In the present review, the current strategy of disgnosis and treatment for condylar fractures was described. Particularly, we introduced that the primary application of not only NSAIDs but also TMJ irrigation to the traumatic arthritis associated with almost condylar fractures could significantly reduce TMJ pain induced by exercise of mandibular motion and contribute to the early recovery of mandibular function. Also, we verified the advantages and disadvantages of each surgical approach for open reduction and internal fixation (ORIF) of condylar fractures, such as submandibular approach using Risidon incision, pre- / endaural approach, retromandibular approach, transmasseteric anteroparotid (TMAP) approach, high perimandibular approach, and transoral approach with/without endoscopy. As a result, high perimandibular approach would be the most valuable technique with respect to the accessibility of securing working space for precise ORIF. As regarding the risk of facial nerve injury, in particular submandibular branch, TMAP approach, high perimandibular approach, and transoral approach were considered to be more advantageous than the other approches. On the other hand, the surgical scar was suggested to be unproblematic in each approach, except for Risdon and retromandibular approaches. In addition, the mandibular function after ORIF was not obviously different among the investgated approaches. Consequently, we would like to recommend the high perimandibular approach as the most useful and fundamental technique for current ORIF of the mandibular condylar fractures.

Surgeons treating maxillofacial bone fractures seek to recover complex preinjury dento-oral and maxillofacial functions including occlusion and mastication, reconstruct pre-trauma bone structure, and regain the pre-trauma facial appearance, thereby facilitating social reintegration. Mandibular fractures are the fractures commonly encountered by oral and maxillofacial surgeons in daily practice. To obtain good clinical results, surgeons must make appropriate diagnoses, be very familiar with the treatment of choice, have an indepth knowledge of anatomy and biomechanics, and have considerable experience with the unique features of the various surgical approaches as well as the use of fixation devices, materials, and osteosynthetic systems. When using conservative treatments, mandibular bone fragments are indirectly reduced and stabilized by re-establishment of the appropriate occlusal relationships; in such cases, an intermaxillary fixation device is generally placed for a limited time. Today, patients demand early restoration of social integration and function; thus, it is key to ensure uneventful bone healing and sound reunion without complications using surgical treatment of open reduction and internal fixation. Titanium plates and screws may be used for mandibular buttressing and to afford rigid fixation/osteosynthesis of mandibular bony fragments or segments. The various osteosynthetic techniques are based on the Champy’s ideal line theory and the AO concepts of load-sharing and load-bearing during osteosynthesis; these parameters are affected by the mandibular fracture type, mode, and pattern. In this review, we introduce and discuss the basic diagnostic and treatment principles of mandibular fractures, excluding mandibular condyle fractures.

Atypical lipomatous tumor (ALT)/well-differentiated liposarcoma, a relatively common malignant soft-tissue tumor, was first described in 1857 by Rudolf Virchow. It generally occurs in the four limbs and the retroperitoneum and rarely develops in the head and neck region. Here we report a case of an atypical lipomatous tumor in the left submandibular region. A 57-year-old man presented with a slowly enlarging mass in the lower left submandibular region. Initial examinations using computed tomography and magnetic resonance imaging revealed heterogeneous internal patterns; therefore, we performed an open biopsy. Histological examination of the specimen indicated lipoma. In February 2011, the patient underwent tumor excision under general anesthesia. The tumor adhered to the lingual nerve; we divided the tumor into parts to save the nerves and resected as much of the tumor as possible. Based on the histological examination of the resected specimens, an atypical lipomatous tumor was diagnosed. We re-operated in April to excise the remainder of the tumor. We excised it along with the lingual nerve via a mandibular swing approach because the tumor was in contact with the medial pterygoid muscle in the medial aspect of the mandible. No signs of recurrence were noted after seven years.

Dentinogenic ghost cell tumor (DGCT) is a locally invasive neoplasm that forms ameloblastomalike epithelial islands associated with dyskeratosis of ghost cells and formation of atypical dentin. It is reported that DGCT has a high recurrence rate. We report a case of DGCT arising in the maxilla. A 42-year-old man was referred to our department with a chief complaint of a palatal swelling in the maxillary anterior tooth region. On radiographic examination a well-circumscribed radiolucent lesion with nonhomogeneous calcifications was seen around the root of the right maxillary lateral incisor. The tooth showed vital pulp. The preoperative clinical diagnosis was a maxillary tumor, and the tumor was enucleated under local anesthesia. The histopathological diagnosis was DGCT. Postoperative healing was uneventful, and there was no sign of recurrence during 18 months of follow-up.

