Major vascular complications of orthognathic surgery: hemorrhage associated with Le Fort I osteotomies

Major intraoperative or postoperative bleeding associated with Le Fort I osteotomies can be venous and/or arterial in nature. Arterial hemorrhage generally involves the maxillary artery and its terminal branches. Arterial hemorrhage tends to be more persistent and can be recurrent, which makes it more difficult to manage. Postoperative bleeding following Le Fort I osteotomies generally presents as epistaxis and usually occurs initially within the first 2 weeks following surgery. Treatment modalities that have been used to successfully arrest postoperative hemorrhage include anterior and/or posterior nasal packing; packing of the maxillary antrum; reoperating with clipping or electrocoagulation of bleeding vessels, or the use of topical hemostatic agents in the pterygomaxillary region; external carotid artery ligation; and selective embolization of the maxillary artery and its terminal branches.     

The inter-relationship between mandibular autorotation and maxillary LeFort I impaction osteotomies

The purposes of the present investigation were to: 1)locate the instantaneous rotation center of mandible autorotation during maxillary surgical impaction; 2) identify the discrepancies between the resultant mandibular position following by maxillary surgical impaction and presurgical predictions, which use the radiographic condylar center as the rotation center for mandibular autorotation; and 3)find the interrelation between the magnitude of maxillary surgical impaction and the sagittal change of mandible. Ten patients underwent maxillary LeFort I impaction without concomitant major mandibular ramus split osteotomies were included. The preoperative (T0) and postoperative (T1) lateral cephalograms were used to evaluate the surgical changes and locate the center of rotation of mandibular autorotation with Reuleaux method. Prediction errors were measured by comparing the predicted (Tp) and postoperative (T1) cephalometric tracings. The magnitude of the maxillary surgical impaction was compared to the positional changes of mandible after mandibular autorotation with correlation and regression analysis. The results demonstrated that the centers of mandibular autorotation located 2.5 mm behind and 19.6 mm below the radiographic condylar center of the mandible in average with large individual variations. By using the radiographic condylar center of the mandible to predict the mandibular autorotation would overestimate the horizontal position of chin by 2 mm and underestimate the vertical position of chin by 1.3 mm following an average of 5 mm surgical maxillary impaction. The magnitude of maxillary impaction was highly and positively correlated to the horizontal displacement of chin position. The rotation centers of mandibular autorotation following by maxillary LeFort I impaction osteotomies might not usually locate at the radiographic condylar center of the mandible also with large individual variations in their positions. Surgeons and orthodontists should be aware of the horizontal and vertical discrepancies of chin positions while planning a two-jaw surgery by using the radiographic center of mandibular condyle as the rotation center in mandibular autorotation.     

Intraoperative lesions of the maxillary artery and its immediate treatment. Presentation of a clinical case

The authors discuss the possible vascular lesions that may occur during mandibular sagittal split ramus osteotomies with particular regard to the maxillary artery. A case of surgical lesion of the maxillary artery is presented and its course and anastomoses are analyzed. The ligation of the external carotid artery and its principal branches is the treatment of choice in case of maxillary artery lesion which is a life threatening event and needs immediate intervention.     

Hypomobility after maxillary and mandibular osteotomies

A retrospective recall study of forty patients was made to examine mandibular function after orthognathic surgery. Maximum maxillomandibular opening, protrusion, and lateral excursions were measured and compared with similar mandibular movements in a control group of patients of comparable age. Six months to 42 months after maxillary and mandibular osteotomies, the majority of patients demonstrated decreased maxillomandibular opening compared to the control group 54.8 mm (SD 4.7). The decrease was most dramatic in patients previously treated with sagittal split ramus osteotomies. The mean maxillomandibular opening after Le Fort I osteotomy to reposition the maxilla superiorly was 48.7 mm (SD 5.7); after bilateral intraoral vertical ramus osteotomies to retract the mandible it was 48.6 mm (SD 5.7); and after bilateral sagittal split ramus osteotomies to advance the mandible it was 35.1 mm (SD 6.7). The presence of mandibular hypomobility after orthognathic surgery and maxillomandibular immobilization may be due to pre-existing or surgically induced muscle or temporomandibular joint dysfunction. Our findings indicate the need for routine clinical assessment of mandibular function preoperatively and for a systematic regimen of muscular and occlusal rehabilitation postsurgically to normalize muscle function, condylar movement, and range of mandibular motion.     

