A comparison of lower lip hypoesthesia measured by trigeminal somatosensory-evoked potential between different types of mandibular osteotomies and fixation

取得学位 : 博士（医学）, 学位授与番号 : 医博甲第1916号 , 学位授与年月日 : 平成20年3月22日, 学位授与大学 : 金沢大学, 主査教授 : 山本 悦秀, 副査教授 : 古川 仭 , 富田 勝

Condylar and disc positions after sagittal split ramus osteotomy with and without Le Fort I osteotomy

金沢大学医学部附属病院歯科口腔外科金沢大学大学院医学系研究科がん細胞学Purpose: The purpose of this study is to examine the changes in temporomandibular joint (TMJ) morphology and clinical symptoms after sagittal split ramus osteotomy (SSRO) with and without a Le Fort I osteotomy. Subjects and Methods: Of 45 Japanese patients with mandibular prognathism, 23 underwent SSRO and 22 underwent SSRO in combination with a Le Fort I osteotomy. The TMJ symptoms and joint morphology, including disc tissue, were assessed preoperatively and postoperatively by magnetic resonance imaging (MRI) and axial cephalography. Results: There were significant differences between pre- and postoperative horizontal changes in the condylar long axis on the right side in the group undergoing SSRO (sagittal split ramus osteotomy) alone. However, there were no other significant differences in pre- and postoperative measurements in this group as compared with the group receiving SSRO plus Le Fort I osteotomy, and the preoperative disc position could not be changed in either group. Conclusion: These results suggest that SSRO, either with or without Le Fort I osteotomy, could not change the preoperative disc position or correct anterior disc displacement, although these procedures did improve the symptoms associated with TMJ dysfunction. © 2007 Mosby, Inc. All rights reserved

Skeletal Stability After Mandibular Setback Surgery: Bicortical Fixation Using a 2.0-mm Locking Plate System Versus Monocortical Fixation Using a Nonlocking Plate System

金沢大学大学院医薬保健研究域医学系Purpose: This study was conducted to compare the time-course changes in condylar long-axis and skeletal stability after sagittal split ramus osteotomy (SSRO) with bicortical plate fixation versus monocortical plate fixation. Patients and Methods: Of a group of 40 Japanese patients diagnosed with mandibular prognathism, 20 underwent SSRO with bicortical plate fixation using a locking plate system and the other 20 underwent SSRO with monocortical plate fixation using a conventional plate system. The time-course changes in condylar long-axis and skeletal stability were assessed through axial, frontal, and lateral cephalograms. Results: Significant differences were found between the 2 groups in changes of the left condylar angle between the initial and 1-month measurements (P = .0454) and in ANB between the 1- and 3-month measurements (P = .0206); however, no significant differences were found between the 2 groups in the other measurements in each time interval. Conclusions: Our findings suggest no significant differences in postoperative time-course changes between bicortical plate fixation using a locking plate system and monocortical plate fixation using a conventional plate system. © 2008 American Association of Oral and Maxillofacial Surgeons

The evaluation of surgical factors related to recovery period of upper lip hypoaesthesia after Le Fort I osteotomy

金沢大学医薬保健研究域医学系Purpose: It is unclear whether surgical factors can affect the upper lip sensitivity. The aim of this study was to assess the factors that can affect the recovery period of hypoaesthesia of the upper lip after Le Fort I osteotomy, using trigeminal somatosensory evoked potential (TSEP) objectively. Patients and methods: Twenty-nine patients with mandibular prognathism underwent Le Fort I osteotomy with and without artificial pterygoid plate fracture. Trigeminal nerve hypoaesthesia at the region of the upper lip was assessed bilaterally by the TSEP method. The distance between the infraorbital foramen and the osteotomy line (IO) or the nearest plate/screw position (IP) was measured on three-dimensional computed tomography (CT). The relationship between the recovery period in upper lip hypoaesthesia and surgical factors (these distances, movement amount, pterygoid plate fracture) were analysed statistically. Results: The recovery period in upper lip hypoaesthesia did not significantly correlate with IO, IP and movement amount. There was no significant difference between pterygoid plate fracture group and non-fracture group. Conclusion: Temporary hypoaesthesia of upper lip after Le Fort I osteotomy could not be avoided, however, osteotomy line, plate/screw position and pterygoid plate fracture in Le Fort I osteotomy did not affect the recovery period of upper lip hypoaesthesia with TSEP. © 2008 European Association for Cranio-Maxillofacial Surgery.This article has not been published yet

