Orthodontic Management of the Edentulous Space Caused by Surgical Removal of a Large Dentigerous Cyst.

Herein, we report the orthodontic management of a patient with excessive bone and permanent tooth loss after surgical cyst removal. The patient was a 13-year-old Japanese boy who was referred to our department by an oral surgeon. He had an edentulous space with alveolar bone loss and loss of 2 permanent molars in the left mandibular region, following surgical removal of a large dentigerous cyst. We decided to close this space orthodontically. First, we moved the left mandibular second premolar into the edentulous region and autotransplanted the left maxillary lateral incisor in the adjacent distal space. We then performed comprehensive orthodontic treatment to establish stable occlusion. Following treatment, functional and stable occlusion of all permanent teeth was achieved without any spaces. The findings from this case suggest that orthodontic treatment is effective in growing patients with edentulous spaces and alveolar bone loss.

Fabrication of mucocompressive splints for free gingival grafts via medical engineering in patients with reconstructed mandibles.

PURPOSE: Acquiring adequate attached mucosa is important in restoring masticatory function with a removable dental prosthesis or dental implant. In patients with inadequate attached mucosa, a free gingival graft (FGG) with a custom stent is used. However, it is challenging to apply the conventional method for fabricating a stent with a reshaped cast in patients with reconstructed mandibles because the reconstructed mandible has limitations due to a titanium mesh, skin flap, and unique bone morphology. In the present report, we have proposed a new design and fabrication process for a mucocompressive splint via medical engineering to acquire the attached mucosa for the prosthodontic treatment of reconstructed mandibles. METHODS: Three-dimensional (3D) craniomandibular models were reconstructed from a computed tomography dataset after mandibular reconstruction. The dentition region was replaced with highly precise scan data of the dental casts using a 3D scanner. The alveolar ridge mucosa and teeth were ideally designed using the 3D model while referring to the anatomical structures. The jig used to fabricate the working dental cast with artificial gum in real space was designed and fabricated using a 3D printer. The alveolar ridge was altered into a simulated configuration on the articulator using a jig. A mucocompressive splint was fabricated on an altered dental cast. The splint was immediately seated on the mandible without any major adjustments after the FGG. CONCLUSION: Adequate attached mucosa for the prosthodontic treatment of a reconstructed mandible was obtained by the pre-surgical fabrication of a mucocompressive splint through medical engineering.

Intravascular papillary endothelial hyperplasia in the mandible: a case report.

Intravascular papillary endothelial hyperplasia (IPEH) is histopathologically characterized by papillary proliferation of vascular endothelial cells. IPEH in the mandible is very rare, such that only four affected patients have been described in the English-language medical literature. Thus, there is a poor understanding of the pathogenesis and clinical features of IPEH in the mandible. This case report describes a patient with IPEH in the mandible who had a history of repeated trauma involving the mandible due to boxing-related and baseball-related injuries. Imaging examinations had diagnostic limitations, in that they showed a multilocular radiolucency suggestive of a simple bone cyst of the mandible, whereas intraoperative findings revealed a fluid-free unicystic cavity lined by a thin red membrane. Thus, histopathologic examinations were necessary for definitive diagnosis. The specimen demonstrated a spongy structure consisting of many small papillary fibrous tissues, lined by a typical monolayer endothelium that expressed CD34, but did not express D2-40 or AE1/AE3. Moreover, the Ki-67 labeling index was <1%. Thus, the lesion was identified as intraosseous IPEH in the mandible. Although the pathogenesis of IPEH has been controversial, our findings in this case suggest that pathogenesis of IPEH may be related to a history of trauma.

Mandibular 3-dimensional finite element analysis for a patient with an aggressive form of craniofacial fibrous dysplasia.