The effects of orthognathic surgery on mandibular range of motion

A prospective study of 55 orthognathic surgical patients was done to determine the effects of surgery on mandibular range of motion. None of the patients had oral physiotherapy during the course of the study. Nineteen patients had mandibular osteotomies, 21 had maxillary osteotomies, and 18 had two-jaw operations. Maximal interincisal opening (MIO), right and left lateral excursion, and protrusive measurements were obtained preoperatively and at six or more months following surgery. MIO was significantly reduced in both categories of mandibular osteotomies. A sagittal split osteotomy to advance the mandible was associated with the greatest mean reduction of 29%, while a vertical subcondylar osteotomy to set the mandible back had a mean reduction of 10%. Likewise, decreases in MIO were noted with combined surgical procedures. Le Fort I and sagittal split osteotomies were associated with a mean decrease in MIO of 28%, while Le Fort I and vertical subcondylar osteotomies had a mean decrease of 9%. Minimal change in MIO were noted with isolated maxillary osteotomies. These results are similar to the findings of other investigators and indicate the critical need for a sound postoperative rehabilitation program following orthognathic procedures to prevent hypomobility.     

Unusual late vascular complications of sagittal split osteotomy of the mandibular ramus

Intraoperative or early postoperative vascular complications are not uncommon problems in sagittal split osteotomies of the mandibular ramus; however, reports of late complications are considerably rarer. Here, we present two patients who sustained late vascular complications after the sagittal split osteotomy. The first patient had a delayed bleeding, which presented itself as a rapidly expanding swelling of the left cheek from the left external carotid artery 18 days postoperatively. During exploration, a 2 mm laceration of the external carotid artery located just proximal to the bifurcation of the internal maxillary artery and the superficial temporal artery was successfully repaired. The prominent bony spike of the cut end of medial cortex of the set-back mandibular ramus was found against the arterial wall and could possibly have caused the progressive necrosis of the wall with subsequent spontaneous rupture. The second patient suffered from a mild noise in the right ear 2 weeks after the initial surgery; however, a pre-auricular arteriovenous fistula between the right external carotid artery and the external jugular vein was discovered 1 year postoperatively. The diagnosis was confirmed by angiography, and the lesion was treated successfully by therapeutic embolization at that time. To avoid vascular injury, sufficient protection of the soft tissue during exposure of the mandibular ramus is mandatory. In addition, the direction of the cut of medial cortex is suggested to avoid the cranialward inclination that creates a sharp, bony end against the artery. Awareness of the possible late vascular complications to facilitate early detection and management is also important.     

Le Fort Ⅰ型截骨术上抬上颌骨与下颌骨自动旋转中心的相关性研究

目的：探讨Le Fort Ⅰ型截骨术上抬上颌骨后,下颌骨自动旋转中心位置变化与上颌骨上抬距离的关系。方法：选取10例患者．均为上颌骨垂直向发育过度导致开唇露齿和下颌骨后下旋转,而下颌骨发育正常,采用单纯Le Fort Ⅰ型截骨术上抬上颌骨,矫正其牙颌面畸形。拍摄术前、术后头颅定位侧位片,利用Reuleaux法测量实际的下颌骨旋转中心位置．应用SPSS10．0软件包对ANS、PNS上抬量与下颌骨自动旋转中心位置进行Spearman秩相关分析。结果：下颌骨平均自动旋转中心位于蝶鞍点下方49．350mm、后方17．100ram处。髁突中心位于蝶鞍点下方24．000mm、后方11．950mm处。下颌骨自动旋转中心垂直向位置与ANS点的上抬量高度相关（P=0．008）。下颌骨自动旋转中心垂直向位置与PNS点的上抬量高度相关（P=0．045）。结论：下颌骨旋转中心位于髁突外。下颌骨自动旋转中心与上颌骨上抬幅度高度相关。     

