Change in condylar long axis and skeletal stability following sagittal split ramus osteotomy and intraoral vertical ramus osteotomy for mandibular prognathia

PURPOSE

The purpose of this study was to compare postsurgical time course changes in condylar long axis and skeletal stability between sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO).

PATIENTS AND METHODS

Of 40 Japanese patients with a diagnosed jaw deformity, 20 underwent IVRO without internal fixation and 20 underwent SSRO with rigid internal fixation. The time course change in condylar long axis and skeletal stability were assessed with axial, frontal, and lateral cephalograms.

RESULTS

A significant difference in the rotation direction of condylar long axis was seen in horizontal axial cephalogram images (P <.01). In Pog-N perpendicular to SN, the IVRO group showed gradual decrease, although SSRO group showed gradual increase in lateral cephalogram (P <.05).

CONCLUSION

The present results suggest a significant difference between SSRO and IVRO in time course changes in proximal segment including condyle and distal segment.

Changes in condylar long axis and skeletal stability after bilateral sagittal split ramus osteotomy with poly-l-lactic acid or titanium plate fixation

This study was designed to assess skeletal stability after bilateral sagittal split ramus osteotomy (BSSO) and fixation with a poly-l-lactic acid (PLLA) plate, as compared to that after BSSO and fixation with a titanium plate, and to analyze the change in the condylar long axis after these procedures. The study group comprised 40 patients who had mandibular prognathism (20, titanium group; 20, PLLA group). The groups were randomized to show similar distributions of preoperative SNB. All patients underwent BSSO setback by the Obwegeser method. Fixation was done with bent titanium plates or bent PLLA plates, applied in a similar manner. Lateral, frontal, and submental-vertical cephalograms were analyzed preoperatively and postoperatively. The maximum mouth opening range and the incidence of temporomandibular disorders were also evaluated. There was no significant difference in the right condylar angle or width between the two groups, but the left condylar angle and width, gonial angle, and ramus inclination differed significantly between them (P<0.05). SNA, SNB, and ANB were similar in both groups. There was no significant difference between the groups in maximum mouth opening range or temporomandibular disorders. We conclude that the change in condylar angle after BSSO and fixation with a titanium plate is greater than that after BSSO and fixation with a PLLA plate, but skeletal stability related to the occlusion is similar for the two procedures.

Effect of Mandibular Setback via Bilateral Sagittal Split Ramus Osteotomy on Transverse Displacement of the Proximal Segment

PURPOSE

The purpose of this study was to evaluate if a correlation exists between: a) transverse changes in the proximal segments because of mandibular setback surgery and b) postsurgical horizontal relapse of the mandible.

PATIENTS AND METHODS

A total of 42 patients underwent bilateral sagittal split ramus osteotomy setback with rigid fixation and Le Fort I osteotomy performed by 1 surgeon between 1986 and 2000. The radiographic material for this study consisted of posteroanterior and lateral cephalometric radiographs for each patient taken preoperatively (T1), early postoperatively (T2), and late postoperatively (T3). Twenty-four of the 42 identified patients had T1, T2, and T3 radiographs, while the remainder of the patients had only T1 and T2 radiographs available. The posteroanterior radiographs were used to evaluate the angulation of the proximal segment and the intergonial width.

RESULTS

Statistically significant increases in intergonial width and proximal segment angulation occurred from T1 to T2. In fact, all 42 patients had an increased intergonial width from T1 and T2. From T2 to T3, most patients underwent some relapse in their transverse dimension changes (21 of 24 patients had a decrease in their intergonial width). Overall, the intergonial width and the proximal segment angulations were significantly increased from T1 to T3. However, there was no significant correlation between the amount of transverse displacement of the proximal segment and horizontal postsurgical relapse of the mandible.

CONCLUSION

The results show that statistically significant changes in the transverse width and angulation between proximal segments occur in patients undergoing bilateral sagittal split ramus osteotomy for mandibular setback with rigid fixation. However, the magnitude of the changes was small, and it is still uncertain as to whether these changes are of any clinical significance.

A Short Period of Maxillomandibular Fixation for Treatment of Fractures of the Mandibular Tooth-Bearing Area

PURPOSE

This study was aimed to determine whether a short period of maxillomandibular fixation (MMF) followed by an arch bar splint wired to the lower jaw is a suitable alternative to conventional MMF for treatment of fractures of the mandibular tooth-bearing area.

