A case of successful treatment of medication-related osteonecrosis of the jaw with conservative treatment for pathological mandibular fracture.

INTRODUCTION: Surgical therapy is effective for medication-related osteonecrosis of the jaw. However, appropriate conservative treatment options are still important for cases in which surgery is contraindicated. We report a case of medication-related osteonecrosis of the jaw successfully treated conservatively for a pathological mandibular fracture. PRESENTATION OF CASE: An 84-year-old female patient presented to our department with a chief complaint of inadequate healing of an extraction tooth socket. She had been taking minodronic acid hydrate for approximately five years for osteoporosis. The clinical examination revealed erythema, diffuse swelling of the left mandibular angle, erythema of the buccal gingiva adjacent to the left mandibular first molar, and fistula formation. Although surgery was recommended, the patient declined to proceed. Therefore, a conservative treatment was initiated. A pathological fracture of the inferior mandibular margin was observed one month after the initial visit. Mouth opening was restricted for six months using a bandage. Two months after the pathological fracture, the inferior margin of the fracture was aligned. Five months later, the inferior margin continued. One year later, the bony union of the fracture was observed. DISCUSSION: Conservative treatment and restricting mouth opening was effective in our case. Three years and seven months after the pathological fracture, no new sequestrum formation was observed, and the patient was doing well. CONCLUSION: Conservative treatment can be effective for medication-related osteonecrosis of the jaw with severe cases.

Presurgical imaging of the subscapular artery with three-dimensional-computed tomography angiography: Application to harvesting subscapular system free-flaps.

A subscapular system free-flap is extremely useful for maxillofacial reconstruction since it facilitates the simultaneous harvesting of multiple flaps using one subscapular artery (SSA) alone. However, cases of aberrations in the SSAs have been reported. Therefore, the morphology of SSA needs to be confirmed preoperatively before harvesting the flaps. Recent developments in imaging, such as three-dimensional (3D) computed tomography angiography (3D CTA), facilitate obtain high-quality images of blood vessel images. Therefore, we examined the utility of 3D CTA in navigating the course of the SSA before harvesting subscapular system free-flaps. We examined the morphology and aberrations of the SSA using 39 sides of the 3D CTA data and 22 sides of Japanese cadavers. SSAs can be classified into types S, I, P, and A. Type S SSAs are significantly long (mean length = 44.8 mm). Types I and P SSAs have short mean lengths, measuring ≤2 cm in approximately 50% of cases. In type A, the SSA is absent. The frequency of types S, I, P, and A SSAs were 28.2%, 7.7%, 51.3%, and 12.8%, respectively. Type S can be advantageous for harvesting the SSA in subscapular system free-flaps, because it is significantly longer. In contrast, types I and P might be dangerous because their mean lengths are shorter. In type A, caution is needed not to injure the axillary artery because the SSA is absent. When surgeons need to harvest the SSA, presurgical 3D CTA is recommended.

Successful treatment with nivolumab in a patient with unresectable oral squamous cell carcinoma following ineffective chemoradiotherapy.

Key clinical message: Nivolumab has been clinically successful in prolonging the overall survival of patients with recurrent and metastatic head and neck cancer, complete remission is rare. Synergistic combinations of immunotherapy and conventional cancer treatments, such as radiotherapy or chemotherapy, are likely to be the most viable strategies for improving patient responses. Abstract: Immune checkpoint inhibitors have revolutionized recurrent, metastatic oral cancer treatment; however complete remission in advanced stages is unusual. We present a case of complete remission of advanced oral squamous cell carcinoma for >4 years in a 64-year-old Japanese woman, that responded poorly to chemoradiotherapy but well to subsequent nivolumab treatment.

Treatment of severe micrognathia in an adult with distraction osteogenesis: A case report.

Key Clinical Message: Distraction osteogenesis (DO) of the mandible is often performed at a young age, and there are few reports after age 30, as in this case. The Hybrid MMF used in this case was useful in that it allowed correction of fine directionality. Abstract: DO is often performed in young patients with a high capability of osteogenesis. We performed distraction surgery for a 35-year-old man who had severe micrognathia with serious sleep apnea syndrome. Four years postoperatively, suitable occlusion and improvement of apnea were observed.

