Orbitofrontal monobloc advancement for Crouzon syndrome

IntroductionUsually, patients suffering from Crouzon syndrome have synostosis of coronal sutures, exophthalmia, hypertelorism, and hypoplasia of the middle third of face. Sometimes maxillary retrusion is absent, so these patients have class I or II relationship. In these cases, frontofacial monobloc advancement, which is the gold standard, increases the maxillo-mandibular dysmorphia. Therefore we propose orbitofrontal monobloc advancement minus dental arch, without splits of the pterygoid plates.Case reportA 12-year-old girl with Crouzon syndrome had intracranial hypertension, exophthalmia, a middle third retrusion and a class II occlusion. We achieved orbitofrontal monobloc advancement which is frontofacial monobloc advancement minus maxillary dental arch. Four distractors KLS Martin were used. After 20 days of distraction, the final advancement was 10.2 mm for cranial distractors and 10.5 mm at fronto-zygomatic. Distractors were removed after 8 months.DiscussionWe offer patients suffering from Crouzon syndrome with class I or II relationship a change from the classic frontofacial monobloc advancement leaving the maxillary dental arch in place, thus avoiding the worsening of the maxillo-mandibular dysmorphia related to surgery. The idea of associating Le Fort I osteotomy with a frontofacial monobloc advancement or Le Fort III osteotomy has already been described, mainly by Tessier and Obwegeser, however they probably achieved a complete Le Fort I osteotomy while we don't split the pterygoid plates.The patient's morphology and his surgical history determine the choice between Le Fort III and monobloc advancement. Dental occlusion needs to be taken into account for surgical indication.     

面中部牵引成骨结合正颌手术治疗Binder综合征

目的：Binder综合征患者有严重的面部凹陷畸形及咬合功能障碍,治疗相对困难且易复发。本研究探讨面中部牵引结合正颌手术在Binder综合征治疗中的价值。方法：4例Binder综合征患者采用改良Le Fort II型截骨术,术后利用颅骨外置式牵引器进行旋转牵引,并随时调整矢状向及垂直向的量,矫正患者面形。半年后进行正颌手术,矫正咬合关系,并随访1~2 a。结果：4例患者均顺利完成整个治疗过程,无明显并发症发生。牵引过程中无明显疼痛及不适。头影测量显示,患者面中部骨骼显著前移,凹陷畸形得以矫治。经过正颌-正畸联合治疗,获得了良好的咬合关系。结论：上颌骨Le Fort II型截骨牵引可以矫治鼻上颌骨发育不足,通过正颌手术可以矫正咬合关系,两者结合是一种较为理想的治疗Binder综合征的方法。     

Le Fort Ⅲ型截骨中位牵引成骨治疗成人面中份发育不全

目的:评价中位牵引成骨治疗成人面中份发育不全的疗效。方法:使用自行设计制作的颌骨牵引装置,在全麻手术下LeFortⅢ型截骨,后将牵引钩置入鼻底或梨状孔侧缘,从鼻孔引出,外部装置采用面弓或坚固外固定支架,对8例面中部凹陷畸形成年患者行前牵引,治疗前后拍摄定位头颅侧位片测量分析。结果:上颌中位前牵引治疗后,患者咬合关系和软组织侧貌改变明显,A点水平前移在9～14.5mm之间,面部上中下各部的前后关系协调,鼻梁及鼻下部挺拔,眼球突出度改进明显。结论:经梨状孔中位牵引成骨可有效矫治面中部发育不全,该牵引技术牵引力点适中,能够使面中份骨骼平衡前移;避免对牙齿牵引造成的不利改变。长期效果有待于进一步观察。     

The influence of orthognathic surgery on ventilation during sleep

Orthognathic surgery has varying effects on respiratory parameters. The authors undertook a prospective study of patients requiring mandibular advancement, mandibular setback and maxillary Le Fort I advancement, and surgically assisted rapid maxillary expansion (SARME). Breathing parameters were monitored in a sleep laboratory the night before the operation and in a mean of 9.5 months after the operation. In patients treated with mandibular advancement, the respiratory disturbance index (RDI), oxygen desaturation index (ODI), and number of obstructive apnoeas (OAs) improved significantly. In patients treated with mandibular setback and maxillary Le Fort I advancement, the RDI, ODI, index of flow limitations (IFL), number of obstructive hypopnoeas (OHs), OA, and oxygen saturation deteriorated. In contrast, patients treated with SARME improved only mildly. These results indicate that bimaxillary surgery for Class III malocclusion increased upper airway resistance, probably because of a more dorsal positioning of the base of the tongue, representing an iatrogenic obstructive sleep apnoea (OSA). A young person would probably be able to balance such a decline in respiratory function using different adaptative mechanisms. Mandibular advancement significantly improved respiratory parameters during sleep. The possible effect of orthognathic surgery on the upper airways should be incorporated into the treatment plan.     

