唇腭裂患者牵张成骨术后的侧貌变化

目的：通过对唇腭裂术后继发上颌骨发育不足患者进行口外支架式前牵张治疗术后6～24个月的随访,观察分析其侧貌变化,为合理使用牵张器提供参考。方法：选取1998—2002年间上海交通大学医学院附属第九人民医院进行牵张成骨治疗、按时随访的唇腭裂患者14例进行术后随访分析。随访期分别为术后3、6、12、24个月,分别拍摄头颅定位侧位片及照片,记录患者的侧貌变化。结果：14例患者在牵张成骨术后6个月,至术后24个月,3例表现为双颌前突畸形,3例仍表现为面中部凹陷,1例表现为前牙开。结论：牵张成骨术治疗唇腭裂术后上颌骨发育不足患者具有一定优势,但牵张方向及牵张量难以控制,术后侧貌时不尽满意。因此,唇腭裂患者继发上颌骨发育不足在行牵张成骨术治疗时,应综合考虑多种因素的影响。     

Segmental distraction of the midface in a patient with Crouzon syndrome

We treated midface hypoplasia in a 20-year-old woman with Crouzon syndrome using a rigid external distraction device. The patient showed severe exophthalmos and maxillary retrusion, although relatively good occlusion had been achieved by long-term orthodontic procedures. We considered that our patient's particular condition could not be resolved by the usual Le Fort III osteotomy/midface distraction procedure, so we devised a segmental approach. The midface, mobilized by Le Fort III osteotomy, was divided into two segments by Le Fort I osteotomy; each fragment was connected to the rigid external distraction device to be distracted separately. Distraction was begun after 1 day at 1 mm/day. The upper and lower segments were distracted over 17 and 12 days, respectively. The patient's occlusion was fully corrected, and her facial contour was significantly improved. After 3 weeks of consolidation, we removed the distraction device. The clinical course was without complication, and no relapse was observed on the cephalogram or computed tomography scan obtained 1 year after the procedure. Our modified technique was helpful in increasing the usefulness of the external distraction system and in refining the midface distraction procedure.     

Relapse rate after surgical treatment of maxillary hypoplasia in non-growing cleft patients: a systematic review and meta-analysis

Maxillary hypoplasia in cleft lip and palate is a complex deformity. Despite surgical improvements, postoperative relapse persists. This systematic review was performed to determine the mean horizontal relapse rates for the surgical techniques used to treat maxillary hypoplasia: Le Fort I osteotomy with rigid fixation, Le Fort I distraction osteogenesis, and anterior maxillary distraction osteogenesis. This study followed the PRISMA statement. The PubMed, Embase, Science Direct, and Web of Science databases were searched through to June 2018. Studies on non-growing cleft lip and palate patients who had undergone one of the three surgical procedures and who had postoperative horizontal maxillary changes assessed at >6 months post-surgery were included. Stata SE was used to estimate pooled means, heterogeneity, and publication bias. The search strategy identified 326 citations, from which 24 studies were selected. Relapse rates following Le Fort I osteotomy with rigid fixation, Le Fort I distraction osteogenesis, and anterior maxillary distraction osteogenesis were 20%, 12%, and 12%, respectively. Relapse rates with and without bone grafting were 19% and 66%, respectively. The relapse rate following distraction osteogenesis with internal distraction was lower than that with external distraction. Study limitations were heterogeneity, which was above moderate, the low number of high-quality studies, and unidirectional assessment of postoperative maxillary movement.     

