Simultaneous superior repositioning of the maxilla and mandibular advancement. A report on stability

Fifty-three patients who underwent simultaneous surgical superior repositioning of the maxilla and mandibular advancement were studied cephalometrically and clinically for at least 1 year after surgery (mean 2.4 years). The pattern of change for the maxilla and the percentage of patients who had 2 mm or more movement of landmarks were consistent with that observed following isolated superior repositioning of the maxilla. Although changes similar to those observed with isolated mandibular movement occurred, because the changes in the maxilla also affected the mandible, a greater percentage of patients experienced postsurgical movement of the mandible in this group than in those undergoing mandibular advancement alone. Clinically, satisfactory or better results were observed in 42 (79%) patients at their longest follow-up examination. The only significant variable associated with clinical outcome was the presence (presurgically) of an open bite (p less than 0.04) in 10 of 11 patients with poor clinical results. There was no statistically significant relationship between cephalometric stability and clinical outcome in this series of patients.     

Superior repositioning of the maxilla: stability and soft tissue osseous relations.

The skeletal stability and soft-tissue changes associated with superior repositioning of the maxilla by Le Fort I osteotomy or simultaneous anterior and posterior maxillary osteotomies was studied in thirty patients by means of a computerized craniofacial model. Excellent skeletal stability was demonstrated 14 months postoperatively. Postsurgically, the reduction in lower face height and amount of maxillary incisor exposure resulted in improved facial balance. The use of a computerized osseous and soft-tissue craniofacial model has added a new dimension to evaluation of surgical changes associated with correction of dentofacial and craniofacial deformities.     

Superior repositioning of the maxilla during growth

Sixteen individuals between the ages of 10 and 16 years who underwent superior surgical repositioning of the maxilla to correct vertical maxillary excess and were followed up for at least one year after surgery were evaluated. Follow-up ranged from 12 to 78 months with a mean of 36.7 months. The effects of subsequent growth on the esthetic, occlusal, and skeletal results achieved immediately following surgery were evaluated through analysis of profile esthetics, dental occlusion, and skeletal changes which occurred from the immediate postoperative period to longest follow-up examination.     

Long-term stability of mandibular orthopedic repositioning.

Mandibular anterior repositioning appliances attempt to diminish temporomandibular joint pain, soft tissue noise, and myofascial discomfort by altering condyle-disc relationships. Secondary stabilization of the occlusion to this arbitrary anterior position through orthodontic tooth movement may significantly alter functional and muscular relationships. A case report is illustrated to show that as the functional environment attempted to reestablish equilibrium through adaptation, relapse occurred as the condyles "seated" posteriorly and superiorly toward their original relationship within the fossa. For all practical purposes, complete relapse of the orthodontic treatment result took place over time.     

Surgical orthodontics and the temporomandibular joint. I. Superior repositioning of the maxilla

