Does Condylar Morphology Affect Maxillary Repositioning in Bimaxillary Orthognathic Surgery?

This study aimed to measure the association between condylar morphology and a measure of the maxillary centroid following bimaxillary surgery using mandibular-dependent splints. The study included skeletal Class III and Class II malocclusion patients, excluding those with facial asymmetry. Based on computed tomography imaging patients were characterized into normal or abnormal temporomandibular joint (TMJ) groups. A computer-aided design/computer-aided manufacturing splints were fabricated to reposition the maxilla in Le Fort I osteotomy. The primary outcome measure was the absolute differences between the maxillary centroid's the planned and actual postoperative positions calculated by superimposing computed tomography scans. The secondary outcome was the measure of other variations in linear and angular maxilla discrepancies. The demographic covariates included the age and sex of the patients. The operative covariates consisted of the dentofacial deformity and the planned movement of the maxilla. Seventy patients with skeletal maxillofacial deformities were included for analysis: 44 patients in the normal and 26 in the abnormal TMJ group. The average maxillary misalignment was 1.04±0.48 mm in the normal and 1.53±0.63 mm in the abnormal TMJ group (P<0.001). A statistically significant relationship existed between the discrepancies of the maxillary centroid and dentofacial deformity (η=0.656, P<0.001). These findings suggest an increased propensity for maxillary malposition in skeletal Class II patients. Furthermore, condylar morphology is a significant prognostic factor influencing maxillary repositioning errors in bimaxillary surgery with mandibular-dependent splints.

Study of Anatomical Changes of the Inferior Nasal Passage After Le Fort I Osteotomy With Superior Repositioning.

The relationship between postoperative morphological changes in the inferior nasal cavity and inferior turbinate after Le Fort I osteotomy remains unclear. This study aimed to investigate how the bone volume of the inferior turbinate affects contact with the inferior nasal cavity of patients who underwent superior repositioning. We evaluated the 3-dimensional relationship between the anatomical changes in the inferior nasal passage before and after surgery in 51 patients who underwent Le Fort I osteotomy with an elevation of >4.0 mm in the first molar. The soft tissue and bone volumes of the inferior turbinate and airway volume of the inferior nasal passage were calculated using Proplan CMF 3.0 and compared according to the size of the bone volume of the inferior turbinate. In addition, we reclassified the maxillary movements in the pitch direction and compared the results. The contact rates of the postoperative inferior nasal airway and the inferior turbinate in the large-bone group was 72.3% and that in the small-bone group was 40.0% in the χ2 test. The reduction in the inferior nasal passage volume was significantly greater in the large-bone group (pitch+) than in the small-bone group (pitch+). For patients with well-developed bony tissue of the inferior turbinate, caution is advised if the maxillary elevation is ≥4.0 mm, because the possibility of postoperative obstruction of the inferior nasal passages exist, which may lead to deterioration of nasal ventilation.

Postoperative stability of bioresorbable plates made of 85:15 poly (L-lactide-co-glycolide) in Le Fort I osteotomy.

OBJECTIVE: Recently, RapidSorb plates (DePuy Synthes) made of 85.15 poly (L-lactide-co-glycolide) have been used for orthognathic surgery; however, reports regarding their effectiveness are limited. We aimed to compare the postoperative stability of RapidSorb plates, RapidSorb combined with titanium (MOJ plates), and MOJ plates in patients who underwent Le Fort I osteotomy at Tokyo Medical and Dental University Hospital. STUDY DESIGN: The use of RapidSorb in the maxilla is a load-sharing application and therefore constitutes an approved indication. Discrepancies in the maxillary positions were measured using postoperative computed tomography data at 1 week and 1 year using the centroid method 3-dimensionally. Treatment with RapidSorb alone showed a more vertical discrepancy in the maxilla treatment with MOJ and RapidSorb+MOJ. The RapidSorb4 group was subdivided into 2 groups (under and over 1.0-mm) based on the change in the maxillary centroid. RESULTS: The bone gap at the lateral border of the piriform aperture was significantly larger in the over-1.0-mm group than in the 1.0-mm group. CONCLUSIONS: The fixation of RapidSorb alone is not appropriate in load-bearing and unstable applications but is not contraindicated for load-sharing indications. Fixation with RapidSorb combined with MOJ was clinically effective, with results similar to titanium plate-only fixation regarding postoperative stability.

