Surgical orthodontic treatment has been reported to improve oral health-related quality of life (OHRQL). Such treatment comprises three stages: pre-surgical orthodontic treatment; orthognathic surgery; and post-surgical orthodontic treatment. Most studies have focused on change in OHRQL between before and after surgery. However, it is also necessary to evaluate OHRQL at the pre-surgical orthodontic treatment stage, as it may be negatively affected by dental decompensation compared with at pre-treatment. The purpose of this prospective study was to investigate the influence of surgical orthodontic treatment on QOL by assessing change in condition-specific QOL at each stage of treatment in skeletal class III cases. Twenty skeletal class III patients requiring surgical orthodontic treatment were enrolled in the study. Each patient completed the Orthognathic Quality of Life Questionnaire (OQLQ), which was developed for patients with dentofacial deformity. Its items are grouped into 4 domains: “social aspects of dentofacial deformity”; “facial esthetics”; “oral function”; and “awareness of dentofacial esthetics”. The questionnaire was completed at the pre-treatment, pre-surgical orthodontic treatment, and post-surgical orthodontic treatment stages. The results revealed a significant worsening in scores between at pre-treatment and pre-surgical orthodontic treatment in the domains of facial esthetics and oral function (p<0.01), and between at pre-surgical orthodontic and post-surgical orthodontic treatment in all domains except awareness of dentofacial esthetics (p<0.05, p<0.01). A significant correlation was observed between a negative change in overjet and worsening OQLQ scores at the pre-surgical orthodontic treatment stage. Significant correlations were also observed between improvement in upper and lower lip difference, soft tissue pogonion protrusion, and ANB angle and improvement in OQLQ scores at the post-surgical orthodontic treatment stage. These results indicate that morphologic change influences OHRQL in patients undergoing surgical orthodontic treatment not only after surgery, but also during pre-surgical orthodontic treatment.

Localization of the nitric oxide (NO)-producing enzyme, nitric oxide synthase (NOS), and its functions are currently being investigated in several tissues and organs. It has been suggested that NO is involved in nerve cell death and the development of neurodegenerative disease. The purpose of this study was to immunohistochemically investigate expression of NOS to clarify its function in the degeneration and regeneration of transected mouse sciatic nerve. Scattered neuronal NOS (nNOS)-positive Schwann cells observed on the central side of the stump on day 1 after transection showed an increase in number on day 7. None were observed at the stump on day 14, however. Expression of nNOS was observed in axons extending from the stump. The number of nNOS-positive axons increased on day 21. Inducible NOS was expressed in inflammatory cells at the stump on day 1. This positive reaction subsequently weakened by day 7, however. Endothelial NOS was expressed in blood vessels at the stump on day 7, but decreased thereafter. The results of the present study suggest that NO is involved in the proliferation and migration of Schwann cells, as well as in axon regeneration at an early stage following nerve transection.

Here, we report a case of fatal bleeding in conjunction with mandibular medicationrelated osteonecrosis of the jaw (MRONJ). A 75-year-old Japanese man was referred to our department with osteonecrosis of the jaw due to bisphosphonate (BP) for multiple bone metastases from prostate cancer. Aggressive surgical intervention was ruled out due to a poor prognosis in terms of life expectancy. Death occurred due to hemorrhagic shock resulting from massive oral bleeding caused by necrosis of the mandible. Numerous reports have suggested that jaw necrosis is induced not only by BP, but also RANKL antibody, steroids, and molecularly-targeted agents. This suggests that the number of cases of MRONJ is likely to increase among elderly patients in whom general health is already poor. The American Association of Oral and Maxillofacial Surgery recommends aggressive treatment only in cases of stage 3 disease. Therefore, such a therapeutic strategy may only be available for cases of jaw necrosis in which the general health status of the patient is otherwise good. To prevent a life-threatening outcome in cases of MRONJ, physicians, who are responsible for determining the drug strategy, should cooperate with oral surgeons in determining the best therapeutic strategy.

The axial displacement of a tooth within the alveolar bone is called traumatic intrusive luxation. The treatment of immature permanent teeth with incomplete root formation is a challenging procedure, as the prognosis is uncertain. The objective of the present article is to report the successful treatment of traumatic intrusive luxation in teeth with incomplete root formation, where mineral trioxide aggregate (MTA) was used as an apical plug to induce apexification. A 10-year-old boy was referred to our department for emergency treatment of dentoalveolar trauma to the maxillary central incisors. After clinical and radiographic examination, the teeth were surgically repositioned and rigidly fixed. Three months later, a pulp vitality test of both teeth elicited a negative response. Endodontic therapy with an MTA plug was used to induce apexification as root formation was incomplete. The root canals were then filled. Clinical and radiographic examination was then performed again at 2 and 4 months later. The MTA apical plug was effective in inducing apexification and maintaining both teeth.