牵引成骨术治疗青少年上颌骨严重发育不足的初步报告

目的 通过青少年上颌骨严重发育不足,特别是继发于唇腭裂术后严重畸形者行改良Ｌｅ Ｆｏｒｔ Ｉ型截骨,并通过颅骨外固定上颌骨牵引成骨前移术,对牵引成骨后硬组织改建及腭咽闭合功能进行初步探讨。方法 采用颅骨外固定牵引装置（ＫＬＳ－ＭＡＲＴＩＮ公司提供）对６例１１～１５岁唇腭裂术后继发上颌骨严重发育不足及发育性上颌骨严重后缩畸形的青少年实施牵引成骨术。运用正颌外科电脑分析软件对术前、术后头颅定位Ｘ线侧位     

Transantral distraction devices in correction of severe maxillary deformity in cleft patients

Maxillary advancement by Le Fort I osteotomy in cleft patients has an average relapse of about 40-60 percent. With extraoral distraction devices it is possible to obtain an almost unlimited advancement of the upper jaw. Due to the social problems the retention period is normally reduced to some monthes. A relapse of 10-25 % can be seen in these cases. Le Fort I internal distraction osteogenesis offers an alternative to one-step orthognathic advancement, with advantages of gradual lengthening through scar and earlier treatment in growing patients. The objective of this study was to present our experience in the treatment of maxillary deficiency in cleft patients using transantral internal distraction devices. The distraction procedure was successfully accomplished in seventeen patients. For all the seventeen patients maxillary distraction device designed by Konrad Wangerin was used. The distraction distances were 8 to 24 mm. Preoperative, postoperative, and follow-up (12 and 24 months) lateral cephalogram measurements were compared including angular and linear changes. A good new bone was found that was formed in distraction pitch between lines of osteotomy. After distraction of median facial zone, occlusion and profile of soft tissues were considerably improved. All patients after postoperative time required final orthodontic treatment and their final occlusal relationships were satisfactory. The transantral distraction device is a new option for the treatment of severe maxillary hypoplasia in cleft patients.     

Trans-sinusoidal maxillary distraction in three cleft patients

The trans-sinusoidal maxillary distractor (TS-MD) was used to achieve maxillary advancement in three patients with repaired cleft lip and palate. After preoperative computer-aided planning of the distraction vectors, each TS-MD was bent on a stereolithographic model of the maxilla of the patient. The devices were intraoperatively positioned using a methyl-methacrylate template. After standard Le Fort I osteotomy the devices were intraorally activated. After distraction the devices remained in situ for 3 months as rigid internal fixation of the maxilla. All patients were successfully distracted according to protocol. Maxillary advancement was 12, 8 and 11 mm. In two patients, additional maxillary widening of 6 and 8 mm was achieved by choosing divergent distraction vectors. After distraction a clockwise rotation of the maxilla was observed in two patients. There was no relapse during the 3 months of consolidation and 12-month follow-up. The TS-MD allows not only distraction but also rigid internal fixation after distraction. It was easy to apply but difficult to remove. Owing to preoperative 3D planning of the distraction vectors, the results were predictable, but clockwise rotation of the maxilla during distraction should be considered in planning. The distractor did not interfere with function or social activities during distraction and retention periods. After removal it left no extraoral scars.     

先天性外胚叶发育不全的牵引成骨治疗:1例报道

目的:探索经LeFortIII型截骨术后,应用外牵引装置矫治面中部发育不足的可行性。方法:外牵引装置使用分为前期和后期,前期主要由Martin公司的外固定支架和自行设计的骨牵引钩2部分组成,后期用额颏支抗式可摘面弓维持牵引。对1例19岁先天性外胚叶发育不全伴面中部的发育不足患者行面部小切口LeFortIII型截骨,显露两侧梨状孔缘,用粗裂钻在梨状孔的外缘外侧约8mm处钻孔,双侧鼻孔引出骨牵引钩,用细钢丝将外固定支架和骨牵引钩连接,手术后第3天开始牵引,20天后达到预定位置。结果:该患者面中部骨骼明显前移,侧面观面容改善明显。面部上、中、下各部关系较为协调。结论:坚强外固定牵引技术能够使面中部骨骼水平前移,LeFortIII型截骨后持续牵引,能够有效矫正面中份发育不足。     

Rapid maxillary distraction protocol utilizing the halo distraction system and rigid internal fixation.

