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.     

Pseudoaneurysm of the facial artery occurred after mandibular sagittal split ramus osteotomy

Introduction

Pseudoaneurysms are caused by rupture of arteries with extravasation of blood. The compressed perivascular tissue forms the wall of aneurysmal sac. Pseudoaneurysm directly related with surgical procedure of sagittal split ramus osteotomy (SSRO) was reported quite rarely especially related with facial artery during the vertical osteotomy.

Case report

SSRO was carried out for a 19-year-old male; the patient visited the emergency room with notable swelling 3 weeks after the surgery. We experienced severe intra-oral bleeding with surgical exploration. Angiography revealed a pseudoaneurysm of the right facial artery that might be related with vertical osteotomy over lateral cortex of the mandibular body during orthognathic surgery. This implies that the minor vascular trauma from vertical osteotomy of the mandibular body during the conventional orthognathic surgery might cause later development of pseudoaneurysm.     

False aneurysm of the facial artery as complication of sagittal split osteotomy.

INTRODUCTION: False aneurysms are rare complications of orthognathic surgery, or other surgical procedures in the head and neck regions. PATIENTS AND METHODS: The following report describes a false aneurysm of the facial artery that occurred after sagittal split mandibular osteotomy. A 17-year-old male presented with a class II skeletal deformity and vertical maxillary excess. A bimaxillary osteotomy was carried out and the immediate postoperative course was uneventful. One week later, the patient was admitted with severe intraoral bleeding. RESULTS: Surgical exploration and temporary occlusion of the facial artery failed to arrest the bleeding. A pressure dressing was reapplied for temporary control of the bleeding, and angiography performed with favourable results. CONCLUSION: Interventional radiology has an important role in the management of false aneurysms and is recommended as the treatment of choice for such cases.     

Sagittal split osteotomy of a vascularised iliac crest free flap to correct residual asymmetry and malocclusion in the reconstructed mandible

Reconstruction of the mandible with a vascularised bone graft from the iliac crest based on the deep circumflex iliac artery is an established and reliable technique. We report two cases in which mandibular asymmetry followed reconstruction with such grafts and was corrected by sagittal split osteotomies.     

Risk factors for a bad split during sagittal split osteotomy

One of the operative complications during sagittal split osteotomy (SSO) in orthognatic surgery is a bad split, meaning an undesired fracture of the mandible during osteotomy. The aim of this study was to find out if there is a relation between the occurrence of bad splits during SSO and the presence of third molars, the patient's age, or the surgeon's experience. Clinical notes of 110 consecutive patients who had had a total of 220 SSOs using the Obwegeser/Dal Pont technique were evaluated and divided into three groups: 1 missing third molar (n=168); 2 retained or impacted third molar that was removed during the SSO (n=23); and 3 third molar left in place during SSO (n=29). There were a total of 12 (6%) bad splits. 9 (5%) in group 1, two (9%) in group 2, and one (3%) in group 3. There were no significant differences between groups 1-3, in particular the surgeon's qualification had no influence on the incidence. Older patients seemed more at risk of a bad split than younger ones.     

Unusual split fracture of the mandible

Mandibular fracture is a common injury and generally treated with or without surgery depending on the case. Diagnosing mandibular fracture may be difficult because of its location and anatomic characteristics. This article presents a case of an unusual split mandibular fracture after an episode of seizure in a patient with epilepsy. This fracture was missed on routine radiographs; however, it was visualized by three-dimensional computed tomography (TCT). The TCT is crucial and should be mandatory for all suspected mandibular fractures instead of routine radiography. The diagnostic efficacies of panoramic radiographs, digitized radiographs, and TCT scans are discussed for the diagnosis of mandibular fractures in this case report.     

The split rib bundle graft in mandibular reconstruction.

This article describes a modified technique for the use of free non-vascularized split ribs (bound together in the form of a tight bundle), to reconstruct different types of mandibular defects. Experience gained over the last 4 years in treating 38 patients with different pathological lesions is presented. The procedure, carried out simultaneously with bone resection proved to be highly effective in providing mesio-distal spanning of the defect, adequate mandibular height as well as bucco-lingual thickness. This technique utilizes the different theories of osteogenesis: (a) from the periosteal cells, (b) from the transplanted living osteocytes and from (c) stimulating host mesenchymal cells to form new bone by bone induction. The surgical technique, results and conclusions are presented in this report.     

Partial palatal split palatoplasty.

A partial palatal split technique is described for use with superiorly based pharyngeal flap palatoplasties. This procedure allows (1) increased facility in dissection, (2) precision in the design of the flap for lateral port control, and (3) construction of a one-piece nasomucosal lining flap in comparison to the standard complete palatal split technique.     

