Stability of the Le Fort I osteotomy with anterior internal fixation alone: a case series.

PURPOSE: The purpose of this case series was to evaluate the late postsurgical stability of the Le Fort I osteotomy with anterior internal fixation alone and no posterior zygomaticomaxillary buttress internal fixation. PATIENTS AND METHODS: Sixty patients with maxillary vertical hyperplasia and mandibular retrognathia underwent a 1-piece Le Fort I osteotomy of the maxilla with superior repositioning and advancement or setback. A bilateral sagittal split ramus osteotomy for mandibular advancement was also performed in 22 patients. Stabilization of each maxillary osteotomy was achieved using transosseous stainless steel wires and/or 3-hole titanium miniplates in the piriform aperture region bilaterally, with no zygomaticomaxillary buttress internal fixation. (Twelve of the 60 identified patients were available for a late postoperative radiographic evaluation.) Lateral cephalometric radiographs were taken preoperatively (T1), early postoperatively (T2), and late postoperatively (T3) to analyze skeletal movement. RESULTS: These 12 patients (5 male, 7 female) had a mean age of 24.5 years at surgery. Mean time from surgery to T2 was 41.2 days; mean time from surgery to T3 was 14.8 months. One patient received anterior wire osteosynthesis fixation, while 11 patients received both anterior titanium miniplate internal skeletal fixation and anterior wire osteosynthesis fixation. Six patients underwent Le Fort I osteotomy with genioplasty, 1 patient underwent Le Fort I osteotomy with bilateral sagittal split ramus osteotomy, and 5 patients underwent Le Fort I osteotomy with bilateral sagittal split ramus osteotomy and genioplasty. These 12 patients all underwent maxillary superior repositioning with either advancement (11 patients) or setback (1 patient). Statistically significant surgical (T2-T1) changes were found in all variables measured. In late postsurgical measurements (T3-T2), all landmarks in the horizontal and vertical plane showed statistically significant skeletal stability. CONCLUSION: This case series suggests that anterior internal fixation alone in cases of 1-piece Le Fort I maxillary superior repositioning with advancement has good late postoperative skeletal stability.     

Stability after Le Fort I osteotomy in cleft lip and palate patients

Le Fort I osteotomies were performed in 20 patients with cleft lip and palate as a one-segment movement, and the fragments were fixed with miniplates without bone grafting. Tracings of preoperative and serial postoperative lateral cephalograms were used to determine changes in maxillary position. The posterior nasal spine, not subjected to extensive changes during surgical procedures and remodeling, was found to be the most reliable landmark for measuring maxillary advancement and stability. The mean maxillary advancement was 5.96 mm. Analysis did not reveal significant changes in linear and angular measurements from immediately postoperative to 6 months postoperative. A modest maxillary advancement by Le Fort I osteotomy, along with alleviation of palatal scar tissue tension and miniplate fixation, is a stable surgical method in patients with cleft lip and palate.     

Comparison of biomechanical behaviour of maxilla following Le Fort I osteotomy with 2- versus 4-plate fixation using 3D-FEA: Part 2: Impaction surgery

The aim of the second part of this study was to evaluate the mechanical behaviour of 2- versus 4-plate fixation and bony structures after Le Fort I impaction surgeries using three-dimensional finite element analysis (3D-FEA). Two 3D-FEA models were created to fixate the impacted maxilla at the Le Fort I level as 2-plate fixation at the piriform rims (IMP-2 model) and 4-plate fixation at the zygomatic buttresses and piriform rims (IMP-4 model). The IMP-2 model contained 225 664 elements and 48 754 nodes and the IMP-4 model consisted of 245 929 elements and 53 670 nodes. The stresses in each maxillary model were computed. The models were loaded on one side, at the molar–premolar region, in vertical, horizontal and oblique directions to reflect the chewing process.It was concluded that the use of 4-plate fixation following Le Fort I advancement surgery provides fewer stress fields on the maxillary bones and fixation materials than 2-plate fixation from a mechanical point of view.     

