Endoscopic vertical ramus osteotomy: a long-term prospective study

The purpose of this prospective study was to evaluate the outcomes of endoscopic vertical ramus osteotomy (EVRO) with rigid fixation for the treatment of mandibular prognathism or asymmetry. Inclusion criteria were age >15 years, adequate clinical and radiographic documentation, and minimum postoperative follow-up of 3 years. Exclusion criteria were refusal to consent, rheumatoid arthritis, steroid use, and smoking. Demographic data, pre-operative (T0), immediate postoperative (T1), and latest follow-up (T2) clinical examinations and cephalometric analysis, procedure data, complications, and length of hospital stay (LOS) were documented. Ten fulfilled the inclusion criteria. Diagnoses included mandibular hyperplasia (n = 5), stable condylar hyperplasia (n = 4), and mandibular asymmetry secondary to condylar resorption (n = 1). In total, 17 EVROs were performed. The mean operative time was 33 min per side. Mean mandibular setback was 4.7 mm. Mean LOS was 1.9 days. Latest follow-up ranged from 3 to 5 years. Skeletal stability was confirmed in nine patients. One patient exhibited recurrence of mandibular prognathism at 5 years due to late growth. No VII nerve deficits were encountered. Inferior alveolar nerve (IAN) paresthesia was noted in four patients, which resolved postoperatively. EVRO was fast and resulted in minimal blood loss, quick recovery, and skeletal stability.     

The use of an intermaxillary fixation screw for mandibular setback surgery.

PURPOSE: To assess skeletal stability after mandibular setback surgery with and without an intermaxillary fixation (IMF) screw. PATIENTS AND METHODS: The subjects were 40 patients with mandibular prognathism. The subjects underwent sagittal split ramus osteotomy with titanium plate fixation and were divided into 2 groups, 1 with and 1 without an IMF screw. A lateral cephalogram was done preoperatively, immediately after surgery, and 1 month, 3 months, and 6 months postoperatively. The 2 groups were then compared statistically. RESULTS: In the comparison of the time-course change between the 2 groups with repeated measure analysis of variance, there were significant differences in occlusal plane (between subjects, F = 2.517; df = 4; P = .0437) and convexity (between subjects, F = 4.048; df = 4; P = .0038). However, there was no significant difference in the other measurements. CONCLUSION: This study suggested that in most measurements, there was no significant difference between 2 groups with and without an IMF screw in time-course skeletal change. However, use of IMF screws was helpful for orthognathic surgery as a rigid anchor of IMF.     

下凳骨骨折坚固内固定268例临床分析

目的：对各类坚固内固定技术在治疗下颌骨骨折中的疗效进行比较评价。方法：单纯了颌骨骨折268例,379处分别采用加压接骨板,普通接骨板及小型接骨板进行坚固内固定,术后追踪期平均5个月,复查项目包括临床检查,牙模分析及X线观察,结果：268例骨折中32鲍术后出现感染,其中9例取板,术后3个月检查,均无骨折错位愈合或不愈合,132列出现He干扰及2例开He。其余咬合关系良好。结论根据下颌骨骨折的不同类型选择正确的坚固内固定方法可以使骨折愈合期缩短,减少或避免颈间固定,早期恢复正常生理功能。     

Stability of mandibular advancement osteotomy using rigid internal fixation

Forty-three patients who underwent surgical lengthening of the mandible using an inverted L osteotomy, bone grafting, and rigid internal fixation between the mandibular segments were evaluated by retrospective cephalometric analysis for longitudinal skeletal and dental changes. Postoperative response (means = 1 year 9 months) was found to demonstrate a high level of stability with some individual variability. No propensity for relapse was observed in any postoperative time interval. Condylar repositioning postoperatively appeared to be an important factor in those patients who exhibited any relapse tendency. Overall postoperative stability of this surgical/fixation technique appears to be significantly improved compared with previously documented techniques.     

Stability of simultaneous maxillary and mandibular osteotomy for treatment of class III malocclusion: an analysis of three-dimensional cephalograms.