The longitudinal change in mandibular volume and configuration was quantitatively evaluated in a patient with craniofacial fibrous dysplasia (FD). The influence of mechanical stress on the enlargement that is characteristic of FD was verified via finite element analysis (FEA). The patient was a 38-year-old man diagnosed with craniofacial FD in the mandible. He underwent surgical reduction of FD, but the lesion continued to grow and caused facial asymmetry and masticatory disturbance because of missing teeth. An occlusal overlay removable partial denture was constructed for his lower jaw. Computed tomography (CT) images were acquired 4 times in 10 years, and 3-dimensional (3-D) models were reconstructed from these data. The 3-D models were analyzed volumetrically and morphologically and used for FEA. The FD lesion in the mandible enlarged nonuniformly and had site specificity. From the results of FEA, it is suggested that compression stress induced by the occlusal force through the denture may have influenced the direction of enlargement in FD.

Lip Morphology in Patients With Facial Asymmetry Can Be Corrected by 2-Jaw Surgery.

PURPOSE: Surgical orthodontic patients with facial asymmetry frequently show asymmetry of the lips, and this is often a major complaint of patients. This study investigated whether lip asymmetry associated with the maxilla and mandible was improved when 2-jaw surgery was performed in surgical orthodontic treatment. MATERIALS AND METHODS: Inclusion criteria for this retrospective cohort study were 1) an anteroposterior maxillary relation defined as skeletal Class I; 2) menton (Me) tranverse deviation greater than 5.0 mm; 3) maxillary cant greater than 3.0°; and 4) 2-jaw surgery. Primary predictor variables in this study were skeletal morphologic measurements (Me deviation, maxillary cant, and maxillary distance ratio) before and after treatment. Outcome variables were lip morphology measurements (labial commissure distance, lip angle, and lip area). Additional variables included age and gender. Vertical distances, angles, and area of the upper and lower lips were measured and compared before and after treatment. Hard tissues were measured using posteroanterior cephalograms. Paired t test and correlation coefficients were calculated. RESULTS: Fourteen patients (4 men [28.5%] and 10 women [71.5%]; mean age, 29 yr) were included. Meaningful changes were observed in distance and angle measurements of the lips from before to after treatment. In area measurement, ratios of the area on the deviated side to that on the contralateral side for the upper and lower lips changed markedly and were close to 1.0 compared with before treatment. A relevant correlation was found between change in Me deviation and change in ratio of the height of the labial commissure. CONCLUSION: In cases of facial asymmetry caused by deviation of the maxilla and mandible, lip asymmetry can be adequately corrected by leveling the canted occlusal plane and positioning the Me toward the midline with 2-jaw surgery.

Clinical Usefulness of Mandibular Reconstruction Using Custom-Made Titanium Mesh Tray and Autogenous Particulate Cancellous Bone and Marrow Harvested From Tibia and/or Ilia.

The objective of this study was to evaluate usefulness of mandibular reconstructions using custom-made titanium mesh (Ti-mesh) tray and particulate cancellous bone and marrow (PCBM). Consecutive 21 patients who underwent mandibular reconstruction were enrolled in this study. They were 13 men and 8 women (mean age, 52.0 years). Virtual reality simulation was performed using computer software based on the preoperative computed tomography data. A 3-dimensional skull model was constructed using 3-dimensional printer. A tray was custom-made from Ti-mesh sheet bent to adapt to the model. After PCBM harvesting from posterior ilia and/or proximal tibia, the tray was fixed to the host bone. New bone formation and configuration of the reconstructed mandible were assessed radiologically. Complications were recorded in each patient during the follow-up period. Patients' satisfaction with postoperative facial contour was evaluated using visual analog scale (VAS score, range, 0-100). In 16 of 21 patients, excellent new bone formation was recognized and expected results were radiologically achieved. In 5 patients, new bone formation was insufficient. Causes of insufficient bone formation included postoperative infection in 2 patients, Ti-mesh tray fracture in 2 patients, and local recurrence of lower gingival cancer in 1 patient. To prevent a tray fracture, a double-layered Ti-mesh tray was useful. Mean VAS score on patients' satisfaction was 77.1. Our results comprehensively suggest that mandibular reconstruction using custom-made Ti-mesh tray and PCBM is clinically useful.

The main occluding area in normal occlusion and mandibular prognathism.

