Shinnosuke Nogami

Risk Factors for Neurosensory Disturbance After Bilateral Sagittal Split Osteotomy Based on Position of Mandibular Canal and Morphology of Mandibular Angle

PURPOSE The aim of the present study was to evaluate the potential morphologic risk factors for postoperative neurosensory disturbance (NSD) after bilateral sagittal split osteotomy. PATIENTS AND METHODS The study subjects were 30 skeletal Class III patients (9 males and 21 females), with a mean age of 22.0 years (range, 16-39 years). All patients underwent bilateral sagittal split osteotomy for setback to correct mandibular prognathism. The bone marrow space between the outer mandibular canal and the lateral cortex of the ramus was measured on transaxial computed tomography images, and the length at the mandibular angle between the retromolar and gonion was measured on the lateral cephalograms. The NSD was tested bilaterally using discrimination to touch with the sharp head of a mechanical probe. Each patient was evaluated at 1, 3, and 6 months postoperatively. RESULTS The median bone marrow space was 1.96 mm (range, 0-4.5 mm), and median length of the mandibular angle was 30.93 mm (range, 23-37 mm). Neurosensory disturbance was present on 15 sides (25.0%) at 1 month postoperatively, 9 sides (15.0%) at 3 months postoperatively, and 7 sides (11.7%) at 6 months postoperatively. The difference in the incidence of NSD with a small bone marrow space and a long mandibular angle from that with a large bone marrow space and short mandibular angle was highly statistically significant (P = .006 and P < .01, respectively). CONCLUSIONS The frequency of NSD after bilateral sagittal split osteotomy in Class III cases was dependent not only on the position of mandibular canal, but also on the length of the mandibular angle. A lateral course of the mandibular canal and a long mandibular angle appeared to result in a high risk of injury to the inferior alveolar nerve, resulting in NSD owing to a compromised splitting procedure.

Removal of dental implant displaced into maxillary sinus by combination of endoscopically assisted and bone repositioning techniques: a case report.

BackgroundAccidental displacement of a dental implant into the maxillary sinus is an infrequent although not uncommon complication encountered in dental clinical practice, with the main cause thought to be inadequate bone height in the posterior maxilla. We report a case of migration of a dental implant into the maxillary sinus, and discuss the benefits of its removal by a combination of endoscopically assisted and bone repositioning techniques.Case presentationA 35-year-old Japanese man with a partially edentulous maxilla underwent implant placement at a private clinic. Three months later, at the time of abutment connection, the implant at the site of his maxillary right first molar was accidentally pushed into the sinus. The hole on the alveolar ridge made for placement of the implant was small and far from the dislocated implant, thus access was achieved in a transoral manner via the frontal wall of his maxillary sinus with an endoscopic approach. Piezoelectric instruments were used to perform an osteotomy. The bone lid was removed, and the implant was identified using a rigid endoscope and removed with a surgical aspirator, followed by repositioning of the bony segment; the area was secured with an absorbable suture. Removal of migrated implants should be considered in order to prevent possible sinusal disease complications.ConclusionsIn the present case, removal of a dental implant displaced into the maxillary sinus by use of a combination of endoscopically assisted and bone repositioning techniques proved to be a safe and reliable procedure.

Clinical comparison between the retromandibular approach for reduction and fixation and endoscope-assisted open reduction and internal fixation for mandibular condyle fractures.

Objective Endoscope-assisted transoral open reduction and internal fixation (EAORIF) for mandibular condyle fractures has recently become popular because it is minimally invasive, provides excellent visibility without a large incision, and reduces surgical scarring and the risk of facial nerve injury. This report describes a retrospective clinical study that compared certain clinical parameters, including postoperative function, between the retromandibular (RM) approach and EAORIF. Methods Fifteen patients were treated by the RM approach, whereas 15 underwent EAORIF between July 2006 and September 2011 at Kyushu Dental College, Japan. Clinical indices comprised fracture line, fracture type, number of plates used, surgical duration, bleeding amount, and functional items, including maximum interincisal opening, mandibular deviation on the opening pathway, malocclusion, facial paresthesia, and temporomandibular joint pain and clicking. Results The areas subjected to either approach included lower neck and subcondyle. The RM approach was used for mandibular condyle fractures with dislocation of a small bone segment. Both groups used 2 plates in all cases. Surgical duration, maximum interincisal opening, mandibular deviation, occlusion, and temporomandibular joint function at 6 months after surgery were comparable between groups. The average bleeding amount in the EAORIF group was greater than in the RM group. One patient from the RM group developed facial paresthesia that persisted for 6 months after surgery. Conclusions It was concluded that surgical treatment was suitable for fractures of the lower neck and subcondylar. Both procedures showed good results in the functional items of this study.