PURPOSE: The current investigation was undertaken to study the three-dimensional (3-D) stability of simultaneous maxillary advancement and mandibular setback using rigid fixation. The study also aimed to analyse the factors involved in postsurgical relapse by evaluation of changes in various parameters. PATIENTS: Twenty-five cases were evaluated of simultaneous Le Fort I maxillary advancement and mandibular setback using rigid fixation. METHODS: Preoperative, immediate and 6-month postoperative skeletal and dental changes were analysed using 3-D cephalograms obtained from biplanar stereoradiography. Maxillary fixation screws were used as landmarks to evaluate postoperative stability. RESULTS: The mean maxillary advancement was 3.7 mm. Relapse in the sagittal, vertical, and transverse planes was not detectable in the maxilla (p > 0.05). However, for an average mandibular setback of 5.7 mm, mean mandibular relapse was 1.1 mm or 19.3% anteriorly (p < 0.05). Surgical or postsurgical skeletal changes in the maxilla had no detectable influence on mandibular relapse (p > 0.05). Vertical alterations of the facial skeleton achieved surgically predicted the mandibular relapse (R2 = 0.27, p < 0.05). CONCLUSION: Maxillary advancement and vertical changes of +/- 2 mm did not influence the postoperative stability of the mandible. Relapse of the mandible seems to be influenced mainly by the amount and direction of the surgical alteration of mandibular position.     

Endoscopic vertical ramus osteotomy: early clinical results.

PURPOSE: The benefits of minimally invasive surgery have been well documented. The purpose of this report was to present early results in a series of patients who had endoscopic mandibular orthognathic surgery.Patients and methods This is a retrospective evaluation of 14 patients who underwent endoscopic vertical ramus osteotomy and rigid fixation for the treatment of mandibular prognathism (n = 9), malocclusion secondary to trauma (n = 3), or other pathology (n = 2). A 1.5-cm incision was made directly below the mandibular angle. The dissection was continued bluntly to the masseter muscle, which was incised using a needlepoint electrocautery. Then, with endoscopic elevators, an optical cavity was created for insertion of a Hopkins endoscope and visualization of the ramus/condyle unit. Anatomic landmarks were identified and the operation carried out with specially designed endoscopic equipment. Preoperative (T0), postoperative (T1), and follow-up (T2) clinical examinations; lateral cephalograms; and panoramic radiographs were used to evaluate the outcomes. RESULTS: The procedures performed included: vertical ramus osteotomy (n = 13 patients, 23 sides) and condylectomy plus vertical ramus osteotomy (n = 1 patient, 1 side). Mean operating time was 37 minutes per side. One patient had temporary marginal mandibular nerve weakness. The occlusal result was as planned in all cases. Panoramic radiographs documented postoperative ramus/condyle unit position and lateral cephalograms documented mandibular position. CONCLUSIONS: The results of this case series indicate that endoscopic vertical ramus osteotomy with rigid fixation is feasible for correction of a variety of mandibular deformities.     

Stability of simultaneous maxillary intrusion and mandibular advancement: A comparison of rigid and nonrigid fixation techniques

This study examines the short-term stability of bimaxillary surgery following Le Fort I impaction with simultaneous bilateral sagittal split osteotomies and mandibular advancement using two standard techniques of postsurgical fixation. Fifteen adults had skeletal plus dental maxillomandibular fixation, and fifteen adults had rigid internal fixation using bone plates in the maxilla and bicortical bone screws between the proximal and distal segments in the mandible. The group with rigid internal fixation did not undergo maxillomandibular fixation. Radiographic cephalograms were analyzed during the postsurgical period to evaluate skeletal and dental stability. There was no statistical difference in postsurgical stability with rigid internal fixation or skeletal plus dental maxillomandibular fixation other than the vertical position of the maxillary molar; the skeletal plus dental maxillomandibular fixation group had a significant amount of postsurgical intrusion of the maxillary molar when compared with the rigid internal fixation group. Although the other measures showed no statistically significant difference between the experimental groups, the amount of variability in postsurgical stability in the group with skeletal plus dental maxillomandibular fixation was greater than that found in the group with rigid internal fixation.     

Skeletal stability after mandibular advancement with rigid versus wire fixation.