人物介绍俞光岩教授

人物介绍俞光岩教授俞光岩，男，１９５２年３月出生。浙江渚暨人。１９７９年８月毕业于浙江医科大学口腔系，１９８２年及１９８７年先后获北京医科大学口腔颌面外科医学硕士及医学博士学位。１９９０年以高级访问学者身份赴德国汉堡大学病理研究所访问进修一年。１９９...     

Management of malunited mandibular condylar fractures

The non-surgical treatment of mandibular condylar fractures, may occasionally result in articular imbalance and temporomandibular joint dysfunction. This may be attributed to condylar head displacement and resorption, resulting in a shortened vertical ramus and lost posterior vertical facial height. Restoring the vertical ramus height is essential in the treatment of such dysfunction, and may be accomplished by unilateral, or bilateral ramus osteotomies. Four examples of patients treated with mandibular ramus osteotomies to restore vertical ramus height, with subsequent improvement in occlusal balance and function are presented. The use of the sagittal split mandibular osteotomy and the external vertical ramus osteotomy, stabilized with small osseous plates, and monocortical screws, is discussed.     

Delayed presentation of pseudoaneurysm after Le Fort I osteotomy

Although the osteotome is positioned in close vicinity to the maxillary artery and its branches during ptergomaxillary separation in a Le Fort I osteotomy, postoperative complications from vascular injuries are rare. The following report describes an unusual occurrence of a maxillary artery pseudoaneurysm following a Le Fort I and bilateral sagittal-split osteotomies for correction of mandibular and maxillary asymmetries in a patient with Goldenhar syndrome. This was recognized 8 months after the procedure when the patient developed acute facial swelling and required an emergent angiogram for uncontrolled bleeding. Vascular anatomy in the ptergomaxillary area is reviewed. A level of suspicion of occult vascular injuries in patients with sudden onset of unilateral facial swelling after orthognathic surgery, even months after the procedure, is recommended.     

The incidence of postoperative wound healing problems following sagittal ramus osteotomies stabilized with miniplates and monocortical screws.

PURPOSE: Titanium plates and monocortical screws are commonly used to stabilize the mandible following sagittal split ramus osteotomies. Despite widespread use of this type of fixation, there is a paucity of large studies evaluating the infection rate and need for hardware removal. MATERIALS AND METHODS: This study is a retrospective cohort evaluation of 1,066 consecutive mandibular sagittal ramus osteotomies in 533 patients, performed between January 2002 and December 2003. All osteotomies were stabilized with 4-hole miniplates and 2.0 mm x 5.0 mm monocortical screws. Study variables included disturbances of wound healing, age, gender, plate and screw position, direction of mandibular movement, adjunctive procedures performed, and the patient's medical history. Data were collected by chart and radiographic review. The above variables were analyzed using Fisher's exact test, Chi-square, Cochran-Armitage Trend Test, and multiple logistic regression. RESULTS: Of 533 patients 26% (138) demonstrated wound healing problems. This occurred in 15% of all 1,066 osteotomy sites. 6.5% of plates required removal in 10% of patients. In no case did disturbance of wound healing or plate removal result in non-union or relapse of the osteotomy. Wound healing problems were fewer when mandibular osteotomies were done in conjunction with maxillary surgery (18.9% versus 29.1%). Disturbances of wound healing were not related to the direction of movement of the mandible and were lower when hardware was placed closer to the inferior border. CONCLUSION: An overall low incidence (6.5%) of hardware infection requiring plate removal was found in this study. Screw proximity to the osteotomy site did not correlate with higher rates of healing problems, but there was a statistically significant trend of fewer disturbances of healing when the hardware was placed closer to the inferior border of the mandible.     