OBJECTIVE: To shorten head frame wear time associated with external halo distraction (HD), we have adapted a protocol for maxillary distraction with the halo system that integrates plate fixation. PARTICIPANTS: All patients had a history of cleft lip and/or palate and maxillary retrusion > or = 8 mm. Five patients treated with this protocol and followed for at least 1 year were included in this study. INTERVENTIONS: The protocol included a 3-day latency period, variable maxillary distraction, and removal of the halo device with simultaneous rigid internal fixation. Two patients had a variable period of maxillomandibular fixation (MMF), which maintained the maxillary advancement and idealized intercuspal position while permitting further callus maturation. Cephalographs were obtained preoperatively, immediately following distractor removal, and 1 year after rigid internal fixation. RESULTS: The mean age at time of surgery was 18.7 years. The maxillary deficiency ranged from 8 to 15 mm (mean = 10.6 mm). All five patients demonstrated excellent occlusion. Cephalometric analysis 1-year post rigid internal fixation revealed minimal (<1 mm) skeletal relapse. CONCLUSIONS: Rapid maxillary distraction followed by MMF to maintain maxillary advancement may reduce halo device wear to 1 to 2 weeks. MMF optimizes occlusion by forcing the maxillary teeth into maximal intercuspal position. Rigid fixation is not only associated with less long-term relapse compared to nonrigid forms of fixation, but also minimizes the incidence of nonunion. This treatment protocol provides the advancement possible with distraction osteogenesis and the accuracy of orthognathic surgery, thereby minimizing external head frame wear.     

Complications in maxillary distraction using the RED II device: a retrospective analysis of 21 patients

Rigid external distraction osteogenesis (DO) in the treatment of midface hypoplasia has been shown to be effective and safe, but there have been several case reports on complications. Here is presented an overview of the complications in a series of 21 patients with various craniofacial anomalies. All patients were treated using the rigid external distraction II (RED II) device after Le Fort I or III osteotomy. Distraction started 1 week postoperatively and continued until Class I occlusion was achieved; it was then continued to include a 15% overcorrection. All data were collected and categorized retrospectively from the patients' files. After a mean period of distraction of 34 days, 42 complications were reported in six different categories. Pin loosening (42.9%) and frame migrations (28.6%) were the most common complications. Of the frame migrations 25% were traumatic. Intracranial penetration of one fixation pin occurred during removal of the RED II device in one patient. From these results it can be deduced that application of the RED II device is associated with a substantial number of specific complications that mainly concern the pins of the halo-frame. The stability of the device is discussed as the distraction distance achieved was less than expected.     

Midface correction in patients with Crouzon syndrome is Le Fort III distraction osteogenesis with a rigid external distraction device the gold standard?

Introduction

Le Fort III distraction osteogenesis with a rigid external distraction device is a powerful procedure to correct both exorbitism and impaired airways in faciocraniosynostosis. The aim of this study was to investigate treatment effect, perioperative parameters and volumetric outcomes after Le Fort III distraction osteogenesis in patients with Crouzon syndrome in a retrospective study design and to explore potential strengths and weaknesses of this procedure.

The skeletal stability of one-piece Le Fort 1 osteotomy to advance the maxilla; Part 1. Stability resulting from non-bone grafted rigid fixation

During the past decade, we have increasingly preferred to do a one-piece Le Fort 1 osteotomy to advance the maxilla, sometimes in isolation to treat patients with maxillary retrusive skeletal Class III patients or combined with mandibular advancement to treat bimaxillary retrusive skeletal Class II. Clinical impressions of rigid fixation techniques have indicated that there is improved stability when compared with wire fixation. There are few studies in the literature that have addressed relapse following one-piece Le Fort 1 osteotomy to advance the maxilla. Such surgery involves one single spatial movement and thereby eliminates other possible surgical variables, which may impact on the degree of stability achievable postoperatively. We studied 45 patients who had undergone a uniform one-piece maxillary advancement with elimination of controllable variables, apart from 15 patients who had simultaneous mandibular advancement. Rigid fixation was adopted throughout the study. The mean surgical change documented was 7.42 mm. The mean stability calculated at 12 months revealed a relapse of 0.72 mm (10%). This was not significant (P = 0.3). We conclude that the Le Fort 1 advancement osteotomy is a stable and surgically predictable procedure that gives only slight relapse at 12 months.     