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.     

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.     

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.     

Stability and morbidity of Le Fort I osteotomy with bioresorbable fixation: a randomized controlled trial

A randomized controlled clinical trial was conducted to compare the use of bioresorbable and titanium mini-plates and screws in Le Fort I maxillary osteotomies for evaluation of clinical morbidity and stability. Forty patients requiring Le Fort I osteotomies were randomly assigned to two groups. One group underwent bioresorbable mini-plate fixation and the other titanium mini-plate fixation. Stability of the maxilla was determined by serial cephalometric analysis at 2 and 6 weeks and at 3, 6 and 12 months postoperatively. Subjective and objective assessment of clinical morbidity was made prospectively. There were no differences in complications between the two fixation materials. Maxillae with bioresorbable fixation were significantly more mobile at the second postoperative week. Bioresorbable plates were initially more easily palpable, but their palpability decreased with time. Titanium plates became significantly more palpable at the 1-year follow-up. There was no difference in neurosensory disturbance between groups. Patients with bioresorbable plate fixation showed significantly more upward displacement in anterior maxilla following impaction and posterior maxilla following downgrafting from the 2nd to 6th postoperative week. The horizontal and angular relapses in the two groups were comparable. Le Fort I osteotomy with bioresorbable fixation results in no greater morbidity than with titanium fixation up to 1 postoperative year.     

Endoskopisch gestützte LeFort-1-Osteotomie

Methods and results. Endoscopically assisted Le Fort 1-osteotomy was performed in a cadaver study with six human skulls. Vertical incisions were used to approach the maxilla using the endoscope. The bone cuts could be carried out with a 4-mm osteotome preserving the buccal mucosa. The downfracture of the maxilla was accomplished without damaging the descending palatal arteries, which could be verified endoscopically. Rigid fixation was performed using 1.5-mm titanium plates (Synthes, Mathys AG, Bettlach, Switzerland) and self-drilling screws. Discussion. This cadaver study showed that the Le Fort 1 osteotomy could be carried out through limited approaches using endoscopic techniques and self-drilling fixation tools. Further experimental work and improvements will help to introduce this technique into clinical application.     

Biomechanical evaluation of Le Fort I maxillary fracture plating techniques.

PURPOSE: This study used a biomechanical model to examine fundamental questions about rigid plate fixation treatment for maxillary Le Fort I fractures. Specifically, we sought to elucidate the principal strain patterns generated in miniplates and bite force transducers secondary to all masticatory forces, as well as the amount of permanent deformations incurred due to these loading forces. MATERIALS AND METHODS: Forty polyurethane synthetic maxillary and mandibular replicas were used to simulate the mandible and maxilla. Ten replicas were controls (group A). The other 30 were divided into 3 groups (10 each), according to the fixation techniques of 3, 2, and 1 miniplates each side (groups B-D), that were osteotomized in the Le Fort I fracture line on the maxilla. Different forces of masseter medial pterygoid, temporalis, and lateral pterygoid muscles were loaded onto the replicas to simulate different functional conditions (anterior incisor, premolar, and molar clenching). Rosette strain gauges were attached at predefined points on the plates and the bite force transducer to compare the stability and bite force of the different fixation methods for maxillary Le Fort I fractures. RESULTS: Statistically significant differences were found for the deformation of the plates among fixation techniques. The order of stability for each technique was: group B greater than group C greater than group D. In regard to bite force, no difference was found between those found with group A and group B (P > .05), whereas the bite forces of groups C and D were less than those of group A (P < .05). CONCLUSIONS: The fixation of 3 miniplates on each side provides sufficient stability and restores the bite force to the level of the intact maxilla. "The ideal fixation" with 2 miniplates on each side restores 90% of the bite force, and there were more deformations of the miniplates with the "ideal fixation" compared to those found with group B. Group D fixation produced the worst effects for the treatment of maxillary Le Fort I fractures with a weak bite force and insufficient stability.     