A comparative CT evaluation of pharyngeal airway changes in class III patients receiving bimaxillary surgery or mandibular setback surgery

金沢大学大学院医学系研究科がん細胞学Objective: The purpose of this study was to compare the morphologic changes of the upper airway space in Class III patients who underwent mandibular setback or bimaxillary surgery (maxillary advancement and mandibular setback) by computed tomography at 2 levels: soft palate and base of tongue. Methods: The sample consisted of 47 subjects in 2 groups who had been diagnosed as having Class III skeletal deformities and had been treated by mandibular setback or bimaxillary surgery (maxillary advancement and mandibular setback). Anteroposterior, lateral, and cross-sectional area dimensions of the airway at the level of soft palate and base of tongue were measured pre- and postoperatively on computed tomography images. Results: Anteroposterior dimensions of the airway decreased in both groups (P .05). Conclusions: This study suggests that bimaxillary surgery can prevent narrowing of the upper airway in the correction of Class III deformities in comparison with mandibular setback surgery used as the sole treatment. Computed tomography was valuable in determining the effects of surgical treatment on pharyngeal airway dimensions. © 2008 Mosby, Inc. All rights reserved

Determining the anatomy of the descending palatine artery and pterygoid plates with computed tomography in Class III patients

金沢大学医薬保健研究域医学系Purpose: Understanding the anatomy of the pterygomaxillary junction region helps prevent blood loss in Le Fort I osteotomy. Here, we determined the location of the descending palatine artery and the structure of the pterygomaxillary region. Patients and methods: The study group consisted of 82 Japanese patients with mandibular prognathism and asymmetry, with and without maxillary retrognathism or asymmetry. A total of 164 sides were measured and divided into right versus left, men versus women, and bimaxillary osteotomy (B) versus mandibular osteotomy (S). Lateral and frontal cephalograms and computed tomography (CT) were analysed for all patients. The relationship between the cephalometric measurements and the measurements of the descending palatine artery and pterygoid plate (PP) were assessed. Results: There were no significant correlations between measurements of cephalograms and those of the descending palatine artery and PPs. There were significant differences between right and left in lateral plate length (p = 0.0014) and thickness of PP (p = 0.0047). There were significant differences between men and women in right width of PP (p = 0.0034), right thickness of PP (p = 0.0063), left posterior length (p = 0.0196), and left thickness of PP (p = 0.0279). The B group had a shorter anterior length than the S group (right: p < 0.0001, left: p = 0.0027). Conclusion: These results suggest that the location of the descending palatine artery and the morphology of the PPs were not significantly associated with any cephalometric measurements. CT examination is necessary to recognize the anatomy of pterygomaxillary region and the exact positions of descending palatine artery before Le Fort I osteotomy. © 2009 European Association for Cranio-Maxillofacial Surgery

Assessment of the Relationship Between the Recovery of Maximum Mandibular Opening and the Maxillomandibular Fixation Period After Orthognathic Surgery

金沢大学大学院医学系研究科がん細胞学Purpose: The purpose of this study was to evaluate the differences in the recovery of maximum mandibular opening (MMO), and the relationship between MMO and the maxillomandibular fixation (MMF) period after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO), with and without Le Fort I osteotomy. Patients and Methods: Sixty-eight patients with diagnosed mandibular prognathism with or without asymmetry were divided into 4 groups (SSRO, IVRO, SSRO with Le Fort I osteotomy, and IVRO with Le Fort I osteotomy). MMO and the MMF period were measured preoperatively and at 1, 3, 6, 12, and 18 months after surgery. The differences among surgical procedures and the relationship between MMO and the MMF period were examined statistically. Results: In relation to time-dependent changes in MMO, there were no significant differences among the groups. There were significant positive correlations between MMO and the MMF period from 1 month to 6 months after surgery. However, there were no significant correlations at 12 and 18 months after surgery. Conclusion: This study suggests that there were no significant differences between single-jaw surgery and double-jaw surgery in terms of postoperative time-dependent changes in the recovery of MMO. However, the MMF period was associated with the recovery of MMO. © 2008 American Association of Oral and Maxillofacial Surgeons

