Sequence of treatment in mandibular prognathism patients

Intraoral vertical ramus osteotomy (IVRO) and advancement genioplasty are effective and predictable methods of treating selective individuals with mandibular prognathism. The sequence of performing these procedures does have a clinical effect, but this is not found in the literature. The purpose of this article is to introduce the clinical implication of the sequence of procedures and to recommend the preferred sequence based on experience. A retrospective study was conducted on 75 patients treated by IVRO with or without genioplasty. In 31 patients, IVRO was performed without genioplasty; only one patient suffered from transient hypoesthesia. When IVRO was performed before genioplasty (sequence I) in 20 patients, nine suffered from mental nerve hypoesthesia. However, when IVRO was performed after genioplasty (sequence II) in 24 patients, permanent mental nerve anesthesia occurred in five patients and mental nerve hypoesthesia in 15 patients. Based on these results, it is recommended that IVRO be performed before genioplasty.     

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.     

Open bite: stability after bimaxillary surgery--2-year treatment outcomes in 58 patients

Stability after bimaxillary surgery to correct open bite malocclusion and mandibular retrognathism was evaluated on lateral cephalograms before surgery, 8 weeks post-operatively, and after 2 years. The 58 consecutive patients were treated to a normal occlusion and good facial aesthetics. Treatment included the orthodontic alignment of teeth by maxillary and mandibular fixed appliances, Le Fort I osteotomy, and bilateral sagittal split ramus osteotomy. Twenty-six patients also had a genioplasty. Intra-osseous wires or bicortical screws were used for fixation. Twenty-three patients had maxillo-mandibular fixation (MMF) for 8 weeks or more, six for 4-7 weeks, 14 for 1-3 weeks, and 15 had no fixation. At follow-up 2 years later, the maxilla remained unchanged and the mandible had rotated on average 1.4 degrees posteriorly. Seventeen patients had an open bite. Among them, eight patients had undergone segmental osteotomies. The relapse was mainly due to incisor proclination. The most stabile overbite was found in the group with no MMF after surgery.     

Effect of Orthognathic Surgery on the Posterior Airway Space in Patients Affected by Skeletal Class III Malocclusion

Introduction

Dentofacial deformity refers to deviations from normal facial proportions and dental relationships that are severe enough to be handicapping. These anomalies involve many aspects of patient’s life and are sometimes also associated with a reduction of pharyngeal air space. Through orthognathic surgery it is possible to treat dentofacial deformities: this kind of surgery has several effects on skeletal structures and it has changes, as it is demonstrated by many studies, also on the upper airways. The orthognathic surgeries commonly used to correct this deformity are the mandibular setback and the maxillary advancement procedures. This study aims to evaluate the effects of maxillary and mandibular surgery on pharyngeal airway dimensions in skeletal class III malocclusions.

Materials and methods

This study considers 76 patients, treated between 2007 and 2013 by maxillary advancement (11 patients), maxillary advancement and mandibular setback (39 patients), maxillary advancement, mandibular setback and genioplasty reduction (26 patients). Cranial latero-lateral radiography was used to compare oropharyngeal airway morphologies before and 1 year after surgery.

Conclusion

The surgeon should consider bimaxillary surgery rather than mandibular setback surgery to correct a class III deformity to prevent the development of obstructive sleep apnea syndrome; in fact, bimaxillary surgery might have less effect on reduction of the pharyngeal airway than mandibular setback surgery only.     

常见正颌手术后咬合关系的维护和调整

目的 探讨临床常见的正颌手术后,如何很好的维护和调整上下牙列的咬合关系,为临床提供有益的参考.方法 选择骨性Ⅰ类双颌前突行根尖下截骨后徙术、Ⅱ类下颌后缩行下颌升支矢状劈开前徙术、Ⅲ类骨性反骀行下颌升支骨切开后退及合并上颌前徙术各6例患者,共18例患者.正颌手术后依据分类分别行3种不同的牵引模式进行咬合调整.结果 18例...     