Maxillary stability following Le Fort I osteotomy in combination with sagittal split ramus osteotomy and intraoral vertical ramus osteotomy: a comparative study between titanium miniplate and poly-L-lactic acid plate.

PURPOSE: The purpose of this study was to compare changes in maxillary stability after Le Fort I osteotomy with titanium miniplate and poly-L-lactic acid (PLLA) plate (Fixsorb-MX; Takiron Co, Osaka, Japan). PATIENTS AND METHODS: The subjects were composed of 47 Japanese patients with diagnosed jaw deformity: 24 underwent Le Fort I osteotomy and sagittal split ramus osteotomy (SSRO); and 23 underwent Le Fort I osteotomy intraoral vertical ramus osteotomy without internal fixation. Each group was divided into titanium plate and PLLA plate groups. Time course changes between plate groups were compared using lateral and posteroanterior cephalography. RESULTS: Significant differences were identified between titanium plate and PLLA plate groups in A point after Le Fort I osteotomy and SSRO (P < .05). Significant differences existed between titanium plate and PLLA plate groups in vertical component of posterior nasal spine after Le Fort I osteotomy in both combinations with SSRO and intraoral vertical ramus osteotomy (P < .05). However, no significant differences were identified in measurements on posteroanterior cephalography. CONCLUSION: These results suggest a slight tendency for vertical impaction after Le Fort I osteotomy both in combination with SSRO and intraoral vertical ramus osteotomy with PLLA plates, although differences in time course changes were not clinically apparent, and normal occlusion was established in all patients.     

Postoperative stability following maxillary downward movement with Le Fort I inclined osteotomy at the lateral nasal cavity wall

Downward movement of the maxilla is regarded as one of the less stable long-term orthognathic surgical procedures. To increase postoperative stability with direct bone contact, the conventional Le Fort I osteotomy was modified with an inclined osteotomy at the lateral nasal cavity wall. The aim of this study was to evaluate the postoperative stability of the new method for Le Fort I inclined osteotomy for downward maxillary movement.The study included 27 patients with anterior vertical deficiency of the maxilla who underwent Le Fort I inclined osteotomy for downward maxillary movement. Patients were classified into two groups according to the amount of downward movement. The amounts of relapse (cephalometric changes) of the two groups were compared and statistically analyzed.The mean amount of relapse was about 1 mm. The tendency of relapse was not increased by a large initial downward movement with Le Fort I inclined osteotomy. Le Fort I inclined osteotomy was used safely for downward movement in order to increase bone height at the piriform aperture area and resulted in direct bone contact, suggesting it is a useful technique for maintaining postoperative stability. A further study with a larger number of patients is necessary.     

Appropriate diameter for screws to fix the maxilla following Le Fort I osteotomy: an investigation utilizing finite element analysis.

BACKGROUND: After Le Fort I osteotomy, there is sometimes a secondary deformity (relapse), with the lower segment deviating from the intraoperatively fixed position. It is hyopothesized that the structural stability of the reconstructed maxilla is affected by the diameter of the fixation screws. The present study aims to elucidate the relationship between the diameters of the screws and the structural stability of the maxilla after Le Fort I osteotomy. METHODS: 3D models were produced on a workstation from 20 dry skulls and a Le Fort I operation was simulated on them. The upper and lower segments of the divided maxilla in each of the 20 models were connected using four plates and 16 screws. Five different diameters of the fixation screws were tested. Thus altogether 100 models were produced. A 180N load was applied to the molar region for each model. Using finite element analysis, the resultant stresses and deviations of the lower segments were calculated. Finally, referring to these values, the relationships between screw diameters and stability of the lower segment were evaluated. RESULT: The stability of the lower segment was greatest when the diameter of the fixation screws was equal to the thickness of the bone at each fixation site. CONCLUSION: In performing Le Fort I osteotomy, it is recommended that bone thickness is measured at each fixation site in advance, and the diameter of the fixation screws matched accordingly; thereby optimum stability of the reconstructed maxilla can be anticipated.     