Day-case bilateral sagittal split osteotomy

In the UK, patients who have bilateral sagittal split osteotomy (BSSO) have generally been thought to require inpatient admission and an overnight hospital stay. However, since the introduction of national standards on day case surgery in the UK in 2011, patients at the Royal Gwent Hospital, Newport, have been treated as day cases, and have been pleased with the results. The aim of this paper was to show that these procedures conform to current national standards, and can be done successfully and safely. We retrospectively reviewed all patients who had isolated BSSO planned as day cases between March 2015 and February 2017. Thirty-four were eligible. Of them, 32 were discharged on the day of operation and two were admitted postoperatively: one because of severe nausea and vomiting and the other because of bleeding. No patients were readmitted within 48 hours of the procedure. BSSO can be done successfully and routinely as a day-case procedure. However, to reduce the rate of unplanned admissions, we recommended that operations start early in the morning.     

Complications after mandibular sagittal split osteotomy

Sagittal split osteotomy has been performed routinely for correction of mandibular prognathism, retrognathia, mild open bite, and asymmetry. Intraoperative and early or late postoperative complications were evaluated in 258 patients operated on by this technique. With meticulous performance of the operation and long-term maxillomandibular fixation, complications can be negligible, and relapse, the most problematic postoperative issue, can be significantly reduced.     

Outcome measures in split mouth caries trials and their statistical evaluation

Abstract – The split mouth study design in trials of fissure sealants and restorative materials neatly controls for confounding by many of the variables associated with poor retention of sealants and occurrence of dental caries. Traditionally, the outcome measures used in split mouth trials have been material retention, (per cent) effectiveness and net gain. A survey of the literature revealed that a large proportion of split mouth studies report no statistical evaluation of outcome measures. In those studies in which statistical evaluation had been conducted, McNemar's x ² was the test most frequently used. This statistic is appropriate for comparing differences between "success" and "failure" tooth pairs (or "positives" and "negatives" in split mouth terminology) but it cannot evaluate directly effectiveness and net gain. The distributions of effectiveness and net gain are different and it would be desirable to estimate confidence intervals for them. In this paper, we consider these statistics, suggest methods by which confidence intervals may be calculated, and provide examples of the calculations. We demonstrate the close relationship between effectiveness (as used in split mouth trials) and relative effect and relative risk (as used in general epidemiological analysis) and recommend that relative risk should be the preferred outcome measure for split mouth trials. Whatever outcome measure is chosen in split mouth trials should always be subjected to statistical evaluation, preferably by the calculation of confidence intervals.     

Modified vertical osteotomy cut in bilateral sagittal split osteotomy

Bilateral sagittal split osteotomy (BSSO) is the most common orthognathic surgical procedure for the correction of facial deformities. Like any other surgical procedure, it is also associated with a risk of complications. One of these is described in the literature as notching at the lower inferior border of the mandible. Such discontinuity in the contour of the lower border is often a concern for patients. To overcome this complication, we recommend a modified vertical osteotomy cut while performing BSSO.     

Neurological damage after sagittal split osteotomy

Neurological damage following the sagittal split osteotomy is a commonly recognised complication. The results of 38 osteotomies in 19 patients following a minimum post-operative period of 2 years is presented. Subjective evaluation demonstrated normal sensation in 73.7% of osteotomy sides. However, objective evaluation demonstrated normal sensation in only 34.2% of sides. The remainder had a variable degree of sensory loss.     

3D打印技术在双侧下颌升支矢状劈开截骨术中的应用

目的 探讨3D打印技术制作的截骨导板在双侧下颌升支矢状劈开截骨术（BSSO）中的应用效果。方法 选择32例（男17例,女15例,年龄19~35岁,平均23.5岁）下颌发育不良的患者为研究对象,进行BSSO（Hunsuck模式,64侧）,所有患者术前均进行锥形束CT（CBCT）扫描并建立下颌骨3D模型,使用3D打印技术制作下颌骨升支内侧水平骨切口截骨导板。64侧手术分别由年轻主治医师或具有丰富正颌手术经验的专家（主任医师）使用或不使用截骨导板来完成,对各组完成下颌升支内侧水平骨切口的时间进行计时。术后复查CBCT并按照LSS（lingual split scale）分类来评估手术效果。结果 术后所有患者口内切口均一期愈合,无严重并发症。各组完成下颌升支内侧水平骨切口时间的差异有统计学意义（F=30.059,P<0.05）,其中主治医师不使用导板组的手术用时明显高于其他3组（P<0.05）,其余各组两两比较无明显差异（P>0.05）。尽管所有64侧手术均按照标准方式进行,仅有59.38%（38/64）的骨折线遵循标准Hunsuck骨劈开线,21.88%（14/64）骨折线累及下颌神经管,其余18.75%（12/64）是其他方式。经列联表分析和Fisher确切概率法检验发现,截骨导板的使用影响舌侧骨劈开线的方式（P<0.05）。结论 3D打印技术制作的截骨导板能够帮助年轻医师更快更好地完成BSSO。     