Clinical comparison between arthrocentesis and conventional conservative treatment with maxillomandibular fixation for unilateral high condylar fractures

This study aimed to compare the effects of arthrocentesis and conventional closed reduction for unilateral mandibular condyle fractures. A total of 30 patients with unilateral condylar fractures were evaluated. Patients with a high condylar fracture and magnetic resonance evidence of joint effusion (JE) were divided into two groups: those treated with intra-articular irrigation and betamethasone injection (group I) and those given conservative treatment and rigid maxillomandibular fixation (MMF) (group II). All patients were assessed for mandibular range of motion (ROM), protrusive movements, lateral excursion movements on the fractured and non-fractured sides, pain in the temporomandibular joint and malocclusion, both before and after treatment. There were no significant differences in regard to protrusion, lateral excursion movement and incidence of malocclusion at 12 months after treatment between the groups (P > 0.05). In group I, ROM and joint pain showed good improvement from the early stages of treatment, and those patients had better outcomes as compared to group II for those parameters at 1 and 3 months after injury. The present findings indicate that arthrocentesis may be more effective and provide faster healing than conventional closed reduction.

Prognosis factors in the treatment of bisphosphonate-related osteonecrosis of the jaw - Prognostic factors in the treatment of BRONJ.

Objectives: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a relatively rare but serious side effect of bisphosphonate (BP)-based treatments. This retrospective study aimed to investigate the risk factors and predictive markers in cases where patients were refractory to a recommended conservative treatment offered in our hospital. Patients and Methods: This single-center study collated the medical records of all patients treated for BRONJ between 2004 and 2011. A complete medical history, including detailed questionnaires, was collected for all patients, focusing on identifying underlying risk factors, clinical features, location and bone marker levels of BRONJ. Results: The mean BRONJ remission rate was 57.6%, and the median duration of remission was seven months. Eighteen patients (34.6%) had persistent or progressive disease with a recommended conservative treatment for BRONJ. Notably, urinary cross-linked N-terminal telopeptide of type 1 collagen (NTX) levels in those resistant to conservative treatment tended to be lower than in patients that healed well. Conclusions: We confirm that a significant proportion of BRONJ sufferers are refractory to a recommended conservative treatment and find that anticancer drugs, periodontal disease, the level of bone exposure and the dosage of intravenous BPs (e.g. zoledronate) represent specific risk factors in BRONJ that may determine the success of a recommended conservative treatment. Additionally, the NTX levels might be able to be a prognostic factor for the conservative treatment of BRONJ; additional research is necessary. Key words:Bisphosphonate, osteonecrosis, jaw, prognostic, retrospective.

Self-activated mesh device using shape memory alloy for periosteal expansion osteogenesis

The present study evaluated the use of this self-activated shape memory alloy (SMA) device, with a focus on its effects in the region under the periosteum. Twelve Japanese white rabbits were used in this study. The device was inserted under the periosteum at the forehead. In the experimental group, the device was pushed, bent, and attached to the bone surface and fixed with a titanium screw. In control group, the device was only inserted under the periosteum. After 14 days, the screw was removed and the mesh was activated in the experimental group. Rabbits were sacrificed 5 and 8 weeks after the operation and newly formed bone was histologically and radiographically evaluated. The quantitative data by the area and the occupation of newly formed bone indicated that the experimental group had a higher volume of new bone than the control group at each consolidation period. Histologically, some newly formed bone was observed and most of the subperiosteal space underneath the device was filled with fibrous tissue, and a thin layer of immature bone was observed in the control group. In the experimental group, multiple dome-shaped bones, outlined by thin and scattered trabeculae, were clearly observed under the SMA mesh device. The use of self-activated devices for the periosteal expansion technique may make it possible to avoid donor site morbidity, trans-skin activation rods, any bone-cutting procedure, and the following intermittent activation procedure.

Evaluation of mandibular reconstruction with particulate cancellous bone marrow and titanium mesh after mandibular resection due to tumor surgery.

There are numerous treatment modalities for mandibular defects after tumor surgery. Autogenous particulate cancellous bone marrow graft combined with titanium mesh (PCBM-MESH) is an alternative procedure. The purpose of this study was to evaluate PCBM-MESH for mandibular reconstruction. There were a total of 10 cases from 2000 to 2011. Mandibles were successfully reconstructed in 9 cases; however, reconstruction failed in 1 case. Overall, the recovery of facial contours was excellent; conversely, the evaluation of prosthetic treatment varied widely. Thus, we suggest 3 steps for mandibular reconstruction: (1) recover the continuity of bone segments; (2) simulate optimum facial contours and dental occlusion; and (3) perform the occlusion with dental prostheses. PCBM-MESH is a valuable method for mandibular defects—particularly for restoring facial contours and a favorable alveolar ridge.