We report a case of peripheral facial palsy after orthognathic surgery in a patient with hemifacial microsomia (HFM). The patient was a 20-year-old woman with right HFM. CT examination revealed hypoplasia of the right mandibular ramus, condyle, maxilla, temporal bone, muscles of mastication and parotid salivary gland. She underwent Le Fort Ⅰ osteotomy and bilateral sagittal split ramus osteotomy. Two days after the operation, right facial nerve palsy appeared. Three months after the operation, the palsy was completely resolved by conservative therapy including pharmacotherapy, stellate ganglion blocks and physiotherapy. Facial nerve palsy might have been caused by nerve ischemia and mechanical damage indirect or direct compression from the distal segment, surgical instruments, edema and hematoma. Furthermore, in this case, it is possible that an underlying cause of facial palsy is hypoplasia of the retromandibular region surrounding the facial nerve associated with HMF.

Blue rubber bleb nevus syndrome (BRBNS) is a rare disease characterized by multiple hemangiomas mainly in the skin and gastrointestinal tract. Here, we report a case of BRBNS due to recurrent intraoral hemangioma.

　The patient was a 63-year-old woman who had recurrent tongue hemangioma and was referred to our department. Upper endoscopy revealed multiple hemangiomas in the stomach. We performed an excisional biopsy on the tongue lesion under general anesthesia, and a definitive diagnosis of cavernous hemangioma was established. The patient had a medical history of multiple hemangiomas of the fingers and a flare, and we finally made a definitive diagnosis of BRBNS. The patient was alive without recurrence or metastasis 40 months after surgery.

　The first-line treatment for BRBNS is conservative treatment. The prognosis is poor in patients with gastrointestinal bleeding or central nervous system/circulatory system impairment. In the present case, there was no apparent gastrointestinal bleeding or invasion into other organs. Therefore, the patient had to be observed. However, in many cases, the lesions recur and develop during observation. Therefore, gastrointestinal examinations should be performed periodically. In addition, since some patients have multiple or recurrent intraoral hemangiomas as did our case, BRBNS should be diagnosed.

Malignant Pleural Mesothelioma (MPM) is a representative asbestos-related disease and occurs mesothelium cell covering the pleura inside. MPM patients have a poor prognosis. We describe a 70-year-old man who had two soft masses in the left lower gingiva. On biopsy, the lesion was histopathologically diagnosed as a metastatic tumor from MPM. Positron emission tomography-CT (PET-CT) showed accumulation in the right pleura, the mesentery lymph node, the left gluteus and the lower left gingiva. After consulting the MPM chief physician, we performed tumor resections under general anesthesia. Four months later, there had been no sign of recurrence, and he started using a partial denture. However, his pulmonary lesion grew worse, and he died 8 months after the operation.

Malformations of the pterygoid hamulus may cause orofacial pain. While there have been some reports of a condition known as pterygoid hamulus bursitis overseas, such reports are extremely rare in Japan. Patients with this condition frequently have numerous symptoms and diagnosis is challenging. In addition, a consensus regarding treatment methods has not been reached. Here we describe a case of soft palatal pain improved by pterygoid hamulus excision. The patient was a 28-year-old man who was examined at our department for a chief complaint of right-sided soft palatal pain. We observed hard protrusions on both sides of the soft palate that resembled bone; the protrusion on the right side was particularly prominent. We also noted slight tenderness and odynophagia in the right-sided soft palatal region, as well as a sense of discomfort in the left-sided soft palatal region. Computed tomographic images revealed an excessively long pterygoid hamulus, bilaterally. We considered that the soft palatal symptoms were caused by malformation of the pterygoid hamulus, we therefore excised both pterygoid hamulus muscles under general anesthesia. Currently, 10 months after the procedure, both soft palatal protrusions have improved, the pain has disappeared, and we successfully achieved a favorable outcome.

Clear cell odontogenic carcinoma (CCOC) is a rare tumor characterized by proliferation of odontogenic epithelial cells with a clear cytoplasm. We report a case of clear cell odontogenic carcinoma of the mandible diagnosed by identification of the EWSR1-ATF1 fusion gene. A 76-year-old man was admitted to our department in February 2014 with swelling of the mandible. He was awaiting surgery while fenestration therapy was performed for a diagnosis of odontogenic cystic lesions, but the hospital visit was interrupted. In July 2018, He was referred again with swelling of the right lower jaw. The EWSR1-ATF1 fusion gene was identified by biopsy, a clear cell odontogenic carcinoma was definitely diagnosed and tumor resection and reconstruction were performed. One year and 10 months after surgery, there have been no signs of recurrence or metastasis.