Condylar displacement after oblique sliding osteotomy of the mandibular rami. A stereometric and plain radiographic study

Condylar displacement after oblique sliding osteotomy was examined in 8 patients by X-ray stereometry and plain radiography. During the first 8 postoperative weeks the displacement was in a medial/superior/posterior direction. After removal of the intermaxillary fixation a continuous lateral translation was found together with an initial inferior and a minor anterior translation which after 6 months postoperatively changed to a posterior translation. At 12 months postoperatively a difference in findings of condylar position was found between the X-ray stereometric and plain radiographic analyses. We regard this difference as due to the sum of remodelling and method errors.     

Combined Le Fort I osteotomy and oblique sliding osteotomy of the mandibular rami. A follow-up

Bimaxillary surgery involving mandibular set-back and maxillary advancement has been performed on eight patients with severe prognathic mandibles and in two patients with pronounced retropositioning of the maxilla. The combined surgical approach turned out to give a very satisfying result both from the functional and aesthetic points of view. Whereas a certain skeletal horizontal relapse occurred in the mandible and a vertical one in the maxilla, the occlusal stability was maintained in all but one case. A good postoperative occlusion obviously retains the teeth in position. The soft tissue adaptation and final configuration postoperatively takes a long time, and should if possible be subjected to more sophisticated analysis before surgery. The bimaxillary approach with step-wise surgery, using an intermediate wafer is, in our opinion, a good solution to marked malpositions and in many cases preferable to single jaw surgery.     

Stability of the osteotomy site after oblique sliding osteotomy of the mandibular rami. A stereometric and plain radiographic study

Displacement of the mandible 2-2 1/2 years after oblique sliding osteotomy of the mandibular rami is reported. Stability of the osteotomy site has been assumed to be complete much earlier, however. In the present stereo radiographic study mobility at the osteotomy site was recorded as late as 2 years after surgery. No sign of delayed healing was recorded in the plain radiographic examination. It seems possible that relapse after oblique sliding osteotomy continues as long as the functional matrix can influence an unstable osteotomy site. As plain radiography does not give full information on the quality of bone, the stability of the osteotomy site can not be assessed by this method.     

Surgical-orthodontic approach to skeletal class III malocclusion. Analysis of 45 cases with evaluation of curved oblique osteotomy and sliding osteotomy.

A curved oblique osteotomy in which the ascending ramus was cut obliquely on a curved line from its anterior border to the angle was used for the treatment of 29 patients with skeletal Class III malocclusion, and 16 other patients were corrected by either an ordinary body ostectomy or a sliding osteotomy in the first premolar region. Both curved oblique osteotomy and sliding osteotomy could easily be performed with a Stryker's reciprocating saw, and osseous healing at the sites of surgery was rapid as a large area of intimate bony contact between the segments was obtained. The resulting profile and skeletal changes studied by cephalograms were excellent, with no significant relapse, and recovery of a stable occlusion was attained. The combined approach with orthodontists which included thorough analysis of each patient, preoperative alignment of the dental arches and postoperative care was essential for obtaining the best results.     

Intraoral or extraoral approach in oblique sliding osteotomy of the mandibular ramus. A cephalometric study

Positional changes of the mandible after oblique sliding osteotomy of the mandibular rami were investigated by means of cephalometric analysis. The patient material comprised 40 patients. Twenty patients were operated upon using an extraoral approach and 20 were operated on using an intraoral approach. The patients were followed up with lateral cephalograms for 18 months after operation. In both groups, a posterior rotation of the mandible took place during the fixation period. This rotation gave a further retro-displacement of gnathion and a shortening of posterior facial height. The incidence of patients with considerable posterior rotation of the mandible was higher in the intraoral than in the extraoral group. The difference between the means of the changes in the mandibular plane angle (dEO = 4.9 degrees, dIO = 6.3 degrees) of the groups was, however, not statistically significant. Nor was there any significant difference in relapse between the two groups after release of the fixation.     

Medial displacement of proximal segments. A complication to oblique sliding osteotomy of the mandibular rami

In a retrospective study of 125 patients operated by oblique sliding osteotomy of the mandibular rami, unilateral medial displacement of the proximal segment was found in 10 patients. In 8 of these retropositioning of the distal segment during surgery was combined with lateral rotation and the amount of retropositioning was small. Medial displacement of the proximal segment had no influence on postoperative stability. In 6 of the 10 patients transient anesthesia for the inferior alveolar nerve was found on the side where the proximal segment was medially displaced.     

