Per Åstrand

Intermediate Bone Grafting of Alveolar Clefts

During the five year period 1980 to 1985 bone grafting was performed in 37 cleft patients before the eruption of the canine tooth (group IBG) and in 30 patients after the eruption of the canine tooth (group SGB). The initial healing was more favourable in the IBG group. In 72.5% of the clefts oro-nasal fistulae were present preoperatively. In all cases the fistulae were successfully closed. In the IBG group with orthodontic closure of the gap in the dental arch the interdental bone height in the grafted area was more than 75% of normal bone height in all clefts. In group SBG this situation was found in only 66% of the bone-grafted areas. There seems to be a clear relation between the age or the developmental stage of the canine tooth on the one hand and the possibility of orthodontic closure of the gap in the dental arch and good interdental bone height on the other hand. This also leads to the suggestion that if bone grafting to the alveolar cleft is required the operation should be performed before the eruption of the canine tooth on the cleft side.

Changes in the temporomandibular joint after oblique sliding osteotomy of the mandibular rami

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.

Planning and control of vertical dimension in Le Fort I osteotomies

Depending on the different anatomy of the soft and hard tissues, concavity or convexity of the face, measurements of inferior or superior repositioning of the maxilla may be less predictable when using only the osteotomy site for this calculation. A more reliable method would be to measure the distance from a bone mark in the forehead to the incisor edges. This method has been practiced by our clinic during the past five years. The method is thought to offer a more accurate estimation of the position of the upper anterior teeth in relation to the lip, although one must anticipate a certain degree of postoperative relapse especially concerning inferior repositioning. In order to evaluate the accuracy of our method, a comparison has been made of the calculated vertical repositioning and the surgical results in two groups. In group I (12 individuals) conventional estimation of maxillary repositioning in the osteotomy line was made; in group II (12 individuals) measurements were made from a bone mark on the forehead to the incisor edges. A satisfying correlation was found between calculated and achieved results in both groups. In comparison between calculated and immediate postoperative measurements the results showed no statistically significant difference between the two methods.

Relation between fragments after oblique sliding osteotomy of the mandibular rami and its influence on postoperative conditions.

Abstract The relation between the fragments after oblique sliding osteotomy of the mandibular rami was investigated in 55 patients with radiographic methods. A lateral angulation of the condylar fragment of about 8° was observed. A slight regression of this angulation (1–2°) occurred during later remodelling. The angulation of the fragments produced at surgery was not significantly correlated with postoperative positional changes of the mandible. The extent to which the fragments overlapped in orthopantomograms varied widely. An almost significant correlation was found between small overlapping areas and upward displacement of gonion during the fixation period.

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.

Mandibular rami osteotomies and their effect on the gonial angle

Radiation-induced obliterative endarteritis causes ischemia and hypoxia in tissue wounds, making them prone to dehiscence, infection and delayed healing. The successful use of hyperbaric oxygen as an adjunct to intensive antibiotic and surgical therapy in the treatment of radionecrosis of the mandible is well established. This report details our experience in four cases of radionecrosis of the mandible of long duration, prior to acceptance of the patients into our hyperbaric oxygen protocol.

Changes in masticatory function after surgical treatment of mandibular prognathism Cineradiographic study of bolus position

The position of the bolus in persons with mandibular prognathism was examined using a cineradiographic method before and after surgical correction of the prognathism. The pre-operative study included 30 persons, 18 women and 12 men. The test foods were bread and toffee. The results showed that the upper incisal region participated more and the premolar and molar regions less frequently in the chewing act than in other patient groups examined earlier with the same method. This was especially the case in persons with pronounced mandibular prognathism. It was concluded that these patients may have a poor masticatory ability.The post-operative registration was carried out on 23 of the patients. The results showed a more «normal» chewing pattern with a higher participation of the molar region. Due to this change the possibilities for a good masticatory function was considered increased after operation, but whether the chewing efficiency was improved could not be decided from the present study.

Extraoral or intraoral approach in the oblique sliding osteotomy of the mandibular rami? Clinical experience and results.

The clinical results of oblique sliding (subcondylar) osteotomy of the mandibular rami performed by the extraoral or intraoral approach were compared. The patient material comprised 40 patients with mandibular prognathism. Twenty patients were operated upon using the extraoral approach and 20 patients were operated on using the intraoral approach. All patients had intermaxillary fixation for 7 weeks. The patients in both groups were followed up for 18 months. The experience of the operations was that the intraoral approach gave a shorter operation time than the extraoral approach. The extraoral approach, however, gave better visibility in the operation field and greater possibilities of manipulating the proximal fragment into an optimal position. In the follow-up evaluation, there were no significant differences between the two surgical techniques with regard to dental relapse, post-operative occlusion and mandibular function.

Mandibular reconstruction with bone grafts

A total of 23 patients with partly resected mandible were repaired with autogenous bone grafts from the iliac crest and ribs. The reasons for reconstruction are presented in Table 1. The grafts healed without complications in 21 cases. With the exception of two of the cases with gunshot wounds, all patients recovered good mobility of the jaw and satisfactory mandibular contours. The patients had been folloed up for 6 months to 11 years. Radiographic examination at the last examination showed that resorption of the graft had been only slight or moderate. Through marrow-spongious bone grafts are regarded as best from an osteogenetic point of view, our cases showed that good results can be achieved also with solid block grafts. The authors discuss the use of plate osteosynthesis without IMF instead of other types of graft fixation and IMF. In six cases where the area of the graft was loaded with a prosthesis, resorption was not more extensive than in the other cases.

Intraosseous wiring in ramus osteotomy

The value of intraosseous wiring of the fragments after oblique osteotomy of the mandibular rami was studied. A wired group (14 patients) and a nonwired group (15 patients) were compared cephalometrically. There were only small differences between the groups but there was a tendency toward a smaller postoperative posterior rotation of the mandible in the wired group. It was concluded that in routine cases of mandibular prognathism wiring is not necessary.