PATIENTS AND METHODS

Thirty patients with mandibular fractures associated with no other facial fractures were selected. They were randomly assigned into 2 groups for treatment with conventional MMF (group A) and MMF for a short period of 2 weeks followed by an arch bar splint wired to the lower jaw (group B). Complications were recorded and post-treatment maximum interincisal mouth opening was measured at 1 week and 3 and 6 months. Age and gender-matched control groups were randomly selected. Groups were then compared for significant differences. A value of P < .05 was considered significant.

RESULTS

The 2 patient groups were not significantly different in relation to site and cause of fracture (P =.995 and P = .682, respectively), the mean time from injury to MMF (P = .234), and the mean time required for fracture healing (P = .315). Delayed union and nonunion were not encountered, and there were no significant differences in relation to postoperative infection ( P = 1) and malocclusion (P = .598). When compared with group A patients, group B patients had an early significantly greater degree in mouth opening (P = .001); at no time was there a significant difference in the degree of mouth opening between group B patients and the control group (1 week, P = .079; 3 months, P = .166; 6 months, P = .378).

CONCLUSION

In selected cases, a short period of MMF followed by an arch bar splint wired to the lower jaw is a suitable alternative to conventional MMF for treatment of fractures of the mandibular tooth-bearing area. The method is effective and significantly reduces the potential adverse effects of long-term MMF.

Multi-center randomized clinical trials in oral and maxillofacial surgery: modeling of fixed and random effects

The multi-center randomized clinical trial (MCCT) is an important tool to evaluate treatment of rare diseases. An important and challenging analytic consideration is how to model the variability of the set of clinical centers composing an MCCT. The purpose of this paper was to demonstrate how changing the assumptions regarding the variability (fixed effect versus random effect) of the set of clinical centers may alter the results. The data for this paper were derived from a recently completed MCCT. The MCCT was designed as a prospective, randomized clinical trial comparing the stability of two techniques, i.e., wire versus rigid internal fixation (RIF), for stabilizing the mandible after bilateral sagittal split ramus osteotomy (BSSO) for patients requiring mandibular advancement. Three treatment centers were involved. The key outcome variable was change in mandibular position (B-point) over time. We developed two different analytic models by varying the underlying statistical assumptions regarding the variability of the clinical treatment centers, i.e., random or fixed effects. Analyses based on the random-effects model demonstrated no significant difference between treatment groups in terms of relapse (P=0.13). With the fixed-effects model, however, wire fixation had significantly more relapse at B-point over time than RIF (P=0.02). The results from these two sets of analyses demonstrate how changing assumptions regarding the variability of the set of clinical centers can alter the interpretation of the treatment effect. The choice of statistical modeling of the set of clinical centers is an important consideration when performing analyses of MCCTs and it is a decision that should be made prior to initiating the study.

A case report of malignant hyperthermia in a dental clinic operating room

A healthy 5-year-old boy presented for arch bar placement under general anesthesia in an operating room in a dental school. The patient had previously undergone general anesthesia without complication, and no family history of anesthetic problems were reported. Halothane mask induction, intravenous catheter placement, and nasal intubation proceeded uneventfully without the aid of a muscle relaxant. Halfway through the procedure, signs and symptoms of malignant hyperthermia, including muscle rigidity, hypercarbia, tachypnea, and tachycardia were noted. Immediate treatment, including discontinuation of the triggering agent, dantrolene administration, and cooling measures were applied, and once stable, the child was transferred to Columbus Children's Hospital for further management. The patient experienced no postoperative complications. Further discussion regarding the pathophysiology and management of malignant hyperthermia is provided.

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.

Management of mandibular angle fractures using the mandibular angle reduction forceps

The aim of this study was to determine whether or not the use of the mandibular angle reduction forceps decreases the incidence of post-operative complications. Forty-six patients, who presented with mandibular angle fractures with a displacement or dislocation, were randomly divided into two treatment groups. Both groups underwent an open reduction with a single upper border miniplate and screw fixation. For 23 patients, the mandibular angle reduction forceps was used to aid in fracture reduction, and for 23 patients, the reduction of the fracture was achieved using IMF. The post-reduction radiographs showed that the reduction forceps group had a higher proportion of precise anatomic alignment of fracture than those in the IMF group. In addition, the former group showed a lower rate of post-operative complications, as compared to the latter group. This study found that the use of the mandibular angle reduction forceps is an important factor for decreasing the incidence of post-surgical complication.

Resorbable plates in maxillary fixation. A 5-year experience

AIM

Metallic plates and screws have become the routine way of stabilizing the facial skeleton; however, there are many disadvantages in the use of metallic devices. Fixation systems made of biocompatible absorbable material, with appropriate load-bearing properties and sufficient degradation rate can overcome these disadvantages. Recently, resorbable materials were tested in maxillary, mandibular and chin osteotomies. Despite a lot of reports on the use of resorbable bone fixation devices in cranio-maxillo-facial application are now available, their use in preprosthetic surgery has yet to be adequately documented. The Authors report their 5-year experience in the employment of resorbable fixation in surgery of the superior maxilla, involving orthognathic and preprosthetic procedures of the upper jaws. The surgical technique is described and usefulness and advantages are discussed.