Prevalence of nasolacrimal canal obstruction and epiphora following maxillary orthognathic surgery

Acquired injuries of the nasolacrimal apparatus may be the result of craniomaxillofacial surgical procedures, facial trauma, or inflammation. Injury to the nasolacrimal duct system following maxillary orthognathic surgery is rarely reported. This study evaluated the importance of early diagnosis and treatment of epiphora developing after Le Fort I surgery. The records of 83 patients who underwent maxillary orthognathic surgery over a 2-year period were reviewed. The prevalence of postoperative epiphora was 3.6% and it persisted for a mean of 32.7 days. No patient required further surgical treatment of the nasolacrimal duct obstruction. Clinicians should evaluate the lacrimal canal position and schedule close postoperative follow-up of injuries to the nasolacrimal apparatus. These may become permanent, necessitating additional surgery.     

Accuracy of Le Fort I osteotomy in bimaxillary splint-based orthognathic surgery: focus on posterior maxillary movements

This retrospective study was performed to verify the accuracy of horizontal and vertical repositioning of the maxilla in bimaxillary osteotomy with a focus on posterior vertical displacement. Data from 39 orthognathic patients undergoing bimaxillary surgery including a one-piece Le Fort I osteotomy with pitch rotation and advancement at the University Hospitals of Leuven (Belgium), between January 2015 and April 2016, were included in the study. Preoperative and 1-week postoperative lateral cephalograms were digitized and imported into cephalometric software. Horizontal and vertical measurements of dental landmarks were used to assess the accuracy of maxillary repositioning, and errors were reported in terms of the mean and absolute mean. The horizontal advancements were randomly under- and over-corrected an average of 1.4 mm ± 1.2 mm. Vertical repositioning of the anterior maxilla followed the planning. A tendency for under-correction was found for posterior vertical intrusion of the maxilla. The same tendency towards under-correction of posterior maxillary inferior repositioning was detected when planned movements were greater than 3 mm. For all studied groups, no significant difference was found between the planning and the results achieved, validating the use of intermediate splints.     

Successful Treatment of Postoperative Mouth Opening Limitation Following Le Fort III Distraction with Bilateral Coronoidectomies

Introduction

Distraction osteogenesis is a powerful tool in craniomaxillofacial surgery, allowing for large advancements of osteotomized segments in the setting of a restrictive soft tissue envelope. Despite its benefits, distraction can have negative functional consequences. We present a case of a patient with Crouzon syndrome who developed reduced mouth opening capability after a Le Fort III midfacial advancement with rigid external distraction.

Technique

Radiographic evaluation revealed that the coronoid process was restricting the normal excursion of the mandible by contacting the posterior zygoma. The patient was subsequently treated with a bilateral coronoidectomy via an intraoral approach, which improved his interincisal opening. Maximum interincisal distance was improved from 18 mm to 33 mm following bilateral cornoid resection.

Conclusion

We report coronoid impingement as a potential complication after Le Fort III distraction. Such a finding suggests the need for a detailed vector analysis in cases undergoing midface advancement with distraction. Post-distraction coronoidectomy is a useful surgical procedure to treat mouth opening limitation due to coronoid impingement against the zygoma after midfacial advancement.

     

Surgical complications of segmental Le Fort I osteotomy

Segmental maxillary osteotomy is a useful adjunct in orthognathic surgery for the correction of vertical and transverse maxillary deformities, but we know of few published reports that document complications. We evaluated the complication rates associated with segmental maxillary surgery in our unit by retrospective review of medical records, radiographs, and study models of 85 consecutive patients (mean age 23.3 years, range 14–51; male:female ratio 1:2) treated from 1995 to 2009. Types of deformity were anterior open bite (n = 30, 35%), transverse maxillary deficiency (n = 24, 28%), anterior open bite with transverse maxillary deficiency (n = 28, 33%), and anterior vertical maxillary excess (n = 3, 4%). There were 70 tripartite (82%), 13 bipartite (15%), and two quadripartite (2%) maxillas. Twenty-one patients (25%) had bone grafts. Fixation was done using titanium miniplates in 80 patients (94%), and titanium miniplates and resorbable plates in five (6%). The overall complication rate was 27%. Three patients (4%) had devitalisation of teeth, three (4%) developed minor periodontal defects, and one had tooth loss. Eight patients (9%) had plates removed, and two patients developed persistent postoperative palatal fistula. There was no segmental loss of bone or teeth. Our results show that complications in this cohort were relatively low, and that segmental maxillary surgery is safe as an adjunct in carefully selected cases.     