Le FortⅠ型骨切开上颌骨整体后退术矫治骨性Ⅱ类上颌骨前突畸形

目的：探讨Le Fort Ⅰ型骨切开（Le Fort Ⅰ osteotomy）上颌骨整体后退术在矫治骨性Ⅱ类上颌骨前突畸形中的价值。方法：对16例骨性Ⅱ类上颌前突患者（上颌骨前突伴下颌骨后缩14例,其中同时伴颏后缩6例;单纯上颌骨前突2例）进行外科-正畸联合治疗。患者治疗前头影测量∠ANB为7.0°～13.1°,平均9.3°。行Le Fort Ⅰ型骨切开上颌骨整体后退术,其中14例同期行双侧下颌支矢状骨劈开术（bilateral sagittal split ramus osteotomy,BSSRO）前移下颌骨,6例行颏成形术（genioplasty）前移颏部。结果：本组行LeFortⅠ型骨切开上颌骨整体后退4～8mm,14例BSSRO下颌骨前移4～7mm,6例颏成形术颏前移6～8mm。1例一侧腭降动脉术中损伤断裂,经结扎处理,无感染及骨块坏死。16例患者伤口均一期愈合。术后及正畸结束后∠ANB为1.6°～3.5°,平均2.9°。结束治疗后随访6～24个月,牙弓形态及[牙合]曲线正常,牙排列整齐,咬合关系良好,外形明显改善,疗效满意。结论：对于骨性Ⅱ类上颌骨前突畸形患者,Le Fort Ⅰ型骨切开上颌骨整体后退术是一种安全、合理、有效的正颌外科术式。     

Bimaxillary osteotomy in a female patient with hemophilia A

We report here a case of a 22-year-old female patient with hemophilia A who had a bimaxillary osteotomy operation. Adequate replacement of Factor VIII and DDAVP(1 deamino-8-D-arginine vasopressin) led to the achievement of hemostasis during and after the surgery. Le Fort I maxillary osteotomy and mandibular sagittal split osteotomies were done to correct the facial profile of this hemophiliac patient with a class III malocclusion and posterior open-bite deformity. Careful preoperative evaluation and close cooperation with the hematologist are required if surgery is to be successful. The operation was uneventful and no postoperative complication was observed.     

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.     

不对称性下颌角肥大的手术治疗

目的　探讨不对称性下颌角肥大的原因及手术治疗。方法　采用下颌角弧形截骨术、下颌骨外板截骨术、颏成形术及颊脂垫取出术等方法,治疗不对称性下颌角肥大患者70例。结果　70例患者术后面部对称性均明显改善。70例患者中仅3例出现并发症,包括术后出血、口唇拉伤增生性瘢痕及术后感染等。结论　治疗不对称性下颌角肥大应根据畸形的特点,选择性应用下颌角弧形截骨术、下颌骨外板截骨术、颏成形术及颊脂垫取出术等方法,其效果良好。     

Concerns and motivations of skeletal Class III patients receiving orthodontic-surgical correction

The objective of this research was to study the impact of skeletal Class III malocclusion on patients' emotional status, as well as patients' motivations for seeking surgical correction of Class III malocclusion. The sample comprised 140 consecutive Chinese patients with skeletal Class III malocclusion who had been treated with a combined orthodontic-surgical approach. A retrospective analysis was performed, based on questionnaires with answers ranked on a numeric scale (O = not at all; 1 = a little; 2 = moderately; 3 = quite a bit; 4 = extremely). Sixty-seven percent of subjects (40 males and 54 females) returned completed questionnaires. Fifty-four percent had bimaxillary deformities, 32% had mandibular hyperplasia, and 14% had maxillary hypoplasia. Seventy-seven percent received bimaxillary surgery, 15% received maxillary advancement, and 8% received mandibular setback. The results showed that nearly half of the patients had a nickname related to their dentofacial problems, and 8 of 10 of these felt embarrassed or angry about their nickname. Ninety-three percent sought improvement of their facial appearance, 85% wanted an improvement in their dental appearance, and 73% desired an improvement in chewing ability. Seventy-six percent were concerned about surgical risks and 63% about possible pain. The vast majority of Class III patients undergoing orthognathic surgery suffered psychologic and functional problems related to their appearance prior to treatment. Esthetic improvement was the driving force behind seeking treatment.     

Is skeletal stability after bimaxillary surgery for skeletal class III deformity related to surgical occlusal contact?

A stable occlusion at the time of surgery is considered important for post-surgical stability after orthognathic surgery. The aim of this study was to determine whether skeletal stability after bimaxillary surgery using a surgery-first approach for skeletal class III deformity is related to the surgical occlusal contact or surgical change. Forty-two adult patients with a skeletal class III deformity corrected by Le Fort I osteotomy and bilateral sagittal split osteotomy with a surgery-first approach were studied. Dental models were set and used to measure the surgical occlusal contact, including contact distribution, contact number, and contact area. Cone beam computed tomography was used to measure the surgical change (amount and rotation) and post-surgical skeletal stability. The relationship between skeletal stability and surgical occlusal contact or surgical change was evaluated. No relationship was found between maxillary or mandibular stability and surgical occlusal contact. However, a significant relationship was found between maxillary and mandibular stability and the amount and rotation of surgical change. The results suggest that in the surgical-orthodontic correction of skeletal class III deformity with a surgery-first approach, the post-surgical skeletal stability is not related to the surgical occlusal contact but is related to the surgical change.     