METHODS

Plates and screws were composed of an 82% poly-L-lactic acid/18% polyglycolic acid copolymer (PLLA-PGA); 50 orthognathic and 5 preprosthetic procedures of upper jaws were involved, performing Le Fort I osteotomies in all cases.

RESULTS

Our operations were were carried out without complications. Follow-up ranged from 6 months to 5 years. One patient developed a localized buccal space infection which resolved after a course of antibiotics given orally.

CONCLUSIONS

Resorbable fixation should be considered adequate for fixation in maxillary surgery.

Three-dimensional finite element analysis used to compare methods of fixation after sagittal split ramus osteotomy: setback surgery-posterior loading

We used three-dimensional finite element analysis to compare the biomechanical stability of bilateral sagittal split ramus osteotomies fixed by lag screws with linear and triangular configuration, and double or single six-hole miniplates with monocortical screws after set-back operation. The three-dimensional finite element model contained 122,717 elements and 25,048 nodes. Posterior occlusal loads were simulated on the distal segments. MSC Marc software was used to calculate the stress fields on both the segments and the fixing appliances. We conclude that either triangular lag screw configuration or double miniplates led to better stability and lower mechanical stresses near the osteotomy than the linear lag screws or single oblique miniplates.

Miniplate fixation of high condylar fracture and postoperative exercise regimen

The aim of this report is to present three cases of high condylar fracture treated with vertical ramus osteotomy, miniplate fixation of fractured condylar neck, and free grafting. The authors also introduce a simple and easy postoperative exercise regimen. A submandibular incision is made and the ascending ramus divided between the sigmoid notch and the angle of the mandible. After the fragment is removed, the dislocated head of the condyle is readily visible and can be retrieved. The reconstructed osteotomized ramus and condylar head can now be reinserted through the wound and plated. Intermaxillary fixation with arch bar is used. The length of the fixation period is about 14 days after surgery. At the end of this period, the bracket is applied to maxillary incisors, the occlusion becomes stable and reproducible, and then aggressive jaw-opening exercise begins. On postoperative day 21, elastics are applied 24 hours a day. They are placed lightly during the daytime to assist guiding protrusion of the mandible. The patient is instructed to protrude the mandible and to open the mouth simultaneously. The exercise is modified to lateral movement. After the bracket is removed on postoperative day 28, the patient exercises the chin laterally without any guiding elastic fixation for approximately 1 week. This regimen can be widely used in ostectomy-osteosynthesis cases.

Fixation of mandibular angle fractures with a 2.0-mm 3-dimensional curved angle strut plate

PURPOSE

The aim of this study was to evaluate our experience and complication rate with the use of a 3-dimensional 2.0-mm curved angle strut plate for mandibular angle fracture fixation.

PATIENTS AND METHODS

This was a retrospective evaluation of 37 patients with noncomminuted mandibular angle fractures fixated with a transorally placed curved 2.0-mm strut plate. Postoperative intermaxillary fixation was used in 5 patients for a mean period of 22 days. A nonchewing diet was prescribed for 6 weeks. Records were reviewed for demographic information, medical history, fracture characteristics, operative management, and complications.

RESULTS

Two patients developed infections requiring plate removal and reapplication of fixation. Both of these patients had a molar in the fracture line that was left in place during the first operation. One patient developed a mucosal wound dehiscence without consequence. After a mean follow-up period of 10 weeks, 39.4% of patients with a postinjury/pretreatment inferior alveolar nerve deficit reported a return to normal sensation. All patients who developed a sensory deficit as a result of surgery reported full recovery of sensation. A persistent sensory deficit appeared to be related to fracture displacement.

CONCLUSION

Fixation of noncomminuted mandibular angle fractures with a 2.0-mm curved angle strut plate was predictable. This plate is low in profile, strong yet malleable, facilitating reduction and stabilization at both the superior and inferior borders. Development of a postoperative infection appeared to be related to failure of removal of a molar in the fracture line. The infection rate of 5.4% found in this study compares favorably with that seen with reconstruction plates. Use of this plate did not appear to cause a permanent sensory deficit in this study.