Here, we report a case of dental implant treatment involving computer-assisted surgery for bilateral agenesis of the maxillary lateral incisors. The patient was a 39-year-old woman with the chief complaint of functional and esthetic disturbance due to maxillary and mandibular malocclusion. The treatment plan comprised non-extraction comprehensive orthodontic treatment and prosthodontic treatment for space due to the absence of bilateral maxillary lateral incisors. A preliminary examination revealed that the mesiodistal spaces left by the absent bilateral maxillary lateral incisors were too narrow for implant placement (right, 5.49 mm; left, 5.51 mm). Additional orthodontic treatment increased these spaces to approximately 6 mm, the minimum required for implant placement if risk of damage to the adjacent teeth due to inaccuracies in directionality of drilling is to be avoided. For dental implant treatment with computer-assisted surgery, preoperative planning/simulation was performed using Simplant^® ver.12 software and a toothsupported surgical template fabricated using stereolithography. Two narrow-diameter implants were placed in a two-stage procedure. It was confirmed that there was sufficient distance between the implant fixtures and the roots of the adjacent teeth, together with no exposure of alveolar bone. Following a 4-month non-loading period, second-stage surgery and provisional restoration with a temporary screw-retained implant crown were performed. Cement-retained superstructures made of customized zirconia abutment and a zirconia-bonded ceramic crown were fitted as the final restoration. At 5 years after implant surgery, there were no complications, including inflammation of the peri-implant soft tissue and resorption of peri-implant bone. Computer-assisted implant surgery is useful in avoiding complications in bilateral agenesis of the maxillary lateral incisors when only a narrow mesiodistal space is available for implant placement.

Sialolithiasis is one of the most common and extensively obstructive disorders of the major salivary glands. Here, we report 3 cases of sialolithiasis in the submandibular salivary gland showing symptomatic similarities to other dental and non-dental disorders of the maxillofacial area. How the various clinical features of this condition and findings on 3D-CT may lead to a misdiagnosis are also discussed. In the first case, that of a 45-year-old woman, a final diagnosis of a non-radiopaque submandibular sialolith allowed the initially indicated surgical extraction of a malerupted and semi-impacted right mandibular 3rd molar to be abandoned. In the second case, that of a 57-year-old woman, radiographic findings had previously led to a diagnosis of ameloblastoma, which had masked the presence of sialolithiasis for at least 9 years, despite the radiopacity of the sialolith. Meanwhile, exacerbation of sialolithiasis was mistaken for lymphadenitis. In the third case, that of a 40-year-old woman, sialolithiasis was diagnosed in a timely manner, despite the fact that the dentists' attention had initially been focused on odontopathological symptoms. One feature of the present report is the concurrence of dental and non-dental pathologies affecting the same sextant as the sialolithiasis. Despite recent advances in imaging technology and diagnostics, cases of sialolithiasis being misdiagnosed continue to occur in clinical practice.

Diagnosing vertical root fracture (VRF) is difficult. Here, we retrospectively investigated the duration from initial symptoms to a definite diagnosis of VRF in dental offices. Data were collected on patients with VRF between July 2013 and June 2015. Initial symptoms were ascertained from clinical records. The focus was on the maxillary second premolars and mesial roots of the mandibular first molars, where VRF is most frequent. All VRF in the bilateral dentition was analyzed. Only cases in which the buccal-lingual plane of the root was fractured were included. Data from 31 dental offices revealed a total of 39 VRFs in the maxillary second premolars and 43 in the mandibular mesial roots of the first molars. The patients comprised 42 males and 40 females, and the average age was 59.7±11.6 years at initial onset of symptoms. The mean duration from initial symptoms to a definite diagnosis in the maxillary second premolars was 18.3±22.5 months, while that in the mandibular first molars was 16.1±17.8 months. The cumulative diagnostic rate was 48.7% at 12 months and 79.5% at 24 months in the maxillary second premolars, and 38.1% at 12 months and 86.0% at 24 months in the mandibular first molars. No significant difference was observed between tooth type. If VRF is suspected, doctors should explain the risks of tooth extraction and begin considering treatment options. The present results revealed that 80% of VRFs were diagnosed within 2 years of initial onset of symptoms.