Risk factors for postoperative facial swelling at 1 week after bimaxillary orthognathic surgery in Class III patients.

OBJECTIVE: To quantify facial swelling at 1 week after Le Fort I osteotomy and bilateral sagittal splitting ramus osteotomy in Class III patients and to identify factors contributing to the swelling based on clinical, morphologic, and surgical variables. STUDY DESIGN: Data from 63 patients were examined in this single-center, retrospective study. Facial swelling was quantitatively measured by superimposing computed tomography data taken in the supine position at 1 week and 1 year postoperatively and extracting the area of maximum intersurface distance. Age, sex, body mass index, thickness of subcutaneous tissue, and of masseter muscle, maxillary length (A-VRP), mandibular length (B-VRP), and posterior maxillary height (U6-HRP), surgical movement (ΔA-VRP, ΔB-VRP, ΔU6-HRP), drainage method, and usage of facial bandages were examined. Multiple regression analysis was performed using the above factors. RESULTS: The median swelling at 1 week postoperatively was 8.35 IQR (5.99-11.47) mm. Multiple regression analysis revealed three factors that were significantly associated with facial swelling: Use of postoperative facial bandages (P=0.03), masseter muscle thickness (P=0.03), and ΔB-VRP (P=0.04). CONCLUSION: Absence of a facial bandage, thin masseter muscle, and large horizontal mandibular movement are risk factors for facial swelling at 1 week postoperatively.

Risk factors of neurosensory disturbances at 1 year postoperatively after bilateral sagittal split osteotomy.

OBJECTIVE: To investigate morphologic and surgical risk factors causing neurosensory disturbances (NSDs) after bilateral sagittal split osteotomy (BSSO). STUDY DESIGN: A total of 237 patients (with 474 sides) who underwent BSSO were followed up for 1 year. Parameters examined included age, sex, asymmetry, mandibular movement direction, mandible cutting devices, split type, intraoperative exposure of the inferior alveolar nerve (IAN), contact between the IAN and screw, distance between mandibular canal and inner surface of the cortical bone (distance A), distance from lateral osteotomy to mental foramen (distance B), and NSD at 1 year postoperatively. RESULTS: NSD was observed in 62 (13.1%) sides of 51 patients. Exploratory factor analysis determined 4 factors (factor 1: distance A; factor 2: direction of mandibular movement; factor 3: distance B and cutting devices; factor 4: IAN exposure). Logistic regression analysis was performed using the above factors and age, sex, and asymmetry, making a total of 7 variables. Age, factor 1, and factor 4 were significant predictors of NSD. CONCLUSIONS: Advanced age, close distance between mandibular canal and inner surface of the cortical bone, and IAN intraoperative exposure are risk factors for NSD 1 year postoperatively. Cases at high risk for NSD must be treated with great care.

Study of Morphological Changes in the Inferior Turbinate After Le Fort I Osteotomy.

OBJECTIVE: There are cases in which patients complain of nasal obstruction after Le Fort I osteotomy, but the relationship with postoperative morphological changes in the nasal cavity, including the septum and inferior turbinate, is not clear. STUDY DESIGN: The authors evaluated the three-dimensional relationship of the morphological changes in the inferior turbinate before and after surgery in 84 patients who underwent Le Fort I osteotomy. Three classifications were made according to superior amount of maxillary movement at the base of nasal cavity. RESULTS: The high elevation group (4.0 mm or more) had 31 sides, the moderate elevation group had 93 sides, and the low elevation group (less than 2.0 mm) had 44 sides. The volume of inferior turbinate was 76.9 ± 12.8% of that before surgery in the high elevation group. The high- and moderate-elevation groups had significantly higher changes than the low elevation group, and the rate of contact between inferior turbinate and nasal cavity floor was 67.7%. CONCLUSIONS: After Le Fort I osteotomy, the volume of inferior turbinate tissue decreased in proportion to the amount of elevation of the maxilla. Although the soft tissue volume may be reduced due to adaptation of respiratory function, the inferior nasal passage was not completely ventilated in the high elevation group. If the elevation exceeds 4.0 mm counterclockwise with maxillary movement, it is necessary to consider the concomitant inferior turbinate resection because it may lead to nasal obstruction.