颅外固定牵引成骨技术矫治重度上颌发育不全术后长期稳定性的初步研究

目的探讨对外置式牵引成骨技术矫治重度上颌后缩术后的长期稳定性。方法对采用外置式牵引器矫治的5例重度上颌发育不足患者拍摄治疗前、稳定期末、术后1年及术后3～6年头颅定位侧位片,分析其X线头影测量结果。结果SNA角术后一年平均复发率23.7%,术后3～6年平均复发率38.0%。A点水平位移术后一年内平均复发率27.6%,术后3～6年平均复发率39.0%。A点垂直位移在术后1年内或上升或下降,但术后1年到术后3～6年内该变量均为向下增长。结论①在外置式牵引器拆除后一年内存在明显复发倾向,一年后复发趋势仍然存在,但明显减弱。②牵引成骨术后上颌骨前部骨质存在不同程度吸收改建。③未成年患者采用外置式牵引成骨术后面中部在垂直方向上存在进一步生长发育的可能。     

Intraoral distraction osteogenesis for the correction of facial deformities following temporomandibular joint ankylosis: a modified technique

The aim of this study was to evaluate the feasibility of transoral bimaxillary distraction osteogenesis before releasing temporomandibular joint (TMJ) ankylosis using intraoral mandibular distractors. Nine patients (5 males, 4 females) aged 14-35 (mean 19) years were included. A bilateral Le Fort I osteotomy was performed together with a mandibular osteotomy on the affected side(s). An intraoral distractor(s) was inserted in the lower jaw, followed by an intermaxillary fixation (IMF) to maintain preoperative dental occlusion. The distractor was activated, after a latency period of 5-7 days, 2 times daily by 0.5 mm. There followed a consolidation period of 6-8 weeks. TMJ ankylosis was then released via a peri-auricular incision, a gap arthroplasty was performed, and mandibular movement was established after removal of the IMF and distractor. Optimal results were achieved clinically and radiologically with minimal relapse and complications. Apart from minor complaints, the distraction process was smooth and tolerable in all cases. Total mandibular elongation ranged from 17 to 25 mm (20.7 mm). Occlusal canting decreased to 0 degrees in 7 patients and to 1 degree in 2 patients (mean 0.2 degrees). After a mean follow-up period of 17 months, a mean postoperative mouth opening of 34.7 mm was achieved (0.6 mm preoperatively) and no re-ankylosis was detected. Intraoral distraction of a deformed mandible and maxilla before releasing TMJ ankylosis is a feasible and perhaps advantageous technique.     

Simultaneous hybrid of maxillary Le Fort I halo distraction and mandibular set-back for patients with severe cleft jaw deformity

One of the surgical tactics and retrospective chart review of clinical cases are described for severe maxillo-mandibular discrepancy. The recently developed Le Fort I Halo distraction combined with mandibular sagittal splitting osteotomy is initially carried out simultaneously. Materials include six adult patients revealing severe jaw deformity with mandibular prognathism somehow ranging from 17-19 years of age. The required adjustment of the maxillo-mandibular discrepancy ranged from 14-23 mm to obtain the preferred occlusion. The simultaneous combination of over 10-mm maxillary Le Fort I Halo distraction with mandibular set-back secured rigidly by sagittal splitting was accomplished. The amount of mandibular set-back ranged from 4-6 mm. The amount of maxillary Le Fort I halo distraction ranged from 10-17 mm (Table I). The retention period of the halo brace was 21-22 days. In addition, the Delair type of face mask was used for 3-4 months as a night splint for consolidation after removal of the halo brace. Satisfactory maxillary distraction and mandibular set-back as planned preoperatively was obtained in all six cases. No particular postoperative complications were noticed. Compared with standard Le Fort I advancement for cleft patients, more advancement can be obtained easily with halo distration, particularly in cases where a large amount of advancement > 10 mm is required. This combination is worthwhile for a severe cleft jaw deformity, and is an alternative for standard double jaw osteotomy.     