PURPOSE: This study examined the stability of skeletal changes after mandibular advancement surgery with rigid or wire fixation up to 2 years postoperatively. PATIENTS AND METHODS: Subjects for this multisite, prospective, clinical trial received rigid (n = 78) or wire (n = 49) fixation. The rigid cases were fixed with three 2-mm bicortical position screws and 1 to 2 weeks of skeletal maxillomandibular fixation with elastics, and the wire fixation subjects were fixed with inferior border wires and had 6 weeks of skeletal maxillomandibular fixation with 24-gauge wires. Cephalometric radiographs were obtained before orthodontics, immediately before surgery, and at 1 week, 8 weeks, 6 months, 1 year, and 2 years after surgery. Linear cephalometric changes were referenced to a cranial base coordinate system. RESULTS: Before surgery, both groups were balanced with respect to linear and angular measurements of craniofacial morphology. Mean anterior sagittal advancement of the mandibular symphysis was 4.92 +/3.01 mm in the rigid group and 5.11 +/- 3.09 mm in the wire group, and the inferior vertical displacement was 3.37 +/- 2.44 in the rigid group and 2.85 +/- 1.78 in the wire group. The vertical changes were similar in both groups. Two years postsurgery, the wire group had 30% sagittal relapse of the mandibular symphysis, whereas there was no change in the rigid group (P < .001). Both groups experienced changes in the orientation and configuration of the mandible. CONCLUSIONS: Rigid fixation is a more stable method than wire fixation for maintaining mandibular advancement after sagittal split ramus osteotomy.     

The fate of resorbable poly-L-lactic/polyglycolic acid (LactoSorb) bone fixation devices in orthognathic surgery.

PURPOSE: The aim of this study was to evaluate the long-term outcome of resorbable poly-L-lactic/polyglycolic acid (PLLA-PGA) bone fixation devices used for fixation of maxillary and mandibular osteotomies. MATERIALS AND METHODS: Twelve patients were postoperatively evaluated. Eight patients who had undergone bilateral sagittal split mandibular osteotomies that had been fixed with PLLA-PGA screws were followed-up for up to 2 years postoperatively with radiographs. One of these patients underwent a bone biopsy for detailed histologic evaluation of the screw fixation sites. Two patients who had undergone mandibular symphyseal osteotomies were also radiographically evaluated at 18 months to 2 years postoperatively. Two patients who had Le Fort I osteotomies fixed with PLLA-PGA plates and screws underwent open exploration of the operated sites for visual examination. RESULTS: All 8 mandibular osteotomy patients showed radiographic screw hole lucency immediately after surgery that remained unchanged in the first year after surgery. By 18 months postoperatively, all 48 screw holes showed near or complete trabecular bone fill. The bone biopsy of one screw hole at 2 years postoperatively showed complete fill with normal trabecular bone. No residual polymer material or fibrous scar was seen. The mandibular symphyseal sites showed complete elimination of all screw holes by 2 years postoperatively, with only faint evidence of intraosseous tunnels. The maxillary sites showed complete bone healing along the osteotomies and no evidence of residual fixation material or bone defects in the screw holes. No communication with the maxillary sinus was seen in the fixation sites. CONCLUSION: This orthognathic patient series showed complete resorption of the PLLA-PGA fixation devices without osteolysis in maxillary and mandibular bone sites by 18 to 24 months after surgery.     

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

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

Long-term stability of mandibular setback surgery: a follow-up of 80 bilateral sagittal split osteotomy patients

The objective of this cephalometric study was to evaluate skeletal stability and time course of postoperative changes in 80 consecutive mandibular prognathism patients operated with bilateral sagittal split osteotomy (BSSO) and rigid fixation. Lateral cephalograms were taken on 6 occasions: immediately preoperative, immediately postoperative, 2 and 6 months postoperative, and 1 and 3 years postoperative. The results indicate that BSSO with rigid fixation for mandibular setback is a fairly stable clinical procedure. Three years after surgery, mean relapse at pogonion represented 26% of the surgical setback (19% at point B). Most of the relapse (72%) took place during the first 6 months after surgery. Clockwise rotation of the ascending ramus at surgery with lengthening of the elevator muscles, though evident in this study and apparently responsible for the early horizontal postoperative changes, does not seem to be associated with marked relapse. Changes occurring in some of the younger patients between 1 and 3 years postoperatively are likely to be manifestations of late mandibular growth.     