Radiography of the temporomandibular joint after oblique sliding osteotomy of the mandibular rami

abstract — A radiographic follow-up of the temporomandibular joint in 25 patients subjected to oblique sliding osteotomy of the mandibular rami showed a remodeling of the condylar head. Distinct double contours in the posterior part of the condylar heads were found in 30 out of 36 joints with a forward-inferior displacement of the condylar head.     

Radiographic changes of the temporomandibular joint after oblique sliding osteotomy of the mandibular rami

64 patients with mandibular prognathism were operated upon with oblique sliding osteotomies of the mandibular rami. The patients were followed with cephalometric and temporomandibular joint (TMJ) radiographs for 3 years. 60% of the TMJs showed skeletal remodelling 3 years postoperatively. The condylar remodelling was significantly correlated to the degree of postoperative displacement of the condyle. The average condyle displacement postoperatively was about 3 mm inferiorly and anteriorly, but the position was almost completely back to normal during the control period, due to a combination of reverse movement of the condyle and remodelling. Mandibular relapse was not correlated to postoperative displacement of the condyle or condylar remodelling. The range of condylar movement was unchanged at follow-up.     

Skeletal remodelling in the temporomandibular joint after oblique sliding osteotomy of the mandibular rami

Skeletal remodelling of the temporomandibular joints took place in 80% of cases after oblique sliding osteotomies of the rami. The new bone formation was found in both the condylar and temporal parts of the joint. It was mostly located on the posterior surface of the condyle and in the roof of the temporal part of the joint. No differences in skeletal remodelling were found between wiring and nonwiring cases.     

Displacement of the mandible after removal of the intermaxillary fixation following oblique sliding osteotomy

In an earlier study (Rosenquist et al., 1985) on oblique sliding osteotomy in 14 patients, operative repositioning and postoperative displacement of the mandible during intermaxillary fixation were presented. In the present stereometric study on the same patients displacement of the mandible after removal of the intermaxillary fixation is presented. A continuous anterior and a minor initial cranial translation and an anterior rotation of the mandible were found. Proclination of both upper and lower incisors was recorded. Correlations were found between operative repositioning and postoperative displacement of the mandible after removal of the intermaxillary fixation. Possible relapse mechanisms are discussed.     

Anterior skeletal fixation as an adjunct to oblique sliding osteotomy of the mandibular ramus. A cephalometric study

Positional changes of the mandible and upper and lower incisors were studied by means of cephalometric analysis after oblique sliding osteotomy for the correction of mandibular prognathism. In addition to intermaxillary fixation, skeletal fixation between the anterior nasal spine and the chin was used. The patients were followed up for 18 months after surgery. During the fixation period no increase in anterior facial height was observed and at 18 months this had decreased by 2.2 mm. Nevertheless, there was an increase in the mandibular plane angle by 3.8 degrees which mainly occurred during the fixation period. The posterior facial height decreased by 4.0 mm. As to the changes of the incisors these varied between individuals, but the mean values were small. Anterior skeletal fixation prevented increase in anterior facial height and seemed to limit the posterior shortening of the mandible and the extrusion of the mandibular incisors. However, the benefits remained rather limited.     

Displacement of the mandible during intermaxillary fixation after oblique sliding osteotomy. A stereometric and cephalometric radiographic study

The X-ray stereometric method was applied for the first time to a series of consecutive patients to record operative repositioning of the mandible during oblique sliding osteotomy and postoperative displacement of the mandible during intermaxillary fixation. Comparison with cephalometric measurements was presented. The operative repositioning pattern was presented. Postoperatively a posterior displacement pattern was found with incisor extrusion in both jaws. Correlation between operative repositioning and postoperative displacement and between the two measurement methods was assessed. The stereometric method offers information on displacement on all three planes and a higher degree of accuracy. To avoid incisor extrusion, besides intermaxillary dental fiscation also skeletal fixation is recommended.     

Changes in the temporomandibular joint after oblique sliding osteotomy of the mandibular rami. A longitudinal radiological study

Changes in the temporomandibular joint following oblique sliding osteotomy of the mandibular rami were studied using axial, frontal and lateral radiographs. The condyle/fossa relationship was also studied with regard to the effect of intraosseous wiring of the proximal fragment. Antero-inferior displacements of the condyles were regularly seen after the osteotomies. The use of intraosseous wiring had no adverse effects on the temporomandibular joint.