Fixation of the split calvarial graft in nasal reconstruction

Reconstruction of nasal contour where skeletal support is deficient or absent has usually been achieved using autogenous bone. Membranous bone taken from the cranium is clearly superior to rib or iliac crest when used as autografting material to the craniofacial skeleton. Conventionally, the bone graft is rigidly fixated to the recipient nasal bone with either metal plate-screw systems or Kirschner wires. Reported here are the results of a single biodegradable screw fixation of the split calvarial graft that is used for nasal reconstruction. Ten patients with moderate to severe saddle nose deformity underwent reconstruction using the open rhinoplasty approach. The graft was harvested from the outer cortex of the parietal bone, shaped, and secured in place with a single bioresorbable screw. No significant resorption has been observed in the grafts and a favorable aesthetic result was achieved in all of the cases. Described modification in fixation of the bone graft in nasal reconstruction avoids some of the disadvantages of permanent materials while preserving the advantages of rigid fixation.     

The purchaser-provider split: implications for dental services.

In July 1991, the National Government announced proposals for a radical restructuring of the New Zealand public health system, a central feature of which is the separation of the purchasing and providing roles currently performed by area health boards. While the competitive market model suggests that the split should improve the efficiency of public health services by effectively creating a market system, this paper suggests that, in practice, there are likely to be a number of obstacles. Other potential sources of efficiency are improved accountability, improved management, and integration of primary and secondary care. For dental health services, the separation of purchaser and provider should introduce greater flexibility into State-funded dental services by opening up options for alternative providers and methods of provision. Factors such as the number and structure of provider units; the contractual arrangements between these units and the RHAs, especially in respect of payment mechanisms; and the regulatory regime which covers these contractual arrangements will all affect service delivery. If real choices between types of providers and methods of provision eventually emerge, a major challenge for RHAs will be to monitor and enforce at reasonable cost any quality measures built into contracts.     

Cross-sectional tomography in evaluation of patients undergoing sagittal split osteotomy

A study was performed to evaluate the possibility of locating the mandibular canal before sagittal split osteotomy by cross-sectional spiral tomography in 55 patients. Visibility of the whole canal wall circumference was excellent or good in 65.5% fair in 18.2%, and poor in 12.7% of cases. Only four canals (3.6%) were invisible. The canal was located lingually in 61 cases, buccally in 9 cases, and centrally in 34 cases. In patients with mandibular protrusion, the mean (+/- SD) buccolingual width was significantly smaller (9.5 +/- 1.51 mm vs 10.4 +/- 1.46 mm, P < .01) and the mandibular canal was more often buccally located than in patients with retrognathia.     

Sagittal split ramus osteotomy-related biomechanical properties

Sagittal split ramus osteotomy (SSRO) is one of the most common maxillofacial operations, and the technique relies on a directed fracture involving different biomechanical variables. The aim of this study was to find out the biomechanical characteristics involved during each step of sagittal split osteotomy. We sampled eight fully dentate human mandibles and used the right side for hardness tests and the left side for a traction-to-fracture test within an unfinished SSRO. Right sides were sampled in five parts underlying the corticotomy course and tested with a hardness testing automatic machine. The mean hardness measures ranked to 21.5 HV (Hardness Vickers Unit): 17.8 HV; 27.4 HV; 22.7 HV; 28.7 HV; for the lingual, diagonal, vestibular, full ramus, and full body samples, respectively. Left sides were cut using Epker’s technique, and split with an electromechanical testing machine. The higher values reached before fracture in the traction-to-fracture tests ranked to 99.1 N/6.7 mm; 137.2 N/10.8 mm; 36.2 N/4.2 mm; 93.0 N/7.3 mm; 74.0 N/8.1 mm; 78.1 N/4.5 mm; 90.9 N/10.6 mm; and 64.7 N/4.1 mm, respectively, for specimens I, II, III, IV, V, VI, VII and VIII. This study provides to our knowledge the first biomechanical characteristics of SSRO and proposes a reproducible method for evaluation.     

Technical improvements in the sagittal split ramus osteotomy

This article addresses the potential sources of morbidity associated with the sagittal split ramus osteotomy. Refinements in the instrumentation and technique are described; these enhance the exactness of the procedure, thereby minimizing the complications and improving the stability of the surgical result.     

A simplified technique of inferior border wiring in the sagittal split osteotomy

The inferior border wire, as originally described by Booth, is a well-accepted means of fixation of the proximal and distal segments in the sagittal split osteotomy. However, it appears that there is some criticism of the technique because of the difficulty in placing drill holes at the appropriate position and angulation and subsequent difficulty with passage of a fixation wire. The technique presented here eliminates the technical difficulties and provides for a rapid, safe, and stable fixation.