A case of peripheral odontogenic fibroma arising in the mandibular premolar region of a teenager.

Peripheral odontogenic fibroma (POdF) is a rare, benign ectomesenchymal tumor. Herein, we report a case of a 15-year-old female patient who developed POdF in the mandible. The lesion was resected along with the periosteum. Histopathological findings revealed a small mass and cord-like epithelium. There was no recurrence 16 months postoperatively.

[Neutrophil-to-Lymphocyte Ratio(NLR)as a Predictive Indicator of the Response to Nivolumab in Patients with Oral Squamous Cell Carcinoma].

BACKGROUND: The immune checkpoint inhibitor (ICI) nivolumab has revolutionized the treatment for recurrent or metastatic advanced oral cancer. Because the response rate remains low, the identification of predictive indicators of the response to nivolumab is among the most critical issues. The neutrophil-to-lymphocyte ratio(NLR)is a potential predictive marker of the response to nivolumab in patients with various cancer types. However, the utility of the NLR as a biomarker for predicting the response of oral cancer patients to ICIs is poorly understood. PATIENTS AND METHODS: In this retrospective cohort study, we evaluated the association between NLR and nivolumab treatment outcome in 13 patients diagnosed with recurrent or metastatic oral squamous cell carcinoma(OSCC)treated with nivolumab at the Toyama University Hospital between December 2017 and December 2019. RESULTS: Complete response(CR)and partial response(PR)rates of 38.5%(5/13)and 0% (0/13), respectively, were observed in responders; stable disease(SD)and progressive disease(PD)rates of 7.7%(1/13) and 53.8%(7/13), respectively, were observed in non-responders. After nivolumab treatment, the median NLR among responders decreased to 3.3(3.0-3.9)from 4.1(3.7-4.3)during pre-treatment assessment and increased from 5.6(3.2- 9.2)at pre-treatment to 9.4(5.3-17.9)among non-responders. Moreover, patients with higher NLRs(≥5)in the post- treatment group had a significantly worse overall survival than those with lower NLRs(<5). Specifically, patients with a higher post-treatment NLR(≥10)had significantly worse outcomes for post-nivolumab salvage chemotherapy. CONCLUSION: The NLR could be a useful marker for predicting the treatment response to nivolumab or post-nivolumab salvage chemotherapy in OSCC patients.

Central mucoepidermoid carcinoma of the maxilla developing from a calcifying odontogenic cyst: A rare case report.

Intraosseous mucoepidermoid carcinoma of the jaw is a rare lesion that has been suggested to originate from the odontogenic epithelium. We report an unusual case of central mucoepidermoid carcinoma in an 18-year-old Japanese man with an odontogenic cyst.

Durable complete response to immunotherapy with anti-PD-1 antibody nivolumab in a patient with oral squamous cell carcinoma presenting with lung metastasis: A case report.

Although the optimal treatment method for metastatic oral cancer remains largely unknown, the present case suggests that immunotherapy is a potentially promising alternative for metastatic oral cancer in which other therapies are no longer effective.

Protumor role of estrogen receptor expression in oral squamous cell carcinoma cells.

OBJECTIVE: Accumulating evidence has demonstrated the protumor role of estrogen receptor (ER)-mediated signaling in multiple cancer types, which is distinct from this signaling in sex steroid-dependent organs. However, its role in oral squamous cell carcinoma (OSCC) remains unclear. STUDY DESIGN: We assessed the expression of ERα and ERß in human OSCC tissues by immunohistochemistry and evaluated the expression of both receptors in OSCC cell lines by immunoblotting and flow cytometry. To further assess the contribution of ER-mediated signals to oral cancer progression, proliferation, invasion, and chemosensitivity, cell lines were stimulated with the ER agonist ß-estradiol. RESULTS: Immunohistochemical analysis of OSCC tissues showed that ERß was present in the cytoplasm and nuclei of OSCC cells. In contrast, ERα was not detected in any of the cases analyzed. Additionally, the proliferation and invasiveness of OSCC cells were significantly elevated following stimulation with ß-estradiol. Chemotherapeutic agent-induced apoptosis of cancer cells was attenuated by pretreatment with ß-estradiol. CONCLUSIONS: ER-mediated signaling plays a crucial role in oral cancer progression by facilitating the proliferation, invasion, and chemoresistance of OSCC cells, indicating its potential for developing novel targeted therapies for this type of cancer.

