Ultrasonic osteotomy as a new technique in craniomaxillofacial surgery

Ultrasound osteotomy is a new surgical technique used in dentistry to section hard tissues without damaging adjacent soft tissues. It was hypothesized that this could also be useful in craniofacial and orthognathic surgery. An ultrasonic device was employed in the following craniofacial surgical procedures: 144 Le Fort I osteotomies, 140 palatal expansions after Le Fort I osteotomies and 140 bilateral sagittal osteotomies; 2 Le Fort III osteotomies for treatment of Crouzon syndrome in two patients; 12 cases of unicortical calvarial bone grafting; removal of superior orbital roof in 25 cases of craniofaciostenosis; removal of external wall of the orbit in 10 cases of orbital cavity tumour; removal of anterior and posterior walls of the frontal sinuses in four cases of orbital cavity tumour. Integrity of soft tissues and surgical time were evaluated. Functional results were good without any soft-tissue damage being observed, but the overall operative time was increased. Ultrasound osteotomy is a new technical procedure that is advantageous for bone cutting in multiple situations, with minimal to no damage in adjacent soft tissues such as brain, palatal mucosa and the inferior alveolar nerve.     

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...     

Wound healing after multisegmental le fort i osteotomy and transection of the descending palatine vessels

Vascular ischemia has been associated with improper soft tissue flap design, stretching of the palatal vascular pedicle, bony segmentation, transection of the descending palatal vessels, or hypotension. This study examined Le Fort I osteotomy wound healing after some of these surgical maneuvers. Clinically analogous four-segment Le Fort I osteotomies were accomplished through circumvestibular incisions in nine adult rhesus monkeys and the animals were killed at 0, 3, 7, 14, and 28 days after surgery. Revascularization and bone healing were studied by microangiographic and histologic techniques. The findings indicated that the palatal mucosa or labial-buccal gingiva and mucosa provide adequate nutrient pedicles for Le Fort I osteotomies accomplished through a circumvestibular type incision. It was concluded that segmentalization, stretching of the vascular pedicles, or transection of the descending palatine vessels have only transitory discernible effects on revascularization and bone healing.     

Accuracy of cephalometric prediction in orthognathic surgery

The reliability of predicting the results of orthodontic surgical treatment was analysed. The sample consisted of 30 patients treated with one of the following six types of surgery: mandibular anterior alveolar surgery; maxillary anterior alveolar surgery; mandibular setback surgery; mandibular advancement surgery; Le Fort I surgery; and a combination of Le Fort I and mandibular setback surgery. Comparisons of tracings of the initial cephalometric radiographs, the prediction tracing and the six-month follow-up film showed great variation in the results both within and between the surgical subgroups. Generally, it was easier to predict the treatment results of alveolar segmental osteotomies, especially in the mandible, than of operations in which the whole mandible was repositioned. The results from Le Fort I surgery with or without a concomitant mandibular setback showed the greatest difference between the predicted and the actual outcome. The postoperative vertical dimension appeared to be particularly hard to predict. Explanations for these discrepancies are offered and possibilities for improvements suggested. It is concluded that prediction tracings are still of value despite the poor accuracy in some cases.     

Precision of Le Fort I osteotomy: planning versus outcome. A multi-centre retrospective study

Introduction: The purpose of this study was to evaluate the accuracy of Le Fort I surgery by comparing planned surgical movements with actual outcomes.

Materials and methods: A minimum number of seven consecutive cases that had undergone a Le Fort I osteotomy procedure alone or in combination with a mandibular osteotomy from six different hospital units in the East of England between 2009 and 2010 were identified. A total of 56 cases met the inclusion criteria where surgical splints were used and model surgery had been performed. Pre- and post-operative lateral cephalograms were digitised using Dolphin^© imaging software (Version 10.0) and three cephalometric points were assessed to measure precision of surgical movements: A point (A-pt); Upper incisor tip (U1 tip); and Upper first molar occlusal point (U6 occ). The final position of the maxilla was compared to the planned position.

Results: In 71% of cases surgical movements were within 2?mm and 20% of this group were within 1?mm of the predicted position. The mean accuracy was 1.39?mm (SD 0.92?mm) for the former and 0.78?mm (SD 0.58?mm) for the latter. Accuracy correlated negatively with increased surgical complexity, particularly posterior differential impactions of the maxilla. There was no statistically significant difference between centres.

Conclusions: Pre-operative surgical planning of Le Fort I osteotomies was generally accurate. This study demonstrates that different operators across six centres produced consistent surgical outcomes and this confirms previously reported data.     