A new Le Fort I internal distraction device in the treatment of severe maxillary hypoplasia.

PURPOSE: The purpose of this pilot study was to test a new Le Fort I internal distraction device. PATIENTS AND METHODS: A new internal Le Fort I distraction device designed by 1 of the authors was used in 3 patients with cleft lip and palate and severe maxillary hypoplasia who needed maxillary advancements in excess of 12 mm. Presurgical planning used CASSOS (SoftEnable Technology, Ltd, Hong Kong SAR, China) prediction tracing software and a stereolithographic model to calculate the distraction vector. The distractors were pre-bent and installed on the stereolithographic model and activated to advance the maxilla. Surgery was performed in a conventional manner, and distraction was started after a 7-day latency phase at the rate of 1 mm/day and continued until the presurgical plan was achieved. The distractor was removed after a 3-month consolidation phase. Cephalometric radiographs were taken at the completion of each phase. RESULTS: This new Le Fort I internal distraction device successfully distracted the maxillae as planned in all 3 patients. At the end of the distraction phase, the maxillary advancement was measured at 15.8 mm, 15.8 mm, and 13.5 mm, respectively. In each patient, a clockwise rotation of the maxilla was observed with a tendency to a posterior open bite. Postoperative radiographs also showed that the actual distraction vectors differed from the planned vectors. After the consolidation phase, radiographs showed a relapse of 2.6 mm, 0 mm, and 5.0 mm, respectively. There was no further relapse on 3-month follow-up radiographs. Each case showed radiographic evidence of excellent new bone formation at the osteotomy sites. CONCLUSION: The new Le Fort I internal distraction device produced the necessary advancement in all 3 patients. The study also showed that the actual distraction vector differed from the planned vector. This discrepancy was caused by a clockwise rotation of the maxilla during the distraction. Finally, the study showed a variable relapse rate not previously reported in maxillary distraction.     

Stability of maxillary advancement for correction of skeletal Class III malocclusion after combined maxillary and mandibular procedures: preliminary results of an active control equivalence trial for semirigid and rigid fixation of the maxilla

In this paper preliminary results are presented of a prospective study designed to examine the effect of maxillary fixation methods on postoperative stability. The purpose of this study was to evaluate the stability of Le Fort I osteotomy stabilized with semirigid fixation of the maxilla (SRMF) or rigid fixation of the maxilla (RMF). All patients had skeletal Class III malocclusion and underwent bimaxillary surgery (Le Fort I maxillary advancement with or without superior repositioning and bilateral sagittal split osteotomies of the mandible). Standardized cephalometric analysis was performed on serial radiographs of 42 patients immediately before surgery, 1 week after surgery, after release of fixation, and 1 year postoperatively. The patients were randomized into 2 treatment groups: 23 patients received RMF (group A), and 19 patients received SRMF (group B). Within the groups, patients showed good stability with regard to their baseline characteristics. To show the therapeutic equivalence of the 2 treatments, analysis of the recorded data followed the approach for an equivalence trial. The mean surgical advancement was 5.34 +/- 1.50 mm for group A and 4.51 +/- 1.37 mm for group B. The mean amount of postsurgical relapse was 0.98 +/- 1.27 mm for group A and 0.30 +/- 1.04 mm for group B. Group A patients experienced 93% of their relapse (0.92 mm) during fixation, while group B patients experienced 96% of their relapse (0.29 mm) after release of fixation. RMF provided better stability than SRMF for all maxillary landmarks in the vertical plane. All considered points both in horizontal and vertical plane exhibited full equivalence for 95% confidence intervals, which seems to indicate equivalent stability between the surgical procedures.     