Stability of mandibular lengthening using bicortical screw fixation

The mandibular lengthening procedure performed with the use of rigid internal fixation yields more stable results than previously demonstrated when nonrigid fixation is used. Twenty patients with Class II malocclusion who had undergone this procedure were examined retrospectively to assess postoperative skeletal change. The mean postoperative interval was 15.7 months. Although there was individual variability, no significant mean postoperative horizontal change was found, which indicated excellent stability.     

Skeletal stability following mandibular advancement and rigid fixation

Twenty non-growing subjects underwent sagittal ramus osteotomies and rigid fixation. Cephalograms were analyzed before surgery, immediately after surgery and at least six months following surgery to evaluate skeletal stability. A mean horizontal relapse of 0.42 mm (8%) and a mean vertical increase in lower face height of 0.2 mm were found six months after surgery. Both were statistically insignificant. The mean backward rotation of the mandible of 0.55 degrees found six months after surgery was statistically significant (P less than 0.015), but was considered to be clinically insignificant. The results of this study show that surgical mandibular advancement with rigid fixation is a very reliable and stable procedure.     

Semirigid fixation of the mandible in bimaxillary orthognathic surgery: stability after 18 months.

The stability of osteosynthesis with the use of semirigid mandibular fixation was evaluated in 15 patients who underwent bimaxillary procedures for correction of Class III malocclusion. All patients received rigid fixation (4 miniplates and screws) in the maxilla. Cephalometric evaluation was performed before the operation, immediately after the operation, and at least 18 months after the operation. At the 18-month follow-up, a mean mandibular relapse of 2.2 mm, associated with an additional advancement of the maxilla of 0.27 mm, was observed. The dental relationship was substantially correct. Stability of mandibular fragments in this sample of patients depended on the stability of the maxilla. In addition, neither clinical damage to the temporomandibular joint nor lesions to the neurovascular bundle were detected.     

Comparative study of skeletal stability between bicortical resorbable and titanium screw fixation after sagittal split ramus osteotomy for mandibular prognathism

IntroductionResorbable screw fixation for orthognathic surgery is widely used in oral and maxillofacial surgery and has several advantages. However, surgeons are concerned about using resorbable screws in orthognathic surgery because of possible postoperative complications such as relapse, screw fracture, and infection. The purpose of this study was to evaluate the skeletal stability of bicortical resorbable screw fixation after sagittal split ramus osteotomies for mandibular prognathism.Materials and methodsThis study included 25 patients who underwent mandibular setback surgery fixed with resorbable screws after sagittal split osteotomy at the Department of Oral and Maxillofacial Surgery at Seoul National University Dental Hospital. Five resorbable screws (Inion CPS^®, Inion Ltd., Finland) were applied bicortically at each osteotomy site via a transbuccal approach. No rigid intermaxillary fixation was applied on the first postoperative day. Passive mouth opening exercises were allowed, using two light, rubber elastics for guidance. The control group was 25 patients fixed with four titanium screws. The follow-up period was 12–22 months (mean 17.8 months). Postoperative skeletal changes on lateral cephalometric radiographs were analyzed and compared between the two groups preoperatively, immediately postoperatively, and 6 months postoperatively.ResultsThe average setback was 6.9 mm and no major intraoperative complications occurred. One patient experienced infection immediately after surgery that was controlled uneventfully. The data did not demonstrate any significant difference in postoperative skeletal stability between the two groups. Differences between the immediate postoperative state and 6 months after surgery were not significant. In earlier cases, especially for patients with severe mandibular prognathism, immediate postoperative elastic traction was needed for stable occlusal guidance.ConclusionsThe results of this study indicate that bicortical resorbable screws offer a clinically stable outcome for the fixation of mandibular sagittal split osteotomies in mandibular prognathism. However the resorbable screws showed less stable results vertically than the titanium screws.     