Ten randomly selected adults who had undergone orthodontic treatment and isolated superior repositioning of the maxilla for vertical maxillary excess (VME) were evaluated clinically and radiographically (mean, 48.7 months postsurgery) for signs and symptoms of masticatory and temporomandibular joint dysfunction. The patients ranged from 18 years to 37 years of age (mean, 26.2 years) when evaluated. A three-part evaluation of the subjects was performed. This consisted of an anamnestic evaluation (previous medical history), a clinical examination, and a radiographic evaluation. The anamnestic evaluation revealed that, prior to surgery, facial pain was reported by one patient and was not present in any of the patients upon follow-up examination. We believed that the pain was not related to the masticatory musculature and/or the temporomandibular joint. No patients reported pain or sounds in their joints preoperatively, while 30 percent (3/10) of the patients related a history of temporomandibular joint sounds immediately after release of intermaxillary fixation, which subsequently was reported to have resolved in all instances without treatment. Clinical examination of the temporomandibular joints at the time of recall evaluated mandibular movements and the presence of pain or sounds during joint function. These examinations revealed that clinical measures of mandibular movements were somewhat reduced relative to normal. All patients were free of temporomandibular joint and masticatory muscle pain during function, upon contralateral masticatory loading, and upon palpation. Fifteen percent (3/20) of the joints examined demonstrated sounds (popping or crepitation) via auscultation. Masticatory loading in the contralateral premolar region did not induce noise in any of the joints examined. Cephalometric laminagraphic radiographs were obtained of each of the twenty temporomandibular joints with the mandible in three positions; maximum intercuspation, mandibular rest position, and maximal opening. Numerous anatomic relations were quantified from these radiographs. However, only three parameters (condylar position, movement, and evidence of arthrosis) were compared to normative data available in the literature. These comparative data suggested that persons who had undergone orthodontic treatment in conjunction with superior maxillary repositioning demonstrated (1) a relatively retropositional condyle within the fossa and (2) reduced condylar movement during maximal mandibular opening. Two of twenty temporomandibular joints demonstrated radiographic evidence of arthrosis; one condyle demonstrated articular surface erosions, and another exhibited articular surface sclerosis. The overall incidence of arthrosis was not much greater than normal, with 20 percent (4/20) of the joints demonstrating a reduced interarticular joint space. Overall, the clinical findings revealed a low incidence of pathologic masticatory muscle and temporomandibular joint symptoms and signs compared to normative data in the literature...     

Soft tissue changes associated with advancement genioplasty performed concomitantly with superior repositioning of the maxilla

A retrospective study of the osseous and soft tissue changes of the chins of ten patients treated for vertical maxillary excess by Le Fort I osteotomy and advancement genioplasty was undertaken. The patients were characterized by excessive lower anterior facial height, obtuse or normal nasolabial angles, prominent maxillary incisors, lip incompetence, everted lower lips, anterior open bites, lack of chin prominence, and excessive chin height. A change in the proportion of osseous to soft tissue of 1.0 to 0.87 was obtained by advancement genioplasty and concomitant superior repositioning of the maxilla by Le Fort I osteotomy.     

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.     

Attaining mandibular stability following repositioning splint therapy. Case report

To maintain the stable temporomandibular joint configuration attained by appliance therapy for cases of anterior meniscal displacement, a stable occlusion is required. A number of treatment modalities can achieve the desired result, but may involve complex orthodontics, orthosurgical, or restorative techniques. This report presents the treatment options, and discusses a simple, non-restorative approach that is useful in selected cases.     

Superior repositioning of the maxilla by a Le Fort I osteotomy: a review of 26 patients

Following surgical procedures in 25 patients, a study was made of the stability of the maxilla after superior repositioning. In cases of open bite, as well as in cases of absolute maxillary hyperplasia or relative mandibular deficiency, a slight overcorrection that led to a stable occlusion was observed. The use of miniplates for stabilization of the maxilla is discussed briefly.     

Autorotation of the mandible: Effect of surgical superior repositioning of the maxilla on mandibular resting posture

Mandibular autorotation is a generally accepted cephalometric phenomenon that occurs when surgical superior repositioning of the maxilla is planned. This investigation was undertaken to determine whether autorotation of the mandible is a biologic phenomenon as well. Fifteen adults with vertical maxillary excess who underwent a mean surgical superior repositioning of 6.2 mm. were evaluated with cephalometric, kinesiometric, and electromyographic instrumentation immediately before and 3 months following surgery. Five persons selected at random from the original group (who also underwent a mean surgical superior repositioning of 6.2 mm.) were similarly evaluated 24 months following surgical intervention. The results of this study, which were analyzed by the Wilcoxon Matched-Pairs Signed-Rank test, revealed that a significant compensatory autorotation of the mandible occurred by the third month and was still constant 2 years later. We propose, on the basis of this preliminary evidence, that an “occlusal programming feedback mechanism” within the central nervous system mediated the compensatory autorotation of the mandible following surgical superior repositioning of the maxilla.     