Elongated styloid process syndrome with prolongation of the superior cornu of the thyroid cartilage: A case report.

INTRODUCTION: Elongated styloid process syndrome represents a group of symptoms, such as recurrent throat pain and neck pain, caused by elongation of the styloid process. We report a case of elongated styloid process syndrome with prolongation of the superior cornu of the thyroid cartilage. CASE PRESENTATION: A 50-year-old man was referred to our clinic with the chief complaint of discomfort on the right side of his neck. He had no history of any disease. Extraoral findings indicated pain during neck rotation. Computed tomography showed prolongation of the styloid process beyond the mandibular plane and close to the hyoid. Moreover, prolongation of the superior cornu of the thyroid cartilage was detected. The discomfort during rotation of the neck was due to the stimulation by the styloid process. Styloid resection was performed using the extraoral approach under general anesthesia. CONCLUSION: Discomfort in the neck was resolved after operation.

CD36 expression on oral squamous cell carcinoma cells correlates with enhanced proliferation and migratory activity.

OBJECTIVE: Recent studies have demonstrated the pro-tumour role of CD36 in multiple cancer types. However, its role has not been well elucidated in oral squamous cell carcinoma (OSCC). Here, we aimed to evaluate the role of CD36 in proliferation and migration of OSCC cells. METHODS: Human OSCC cell lines HSC-2, HSC-3, HSC-4 and Ca9-22 were assessed for proliferation by staining with the cell proliferation marker Ki-67. We also assessed migration activity, and the expression of cell adhesion molecules such as E-cadherin and ß-catenin and platelet-derived growth factor receptors (PDGFRs) of CD36-positive cells. RESULTS: CD36-positive cells showed increased expression of Ki-67 and migration activity compared with CD36-negative cells. Moreover, CD36-positive cells showed reduced expression of E-cadherin and ß-catenin, whereas the expression of PDGFRs increased compared with that in CD36-negative cells. CONCLUSIONS: Our results strongly suggest that CD36 has an important role in facilitating the proliferation and migration activity of OSCC cells, indicating its usefulness in the diagnosis of high-grade tumour and targeted therapy of oral cancer.

Alterations in composition of immune cells and impairment of anti-tumor immune response in aged oral cancer-bearing mice.

OBJECTIVES: Aging has been suggested to be associated with immune dysregulation. An understanding of alterations in the host immunity with advancing age is, therefore, important for designing immune therapy for elderly cancer patients. In this context, not much is known about age-associated alterations in the immune system in oral cancer. METHODS: To evaluate age-associated alterations in the immune system, which might affect anti-tumor immune responses in oral cancer, we performed a comparative analysis of the proportion of different immune cells, the proliferative capacity of T cell compartment, and the response against immune therapies targeting immune check point molecules between young and aged oral cancer-bearing mice. RESULTS: The proportion of immune regulatory cells, such as regulatory T cells and myeloid derived suppressor cells, was significantly increased in aged mice compared to that in young mice. Moreover, the expression of PD-1 and CTLA-4 on both CD4+ and CD8+ T cells was elevated in aged mice compared to that in young mice, and the proliferative abilities of CD4+ and CD8+ T cells derived from aged mice were significantly reduced following stimulation of T-cell receptors. Moreover, tumor growth was significantly enhanced in aged mice compared to that in young mice. However, immunotherapies targeting PD-1, CTLA-4, and PD-L1 resulted in faster tumor regression in aged mice than in young mice. CONCLUSIONS: Together, our results indicate that age-associated alterations in the immune system are directly associated with the impairment of anti-tumor immunity in aged mice bearing oral cancer, and might facilitate the progression of the tumor.