正颌外科治疗阻塞性睡眠呼吸暂停综合征

为了总结使用正颌外科方法治疗严重的小颌或下颌后缩畸形伴阻塞性睡眠呼吸暂停综合征（ｏｂｓｔｒｕｃｔｉｖｅｓｌｅｅｐａｐｎｅａｓｙｎｄｒｏｍｅ，ＯＳＡＳ）后，患者面型、关系以及口颌系统功能获得的改善，作者通过１０例患者的手术治疗对颌骨和舌骨的移动，同时改善面型、口颌系统功能并扩张舌根水平的上气道，从而治疗ＯＳＡＳ。讨论了治疗ＯＳＡＳ的正颌外科手术方法，并提出了正颌外科治疗ＯＳＡＳ的适应证和外科治愈指标。     

Alterations of upper airway volume caused by Le Fort III osteodistraction in children

PurposeThe aim of the study was to assess changes in the upper respiratory tract and sleep quality in patients who were suffering from midfacial hypoplasia and treated with the movement of underdeveloped middle segment of the face with an Le Fort III osteotomy and distraction.MethodsIn this study patients aged 7–19, suffering from Crouzon syndrome, Apert syndrome, or other craniosynostosis were treated with Le Fort III osteotomy and midface distraction. Patients were subjected to radiological examination and polysomnography before and after the treatment. Typical anthropometric points were identified on lateral cephalograms, and were used to take linear and angular measurements. The surface and the volume of the upper respiratory tract were measured with the Dolphin Imaging software. Apnoea Hypopnea Index (AHI) was used to assess the sleep quality.ResultsIn all 18 patients the analysis showed statistically significant changes of the AHI and in the linear, angular and volumetric measurements. Mean change of the volume of the upper respiratory tract was 12,4 ± 11,3cm3(p = 0,0001) and of the surface was 615 ± 521 mm² (p = 0,0000000002). Mean improvement of AHI was 9 ± 6,2 (p = 0,00006). In three cases patients had tracheostomy prior to operation and none of them required tracheostomy after the operation.ConclusionsThe use of distraction osteogenesis of the middle segment of the face combined with Le Fort III osteotomy results in dilation of the upper respiratory tract at the nasopharyngeal level and at the soft palate level resulting in elimination of sleep and respiration disorders. Further studies with polysomnography are necessary, as well as observation of patients over time and monitoring of treatment stability.     

Le Fort Ⅰ型截骨术在唇腭裂正颌外科中的应用与评价

目的:观察分析Le Fort Ⅰ型截骨术在唇腭裂正颌外科中的应用效果.方法:回顾2004年3月至2006年12月武汉大学口腔医学院口腔颌面外科收治的唇腭裂患者的临床资料,并进行总结与分析,所有患者均进行了以Le Fort Ⅰ型截骨术为主的正颌外科治疗.结果:共收集相关病例16例,其中男9例,女7例,平均年龄22.4岁.术前∠SNA平均73.2°,术后LSNA平均79.5°;上颌前移距离平均8.13mm.平均随访时间7.3个月.所有患者术后面容改善明显,经正畸治疗后咬合关系满意.结论:以Le Fort Ⅰ型截骨术为主的正颌外科治疗,可以显著改善唇腭裂患者的颌骨与面容畸形.     

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.

