysis.Results:Patient characteristics, frequency of inciting factors of osteonecrosis, and treatment results showed no significant differences between the two groups. In the BRONJ group, treatment result of sequestrectomy was significantly better than conservative therapy/sequestrum curettage (P < 0.001), however, no significant difference was observed in the non-BRONJ group. No significant difference was found in correlation between the administration route of BPs and treatment results in the BRONJ group.Conclusion:Treatment outcome of sequestrectomy was better than conservative therapy/sequestrum curettage in BRONJ stage 2 cases with sequestrum.

Most clinicians throughout the world are probably unaware of the existence of masticatory muscle tendon-aponeurosis hyperplasia (MMTAH), potentially leading to misdiagnoses such as temporomandibular joint disorder (TMD). Here, we introduce this disease from the viewpoint of education. In February 2013, a 39-year-old woman presented with limited mouth opening. Her facial configuration was characterized by a square mandible. There was no evidence of TMD. Magnetic resonance imaging (MRI) showed bilateral enlargement of the masseter muscles. Additionally, a ‘thick’ aponeurosis of the anterior aspect of the masseter muscle was noted bilaterally. On maximal mouth opening, intraoral palpation along the anterior border of the masseter muscle confirmed a hard cord-like structure, consistent with the findings on MRI. MMTAH was diagnosed. When clinicians notice limited mouth opening on oral examination, they should be knowledgeable about diseases associated with limited mouth opening and a square mandibular configuration, such as MMTAH.