Conservative treatment of paediatric mandibular fracture by the use of orthodontic appliance and rubber elastics: report of a case

Treatment principles of paediatric mandibular fractures may differ from the treatment of the adult population in that a conservative approach is in most cases advocated before the use of internal rigid fixation with plates and screws. This is because of a relative high risk of disturbed facial skeletal growth and risk of damaging unerupted teeth. Knowledge of conservative treatment options is essential in order to minimize these risks and one option is presented in this paper. This case report describes a 5-year-old girl that sustained an open fracture of the mandible and who was successfully treated by the means of applying orthodontic brackets and an arch bar combined with ligatures and rubber elastics.

Fixation of zygomatic fractures with a biodegradable copolymer osteosynthesis system: short- and long-term results

Biodegradable osteosynthesis devices can be viewed as addition to, not yet replacement for conventional metal osteosynthesis materials. In a series of 65 patients with zygomatic fractures, a short-term complication/sequelae rate of 22.8% and a long-term complication rate of 9.4% were recorded. Lactosorb plates, panels and screws were the only devices used for osteosynthesis. All complications associated with the biodegradable material could be considered minor and were resolved by the use of minor surgical procedures or conservative measures. The results of this study indicate that treatment of zygomatic fractures with biodegradable osteosynthesis material has no major long-term adverse effects beyond the total material resorption time.

Mechanical characteristics of the mandible after bilateral sagittal split ramus osteotomy: Comparing 2 different fixation techniques

PURPOSE

Using finite element (FE) computer model simulation, we compared the mechanical characteristics of the mandible after bilateral sagittal split ramus osteotomy (BSSRO) through the use of 2 different techniques to stabilize the osteotomy.

MATERIALS AND METHODS

Based on the reconstructed geometry from computed tomography scans of dry adult skull with a mandibular deformity requiring surgical correction, we developed 3-dimensional FE models that simulate BSSRO with 2 different techniques to stabilize the osteotomy. Technique 1 uses 3 bicortical titanium screws. Technique 2 uses a curved titanium plate with 4 monocortical screws. Five different load cases were applied to the mandible after the simulated BSSRO with the mandible being constrained at both temporomandibular joints. To evaluate the efficacy of these 2 stabilization techniques, we compared 1) the resulting deflections at the central incisor, 2) the mechanical stresses developed in the bone in the vicinity of the stabilizing implants, and 3) the mechanical stresses developed within the screw/plating system themselves.

RESULTS

Technique 1, using 3 bicortical titanium screws, leads to smaller deflections at the central incisor for all 5 load cases, suggesting higher mechanical stability. Technique 1 also leads to lower mechanical stresses in the bone and in the implanted screws, whereas technique 2 is associated with higher values in each of these quantities.

CONCLUSIONS

To stabilize osteotomies after a 3-dimensional simulated BSSRO, 3 bicortical screws forming an inverted-L configuration are shown to offer more effective load transmission in the mandibular construct. This technique, when examined in an FE model, leads to higher stability with lower mechanical stresses in the bone near the bicortical screws.

Stabilisation of sagittal split advancement osteotomies with miniplates: a prospective, multicentre study with two-year follow-up. Part II. Radiographic parameters

This prospective study implied a two-year follow-up on a group of patients that underwent a Bilateral Sagittal Split Osteotomy (BSSO) for advancement (n=222) of the mandible that were treated in seven institutions following the same treatment protocol. The aim of Part II of this study was to correlate the clinical findings on stability and relapse as reported in Part I (clinical parameters) of this series of articles with the cephalometric findings. The mean skeletal relapse at pogonion of the whole group after two years was 0.9 mm. The clinically stable group, however, had only 0.4 mm relapse, whereas the clinical relapse group showed a mean relapse of 3.3 mm. The findings underline a relationship between the amount of advancement and relapse. The tendency for both, horizontal and vertical movement is the same, i.e., the larger the surgery effect, the larger the relapse. The angle post plane/mandibular plane showed the highest explained variance 9%. Patients with a high mandibular plane angle may be more prone to relapse. The explained variance of all considered prognostic factors together, however, is small (13%). The findings of this study express that patients with a clinical stable occlusion after a BSSO advancement, stabilised with miniplates, have a minimal to no skeletal relapse as measured on the cephalometric radiograms. The clinically non-stable group, however, appeared to have considerable skeletal relapse.

A retrospective evaluation of rigid fixation in orthognathic surgery using a biodegradable self-reinforced (70L:30DL) polyactide

OBJECTIVE

This study was designed to evaluate clinical and radiological evidence of osteotomy site healing in orthognathic surgery after rigid fixation using a biodegradable plating system.