Increased Levels of Interleukin-6 in Synovial Lavage Fluid From Patients With Mandibular Condyle Fractures: Correlation With Magnetic Resonance Evidence of Joint Effusion

PURPOSE The aim of the present study was to investigate the relation between magnetic resonance (MR) evidence of joint effusion and concentrations of proinflammatory cytokines, including interleukin (IL)-1β and IL-6, in washed-out synovial fluid samples obtained from patients with mandibular condyle fractures. PATIENTS AND METHODS Twenty-five joints in 23 patients with mandibular condyle fractures were examined. Computed tomography was used to determine the position of the fracture and MR examination was performed in all cases. Twenty-five joints underwent temporomandibular joint (TMJ) irrigation before surgical treatment for the fractures. The detection rates and concentrations of the tested cytokines were determined, and their relations to evidence of joint effusion and positions of the condylar fractures were analyzed. RESULTS Six TMJ fractures were found in the head, 10 in the upper neck, 4 in the lower neck, and 5 in the subcondyle. MR evidence of joint effusion was observed in 17 of 25 TMJs (68.0%). The detection rate and concentration of IL-6 were significantly higher in patients with MR evidence of joint effusion and those with high condylar fractures. Moreover, there was a correlation between joint effusion grade and IL-6 concentration. CONCLUSIONS The present findings showed a correlation between MR evidence of joint effusion and concentration of IL-6 in washed-out synovial fluid samples collected from patients with mandibular condyle fractures. These results may provide support for arthrocentesis as a reasonable treatment modality for high condylar fractures.

Clinical evaluations of autologous fibrin glue and polyglycolic acid sheets as oral surgical wound coverings after partial glossectomy

Polyglycolic acid (PGA) sheets and commercial fibrin glue are commonly used to cover open wound surfaces in oral surgery. Compared to commercial fibrin glue composed of pooled allogeneic blood, autologous fibrin glue is less expensive and poses lower risks of viral infection and allergic reaction. Here, we evaluated postoperative pain, scar contracture, ingestion, tongue dyskinesia, and postoperative bleeding in 24 patients who underwent partial glossectomy plus the application of a PGA sheet and an autologous fibrin glue covering (autologous group) versus 11 patients in whom a PGA sheet and commercial fibrin glue were used (allogeneic group). The evaluated clinical measures were nearly identical in both groups. Remarkable wound surface granulation was recognized in two cases in the autologous group. No complications were observed in either group, including viral infection or allergic reaction. Abnormal postoperative bleeding in the wound region was observed in one case in the allogeneic group. Coagulation and adhesion of the autologous fibrin glue were equivalent to those of conventional therapy with a PGA sheet and commercial fibrin glue. Thus, our results show that covering wounds with autologous fibrin glue and PGA sheets may help avoid the risks of viral infection and allergic reaction in partial glossectomy cases.

Risk factors related to aggressive condylar resorption after orthognathic surgery for females: retrospective study

Objective: The aim of the present study was to identify the risk factors for aggressive condylar resorption (ACR) after orthognathic surgery. Methods: A total of 25 female patients with osteoarthritis (OA) scheduled for orthognathic surgery were divided into two groups: those who exhibited ACR (ACR (+), n = 8) and those who did not exhibit ACR (ACR (−), n = 17) after surgery. Clinical indices were used to determine the extent of mandibular advancement, the presence of temporomandibular disorder (TMD), and relevant medical treatment histories (including the use of oral contraceptive (OC) medication. TMJ dysfunction was clinically evaluated in terms of pain, the presence of sounds (clicks or crepitus), and disc displacement, joint effusion (JE), and synovial hyperplasia (SH); these were further investigated with the aid of magnetic resonance imaging (MRI). The cephalographic findings were compared with the normal profiles of Japanese subjects. Results: The mean (with SD) extent of mandibular advancement was 11.4 mm (2.4) in ACR (+) and 4.1 mm (1.8) in ACR (−). The TMD medical history of ACR (+) was much more extensive than that of ACR (−); all patients in ACR (+) had a history of OC use. More patients in ACR (+) than in ACR (−) had TMJ dysfunction and disc displacement, JE, and SH on MRI. Preoperative cephalograms showed that ACR (+) patients exhibited counterclockwise rotation of the mandible and retrognathism that was attributable to a small sella–nasion–B (SNB) angle, a wide mandibular plane angle, and a negative inclination of the ramus. Conclusions: The present findings suggest that the development of ACR after orthognathic surgery to treat mandibular retrognathism may be associated with coexisting TMJ pathologic abnormality.