Changes in the Duration of the Chewing Cycle in Patients With Skeletal Class III With and Without Asymmetry Before and After Orthognathic Surgery

金沢大学医薬保健研究域医学系Purpose: The purpose of this study was to examine the changes in the chewing rhythm before and after mandibular ramus osteotomy in patients with prognathism with and without asymmetry. Patients and Methods: We divided 12 men and 22 women with mandibular prognathism into groups on the basis of symmetry and osteotomy procedure. The duration of the chewing cycle was recorded preoperatively and postoperatively. The duration of the chewing cycle and coefficient of variation were compared between groups, and the differences were analyzed statistically. Results: No significant differences in each of 3 phases of the chewing cycle and total duration were found between groups on the basis of symmetry or osteotomy procedure. However, there were significant differences between the preoperative and postoperative coefficients of variation for the undeviated side in the asymmetry group (P = .0037) and in the group undergoing sagittal split ramus osteotomy (P = .0166). Conclusion: This study suggests that surgical orthodontic treatment does not significantly change the duration of the chewing cycle. © 2009 American Association of Oral and Maxillofacial Surgeons

Horizontal changes in the condylar head after sagittal split ramus osteotomy with bent plate fixation

金沢大学医薬保健研究域医学系Objective: The purpose of this study was to evaluate the horizontal changes in the condylar head with bent plate fixation after sagittal split ramus osteotomy (SSRO) with and without a Le Fort I osteotomy. Study design: Of 47 Japanese patients with mandibular prognathism, 24 underwent SSRO and 23 underwent SSRO in combination with a Le Fort I osteotomy. A 3-5-mm gap was made between the proximal and distal segments, and a bent plate was fixed with 4 screws in each side of the mandible. The angle of the condylar long axis, as well as the anteroposterior and mediolateral displacement of the condylar head were assessed preoperatively and postoperatively by computerized tomography (CT). Results: There was no significant difference in reduction in mandibular length between SSRO alone and SSRO with Le Fort I on the axial view of a 3-dimensional CT. There were no significant differences between pre- and postoperative horizontal changes in the condylar long axis or in the anteroposterior and mediolateral displacement of the condylar head, although the length of the proximal segment in SSRO with Le Fort I osteotomy was significantly shorter than in SSRO alone (P < .05). Conclusion: These results suggest that the use of a bent plate for SSRO does not change preoperative angle or position significantly in setback surgery, regardless of the addition of Le Fort I osteotomy. © 2008 Mosby, Inc. All rights reserved.This article has not been published yet

The effects of changing position and angle of the proximal segment after intraoral vertical ramus osteotomy

金沢大学医薬保健研究域医学系The authors evaluated changes in position and angle of the proximal segment, including the condyle, after intraoral vertical ramus osteotomy (IVRO) with and without a Le Fort I osteotomy to verify whether displacement of the proximal segment could induce postoperative complications. Changes in condylar angle, ramus angle, and displacement of proximal segment were measured pre- and postoperatively. The position of the temporomandibular joint (TMJ) disc was examined pre- and postoperatively. Trigeminal nerve hypoesthesia in the lower lip was assessed bilaterally. The postoperative horizontal condylar angle was significantly smaller than the preoperative one on the deviated and non-deviated sides (P<0.0001). The postoperative coronal condylar angle was significantly larger than the preoperative one on the deviated side (P=0.0483). The postoperative sagittal ramus angle was larger than the preoperative one on the deviated (P<0.0001) and non-deviated (P=0.00005) side. Most joints with an anteriorly-displaced disc with and without reduction improved on the non-deviated side; 5 of 16 joints improved on the deviated side. Results suggest the position and angle of the proximal segment, including the condyle, could change after IVRO. This could be associated with symptomatic improvement in TMJ, and extreme medial displacement of the proximal segment could delay recovery from lower lip hypoesthesia. © 2009 International Association of Oral and Maxillofacial Surgeons