STUDY DESIGN

A follow up of 30 patients who underwent orthognathic surgery using a biodegradable self-reinforced (70L:30DL) polylactide plating system was presented. The follow-up schedule for all patients consisted of regular appointments at 1-180 days after surgery. Clinical evaluation involved notation of any abnormal swelling, infection, discoloration, or discharge at the osteotomy sites. Stability was evaluated by manual palpation. For radiographic evaluation, panoramic radiographs were taken immediately after surgery, and again at 7-180 days. The radiographs were analyzed for any visual changes in osteotomy fragments, resorptive changes in osteotomy fragments, callus formation, and union of the osteotomy segments.

RESULTS

No clinical complications and no radiological changes in the osteotomy sites were observed. Regarding the clinical usefulness of the biodegradable fixation system, fixation at the time of operation was considered as excellent in all 30 cases.

CONCLUSIONS

The conclusions of this study were that self-reinforced (70L:30DL) polylactide was considered to be comparable to other forms of rigid internal fixation for orthognathic surgery.

Stabilisation of sagittal split advancement osteotomies with miniplates: a prospective, multicentre study with two-year follow-up

This prospective study implied a two-year follow-up in a group of patients that underwent a Bilateral Sagittal Split Osteotomy (BSSO) for advancement of the mandible that were treated in seven institutions following the same treatment protocol (using two miniplates). The aim of Part III of this study was to define a Condylar Morphology Scale (CMS) and to analyse radiological changes in the TMJ after BSSO in relation to postoperative relapse and to determine the incidence of morphologic changes and its risk factors. It was concluded that the used 3-point CMS served its purpose well. In eight patients (4%) resorption of the condyle developed postoperatively. The value of preoperative cephalograms to predict condylar alterations appeared to be limited (12% explained variance). Patients treated at a relative low age (< or = 14 years) appeared to be at risk for the occurrence of condylar alterations including resorption. A steep mandibular plane angle and the low facial height ratio (post:ant) were also significantly related to the occurrence of condylar alteration, but the multi variance regression showed that these parameters had only limited value. The occurrence of pain and TMJ sounds in the first few months postoperatively are highly suspicious for condylar changes to occur in the next months.

The Elastic Internal Traction (EIT): an effective method to reduce the displaced facial fractures

Open reduction and rigid fixation are commonly used to treat displaced fractures of the facial skeleton. Manual reduction can be performed by means of forceps or transosseus wires to close the bone fragments. In order to reduce facial fractures, we used a technique, called Elastic Internal Traction (EIT), based on the elastic action of rubber bands stretched between screws placed on both sides of the fracture line. We have used EIT in 104 patients suffering from mandibular fractures, and 40 cases of patients with orbito-maxillary complex fractures out of the 707 patients treated for trauma between July 2000 and August 2002 at our hospital. In our opinion, this technique provides an effective reduction and a stable primary fixation of the bone before the final fixation. It also has the advantage that the surgical field is clear of the assistant's hands and surgical instruments that are usually used to lock the reduction. The resulting operative time is shortened, and the plating of the bone is simplified.

Transalveolar screws and the incidence of dental damage: a prospective study

The incidence of screw/tooth contact in the placement of transalveolar screws was prospectively studied. The clinical significance of such contact when it occurred was assessed. Patients with fractures of the mandible requiring intra- or post-operative control of their occlusion with transalveolar screws were entered into the study. Following screw removal, contact was assessed radiographically and all teeth adjacent to screws were tested for vitality. Any contacts were judged to be minor if less than 50% of the diameter of the screw hole impinged on a tooth root or major if this was more than 50%. Fifty-four male and one female patients completed the study. There were 232 screws placed in these patients adjacent to 440 teeth. Twenty-six screws (11.2%) had major contacts and 37 (15.9%) had minor contacts. Seventeen teeth tested as non-vital with electronic pulp testing but of these only 6 showed any impingement by screws. Two screws were associated with complications in two patients. Screw/tooth contact does occur using transalveolar screws, however, the incidence of clinically significant damage appears to be very low.

A new method for temporary maxillo-mandibular fixation

We present a novel device which is an alternative to surgical wire for per operative maxillo-mandibular fixation prior to plate placement. It is easy to apply, causes minimal mucosal trauma and can be used in association with elastic chain.

The skeletal stability of one-piece Le Fort 1 osteotomy to advance the maxilla

The stability of orthognathic surgery has been the subject of numerous publications over the last 20 years. It is now apparent that studies must pay attention to the homogeneity of the patients investigated and in particular, surgical techniques. In Part 2 of our study of 45 patients who had a uniform one-piece maxillary advancement with rigid fixation to advance the maxilla, we found that uncontrollable variables, including patients age, sex, the degree of advancement, and simultaneous mandibular advancement, had no effect on post-operative skeletal stability.

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.