Reaching the vertical versus horizontal target position in multi-segmental Le Fort I osteotomy is more difficult,but yields comparably stable results to one-segment osteotomy

This retrospective cohort study evaluated the postoperative outcomes of preoperatively planned positional changes for Le Fort I osteotomy in 77 patients (average age 26.6 years). Movement relapse and planning accuracy were evaluated by lateral cephalometric analysis, with an average follow-up of 257 days. In one-segment osteotomy cases, 73% of the horizontal movements were positioned within 2 mm of the surgical plan. With posterior–inferior repositioning of the maxilla, results fell within 2 mm of the prescribed plan in 60% of cases. Maxillary advancement and superior repositioning proved more stable than inferior maxillary repositioning. Relapse did not differ between three-piece and one-piece osteotomies for any movements; however, in three-piece cases, only half of the positional changes on average stayed within 2 mm of the prescribed surgical plan. Relapse did not vary with bone grafting among the groups. To summarize, in most Le Fort I osteotomy cases, the surgical plan is achieved within 2 mm, with posterior extrusion of the maxilla showing the greatest deviation both in reaching the target and maintaining the result achieved. Although maxillary segmentation makes the surgical plan more difficult to achieve, the results are at least as stable as those of one-piece osteotomies.     

Virtual planning in Le Fort III distraction osteogenesis: A case series

The objective of this study is to determine the value of using 3D planning tools and 3D printed cutting guides in Le Fort III osteotomies with external frame distraction osteogenesis.The process of planning and transfer of the virtual planning to the operating room is illustrated with 5 case. The virtual planning is transferred to the operating room using a 3D-printed supra-orbital reference bar with puzzle connections for the planned osteotomy guides. Different systems are presented to transfer the vector of distraction and the position of the external midface distractor.Three-dimensional planning tools and cutting guides help to design the Le Fort III osteotomy and the distraction vector, to anticipate possible difficulties, and to avoid adverse events.     

Modified Le Fort III osteotomy: A simple solution to severe midfacial hypoplasia

Purpose

There are multiple conditions that may affect the development of the middle third of the face and with varying degrees of severity. The surgical treatment alternatives for major midfacial sagittal deficiencies consist in Le Fort I, II, or III with conventional osteotomies or with distraction osteogenesis (DO). Both techniques have advantages and disadvantages that should be evaluated specifically in each case. The aim of this report is to present a group of patients with severe hypoplasia of the middle third of the face, with different origins, and their treatment with a Modified Le Fort III osteotomy and distraction osteogenesis, using a minimally invasive surgical approach.

Adie's pupil following Le Fort I maxillary osteotomy: case report

Complications after Le Fort I osteotomy are rare. We report, to our knowledge, the first case of bilateral Adie's pupil after Le Fort I osteotomy.     

Cranial nerve injuries in Le Fort I osteotomy: a systematic review

The aim of this systematic review was to describe the anatomical and surgical factors related to cranial nerve injuries in Le Fort I osteotomy. The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO). Two independent reviewers performed an unrestricted electronic database search in the MEDLINE/PubMed, LILACS, Scopus, Web of Science, and Cochrane databases up to and including August 2018. Thirty-two articles were selected for data extraction and synthesis: 30 studies were identified in the main search and two by a manual search. The level of agreement between the reviewers was considered excellent (κ = 0.779 for study selection and κ = 0.767 for study eligibility). This study revealed that the main nerve affected was the trigeminal nerve, followed by the oculomotor, abducens, optic, facial, and vagus and accessory nerves. Cleft lip and palate patients presented the highest incidence of cranial nerve damage. Cranial nerve damage after Le Fort I osteotomy is not rare. Anatomical and structural knowledge of the patient are necessary in order to minimize the risks of cranial nerve injury in Le Fort I osteotomy.     

Changes in border movement of the mandible in skeletal Class III before and after orthognathic surgery

The purpose of this study was to examine the changes in border movement of the mandible before and after mandibular ramus osteotomy in patients with prognathism. The subjects were 73 patients with mandibular prognathism who underwent sagittal split ramus osteotomy (SSRO) with and without Le Fort I osteotomy. Border movement of the mandible was recorded with a mandibular movement measure system (K7) preoperatively and at 6 months postoperatively. Of the 73 patients, 21 had measurements taken at 1.5 years postoperative. Data were compared between the pre- and postoperative states, and the differences analyzed statistically. There was no significant difference between SSRO alone and SSRO with Le Fort I osteotomy in the time-course change. The values at 6 months postoperative were significantly lower than the preoperative values for maximum vertical opening (P = 0.0066), maximum antero-posterior movement from the centric occlusion (P = 0.0425), and centric occlusion to maximum opening (P = 0.0300). However, there were no significant differences between the preoperative and 1.5 years postoperative measurements. This study suggests that a postoperative temporary reduction in the border movement of the mandible could recover by 1.5 years postoperative, and the additional procedure of a Le Fort I osteotomy does not affect the recovery of mandibular motion after SSRO.