Importance of soft tissue for skeletal stability in maxillary advancement in patients with cleft lip and palate.

OBJECTIVE: Assessment of stability of the advanced maxilla after two-jaw surgery and Le Fort I osteotomy in patients with cleft palate based on soft tissue planning. SUBJECTS: Between 1995 and 1998, 15 patients with cleft lip and palate deformities underwent advancement of a retruded maxilla, without insertion of additional bone grafts. Eleven patients had bimaxillary osteotomies and four patients only a Le Fort I osteotomy. Relapse of the maxilla in horizontal and vertical dimensions was evaluated by cephalometric analysis after a clinical follow-up of at least 2 years. RESULTS: In the bimaxillary osteotomies, horizontal advancement was an average 4 mm at point A. After 2 years, there was an additional advancement of point A of an average of 0.7 mm. In the mandible, a relapse of 0.8 mm was seen after an average setback of 3.9 mm. In the four patients with Le Fort I osteotomy, point A was advanced by 3.8 mm and the relapse after 2 years was 0.9 mm. Vertical elongation at point A resulted in relapse in both groups. Impaction of the maxilla led to further impaction as well. CONCLUSION: Cephalometric soft tissue analysis demonstrates the need for a two-jaw surgery, not only in severe maxillary hypoplasia. Alteration of soft tissue to functional harmony and three-dimensional correction of the maxillomandibular complex are easier to perform in a two-jaw procedure. It results in a more stable horizontal skeletal position of the maxilla.     

Soft tissue changes after mandibular setback and bimaxillary surgery in Class III patients

Objective:To evaluate the relationship between soft tissue and bone structure for Class III patients before and after bilateral sagittal split osteotomy (BSSO) and bimaxillary orthognathic surgery; to determine the impact of other factors on soft tissue change; and to evaluate correlations between thickness of tissue before surgery, SNA, SNB, and ANB angles, and soft tissue changes.Materials and Methods:The study included 78 Class III patients treated only with BSSO or with BSSO and Le Fort I osteotomy. Lateral cephalograms were taken before and 3 months to 1 year after surgery. After all points of the Zagreb82 and Legan and Burstone profile analysis were traced, the ratio of five soft tissue points before and after surgery was evaluated.Results:Soft tissue between points Sn and A and upper lip showed statistically significant changes for patients treated with bimaxillary surgery and BSSO. Only gender had an influence on soft tissue change. The correlation between soft tissue thickness and changes after surgery was significant. A change in SNB angle correlated with upper lip thickness for patients treated with BSSO but not for patients treated with BSSO and Le Fort I. SNA angle changes correlated with soft tissue changes between points Sn and A.Conclusion:Results of this study show soft tissue changes after BSSO and BSSO and Le Fort I and eliminate the deficiencies that were indicated in the meta-analysis of soft tissue changes from a previous study.     

Predictability of soft tissue profile changes following bimaxillary surgery in skeletal class III Chinese patients

PURPOSE: The aim of this study was to evaluate the accuracy of soft tissue profile predictions generated by a recently developed computer program (Computer-Assisted Simulation System for Orthognathic Surgery [CASSOS] 2001, SoftEnable Technology, Ltd, Hong Kong) in Chinese skeletal Class III patients treated with bimaxillary surgery. MATERIALS and METHODS: Presurgical and posttreatment lateral cephalograms of 35 Chinese patients who had combined 1-piece Le Fort I and bilateral sagittal split osteotomies were digitized using the CASSOS 2001 program, and a cranial base superimposition was performed. The hard tissue movements were simulated on the presurgical cephalogram until good superimposition of the hard tissues on the presurgical and posttreatment cephalograms was achieved. A customized cephalometric analysis consisting of 32 linear measurements was used to analyze the differences in the soft tissue profile between the actual posttreatment results and the computer-generated predictions. RESULTS: Comparison of the predicted and actual changes found that 16 of the 32 soft tissue measurements were significantly different ( P <.05). Most of the significant prediction errors were observed in the upper and lower lip region. The software tended to underestimate the vertical position of both the upper and lower lip and overestimate the horizontal position of the lower lip. However, the mean differences were relatively small, with the greatest mean difference being 2 mm in the vertical position of stomium inferius. The CASSOS 2001 program produced a clinically useful prediction of soft tissue profile changes following bimaxillary surgery in skeletal Class III Chinese patients.     