OBJECTIVE: To clarify whether the concept of main occluding area, where hard food is initially crushed, exists in patients who have a jaw deformity. MATERIALS AND METHODS: Nineteen subjects with normal occlusion, 18 patients with mandibular prognathism, and 11 patients with mandibular prognathism who had undergone orthognathic surgery participated in this study. The main occluding area was identified by clenching Temporary Stopping. The coincidence, location of the main occluding area, and distance from the first molars to main occluding area were examined. RESULTS: High coincidence of the main occluding area was obtained in all groups, signifying that the main occluding area exists even in these patients. Mandibular main occluding area was located on the first molar in all groups. Maxillary main occluding area in subjects with normal occlusion was located on the first molar. However, it was located on the second premolar and first molar in patients with mandibular prognathism, and on the first and second molars in patients with mandibular prognathism who had undergone orthognathic surgery. There was a statistically significant difference in distance from the maxillary first molar to the main occluding area among groups, but there was no difference in the distance from the mandibular first molar among groups. CONCLUSION: The main occluding area is more stable on the mandibular first molar than the maxilla in all groups.

Surgical Intervention for Masticatory Muscle Tendon-Aponeurosis Hyperplasia Based on the Diagnosis Using the Four-Dimensional Muscle Model.

OBJECTIVES: The surgical target of Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is the masseter or temporal muscle. In our clinic, the 4-dimentional muscle model (4DMM) has been used to decide if we should approach to the masseter or temporal muscle. The aim of this study is validate the clinical usefulness of 4DMM on the basis of the surgical results. METHODS: The 4DMM was constructed from the digital data of 3D-CT and 4-dimentional mandibular movements of the patients. It made us to able to visually observe the expansion rate of masticatory muscles at maximum mouth opening comparing to their length at closed mouth position. Fifteen patients were applied the 4DMM before the surgical treatment and 2 healthy volunteers were enrolled as control group. RESULTS: The expansion rate of temporal muscle at the maximum mouth opening in the patient group was significantly less than that in the control group (P < 0.05). On the other hand, the masseter muscles of all patients were expanded as same as the control group. Therefore the main cause of limitation of mouth-opening was suggested to be a contracture of the temporal muscle. Consequently, we performed successful bilateral coronoidectomy with no surgical intervention to the masseter muscles in all patients. CONCLUSION: The present 4DMM would be valuable modality to decide the target muscle of surgical treatment for patients with MMTAH. In this pathology, contracture of the temporal muscle seems to be main cause of limited mouth opening.

Management of open bite that developed during treatment for internal derangement and osteoarthritis of the temporomandibular joint.

This case report describes the orthodontic treatment performed for open bite caused by internal derangement (ID) and osteoarthritis (OA) of the temporomandibular joint (TMJ). A Japanese woman, aged 31 years and 11 months, referred to our department by an oral surgeon had an open bite with clockwise rotation of the mandible and degeneration of the condyle. The overbite was corrected through intrusion of the maxillary and mandibular molars using mini-screw implants to induce counterclockwise rotation of the mandible. Then, the mandibular second premolars were extracted and comprehensive orthodontic treatment was performed to establish a Class I molar relationship with distalization of the maxillary arch and to eliminate anterior crowding. Following treatment, her facial profile improved and a functional and stable occlusion was achieved without recurrence of the TMJ symptoms. These results suggest that orthodontic intrusion of the molars is one of the safer and less stressful alternatives for the management of open bite due to degeneration of the condyles caused by ID and OA of TMJ.

Solitary myofibroma of the mandible in an adult with magnetic resonance imaging and positron emission tomography findings: a case report.

Myofibroma is a benign tumor composed of myoid spindle cells. The prevalence of myofibroma in the oral cavity is very low, with the mandible being the most common site. This report describes an adult case of myofibroma that arose on the mandible and includes magnetic resonance imaging (MRI) and positron emission tomography (PET) findings. On the MRI T1-weighted images, the tumor appeared with signal iso-intensity and was highly and heterogeneously enhanced with contrast material. On the T2-weighted images, it appeared with increased signal intensity. 18 F-fluorodeoxyglucose (FDG)-PET imaging showed abnormal strong accumulation of FDG in the left mandibular region. The tumor was removed by marginal resection of the left mandible under general anesthesia. Histopathological findings revealed that the tumor stroma contained abundant thin-walled vessels. The postoperative course was uneventful, and we found no evidence of recurrence at the postoperative 34-month follow-up.