Morphological changes in the pharyngeal airway of female skeletal class III patients following bimaxillary surgery: A cone beam computed tomography evaluation

Using cone beam computed tomography (CBCT), the present study compared three-dimensional (3D) changes in the pharyngeal airway and surrounding tissues in female skeletal class III patients treated with bimaxillary surgery. Twenty-nine female skeletal class III patients with both maxillary hypoplasia and a mandibular excess underwent bilateral sagittal split ramus osteotomy for mandibular setback combined with Le Fort I osteotomy for maxillary advancement. Volumetric measurements were performed using CBCT scans taken at 1 week presurgery and 6 months post-surgery. The oropharynx volumes and the cross-sectional area behind the soft palate decreased significantly. There was an insignificant change in the volume of the nasopharynx (P > 0.05). The hyoid bone moved downward and posteriorly after surgery. The morphology of the soft palate also changed dramatically, with an increase in the length and thickness. Negative correlations were found between the pharyngeal airway space and the position of the hyoid bone. The change in morphology of the soft palate was significantly correlated with the changes in hyoid bone position. These 3D results suggest that bimaxillary orthognathic surgery significantly changes the position of the hyoid bone and the soft palate together with a significant decrease in the pharyngeal airway space in the correction of skeletal class III malocclusion.     

Computer-assisted osteotomy guides and pre-bent titanium plates improve the planning for correction of facial asymmetry

This study investigated the surgical outcomes and accuracy of computer-assisted osteotomy guides and pre-bent titanium plates in the treatment of patients with facial asymmetry. Thirteen patients with facial asymmetry undergoing bimaxillary orthognathic surgery were included. Virtual simulation of Le Fort I osteotomy, sagittal split ramus osteotomy, and genioplasty, if needed, was conducted on the preoperative three-dimensional model. Computer-assisted osteotomy guides and pre-bent titanium plates were produced and used in the actual operation. The postoperative outcome was assessed for facial symmetry and surgical accuracy. All patients were followed up for at least 18 months and their level of satisfaction was investigated. Use of the computer-assisted osteotomy guides and pre-bent titanium plates was successful in all patients. Maxillary canting, mandibular ramus inclination, and mandibular length were corrected on both sides postoperatively. Superimposition of the surgical simulation and postoperative images demonstrated favourable accuracy. Quantitative analysis revealed a mean linear difference of <0.60 mm in the maxilla and 1.57 mm in the mandible. All patients were satisfied with the surgical outcome; there were no complications or cases of relapse during follow-up. The application of computer-assisted osteotomy guides and pre-bent titanium plates achieved favourable outcomes and accuracy, improving planning for the correction of facial asymmetry.     

Evaluation of long-term hard tissue remodelling after skeletal class III orthognathic surgery: a systematic review

This systematic review was performed to investigate the long-term hard tissue stability in orthognathic surgery patients with skeletal class III malocclusion. A literature search was conducted using the Embase, Cochrane Central, Web of Science, and PubMed databases, yielding 3690 articles published up to June 2018. Nine articles met the inclusion criteria; these reported skeletal changes in 886 patients with between 5 and 12.7 years of follow-up. Risk of bias was assessed according to the Cochrane Handbook. Results showed variations in stability based on age, facial pattern, surgical procedure, and fixation type. Young patients showed a greater increase in mandibular length and higher A-point stability after bimaxillary surgery than older patients. Dolichofacial patients showed skeletal relapse with a facial clockwise rotation, whereas counterclockwise rotation was observed in brachyfacial patients. Single mandibular setback surgery was linked to stability loss with decreased mandibular ramus and gonion angle; meanwhile, genioplasty fell into the highly stable surgery category. The hyoid bone relapsed significantly postero-inferiorly, which correlated with suprahyoid muscle changes but little to no mandibular position changes. Fixation with monocortical miniplates showed higher patient satisfaction and better stability compared to bicortical screw fixation. These conclusions should be regarded with caution because of the lack of current evidence from three-dimensional imaging.     

Three-part bi-maxillary osteotomy: a case report involving resorbable plates

Abstract

This case report describes a patient who presented with a severe class 2 skeletal discrepancy together with a Class II malocclusion and a large anterior open bite. The malocclusion and skeletal discrepancy were managed with a combination of orthodontic and orthognathic treatment.