Comparison of biomechanical behaviour of maxilla following Le Fort I osteotomy with 2- versus 4-plate fixation using 3D-FEA: Part 3: Inferior and anterior repositioning surgery

Having studied the effect of maxillary advancement and maxillary impaction in parts 1 and 2 of this research, the purpose of this study was to investigate the biomechanical behavior of different fixation models in inferiorly and anteriorly repositioned maxilla following Le Fort I osteotomy. Two separate three-dimensional finite element models, simulating the inferiorly advanced maxilla at Le Fort I level, were used to compare 2- and 4-plate fixation. Model INF-2 resulted in 247 897 elements and 53 247 nodes and INF-4 consisted of 273 130 elements and 59 917 nodes. The stresses occurring in and around the bone and plate–screw complex were computed. The highest Von Mises stresses on the plates and maximum principal stresses on the bones were found in INF-2, especially under horizontal and oblique loads, when compared with INF-4. The present biomechanical study shows that the traditionally used 4-plate fixation technique, following Le Fort I inferior and anterior repositioning surgery, without bone grafting, provides fewer stress fields on the maxillary bones and fixation materials.     

Stability of skeletal Class III malocclusion after combined maxillary and mandibular procedures: titanium versus resorbable plates and screws for maxillary fixation.

PURPOSE: The aim of this study was to evaluate skeletal stability after double jaw surgery for correction of skeletal Class III malocclusion to assess if there were any differences between resorbable plate and screws and titanium rigid fixation of the maxilla. PATIENTS AND METHODS: Twenty-two Class III patients had bilateral sagittal split osteotomy for mandibular setback stabilized with rigid internal fixation. Low level Le Fort I osteotomy for maxillary advancement was stabilized with conventional titanium plate and screws in 12 patients (group 1) and with resorbable plate and screws in 10 patients (group 2). Lateral cephalograms were taken before surgery, immediately postoperatively, 8 weeks after surgery, and 1 year postoperatively. RESULTS: Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary stability was excellent in both groups. In group 1 no significant correlations were found between maxillary advancement and relapse. In group 2, significant correlations were found between maxillary advancement and relapse at A point and posterior nasal spine. No significant differences in postoperative skeletal and dental stability between groups were observed. CONCLUSION: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure for maxillary advancements up to 5 mm independently from the type of fixation used to stabilize the maxilla. Resorbable devices should be used with caution for bony movements of greater magnitude until their usefulness is evaluated in studies with large maxillary advancements.     

A comparative biomechanical evaluation of mandibular condyle fracture plating techniques.

OBJECTIVES: The aim of this study was to comparatively evaluate the resistance of 3 plating rigid internal fixation techniques for mandibular condylar process fractures. MATERIALS AND METHODS: Synthetic hemi-mandible replicas made in polyurethane were used to evaluate a control, and 3 mandibular condyle plating techniques using 2-mm system plates and screws. The plating techniques were fixation with a 4-hole plate and 4 6-mm screws, fixation with a 4-hole plate and 4 8-mm screws and fixation with 2 4-hole plates with 4 6-mm screws each. Each group was subjected to linear loading in medial to lateral and anterior to posterior directions by an Instron 4411 servohydraulic mechanical testing unit (Instron Corp, Norwood, MA). Load peak value and peak displacement were measured. Means and standard derivations were derived and compared for statistical significance using an analyses variance (P < .05) and compared by Tukey test. RESULTS: Statistically significant differences were noted between fixation groups for the different mechanical measures evaluated under the different directions of linear loading. The 2-plate fixation system presented better behavior, followed by 1 plate with 4 8-mm screws and 1 plate with 4 6-mm screws. The fixation systems used were more resistant to antero-posterior load and the use of 8-mm screws improved the resistance of the fixation when compared with 6-mm screws only in the antero-posterior test. CONCLUSION: Under the conditions tested the 2-plate fixation system provided the most favorable mechanical behavior. We can suggest that lengthy screws, with bicortical engagement, can increase the stability at fixation of mandibular condylar process fractures.     

