In 2003, the Japanese Society of Oral and Maxillofacial Surgeons (JSOMS) issued“ Promoting Anti-Smoking Declaration” and recognized the results of 14 years of research and experience. Since then, scientific evidence of the health hazards of smoking on oral diseases has been recognized globally. In this regard, OMS members are encouraged to quit smoking and encourage smoking cessation in their patients. At the 2016 61st General Meeting of the JSOMS, the Committee for Tobacco-Free Society (CTFS) held a symposium titled, “Creating a smoke-free society of members.” The objective of this review is to summarize the symposium and encourage our colleagues to create a smoke-free society.

　Because tobacco use and oral diseases, such as oral cancer and precancer, are strongly associated, OMSs are expected to provide and encourage appropriate tobacco cessation support and consecutive treatment as an integral part of comprehensive surgical management. However, there is a gap between Japanese and American OMSs in terms of smoking frequencies as well as tobacco cessation activities of their patients with respect to tobacco-related oral diseases. In addition, smoking should be banned in all dental schools and their campuses, and tobacco cessation outpatient clinics in OMS departments should be instituted.

　The CTFS of the JSOMS promotes a smoke-free society of members and supports tobacco abstinence. In order to achieve this, undergraduate dental education systems should be promoted regarding tobacco prevention and cessation and continuing training opportunities such as e-learning should be established.

　All health personnel are responsible for maximizing efforts to create a smoke-free society in their organizations. In 2016, a proposal in the“White Paper on Tobacco, Japan” is encouraging further efforts by the JSOMS to promote tobacco cessation in dental practices covered by the National Health Insurance in collaboration with the Japan Dental Association and other dental societies. We are confident that a strong stand on smoking cessation by OMSs will greatly influence future dental care in Japan.

The non-vitamin K antagonist, oral anticoagulant (NOAC) direct thrombin inhibitor dabigatran and the Xa inhibitors rivaroxaban and apixaban are now being used clinically. We retrospectively studied tooth extraction in patients who received NOACs in our department. The medical charts of these patients were investigated. From April 2011 through November 2015, 31 patients who were receiving NOACs underwent tooth extraction in the hospital. Among the 31 patients, 16 patients received dabigatran, 7 rivaroxaban, and 8 apixaban. Tooth extraction was performed in 19 patients who were receiving NOACs while maintaining conventional anticoagulant therapy and in 12 patients in whom NOACs were withdrawn before tooth extraction and resumed within 24 hours. The activated partial thromboplastin time (APTT) and the prothrombin time-international normalized ratio (PT-INR) were checked at the initial visit and immediately before tooth extraction, and were both prolonged slightly. There was no bleeding episode or thromboembolism in any patient who received NOACs. Monitoring of the APTT and PT-INR has been reported to be useful, and tooth extraction has to be performed with care in patients with markedly prolonged APTT and PT-INR. In patients who undergo tooth extraction while receiving NOACs, maintaining conventional anticoagulant therapy or stopping therapy before tooth extraction and resuming it within 24 hours has been suggested to be an effective way to reduce the risk of postoperative bleeding.

We report an extremely rare case of peripheral osteoma occurring in the maxilla and associated with bony swelling in the subcutaneous nasal vestibule. A 66-year-old man was referred to our department because of a painless swelling of the left nasal vestibule. Intraoral examination revealed a firm, bony, round swelling in the left maxillary gingivolabial fold. Radiographic and computed tomographic examinations demonstrated that the lesion was radiopaque with well-defined margins and a narrow region in contact with the maxilla. The patient received surgical resection of the maxillary tumor under general anesthesia. Histopathological examination revealed areas of mature compact bone formation diagnosed as osteoma. This is an extremely rare report of peripheral osteoma arising in the nasal vestibule. At present, the patient is well and has had no recurrence of the tumor.

Cowden's disease is an autosomal dominant disorder caused by mutation of the phosphatase and tensin homologue deleted on chromosome 10 (PTEN). Cowden's disease is characterized by symptoms such as hamartomas developing in multiple organs, papillomatous hyperplasia, and papules on the face or limbs. We describe a 69-year-old woman with a chief complaint of gingival swelling who was found to have multiple papillomatous hyperplastic lesions of the maxillary and mandibular gingiva within the oral cavity and small papules on the skin of the neck. Upper gastrointestinal endoscopy revealed multiple polyps in the esophagus and stomach. Cowden's disease was diagnosed after detection of the PTEN mutation on genetic analysis. Caution is required in differential diagnosis when multiple papillomatous papules are present within the oral cavity, because this could be an oral symptom of a disorder such as Cowden's disease.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) occurs in patients who are receiving bisphosphonate preparations, and the clinical features resemble both chronic osteomyelitis and osteonecrosis. Gas gangrene, on the other hand, is rapidly progressive and complicated by sepsis or disseminated intravascular coagulopathy (DIC) and has a very poor prognosis. Gas gangrene more commonly occurs in the extremities, and rare develops in the head and neck region. We describe a 97-year-old woman who presented to our clinic with painful swelling in the buccal region associated with unhealed extraction sockets of the left mandibular canine and first premolar of 2 months duration. Intraorally, there were open extraction sockets of the mandibular left canine and first premolar, associated with bone exposure, purulent discharge, and a sinus track through the cheek. BRONJ with gas gangrene was diagnosed. The patient was hospitalized immediately and underwent surgical drainage and antibiotic treatment. The surgical management was uneventful. The skin defect spontaneously closed 1 month after surgery.

Kissing molars is an extremely rare condition of impacted permanent molars that have occlusal surfaces in contact with each other in a single follicular space, with roots pointing in opposite directions. Fully-impacted permanent molars occur only in the mandible.

　The patient was a 26-year-old woman with discomfort of the mandibular right molars. Panoramic radiography and computed tomography showed the full impaction of the second and third mandibular right molars, which had occlusal surfaces in contact with each other in a single follicular space, with their roots pointing in opposite directions. Associated follicular tissue was removed along with both molars. Histopathologically, the lesion was diagnosed as a dentigerous cyst. The postoperative course was uneventful.

We report a case of large tophaceous pseudogout occupying the infratemporal fossa arising in the temporomandibular joint (TMJ). A 62-year-old woman was referred to our hospital with a chief complaint of pain in the right TMJ when she opened her mouth. She had diffuse swelling with mild tenderness in the right preauricular and the right buccal mucosal regions. Contrast-enhanced computed tomography revealed a 54-mm calcified mass-like lesion in the major axis occupying the infratemporal fossa. Compressive bone resorption in the condylar head, inner mandibular ramus, and the base of the skull, which was in contact with the mass, were also seen. Clinically, a masticator space tumor was suspected, and a biopsy of the mass was performed from the buccal mucosa region. The biopsy specimen revealed deposits of calcium pyrophosphate dehydrate (CPPD) crystals, and tophaceous pseudogout was thus diagnosed. With the patient under general anesthesia, an operation was performed from a preauricular and temporal approach as well as an intraoral approach to divide and remove the mass as much as possible. Although part of the mass remained, clinical symptoms disappeared after surgery. Three years 7 months postoperatively, the patient has not had any symptoms.