Surgical mandibular advancement in adolescents: postsurgical growth related to stability.

Ten of 12 adolescents treated with surgical mandibular advancement showed postsurgical mandibular growth, as indicated by an increase in the distance from condylion to pogonion. In all cases, the growth was expressed vertically relative to the cranial base, so that the chin did not come forward. None of the patients had significant increments of anterior maxillary growth postsurgically. Several patients had vertical maxillary growth, which was compensated by vertical mandibular growth, so that the anteroposterior position of the chin was maintained. Forward growth of the maxilla is minimal after the peak of the adolescent growth spurt, and results of mandibular advancement surgery can be acceptably stable after that time.     

Long-term stability of mandibular advancement with bilateral sagittal split osteotomy

Introduction

Aim of this study was 1) to evaluate long-term dental/skeletal stability in patients with mandibular retrognathia corrected by BSSO, and 2) to examine factors associated with relapse.

Three-dimensional stability analysis of maxillomandibular advancement surgery with and without articular disc repositioning

This retrospective cohort study aimed to assess, three-dimensionally, mandible and maxilla changes following maxillomandibular advancement (MMA), with and without repositioning of TMJ articular discs. The sample comprised cone-beam computed tomography data from 32 subjects: group 1 (n = 12) without disc displacement and group 2 (n = 20) with bilateral disc repositioning. An automatic cranial base superimposition method was used to register the images at three time points: T1 (preoperative), T2 (postoperative), and T3 (at least 11 months follow-up). To assess surgical changes (T2–T1) and adaptive responses (T3–T2), the images were compared quantitatively and qualitatively using the shape correspondence method. The results showed that surgical displacements were similar in both groups for all the regions of interest except the condyles, which moved in opposite directions — group 1 to superior and posterior positions, and group 2 to inferior and anterior positions. For adaptive responses, we observed high individual variability, with lower variability in group 2. Sagittal relapse was similar in both groups. In conclusion, there were no significant differences in skeletal stability between the two groups. The maxillomandibular advancement surgeries, with rotation of the occlusal plane, had stable results for both groups immediately after surgery and at 1-year follow-up.     

A simple method to predict changes of mandibular landmarks following superior repositioning of the maxilla

Adult patients who have vertical maxillary excess usually are candidates for superior repositioning of the maxilla (SRM). In proportion to the amount of SRM, the mandible autorotates forward and upward. It is necessary for clinicians to predict the changes in mandibular landmarks following surgery. A new method is presented in this article with which one can calculate the horizontal and vertical changes of any skeletal or dental mandibular landmarks. The method is based on measuring only 2 angles and 1 line for any landmark.     

Logopaedic findings following advancement of the maxilla.

From 1972 to 1974, the authors carried out logopaedic examinations of over 100 patients with retrodisplaced maxillae at the Clinic for Maxillo-Facial Surgery at the University of Zurich (Director: Prof. H. Obwegeser, M.D., D.M.D.). From this clinical material, 40 cases which were fully documented in respect of medical history, surgical treatment and speech behavior were selected, and the effect of the advancement of the maxilla on the individual ability to articulate was studied.     

A comparative study of stability after mandibular advancement surgery

The postsurgical stability of two groups of patients treated with different fixation techniques after mandibular advancement was evaluated retrospectively. Sixteen patients (group 1) underwent rigid osseous fixation, and another group of 16 patients (group 2) underwent intraosseous wiring fixation. Our findings suggested that skeletal and dental changes occurred in both groups as a result of adaptation to the altered functional equilibrium. Relapse resulting in a percentage loss of the initial advancement occurred primarily 6 to 8 weeks postsurgically. No statistically significant difference was found to exist in the short-term and long-term rates between the two groups. For the population studied, relative stability after mandibular advancement surgery was affected more by individual variability than by the fixation technique.