Mandibular reconstruction using custom-made titanium mesh tray and particulate cancellous bone and marrow harvested from bilateral posterior ilia.

The objective of this study is to evaluate usefulness of mandibular reconstructions using a custom-made titanium mesh (Ti-mesh) tray and particulate cancellous bone and marrow (PCBM). A consecutive nine patients who underwent mandibular reconstruction were enrolled in this study. They were five men and four women (mean age: 53.9 years). Virtual reality simulation was performed using computer software based on the pre-operative computed tomography data. A 3-dimensional (3-D) skull model was constructed using a 3-D printer. A tray was custom-made from a Ti-mesh sheet bent to adapt to the model. After PCBM harvesting from bilateral posterior ilia, the tray was fixed to the host bone. New bone formation and configuration of the reconstructed mandible were assessed radiologically. Complications were recorded in each patient during the follow-up period. Patients, satisfaction with post-operative facial contour was evaluated using a visual analogue scale (VAS score, range = 0-100). In six of nine patients, excellent new bone formation was recognised and expected results were radiologically achieved. Complications occurred in four patients. These complications included Ti-mesh fracture, Ti-mesh exposure in the oral cavity, and delayed infection. Mean VAS score on patient satisfaction was 77.6. Although the data are preliminary, the results suggest that this method is clinically useful.

Solitary fibrous tumor of the buccal space resected in combination with coronoidectomy.

Solitary fibrous tumor (SFT) is an uncommon spindle-cell mesenchymal tumor of probable fibroblastic derivation that most often occurs in the pleura, where it is typically benign. This report describes a case of a large SFT that arose in the buccal space, and includes computerized tomography, magnetic resonance imaging, and positron emission tomography (PET) findings. (18)F-Fluorodeoxyglucose (FDG) PET axial imaging showed weak abnormal accumulation of FDG in the left buccal region. The tumor was located behind the posterior wall of the maxilla, adjacent to the medial aspect of the coronoid process and was compressed between the coronoid and maxillary alveolar processes. We resected it with the use of a transoral approach in combination with coronoidectomy. Coronoidectomy was chosen because it facilitated safe removal of the tumor by improving its visibility and providing enough working space to resect it through a transoral approach.

The levels of vascular endothelial growth factor in the synovial fluid correlated with the severity of arthroscopically observed synovitis and clinical outcome after temporomandibular joint irrigation in patients with chronic closed lock.

OBJECTIVE: This study aimed to investigate the level of vascular endothelial growth factor (VEGF) in the temporomandibular joint (TMJ) synovial fluid (SF) and the severity of arthroscopically observed synovitis before and after visually guided TMJ irrigation (VGIR) in patients with chronic closed lock (CCL). In addition, the findings were correlated with the clinical outcome. STUDY DESIGN: Twenty-four patients with unilateral CCL, who underwent a second VGIR either as a repeated therapeutic TMJ irrigation or as a follow-up arthroscopy, were enrolled in the study. They were divided into either successful (s-group; n = 11) and unsuccessful (u-group; n = 13) groups. The VEGF level in the aspirated SF and the severity of synovitis were compared between the s- and u-groups. In each group, the same parameters were compared before and after VGIR. The correlation of the VEGF level with the severity of synovitis was also studied. RESULTS: At the first VGIR, the VEGF levels showed no significant differences when comparing s- and u-groups. At the second VGIR, the VEGF level was significantly higher in the u-group. The VEGF level significantly decreased after the first VGIR in the s-group but remained unchanged in the u-group. There was no significant correlation between the VEGF level and the severity of synovitis. CONCLUSIONS: The level of VEGF in TMJ SF seems to reflect the clinical status in patients with CCL. Moreover, VEGF may be an important target molecule in future chemotherapy of TMJ CCL.

The changes of joint effusion on MRI and arthroscopic findings after visually guided TMJ irrigation correlated to the clinical outcome.

