In recent years, some studies of postoperative computed tomography evaluations of secondary bone grafting into the alveolar cleft have been reported. Here we report a study of volumetric evaluation and prognostic factors for bone bridge formation after secondary bone grafting into the alveolar cleft using computed tomography. In 60 patients with unilateral cleft lip and palate (30 with unilateral cleft lip and alveolar ridge: UCLA, 30 with unilateral cleft lip and palate: UCLP), we performed computed tomography scanning pre- and post-operatively. We calculate bone bridging ratio from the bone defect volume and evaluated prognostic factors for it. The median bone bridge ratio was 83.6% and 66.3% in UCLA and UCLP, respectively. Both univariate and multivariate analysis indicated that the presence of cleft palate and preoperative bone defect volume were statistically significant prognostic factors. The type of tooth inducted into the alveolar cleft or its state of eruption were not related to prognosis.

Granular cell tumor (GCT) is a rare benign tumor that can arise everywhere in the body. As a histopathological feature of this tumor, this lesion is not encapsulated, and there can be the presence of a pseudo-invasive pattern, such as pseudoepitheliomatous hyperplasia (PEH). The high frequency and diversity of locally invasive features, particularly of vascular invasion, in granular cell tumors of the skin was reported. In the period between 1994 and 2018, we evaluated the clinical and histopathological characteristics of 19 cases of GCT arising in the oral cavity.

　Six patients were male, and 13 were female. The mean age of the patients was 44.5 years (range 21 to 79 years). Tumors arose in the tongue in 15 patients (78.9%), the lower lip in 2 patients (10.5%), and the lower gum and buccal mucosa in one patient (5.3%). Histopathologically, vascular invasion was found in 5 patients (26.3%). PEH was observed in the overlying mucosa of the tumor in 6 patients (31.6%). No patient showed evidence of local recurrence or malignancy.

The Committee for Tobacco-Free Society of the Public Interest Incorporated Association for the Japanese Society of Oral and Maxillofacial Surgeons (JSOMS) performed a web questionnaire survey on smoking habits as well as tobacco-free policies among 7189 eligible members who had registered their e-mail addresses with the society in September 2018.

　Among all eligible members, 1877 provided valid responses (26.1%; male 78%, female 22%). The prevalence of current smokers, ex-smokers, and never smokers was 7.2% (male 8.5%, female 2.2%), 33.3% (male 40.0%, female 9.3%), and 59.5% (male 51.5%, female 88.5%), respectively. The smoking rate was the highest in the 40s (8.6%) age group, followed by the 30s (7.8%), 20s (7.1%), and 50s (6.0%) age groups. The smoking rate was the highest among members who worked in private clinics (9.3%), followed by those who worked in dental teaching hospitals (8.1%), general hospitals (6.7%), and medical teaching hospitals (4.3%). The rate of asking patients about their smoking status regularly was the highest among members who worked in medical teaching hospitals (70%), followed by those who worked in private clinics (63%), dental teaching hospitals (62%), and general hospitals (56%). As for passive smoking measures, 96% of members responded that there should be a smoke-free policy in their hospitals/clinics.

　Overall, the smoking rate of JSOMS members has declined by 3.3% points since the last survey in 2007 (10.5%). The tobacco-free policy should be further strengthened for all society members with respect to tobacco secession advice and passive smoking measures.

A 73-year-old man was referred to our department because of a maxillary swelling. An elastic-soft oval swelling, measuring 55×49 mm, was found on the gingiva of the left palate. CT imaging showed a clearly demarcated unicystic-like lesion measuring 60 × 60 × 50 mm in the left maxillary sinus. After establishing a clinical diagnosis of odontogenic cyst, a biopsy examination of the lesion was performed by two-channel endoscopic sinus surgery. The histopathological diagnosis was a suspected calcifying odontogenic cyst. Odontogenic epithelium with ghost cells was found in the part of the cyst wall. Although additional surgery was required, the patient did not want to undergo it. After 2 and a half years, the left upper jaw showed swelling. CT imaging demonstrated a solid lesion with internal calcification at the same site as the previously extirpated lesion. A biopsy was performed, and pathological examination showed odontogenic epithelium resembling ameloblastoma with many ghost cells. Maxillary sub-total resection was therefore performed. The pathological diagnosis was a dentinogenic ghost cell tumor (DGCT). We have reported a rare case of DGCT arising in the maxilla, associated with transition from the cystic type to solid type. The patient was followed for 5 years after the surgical intervention, had no recurrence, and is still being followed up.

Simple bone cyst (SBC) is a lesion characterized by a bone cavity with a clear boundary without an epithelial lining. SBC often occurs in long bones, such as the humerus and femur, but is relatively rare in the maxillofacial regions. A 40-year-old woman was referred to our department because of a radiolucent region of the lower jaw observed on dental examination. In our department, X-ray examination revealed multiple cysts in the maxilla and mandible. Biopsy of one cyst of the left mandibular first molar region was indicated a diagnosis of SBC. Curettage of all cysts was performed in August 2017. Histopathological examination revealed no epithelial lining in the cyst. Moreover, the interior of the cystic cavity was hollow. A fibro-osseous lesion was found on the left maxillary cyst wall without an epithelial lining. It was finally diagnosed as an SBC with cemento-osseous dysplasia (COD). In recent years, simple bone cysts involving cemento-osseous dysplasia have been reported to recurrence. One year postoperatively, there has been no sign of recurrence, yet complete follow-up is imperative in the future.