Changes in the condylar volume and skeletal relapse following orthognathic surgery in patients with dentofacial deformity: A retrospective study.

OBJECTIVE: To evaluate the relationship between the changes in condylar volume and maxillofacial skeletal morphology according to sex as well as the relationship between condylar volume reduction and skeletal relapse in patients who underwent orthognathic surgery. METHODS: Ninety-five patients were categorized into skeletal Class III, Class II, and facial asymmetry groups. Computed tomography scans taken preoperatively and at 1 year postoperatively were used for quantitative measurement. RESULTS: Postoperative condylar volume was reduced in both the Class II group and the deviated side of the asymmetry group. Both female and Class II deformity were significant predictors of postoperative reduction in the condylar volume. There was a significant correlation between skeletal relapse and postoperative change in condylar volume in the Class II group. CONCLUSION: Postoperative condylar resorption may be associated with preoperative maxillofacial skeletal morphology and sex and also with skeletal relapse in the Class II group.

Short-Term Stability After Segmental Le Fort I Maxillary Impaction Surgery With Mandibular Autorotation in Seven High-Angle Class II Patients: A Case Series.

PURPOSE: To retrospectively evaluate skeletal stability after Le Fort I maxillary impaction surgery and mandibular autorotation without bilateral sagittal split osteotomy (BSSO) in high-angle class II patients. MATERIALS AND METHODS: Seven female high-angle class II patients who underwent maxillary impaction surgery and mandibular autorotation without bilateral sagittal split osteotomy were included in this study. Surgical changes and relapse were measured on lateral cephalograms taken preoperatively and at 1 month, 6 months and 1 year postoperatively. RESULTS: The horizontal movement of the maxilla at point A was 5.8 ±â€Š3.3 mm backward, and the upward movement at the posterior nasal spine was 3.3 ±â€Š1.4 mm. The mean horizontal change at point A during the 1-year follow-up period was 0.1 ±â€Š0.2 mm, and the vertical change at posterior nasal spine was 0.2 ±â€Š1.3 mm, which were not statistically significant. The horizontal surgical change at point B was 4.0 ±â€Š1.8 mm forward and the vertical surgical change at point B was 4.7 ±â€Š1.8 mm upward. Postoperative relapse was 10.9% and 13.7% in the horizontal and vertical directions, respectively. CONCLUSIONS: Le Fort I maxillary impaction surgery with mandibular autorotation may be 1 of the suitable procedures for high-angle class II patients.

Long-term follow-up after arthroplasty for pediatric temporomandibular joint ankylosis performed before the critical period of mandibular growth: A case report.

INTRODUCTION AND IMPORTANCE: Pediatric temporomandibular joint (TMJ) ankylosis can lead to significant difficulties in opening the mouth, as well as stunted mandibular growth resulting in a small mandible and facial asymmetry. For pediatric TMJ ankylosis, the ideal time to perform TMJ mobilization in order to achieve standard mandibular growth is unclear. CASE PRESENTATION: An 11-year-old boy with limited mouth opening was referred to our hospital. The patient had previously sustained a fracture of the left articular process of the mandible. Clinical examination revealed bony ankylosis of the left TMJ, and the condylar head was dislocated anteromedially. The bony ankylosis was removed at the age of 12 years. Mouth-opening exercises were started postoperatively. His mouth opening recovered without the development of severe facial asymmetry, and the dislocated condylar process served as a new joint and provided good jaw function until the most recent follow-up at the age of 21 years. CLINICAL DISCUSSION: It is practical to perform surgical intervention after the child has achieved some growth and at a time when the surgery would not interfere with jaw development because the mouth opening can be improved by postoperative physical therapy. No interpositional implant was used because strict postoperative mouth opening exercises and the displaced condylar process, which was maintained to almost normal TMJ structure, were expected to preserve the gap between the ramus and the zygomatic arch. CONCLUSION: Surgical intervention in the appropriate growth period is important to prevent the sequelae of mandibular growth suppression due to pediatric TMJ ankylosis.