Treatment of skeletal open bite using a navigation system: CAD/CAM osteotomy and drilling guides combined with pre-bent titanium plates

Severe skeletal open bite associated with posterior vertical maxillary excess and mandibular deformity is considered a difficult problem in orthodontic and surgical treatment. This study used a navigation system for the correction of severe skeletal open bite in order to accurately transfer the virtual plan to the actual operation and achieve precise rigid internal fixation in bimaxillary osteotomies of the jaws. Twelve patients with a severe skeletal open bite associated with vertical maxillary excess and mandibular deformity were recruited. All patients underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy with the guidance of this navigation system. Computed tomography and cephalometric examinations were performed to evaluate the correction of the deformity. Deviations between the simulated plan and actual postoperative outcome were measured to determine the precision of the surgery. Satisfactory and stable results were achieved in all patients postoperatively, without complications or relapse during follow-up. Photographs and cephalometric evaluations showed that the facial profile and occlusion were improved. Assessment of the deviations between the simulated plan and actual postoperative outcome showed that the navigation system can precisely transfer the virtual plan to the actual operation. The results suggest that the navigation system can accurately transfer the virtual plan to the actual operation during bimaxillary jaw osteotomies, without relapse, in patients with a severe skeletal open bite.     

超声骨切割技术在正颌外科中的应用

目的：与传统骨切割技术对比,探讨超声骨切割技术在正颌外科应用中的安全性和有效性。方法：本组病例12例,其中男2例,女10例;20～65岁;双颌畸形7例,上颌后缩3例,下颌前突2例;行Le FortⅠ型截骨术10例,下颌升支矢状劈开截骨术8例,下颌全牙列根尖下截骨术1例,颏成形术5例。超声骨刀在切骨时选Ⅰ～Ⅲ级切骨模式,调节出水量,刀头选OT7或OT7A。骨断端行坚强内固定。结果：切割精度高,对周围软组织无损伤,术中出血少,骨断端无坏死,创口一期愈合。结论：与传统骨切割技术对比,超声骨切割技术弥补了其存在的缺点和不足。超声骨刀的技术优势为：1）能识别软硬组织,只切割硬组织,对软组织无损伤,提高了手术安全性;2）切割时产热少,再加上冷水喷雾降温,不会对骨组织产生不可逆性坏死;3）切割时无震动,刀柄握持力轻,可控性强,避免了误操作,提高了切割精度,切割线不受限制,创口清晰,切骨线规则平整。故超声骨切割技术在正颌外科中的应用具有一定实用价值。     

Intra-operative complications in sagittal and vertical ramus osteotomies

In orthognatic surgery of the mandibular ramus, intra-operative complications as a lesion of the inferior alveolar nerve, fractures of the osteotomised segments, incomplete sectioning, malpositioning of segments and haemorrhage may occur. In this report, intra-operative complications in 124 sagittal split osteotomies and 34 vertical ramus osteotomies, carried out in 80 patients, are described. The incidence of intra-operative complications in the sagittal split osteotomies was 25.8%. The complication occurring most frequently was incomplete sectioning (11.2%). This may be avoided by using the modified sagittal split technique. The incidence of complications in the vertical ramus osteotomies was 11.8%.     

Aseptic necrosis of the mandible: report of two cases

It appears that clinically significant aseptic necrosis following mandibular osteotomies is a more infrequent occurrence than that following maxillary surgery because only two cases were reported in a questionnaire dealing with major vascular complications following orthognathic surgery. Significant necrosis is unlikely to occur if a surgeon follows the basic principle of stripping the minimal amount of mucoperiosteum and muscle attachment from the osteotomized segments commensurate with the successful completion of the osteotomies.     