Postoperative changes in mandibular prognathism surgically treated by intraoral vertical ramus osteotomy

This study investigated short- and long-term postoperative skeletal changes following intraoral vertical ramus osteotomy (IVRO) for mandibular prognathism, as determined from lateral cephalograms. The subjects were 20 patients with mandibular prognathism who had undergone surgical orthodontic treatment combined with IVRO. Lateral cephalograms were taken at six time points: 1 month before surgery, and 1 day, 3 months, 6 months, 1 year, and approximately 2 years after surgery. Intermaxillary fixation (IMF) with four monocortical screws was maintained for 1 week in all patients. Mean posterior movement of the menton (Me) was 5.9 mm at surgery. 3 months after surgery, the FMA and FH-CorMe angles had increased 6.3 and 6.2 degrees, respectively, indicating clockwise rotation of the distal segment of the mandible. This rotation was observed in all 20 patients, suggesting that postoperative rotation of the mandible in the postoperative short term is likely to occur after IVRO and could be considered an adaptation of the mastication system newly established by surgery. In the long term after IVRO, Me had moved anteriorly by only 0.9 mm and the relapse ratio was 15.3%. These findings suggest the excellent long-term stability of surgical orthodontic treatment combined with IVRO in patients with mandibular prognathism.     

Comparison of methods to assess neurosensory alterations following orthognathic surgery

Orthognathic surgery may damage branches of the trigeminal nerve, resulting in postoperative neurosensory disturbances. Alterations may be due to surgical edema, stretching, or direct trauma to the nerve. Lack of a standard and objective method of assessment hinders efforts to study and/or reduce the incidence of neurosensory disturbances. This study compared three methods of assessing neurosensory disturbances in patients who underwent bilateral mandibular ramus sagittal split osteotomies. Forty patients (26 female, 14 male) ranging in age from 23 to 47 years participated in the study. All of the patients had bilateral mandibular ramus sagittal split osteotomies and were stabilized with rigid skeletal fixation. Neurosensory testing was performed prior to surgery, and at 2 weeks, 1 month, 3 months, 6 months, and 1 year following surgery. Methods of assessment included two-point discrimination, threshold to electrical stimulation, and somatosensory evoked potentials. Threshold to electrical stimulation and two-point discrimination were obtained by the two-alternate forced choice technique.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rigid internal fixation of mandibular fractures. An analysis of 270 fractures treated using the AO/ASIF method.

The results are reported on 214 patients treated for 270 mandibular fractures, using rigid internal fixation. Of these, 172 fractures (63.7%) in 131 patients had been re-evaluated at final follow-up in connection with plate and screw removal, on average 15.2 months, postoperatively. Although one-third of the patients had a history of alcohol abuse, and 86% were treated with a delay of more than 24 h (mean 3.2 days), good primary bone healing was observed in 93.9% of the patients. Infections, seen in 6.1% of the patients, were related exclusively to inadequate stability of the fracture. Malocclusion, observed in 18.2% of 159 dentate patients, was caused by incorrect plate bending and insufficient fracture reduction. Immediate postoperative dysfunction of the inferior alveolar nerve in 58.1% of the cases, and of the mandibular branch of the facial nerve in 12.7%, was followed by almost total recovery 1 year after operation. It is concluded that rigid internal fixation is a reliable method of treatment, especially indicated for patients with reduced healing capacity and poor co-operation.     

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.     

The stability of facial osteotomies. 4. Maxillary and mandibular (with or without chin) advancement with rigid internal fixation

The short-term (6 weeks postoperative) and long-term (12 months postoperative) horizontal skeletal stability of combined maxillary and mandibular advancement was evaluated by cephalometric analysis of 15 patients.
The mean horizontal advancement of the maxilla was 5.84 mm. Six weeks later a mean horizontal relapse of 0.03 mm (0.05%) was identified. The mean horizontal relapse at long-term follow-up was 0.59 mm (10.1%).
The mean horizontal advancement of the mandible was 12.35 mm at menton and 12.65 mm at pogonion. At 6 weeks, mean horizontal relapse, respectively at the above landmarks, was 0.11 mm and 0.21 mm (1.3%). The mean horizontal relapse at long-term follow-up was 2.19 mm and 1.98 mm (16.6%) respectively for the same landmarks.
Subjectively and objectively, improvements were seen in facial aesthetics and dental occlusion. The results indicate that rigid fixation of osteotomies undertaken to correct 'horizontal facial deficiency' is a surgically predictable and relatively stable procedure when reviewed up to 12 months after surgery.