Ramucirumab-related Oral Pyogenic Granuloma: A Report of Two Cases.

Pyogenic granuloma (PG) is a granulomatous elevated lesion that occurs on the skin and mucous membranes. We herein report two cases of intra-oral PG that developed during the administration of ramucirumab for gastric cancer. Case 1 involved a 55-year-old man with a 6-mm tumor on the right tongue, and case 2 involved a 67-year-old man with a 5-mm tumor on the upper lip. The imbalance in angiogenesis caused by ramucirumab and the deterioration in the local oral environment were suggested to have caused the PG. Medical and dental collaboration is essential during the administration of ramucirumab.

Does the amount of mandibular setback during bimaxillary surgery correlate with the degree of surgical relapse?

OBJECTIVE: The aim of this study was to investigate postoperative horizontal relapse of the mandible in terms of the effects of the magnitude of mandibular setback movement and ramus inclination after LeFort I osteotomy and sagittal split ramus osteotomy. STUDY DESIGN: A retrospective study of patients who underwent orthognathic surgery for mandibular prognathism was performed. Postoperative relapse at point B was analyzed with regard to the magnitude of mandibular setback and the ramus inclination. Serial cephalograms were used to measure surgical changes and evaluate postoperative relapse. RESULTS: Nineteen men and 31 women (mean age 23.1 years) were retrospectively enrolled. Mean surgical backward movement of the mandible at point B was 8.2 mm, mean ramus inclination was 3.56 degrees, and mean relapse 1 year postoperatively was 0.95 mm (11.6%). Horizontal relapse of the mandible was significantly correlated with the magnitude of mandibular setback (r = -0.52; P = .007) and ramus inclination (r = 0.48; P = .014). CONCLUSIONS: Increased horizontal mandibular relapse after bimaxillary surgery was associated with greater mandibular setback movement and increased proximal segment clockwise rotation. Mandibular relapse after bimaxillary surgery may be minimized via adequate control of intraoperative clockwise rotation of the proximal segment.

Primary ameloblastic carcinoma of the maxilla: A case report and literature review.

Ameloblastic carcinoma (AC) is a rare malignant odontogenic neoplasm that tends to occur in the mandible rather than in the maxilla. This malignancy is classified as a tumor that combines the morphological features of ameloblastoma and carcinoma, regardless of the presence or absence of metastasis. In addition, AC has been classified into two types, primary and secondary. The former develops de novo and the latter develops by malignant transformation of a pre-existing benign ameloblastoma. The present study describes the case of a 22-year-old patient with primary AC of the maxilla. A review of the literature focusing on the clinical details, treatment results and histopathological and phenotypic information available for ameloblastic carcinoma of the maxilla from a 60-year period was also performed. As a result, it was found that primary AC is dominant in the maxilla and does not exhibit an aggressive phenotype compared with secondary AC. In addition, the presence of recurrence was found to correlate with mortality, indicating that early, aggressive and complete removal of the tumor is the best treatment for survival.

A structural modulator of tumor necrosis factor type 1 receptor promotes bone formation under lipopolysaccharide-induced inflammation in a murine tooth extraction model.