Modified technique for completing the intraoral vertical osteotomy

A modification of the intraoral vertical ramus osteotomy for the correction of mandibular prognathism has been presented. This technique allows the vertical transection of the ascending mandibular ramus to be effected with a minimum amount of surgical manipulation and time expenditure; consistently uniform osteotomies are thus created.     

Control of the condylar-proximal mandibular segments after sagittal split osteotomies to advance the mandible

Maintenance of the normal or presurgical anatomic position of the mandibular condyles and contiguous proximal mandibular ramus segments after sagittal split ramus osteotomies is important, not only to enhance the stability of results but also to avoid iatrogenic temporomandibular joint complications. Accordingly, during the past few years, we have attempted to improve the surgical control of condyle and proximal segment position while using the sagittal split ramus osteotomy to advance the mandible. After several modifications, the device reported herein was used and the results evaluated in ten consecutive patients who underwent bilateral sagittal split ramus osteotomies with symmetric advancement of the mandible. This device enables the surgeon to obtain very precise reproduction of the "normal" proximal segment and condyle position at the time of surgery. The use of the device and documentation of its efficiency are presented.     

The mandibular foramen: an anatomic study and its relevance to the sagittal ramus osteotomy

The sagittal split ramus osteotomy is the most commonly used procedure to reposition the mandible surgically. Because it is more technically difficult and associated with a higher incidence of complications compared with other mandibular osteotomies, thorough knowledge of the anatomy of the mandibular ramus is a prerequisite. Anatomic measurements related to the mandibular foramen were obtained from 57 formalin-preserved non-Asian hemimandibles. As shown in previous reports, great variability was noted in the position of the mandibular foramen. However, these studies utilized Asian mandibles with a clear discrepancy in key anatomic measurements in comparison with the authors' data. This brings into question the validity of these earlier studies when applying their data to non-Asian groups. The "fade-out" point of the internal oblique ridge was found not to be a reliable anatomic reference for placement of the horizontal osteotomy along the medial ramus. Thus, familiarity with the described relationships of the mandibular foramen will assist in performing properly a sagittal split of the ramus and will reduce the chance for an unfavorable split.     

Anatomic study of the mandibular foramen, lingula and antilingula in dry mandibles, and its statistical relationship between the true lingula and the antilingula

The authors verified the anatomical location of the mandibular foramen, lingula and antilingula in dry mandibles, aiming to obtain information that could be used when performing mandibular osteotomies. Forty-four mandibles (88 sides) were evaluated. The distances were measured using a sliding calliper, with the mandibles fixed in a reproducible position. Results showed that the mandibular foramen is on average 5.82 mm below the lingula. Regarding the statistical comparison between the mandibular foramen entrance and the antilingula position, there is no correlation between the position of those two structures in the studied sample. The mandibular foramen is slightly posterior in relation to the centre of the ramus. The lingula is an important anatomic landmark for ramus surgery, and for determining the distance to the mandibular foramen entrance. The use of the antilingula as a landmark for the position of the vertical ramus osteotomy is not recommended.     

Massive repeated nose bleeding after bimaxillary osteotomy

In LeFort I surgery, the separation of the pterygomaxillary junction is done by osteotomy. Although the osteotome is positioned too close to the maxillary artery and its branches during pterygomaxillary separation, postoperative complications from vascular injuries are uncommon. We describe an unusual occurrence of a maxillary artery pseudoaneurysm after LeFort I and bilateral sagittal split osteotomies for maxillary advancement and mandibular setback as well as (anterior sliding) genioplasty. In a patient with class III occlusion and midface retrusion, the significant bleeding began 10 days postoperatively, which was controlled by anterior and posterior nasal packing. The bleeding recurred 28 days after surgery; thus, vascular anatomy in the pterygomaxillary area is reviewed, pseudoaneurysm was diagnosed on selective carotid angiography and successfully treated by embolization; and 2-year follow up was uneventful.