Modified Le Fort I osteotomy with preservation of the anterior nasal spine position: preliminary report

We present a modification of the traditional Le Fort I osteotomy by means of which the anterior nasal spine is left intact. The osteotomies advance from the posterior-lateral side of the maxillary bone through the tuberosity to the inferior-lateral wall of the piriform opening. Two other vertical osteotomies from the lateral side of the piriform opening are placed in a 90 degree fashion to connect with another horizontal osteotomy that runs 5 mm below the floor of the nasal cavity and the anterior nasal spine. In a series of 50 patients with Le Fort I osteotomies, we have performed this new technique in 5 patients. We have observed better esthetic results in terms of nasal tip position and a more predictable value for the nasolabial angle. We believe that this technique is more appropriate for larger advancements in which a large gap may occur at the end of the movement.     

Comparison between patient specific implants and conventional mini-plates in Le Fort I osteotomy with regard to infections: No differences in up to 3-year follow-up

Individually designed osteotomies and milled or printed patient-specific osteosynthesis materials are rapidly becoming a standard in maxillofacial reconstructive surgery. The benefits of using patient-specific implants (PSIs) in orthognathic surgery are especially clear in complex cases, and for this reason they are rapidly becoming common practice. We have earlier reported the benefits related to the use of PSIs as reposition and fixation system in Le Fort I osteotomy. The aim of this study was to compare complications associated with fixation with PSIs (31 patients) versus conventional mini-plates (37 patients) in Le Fort I osteotomy. No statistically significant differences in infection, reoperations or soft tissue problems were observed between the two systems used. Interestingly, three of the 37 patients in the mini-plate group underwent reoperation due to insufficient advancement or malocclusion, whereas none of the patients in the PSI group needed reoperation. In conclusion, PSIs are reliable for use in orthognathic surgery, with no signs of infection associated complications.     

Postoperative skeletal stability and accuracy of a new combined Le Fort I and horseshoe osteotomy for superior repositioning of the maxilla

Postoperative skeletal stability and accuracy were evaluated in a combination of Le Fort I and horseshoe osteotomies for superior repositioning of maxilla in bi-maxillary surgeries in 19 consecutive patients. 9 underwent Le Fort I osteotomy alone (preoperative planned superior movement <3.5 mm). 10 underwent Le Fort I and horseshoe osteotomy (combination group) (preoperative planned superior movement >3.5 mm). The maxilla was osteotomized and fixed with 4 titanium Le Fort plates followed by bilateral sagittal split ramus osteotomy of the mandible, fixed with 2 semi-rigid titanium miniplates. Maxillomandibular fixation was performed for 1 week. Lateral cephalograms were obtained preoperatively, 1 week postoperatively, 3, 6, 12 months later. The changes in point A, point of maxillary tuberosity, and upper molar mesial cusp tip were examined. Discrepancy between the planned and measured superior movement of the maxilla in the Le Fort I and combination groups was 0.30 and 0.23 mm, respectively. The maxillae in both groups were repositioned close to their planned positions during surgery. 1 year later, both groups showed skeletal stability with no significant postoperative changes. When high superior repositioning of the maxilla is indicated, horseshoe osteotomy combined with Le Fort I is reliable and useful for accuracy and postoperative stability.     

Incidence of nasolacrimal injury and turbinectomy--associated atrophic rhinitis with Le Fort I osteotomies

Injury to the lacrimal system can occur with trauma, craniofacial surgery, rhinoplasty and nasal antrostomy. Nasolacrimal duct injury may potentially occur with Le Fort I superior repositioning. Atrophic rhinitis is also a potential complication secondary to turbinectomy required during Le Fort I superior repositioning. A review of thirty-four cases over three years of Le Fort I osteotomies with superior repositioning found no postoperative lacrimal injury and no subsequent atrophic rhinitis associated with turbinectomy. An anatomical study relating the position of the nasolacrimal duct opening within the inferior meatus and the distance available for maxillary impaction is reviewed.     

Le Fort I miniplate osteosynthesis: a randomized, prospective study comparing resorbable PLLA/PGA with titanium

The aim of this study was to compare the use of resorbable osteosynthesis material (LactoSorb) with titanium osteosynthesis for the fixation of Le Fort I osteotomies with respect to long-term stability and morbidity. To achieve exact cephalometric measures, five tantalum micro implants were inserted in the maxilla during surgery. A total of 60 patients undergoing a non-segmented Le Fort I osteotomy were randomized to one of the treatments and were followed for 1 year postoperatively. For the osteotomies fixated with LactoSorb, the lateral cephalometric analysis demonstrated a statistically significant difference in the vertical position of the maxilla after 6 weeks as the position became more superior compared with the postoperative situation (mean change of 0.6 mm). In the titanium group no significant changes in position were observed. There were no statistically significant changes in the position of the maxilla from 6 weeks to 12 months in either of the treatment groups. The changes in maxillary postion were not clinically noticeable in either of the treatment groups, and all treatments were completed with satisfactory results. There were two cases of infection and wound dehiscence in the LactoSorb group, whereas titanium osteosynthesis was more often palpable after 6-12 months and required surgical removal in three cases.     