Maxillomandibular advancement surgery in 23 patients with obstructive sleep apnea syndrome

Twenty-three patients with obstructive sleep apnea syndrome (OSAS) documented by polysomnography underwent maxillomandibular advancement via Le Fort I, and sagittal ramus split osteotomies followed by rigid fixation with miniplates and bicortical screws. Partial turbinectomies and septal reconstruction were simultaneously performed. Pre- and post-operative cephalometric radiographs were analyzed by computer. Hyoid position and posterior airway space changes did not correlate with clinical success. The surgical success (respiratory disturbance index less than 10) with maxillomandibular advancement was 65%. The total desaturations below 90% greatly decreased. Ninety-six percent of patients were subjectively and objectively improved.     

Skeletal relapse of maxillary osteotomies in unilateral cleft lip and palate patients

The outcomes of a consecutive series of 10 adults who had unilateral cleft lip and palate and who had undergone Le Fort I advancement fixed with miniplates were investigated. The amount and timing of horizontal and vertical relapse, the correlation between advancement and relapse, and the effectiveness of various methods of internal fixation were analyzed with respect to the authors' clinical experience and the data from the international literature. Tracings of the preoperative and serial postoperative lateral cephalograms--taken immediately and during the 1 1/2 to 2 postoperative years--were analyzed to calculate horizontal and vertical maxillary change. We found that the use of rigid fixation is associated with a significantly more stable postoperative result, as described by other authors. Our study suggests that this useful technique does not eliminate but reduces and controls the problem of relapse in a series of unilateral cleft lip and palate adult patients undergoing Le Fort I osteotomy.     

Post-operative stability of the maxilla treated with Le Fort I and horseshoe osteotomies in bimaxillary surgery

In this study, the post-operative change of the maxilla in six non-cleft patients who underwent combination (Le Fort I and horseshoe) osteotomy for superior repositioning of the maxilla was investigated. In all patients, the maxilla was first osteotomized and fixed with four Luhr plates. No iliac bone graft was applied to the maxilla. A bilateral sagittal split ramus osteotomy of the mandible (BSSRO) was then carried out and titanium screw fixation was performed. No maxillo-mandibular fixation (MMF) with stainless steel wire was used post-operatively in any patient. Lateral cephalograms were obtained pre-operatively, 5 days post-operatively, and 3, 6, and 12 months after surgery. The changes in anterior nasal spine (ANS), point A, upper incisor (U1), and point of maxillary tuberosity (PMT) were examined. The maxillae in the six subjects were repositioned nearly in their planned positions during surgery and no significant post-operative changes in the examined points of the maxilla were found. These results suggest that a combination of a Le Fort I and horseshoe osteotomy is a useful technique for reliable superior repositioning of the maxilla. The post-operative change in the maxilla using this combination osteotomy is comparatively stable.     

Strategies for surgically assisted rapid maxillary expansion according to the region of transverse maxillary deficiency

This study evaluated different techniques for surgically assisted rapid maxillary expansion (SARME) according to the type of transverse maxillary deficiency using computed tomography (CT). Six adult patients with bilateral transverse maxillary deficiencies underwent SARME. The patients were equally divided into three groups: Group I, maxillary atresia in both the anterior and posterior regions; Group II, greater maxillary atresia in the anterior region; and Group III, increased maxillary atresia in the posterior region. In Group I, a subtotal Le Fort I osteotomy was used. In Group II, a subtotal Le Fort I osteotomy was used without pterygomaxillary suture disjunction. In Group III, a subtotal Le Fort I osteotomy was used with pterygomaxillary suture disjunction and fixation of the anterior nasal spine with steel wire. The midpalatal suture opening was evaluated preoperatively and immediately after the activation period using CT. For Group I, the opening occurred parallel to midpalatal suture; for Group II, the opening comprised a V-shape with a vertex on the posterior nasal spine; and for Group III, the opening comprised a V-shape with a vertex at the anterior nasal spine. The conclusion was that the SARME technique should be individualized according to the type of transverse maxillary deficiency.