The stability of facial osteotomies. Part 5. Maxillary advancement with miniplate and screw fixation

Surgical repositioning of the dento-skeletal components of the middle-third of the face, combined with appropriate orthodontic treatment, can be used to improve function and aesthetics. However, the attainment of three-dimensional stability following corrective jaw surgery continues to be a major problem in the postsurgical period.
This paper examines the short-term (six weeks postoperative) and long-term (12 months postoperative) horizontal skeletal stability of Le Fort I maxillary advancement in 15 patients. The mean horizontal advancement of the maxilla was 8.76 ± 0.99 mm. Six weeks later, a mean relapse of 0.22 ± 0.19 mm was identified. The mean relapse at long-term follow-up was 0.61 ± 0.26 mm (6.96%).
These results indicate that rigid miniplate and screw fixation of Le Fort I osteotomy undertaken to correct horizontal mid-dentofacial deficiency is both statistically and surgically predictable and stable when reviewed up to twelve months after surgery.     

Maxillary distraction osteogenesis using Le Fort I osteotomy without intraoperative down-fracture

The aim of this study is to present a technique for maxillary distraction osteogenesis using Le Fort I osteotomy without down-fracture. Six cleft-related patients suffering from severe midfacial deficiency were treated with maxillary distraction osteogenesis. The RED II system was chosen as the extraoral device and the Leipzig retention plate system to anchor the maxillary segment. Maxillary distraction osteogenesis was successful in all cases. Cephalometric and clinical evaluation after an average follow-up period of 1 year showed stable results with respect to skeletal and dental relationships. The SNA angle increased from 72.3 degrees to 81.4 degrees and the ANB angle increased by 11.0 degrees immediately after removing the distraction device. After 1 year, the sagittal bone gain remained and the SNA angle had decreased by 0.8 degrees . This technique seems to minimize the risk of the surgical procedure and shorten the operation time. It may become an alternative method for the treatment of patients with severe midfacial hypoplasia.     

Stability of skeletal class III malocclusion after combined maxillary and mandibular procedures: rigid internal fixation versus wire osteosynthesis of the mandible.

PURPOSE: The aim of this study was to evaluate skeletal stability after double-jaw surgery for correction of skeletal Class III malocclusion to assess whether there were any differences between wire and rigid fixation of the mandible. PATIENTS AND METHODS: Thirty-seven Class III patients had Le Fort I osteotomy stabilized with plate and screws for maxillary advancement. Bilateral sagittal split osteotomy for mandibular setback was stabilized with wire osteosynthesis and maxillomandibular fixation for 6 weeks in 20 patients (group 1) and with rigid internal fixation in 17 patients (group 2). Lateral cephalograms were taken before surgery, immediately after surgery, 8 weeks after surgery, and 1 year after surgery. RESULTS: Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary sagittal stability was excellent in both groups, and bilateral sagittal split osteotomy accounted for most of the total horizontal relapse observed. In group 1, significant correlations were found between maxillary advancement and relapse at the posterior maxilla and between mandibular setback and postoperative counterclockwise rotation of the ramus and mandibular relapse. In group 2, significant correlations were found between mandibular setback and intraoperative clockwise rotation of the ramus and between mandibular setback and postoperative counterclockwise rotation of the ramus and mandibular relapse. No significant differences in postoperative skeletal and dental stability between groups were observed except for maxillary posterior vertical position. CONCLUSIONS: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure independent of the type of fixation used to stabilize the mandible.     

Le Fort III distraction osteogenesis: modification of the intraoral splint in the rigid external distraction

Le Fort III distraction osteogenesis (DO) is a useful procedure for treating midface hypoplasia. The external distraction system has the advantage of allowing modification of the distraction vector during the activation period. This system needs an intraoral splint for the anchorage points. The intraoral splint has an important role in conducting the distraction force to the midface and in forming the advancement vector. The authors developed a modified type of splint to improve the outcome of Le Fort III DO.The intraoral splint is composed of a modified headgear face bow, molar bands, and a palatal acrylic plate without covering the teeth. Four suspension wires were applied to reinforce the stability. The zygomatic bones and the loops of the splint are selected as 4 anchorage points for Le Fort III DO. This procedure was applied to 2 patients.The midface had an advancement of more than 20 mm in both patients. The dental movement of the upper incisors and the upper first molar was minimal.The dental effect was nearly absent. The amount and vector of distraction could be decided under direct observation without blocking the dental occlusion. The vector of distraction could be adjusted during the activation period. The results of DO were satisfactory.