The orthognathic surgery was undertaken following orthodontic decompensation using sectional mechanics to allow a segmental bimaxillary osteotomy and genioplasty to be performed. Although the discrepancy was severe using this combination of treatment, a successful outcome, both facially and occlusally, was achieved.     

下颌前突畸形的正颌外科矫治

目的 总结正颌外科矫治下颌前突畸形的临床经验。方法 对32例下颌前突畸形患者进行了正颌外科手术，其中12例行双侧SSRO，4例行双侧IORO，10例行双侧IVRO，5例行上下颌前部根尖下截骨，1例行下颌骨体部截骨，同期搭配施行水平截骨颏成形术12例，畸形涉及上颌骨行LeFortⅠ型截骨9例。结果 32例下颌前突畸形患者术后外观及功能均获得满意效果。并发症有术后下颌前突轻度复发4例，明显复发1例，下颌骨升支骨折一侧1例，下牙槽神经一侧断离1例，结论 随访结果显示应用IVRO，SSRO等术式治疗下颌前突畸形只要术式选择及操作得当，能获得较满意效果。文中就手术方法，注意事项及并发症等进行了讨论。     

Two-stage orthognathic treatment of severe class III malocclusion: report of a case

We report a two-stage orthognathic operation for a 16-year-old boy with a repaired isolated cleft palate. He had a severe class III malocclusion with an overjet of 20.4 mm. In the first stage, we did an anterior subapical segmental osteotomy with symphyseal ostectomy to reposition the mandibular anterior segment posteriorly and to reduce the transverse width of the mandible. During the second stage, we did a maxillary advancement by Le Fort I osteotomy, mandibular set-back by sagittal split osteotomy, reduction genioplasty, and shortening of the tongue. This unique two-stage surgical and orthodontic treatment considerably improved his overall facial aesthetics and occlusion.     

2种不同正颌术式对骨性Ⅲ类错畸形患者上气道形态的影响

目的： 建立骨性Ⅲ类错畸形患者正颌手术前、后上气道三维模型，比较不同正颌术式对骨性Ⅲ类错畸形患者上气道各截面积及容积的影响。方法： 28例骨性Ⅲ类错畸形患者经正颌-正畸联合会诊，制定手术方案，分为2组，实验A组（12例）为单纯双侧下颌支矢状劈开术（BSSRO）后退，即单颌手术组，实验B组（16例）为下颌骨BSSRO 后退 +上颌骨Le Fort I型截骨术前移，即双颌手术组。所有患者于正颌手术前（T1）和术后3个月（T2）分别行CT扫描，基于CT图像，应用Dolphin Imaging 11.7软件建立包含腭咽、舌咽和喉咽腔在内的上气道三维模型，测量、比较2组患者在正颌手术前、后的上气道各截面、腔隙的矢状径、冠状径、横截面积和容积改变的差异。采用SPSS 16.0 软件包进行统计学分析。结果： 在腭咽段，实验A组手术后各项数值均较术前减小；实验B组手术后除冠状径外，其余数值均较术前增大，且2组变化有显著差异（P<0.05）。在舌咽段及喉咽段，2组手术后数值均减小。在横截面积和容积方面，实验A组较实验B组减小更加明显，2组的减小量有显著差异（P<0.05）。结论： 与单颌手术相比，双颌手术对骨性Ⅲ类错畸形患者上气道形态的减小改变影响较小。     

Correction of skeletal Class III malocclusion with clockwise rotation of the maxillomandibular complex

A 19-year-old woman with skeletal Class III malocclusion, paranasal depression, and a low mandibular plane angle was treated with orthodontics and orthognathic surgery. Dental decompensation and protraction of maxillary right third molar to replace maxillary right second molar were performed before surgery. Clockwise rotation of maxillo-mandibular complex was applied by Le Fort I osteotomy and bilateral sagittal split osteotomies to achieve facial balance. The active treatment period was 12 months. The stable occlusion and skeletal relationship were observed after a 10-month follow-up period.     

Three-part bi-maxillary osteotomy: a case report involving resorbable plates

This case report describes a patient who presented with a severe class 2 skeletal discrepancy together with a Class II malocclusion and a large anterior open bite. The malocclusion and skeletal discrepancy were managed with a combination of orthodontic and orthognathic treatment. The orthognathic surgery was undertaken following orthodontic decompensation using sectional mechanics to allow a segmental bimaxillary osteotomy and genioplasty to be performed. Although the discrepancy was severe using this combination of treatment, a successful outcome, both facially and occlusally, was achieved.