Recently, simulation and computer assisted surgery (CAS) have been applied to oral and maxillofacial surgery in Europe and USA. However, they have not become still sufficiently widespread in Japan. Because they have been introduced since 2005 in Yokohama City University Hospital, I report current status and future perspective of simulation and CAS in oral and maxillofacial region.
The number of patients with oral cancer is tending to increase in Japan. It has been reported that oral cancer is most highly prevalent in men 60 years or older. However, the numbers of affected females and young patients have tended to increase in recent years.
Between 1982 and 2016, a retrospective study was conducted on 936 primary cases of oral squamous cell carcinoma treated by curative surgery in Tokyo Dental College Chiba Hospital, and a clinical study on the trends of female patients was conducted. Female patients during the same period accounted for 388 cases (41.5% of the total). The ratio of female patients with oral squamous cell carcinoma increased significantly during the 34 years. The male-female ratio was 1.41:1. The mean age of female patients was 67.3 years. The tongue was the most frequency encountered primary site among female patients, accounting for 46.9% of cases. Well-differentiated type was most common, accounting for 75.8% on histopathological differentiation typing. The incidences of stages I, II, III and IV oral squamous cell carcinoma according to the TNM staging system were 27.1%, 30.7%, 22.9%, and 19.3%, respectively. As for life history, 36.3% of the female patients had drinking habits, and the sake index was 22.8. The ratio of smoking habits was 28.1%, and the Brinkman index was 141.4. The 5-year disease-free survival rate was 77.7%, and the 5-year overall survival rate was 86.4%. Although the survival rate of female patients did not differ significantly from that of male patients, outcomes were slightly more favorable among female patients than male patients.
Angioimmunoblastic T-cell lymphoma (AITL) is one of the subtypes of non-Hodgkin lymphoma. The neoplasm is characterized by aggressive, rapid growth and a poor prognosis. A standard treatment protocol has not been established. In our literature review, only one case of AITL of the head and neck was diagnosed. We report a case of AITL diagnosed by submandibular lymph node biopsy. A 74-year-old woman visited our department because of a swelling in submandibular region. Magnetic resonance imaging showed multiple lymphadenopathy in the bilateral submandibular region. Positron-emission tomography-computed tomography showed the abnormal uptake of FDG in lymph nodes of the entire body. A submandibular lymph node biopsy was performed, and AITL was diagnosed histopathologically. CHOP or Hyper-CVAD, which are standard treatments for non-Hodgkin lymphoma, were proposed, but were not accepted by the patient. Alternatively, anti-CCR4 antibody therapy was conducted, but resulted in poor control of the disease. Finally, palliative care was performed until the patient died of the disease.
We performed nerve reconstruction concurrently with resection of a benign tumor-like lesion in the inferior alveolar nerve and obtained good sensory recovery. The patient was a 65-year-old woman who had had sensory disturbance in the left mental nerve region since July 2015 and was referred to our department by a dentistry department of a nearby hospital in October 2015 with a chief complaint of sensory disturbance at the same site. Panoramic radiography and computed tomography scanning confirmed enlargement of the left mental foramen, while magnetic resonance imaging revealed low signal intensity on T1-weighted images. The above-mentioned findings led to the clinical diagnosis of a neurogenic tumor, for which reconstruction of the inferior alveolar nerve that was resected during tumor resection under general anesthesia was performed in November 2015. Histopathological findings led to the diagnosis of schwannoma-like benign tumor-like lesion. On assessment 18 months after the operation, the sensory disturbance of the mental nerve region showed improvement.
Lesch-Nyhan Syndrome (LNS) is caused by an abnormality in purine metabolism due to X-linked recessive deficits of hypoxanthine-guanine phosphoribosyltransferase. The patients bite their lips, fingers, and hands. It is difficult to prevent and cure self-mutilation. We describe a 2-year 6-month-old boy who had a diagnosis of LNS. He had injuries of the buccal mucosa, lower lip, and tongue caused by self-mutilation. He underwent a medical examination in our hospital for the treatment of oral injury. There were symptoms of mental and motor retardation, as well as involuntary movement. A buccal mucosa ulcer, caused by the sharp cusps of the mandibular second primary molar, was treated with a mouthpiece. More follow-up is important because self-injurious behavior continues through adolescence.
Most meningiomas are intracranial tumors arising from meningothelial cells. However, extracranial meningiomas can develop as a true primary extracranial meningioma or as a direct extension or distant metastasis from a primary intracranial meningioma. Extracranial meningiomas of the jaw are extremely rare. To the best of our knowledge, only nine cases of extracranial meningioma of the mandible have been reported to date. Here we report a case of extracranial meningioma of the mandible arising in an 83-year-old man who presented with a painless swelling in the left side of the mandible. Radiographic examination revealed a radiolucent lesion in the left side of the mandible, which was diagnosed as a meningothelial meningioma on biopsy. The patient previously underwent intracranial tumorectomy for a convexity meningioma and CyberKnife treatment for a residual tumor after surgery. Therefore, this lesion was considered mandibular bone metastasis from intracranial meningioma. Surgical therapy was proposed for treatment; however, consent was not obtained. After continued follow-up, no increase in the tumor was observed for 2 years after the first visit..
Dermoid cysts of the tongue are rare. We present a case of dermoid cyst in the tongue muscle. An 18-year-old woman was referred to our department because of bleeding of the tongue. A small mass had been present since birth, but was never diagnosed. The mass was present in the tongue muscle and had formed a fistula on the dorsal surface of the tongue. Previous reports indicated that dermoid cysts of the tongue were smaller and occurred in patients at younger ages as compared with those found at other sites. The patient showed no evidence of recurrence 2 years postoperatively.
We report the case of accidental insertion of a broken disposable injection dental needle into the masticatory muscle space during an inferior alveolar nerve block, performed using an anterior injection technique with a misused instrument. We removed the needle under X-ray fluoroscopic guidance.
At a private dental clinic, a 26-year-old woman underwent extraction of the right lower horizontal impacted wisdom tooth under invasive anesthesia. At that time, infiltration anesthesia was ineffective and a disposable dental injection needle was used to induce conduction anesthesia of the mandibular foramen. Insertion of a broken needle was confirmed, and the patient made an emergency visit to the Dental and Oral Medical Center, Kurume University School of Medicine.
Imaging studies showed a needle-like impermeable substance near the right mandibular foramen. The next day, with the patient under general anesthesia, the broken needle was surgically removed under X-ray fluoroscopic guidance. Opening obstruction was observed postoperatively, but the patient was discharged on the 8th postoperative day. To avoid broken and accidental insertion of an injection dental needle, it is preferable to use inferior alveolar nerve block instead of the anterior injection technique.