Life-threatening haemorrhage after 750 Le Fort I osteotomies and 376 SARPE procedures

This study assessed the incidence, presenting symptoms, diagnosis, and management of patients with life-threatening postoperative haemorrhage after total Le Fort I osteotomy and surgically assisted rapid palatal expansion (SARPE). The medical records of 750 consecutive Le Fort I osteotomies and 376 consecutive SARPEs, both of which involved pterygomaxillary separation with a curved osteotome and a mallet, were analysed prospectively. Two cases of life-threatening haemorrhage were observed in the Le Fort I osteotomy group, both initiated on postoperative day 7. Anterior and posterior nasal packing were successful in one patient; the other required two embolizations for bleeding control (incidence of life-threatening postoperative haemorrhage: 2/750; confidence interval: 0.03-0.96%). In the SARPE group, one brisk epistaxis on the first postoperative day was controlled with anterior and posterior nasal packing under general anaesthesia. This haemorrhage was not considered life threatening (incidence of life-threatening postoperative haemorrhage: 0/376; confidence interval: 0-0.98%). In no case could the source of bleeding be established during re-explorative surgery or during diagnostic arteriography. The authors conclude that life-threatening haemorrhage is an exceptional finding after Le Fort I osteotomy; the observed incidence was 2/750, and life-threatening haemorrhage was not observed after SARPE in this series, despite the use of identical pterygomaxillary separation.     

Subcutaneous emphysema after Le Fort I osteotomy: report of two cases.

Two cases of subcutaneous emphysema that occurred after Le Fort I osteotomies are reported, and diagnosis and treatment are discussed.     

Use positional screws for Le Fort I osteotomy fixation: technical note

In recent years, several studies related to fixation systems have been published, but few suggest any variations of the Le Fort I osteotomy technique, and the use of plates and screws placed along the canine and zygomatic pillar are common. The 20-year-old patient with Crouzon syndrome presented with severe hypoplasia of the maxillary, mandibular prognathism, and class III facial pattern. The patient underwent orthognathic surgery and high Le Fort I osteotomy with the fixation of eight positional screws. The aim of this paper is to describe a different technique for the fixation in high maxillary osteotomies, which can be used in specific cases.     

The effects of early Le Fort I osteotomies on craniofacial growth of juvenileMacaca nemestrina monkeys

Le Fort I osteotomies were performed on three juvenileMacaca nemestrina monkeys with midface deficiencies from prior extraoral traction. The maxillas of these monkeys were moved anteriorly an amount necessary to achieve about 8 mm. of horizontal overjet. Interosseous wires were used to stabilize the segments; the animals were not placed in intermaxillary fixation. Craniofacial growth in the three experimental monkeys and in three control monkeys was monitored for 2 years with serial cephalometric radiographs. Compared to the controls, the maxillas of the experimental animals demonstrated less anterior growth, and this was manifested clinically in anterior dental cross-bite relationships. Histologic examination of the circummaxillary sutural complex revealed normal morphology. It is concluded, therefore, that early Le Fort I osteotomies significantly affect subsequent maxillary growth in monkeys and that this effect probably is due to formation of scar tissue.     

Meningoencephalitis following Le Fort I osteotomy: a case report

Le Fort I osteotomies, although they are common procedures, carry a degree of risk of injury to the surrounding structures. Skull base fractures and cerebrospinal fluid rhinorrhoea are amongst the most serious on the list of complications. This is the first reported case of meningoencephalitis post Le Fort I osteotomy, shedding some light on its identification, causes, and management.     

Blindness after Le Fort I osteotomy: a possible complication associated with pterygomaxillary separation.

INTRODUCTION: Visual loss after Le Fort I osteotomy is a devastating complication the mechanism of which is not always clear. METHODS: A case report of blindness following Le Fort I osteotomy is presented. The literature on the various skull base complications associated with Le Fort I osteotomies is reviewed and the mechanisms of these complications discussed. CONCLUSION: The radiological findings in this case are similar to those previously reported. They strongly support the hypothesis that an adverse transmission of forces associated with pterygomaxillary separation via the sphenoid bone to the intra- and extracranial portions of the skull base is the main reason for injury to the optic and other cranial nerves as well as to the branches of the carotid artery.