Recently an increase in the serum levels of a bone formation marker after anti-tumor necrosis factor (TNF)-α therapy in rheumatoid arthritis patients has been reported. However, there remains no direct evidence that TNF-α antagonist could accelerate bone formation under inflammatory condition. Cavity-induced allosteric modification (CIAM) compound, F002, is a newly developed-TNF-α antagonist, which was designed by using the structure of TNF type 1 receptor, thus preventing TNF-α-induced signaling. In this study, we examined whether the CIAM compound can promote bone formation under inflammatory condition induced by lipopolysaccharide (LPS). Thirty-six 10-week-old male mice (C57BL/6J) were used. Half of the mice received 10 mg/kg LPS, while the other half received PBS. Thereafter, incisor extraction was performed at 4 days after either LPS or PBS injection. Intraperitoneal injections of 2 mg/kg/day, 4 mg/kg/day CIAM, or vehicle (10% DMSO) were performed once a day from day 0 to day 7 after incisor tooth extraction. The mice were sacrificed at 21 days after the extraction. The regenerated bone mineral density (BMD) in the tooth socket, and the mineral apposition rate and the bone formation rate, direct evidences of bone formation, were significantly decreased in the LPS-injected group compared to the PBS-injected group. CIAM compound dose-dependently prevented the decrease of BMD under the LPS-injected condition, and promoted both the mineral apposition rate and the bone formation rate significantly compared to the LPS-injected group. We did not observe any significant differences among the PBS-injected groups. Taken together, TNF-α antagonist CIAM compound, was found to accelerate bone formation under LPS-induced inflammatory condition.

Polysaccharide nanogel delivery of a TNF-alpha and RANKL antagonist peptide allows systemic prevention of bone loss.

We report here a nanogel-mediated peptide drug delivery system. Low stability is a major drawback towards clinical application of peptide drugs. The W9-peptide, a TNF-alpha and RANKL antagonist, was used as a model for testing the feasibility of cholesterol-bearing pullulan (CHP)-nanogel as the drug delivery system. We found CHP-nanogel could form complex with the W9-peptide and prevents its aggregation in vitro. Murine bone resorption model using low dietary calcium was used to investigate the in vivo effect. Two-time-injection of 24 mg/kg W9-peptide per day with or without CHP-nanogel was given for 7 days. Thereafter, radiological, and histological assessments were performed. The injections of the W9-peptide (24 mg/kg) with CHP-nanogel prevented the reduction in bone mineral density whereas the same dose without CHP-nanogel could not show any inhibitory effect. Histomorphometric analysis of tibiae showed significant decrease of osteoclast number and surface in CHP-W9 complex treated group and the levels of urinary deoxypyridinoline reflected these decrease of bone resorption parameters. Taken together these data shows that CHP-nanogel worked as a suitable carrier for the W9-peptide and it prevented aggregation and increased the stability of the W9-peptide. This study reveals the feasibility of CHP-nanogel-mediated peptide delivery in preventing bone resorption in vivo.

LPS-induced inhibition of osteogenesis is TNF-alpha dependent in a murine tooth extraction model.

TNF-alpha is a major etiologic factor of inflammatory bone diseases such as periodontitis and rheumatoid arthritis. In addition, patients with metabolic diseases such as chronic heart disease and diabetes have significantly increased plasma levels of TNF-alpha. Several lines of evidence show inhibition of osteoblastogenesis by TNF-alpha in vitro. Therefore, bone formation and osteogenesis in these patients might be inhibited because of TNF-alpha. However, little is known about the inhibitory role of TNF-alpha in bone formation/osteogenesis in vivo. The purpose of this study was to investigate the role of TNF-alpha in osteogenesis using a murine tooth extraction model. Lipopolysaccharide (LPS) was injected subcutaneously into the calvariae of either wildtype (WT) or TNF-alpha-deficient (KO) mice. The left incisor was extracted 4 days after LPS injection. The measuring area was established as the tooth socket under the mesial root of the first molar. A significant increase in serum TNF-alpha levels after LPS injection was observed in WT mice. The BMD of the tooth socket was significantly decreased by LPS injection 21 days after extraction in WT but not in KO mice. Histomorphometric analysis showed a significant decrease in the mineral apposition rate after LPS injection, which appeared at an early stage in WT but not in KO mice. Injection of a peptide that blocked the TNF-alpha signaling pathway by preventing transmission of the NF-kappaB signal recovered the inhibition of osteogenesis observed after LPS injection. In conclusion, TNF-alpha might play a major role in LPS-induced inhibition of osteogenesis under inflammatory conditions.