OBJECTIVE: This study aimed to investigate the changes of joint effusion (JE) on the MRI and arthroscopically observed pathology after visually guided TMJ irrigation (VGIR) in patients with chronic closed lock. The correlation of these findings to the clinical outcome was also studied. STUDY DESIGN: Forty patients with unilateral chronic closed lock who underwent 2-time VGIR, were divided into either the good outcome (g-) group (n = 29) or poor outcome (p-) group (n = 11) after the first VGIR. Before each VGIR, the each severity of JE, osteoarthritis, synovitis, and fibrous adhesion were assessed. They were compared between the g- and p-groups, or between the first and second VGIR. RESULTS: The severity of JE at the first VGIR was significantly worse in the p-group. In both groups, JE significantly improved after the first VGIR. In the g-group, synovitis significantly improved after the first VGIR, but fibrous adhesion significantly became worse. CONCLUSIONS: JE may be predictive for the clinical outcome of TMJ irrigation in chronic closed lock patients. Moreover, the severity of JE and arthroscopically observed synovitis could reflect the clinical state to some degree.

Evaluation of 15 mandibular reconstructions with Dumbach Titan Mesh-System and particulate cancellous bone and marrow harvested from bilateral posterior ilia.

This study reports on 15 mandibular reconstructions using the Dumbach Titan Mesh-System and particulate cancellous bone and marrow harvested from bilateral posterior ilia. All cases showed segmental defects. Eleven cases involved patients with malignant tumor. Six patients had received irradiation of 40-50 Gy. Reconstructions were performed immediately in 1 patient and secondarily in the remaining 14 patients. In 13 cases, mandibles were successfully reconstructed. Of these 13 patients, 9 reconstructions were completed without complications, whereas the other 4 cases showed complications. In 2 cases, reconstruction failed completely. Overall success rate was 87%. Statistical analysis revealed the extent of mandibular defect, but not malignancy of the original disease or radiotherapy of

Severity of arthroscopically observed pathology and levels of inflammatory cytokines in the synovial fluid before and after visually guided temporomandibular joint irrigation correlated with the clinical outcome in patients with chronic closed lock.

OBJECTIVE: This study aimed to investigate the severity of arthroscopically observed pathologies and the levels of a set of inflammatory cytokines in aspirated synovial fluid (A-SF) in patients with chronic closed lock (CCL) of the temporomandibular joint (TMJ) before and after visually guided TMJ irrigation (VGIR). Furthermore, the findings were correlated with the clinical outcome after VGIR. STUDY DESIGN: VGIR was performed in 56 consecutive patients with unilateral CCL. Forty-nine of them, who underwent a second VGIR either as a follow-up arthroscopy or as a repeated therapeutic irrigation, were analyzed. They were assigned to either the successful (s-) group (n = 31) or unsuccessful (u-) group (n = 18), according to the clinical success criteria. The severity of arthroscopic findings of osteoarthritis (OA), synovitis, and fibrous adhesion (FA) were evaluated as arthroscopic scores. The levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, IL-8, IL-12, and IL-10 in the A-SF were measured. At the first and second VGIR, the arthroscopic scores and the levels of each investigated cytokine were compared between the s- and u-groups. In each group, same parameters were compared between the first and second VGIR. RESULTS: At the first and second VGIR, there are no differences in the arthroscopic scores between the s- and u-groups. After the first VGIR, the severity of synovitis significantly improved, that of OA was unchanged, and that of FA became worse in the s- and u-groups. At the first VGIR, the levels of IL-6 and IL-8 were significantly higher in the u-group, and the IL-10 level was significantly higher in the s-group. At the second VGIR, however, there were no differences in the levels of each investigated cytokine between the s- and u-groups. The levels of each cytokine did not significantly change between the first and second VGIR, regardless of the clinical outcome. CONCLUSIONS: VGIR may contribute to the remission of synovitis in patients with TMJ CCL. However, the severity of arthroscopically observed pathologies and the levels of each investigated cytokine do not seem to be reflected by the clinical state. Moreover even if the intra-articular inflammation is asymptomatic, an exacerbation may not be ruled out even after a successful VGIR.