Renal osteodystrophy (ROD) is characterized by specific changes in bone morphology in patients with end-stage renal failure and develops as a result of alterations in the metabolism of calcium and phosphate, or secondary hyperparathyroidism．

　We report a case of ROD detected with cellulitis of the floor of the mouth. An 82-year-old man was referred to our department because of swelling of the floor of the mouth. The patient had been given a diagnosis of with chronic renal failure and treated. Blood tests showed severe renal dysfunction and increases in inflammatory markers and intact parathyroid hormone (PTH). Computed tomography images showed findings of osteolysis and osteosclerosis in the mandible. Therefore, the patient was given a diagnosis of ROD. He was admitted and immediately received antibacterial chemotherapy and drainage. Then his symptoms improved, and he was discharged on day 22．

　On 1 year 2 months after first visit，the calcium and phosphate levels in blood tests were maintained within the normal range, and bone formation was observed in the mandible.

　It is important to perform careful follow up because patients with ROD tend to have an increased risk of infection.

IgG4-related disease (IgG4-RD) is a chronic inflammatory disease characterized by a thick tumor-like mass, dense infiltration of IgG4-positive plasma cells, and a high serum level of IgG4. We report a case of suspected benign tumor in the mandible, which was removed surgically. However, the clinical and histopathological characteristics ultimately led to a diagnosis of IgG4-RD arising from the inferior alveolar nerve. After 1 year 6 months, but there was no recurrence of the lesion and good progress. However, the serum IgG4 level remained high. I combined internal medicine concepts and examined it, followed by an additional examination by imaging. This case illustrates the importance of differential diagnoses of diseases of the inferior alveolar nerve domain with consideration of IgG4-RD.

Acquired hemophilia A is a rare disease diagnosed in the absesnce of a previous history of easy bleeding. The annual incidence rate is reported to be approximately 1.48 patients per million population. We report a case of acquired hemophilia A diagnosed owing to unexpected tongue bleeding during toothbrushing. A 77-year-old woman was referred to our department because of tongue bleeding. The patient had no previous episodes of bleeding tendency. The activated partial thromboplastin time (APTT) was longer than normal on laboratory tests, and the coagulation activity of factor Ⅷ was decreased. In addition, factor Ⅷ inhibitor expression was detected. The patient was given a diagnosis of acquired hemophilia A by our hematologist and was admitted to the hospital. For a diagnosis of hemophilia A, the patient received immunosuppressive and bypass therapies. The APTT and coagulation activity of factor Ⅷ improved gradually after hospitalization for treatment, which consequently stopped the tongue bleeding. So far, no rebleeding has occurred for 7 months. On the basis of our experience, hematologic diseases such as acquired hemophilia A should be considered in the diagnosis of oral bleeding due to unlikely causes.

Venous aneurysm is defined as a localized dilating lesion of a vein. It is a lesion showing localized saccular dilatation of a vein, which differs from a varix showing venous tortuosity and various extensions. Venous aneurysms have been reported to occur primarily in the extremities. Few cases have been reported in the head and neck region, and cases occurring in the submandibular region are extremely rare. We report a rare case of venous aneurysm in the submandibular region, which was difficult to diagnose based on clinical and imaging findings. A 74-year-old woman visited our hospital because of a swelling in the left side of the submandibular region. Contrast-enhanced computed tomography (CT) revealed a mass measuring 30×26×23mm with enhanced components at the rim. Under a clinical diagnosis of left submandibular tumor, tumor resection with concurrent resection of the left submandibular gland was performed under general anesthesia. Histopathological examination revealed a venous aneurysm with thrombus. The postoperative course has been uneventful.

Fixed eruption is a condition characterized by the recurrence of erythematous lesions after ingestion of a causative agent. It can be induced by medical drugs, food, or food additives. It might be more difficult to identify suspicious material in cases where food and food additives are responsible rather than a medical drug. A 40-year-old man presented with fixed eruption due to quinine. He noticed repeated eruptions on his lips and erythema of his limbs once a year five years before presengtation to our hospital. Cytologic examinations revealed negative results for the herpes simplex virus-specific antigen, and no cytopathic changes were detected. His medical interview indicated that symptoms developed after ingesting gin and tonic containing quinine during his stay in the Philippines; because there were similar episodes in the past, we suspected that tonic water was the causative agent. A patch test for quinine at the site of his eruption (back of left hand) revealed positive results, whereas that at the site of no eruption (back) revealed negative results. Therefore, we diagnosed this case as fixed eruption caused by quinine in tonic water. It is necessary to conduct medical interviews to establish whether the presence or absence of drinking tonic water containing quinine as a food additive should be considered, in addition to drug history, in cases where fixed eruption is suspected.