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Biomedical subjects

J P Bouwman

Publications and source records attributed to J P Bouwman.

7 recordsLinked to original sources
PubMed1999

Biodegradable osteosynthesis in mandibular advancement: a pilot study.

In this pilot study four patients are presented who underwent bilateral sagittal split osteotomies of the mandibular ramus for mandibular advancement. Biodegradable osteosyntheses were used for internal fixation. All patients were from the same dentofacial category: mandibular retrognathia with a low to normal mandibular plane angle. In two patients cylindrical self-reinforced polyglycolide (PGA) rods were used for internal fixation of the osteotomy segments. Long-term evaluation showed a complete ossification at the sites of biodegradable rods. In two other patients, self-reinforced poly(L-lactide) (PLLA) screws with a diameter of 2 mm were used to stabilize osteotomy segments. The two different techniques of osteosynthesis and the problems encountered are discussed.

Absorbable Implants↗
PubMed1997

The value of long-term follow-up of mandibular advancement surgery in patients with a low to normal mandibular plane angle.

The objective of this study was to evaluate retrospectively the stability of mandibular advancement via bilateral sagittal split osteotomies. Two fixation methods were compared: intermaxillary fixation (IMF) and rigid internal fixation (RIF). The hypothesis was that, in patients with a low to normal mandibular plane angle (MPA) in retrognathia, the bilateral sagittal split osteotomy (BSSO) to advance the mandible is a predictable and stable procedure and that no significant changes occur after 1 year. Twelve patients with mandibular deficiency with a low to normal MPA (mean 24.7 degrees, range 20.3 degrees-30.7 degrees) underwent BSSO with IMF. The follow-up period was at least 5 years (mean 6.3, range 5-9.1 years). Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T0), within 6 weeks postoperatively (T1), 1 year postoperatively (T2), and at least 5 years postoperatively (T3). The average advancement at B point was 4.7 mm (range: 3-7 mm). The assessment of B point in regard to relapse showed no significant change. One patient showed a relapse due to condylar resorption. Forty-five consecutive patients were treated with RIF. Radiographs were taken preoperatively (T0), 6 weeks postoperatively (T1), and 1 year postoperatively (T2). This group had a mean MPA of 26.2 degrees, range 10 degrees-32 degrees. The average B-point advancement was 4.4 mm (range 1-10 mm). No patient showed a clinically significant relapse at T2.

Adult↗
PubMed1995

Screw fixation following bilateral sagittal ramus osteotomy for mandibular advancement--complications in 700 consecutive cases.

The use of transbuccal positional screws for stabilisation of bony segments following bilateral sagittal split osteotomy for mandibular advancement was assessed in 700 consecutive cases. In 19 patients (2.7% of cases) screw fixation was not used as the method of fixation. Screw removal was performed in 20 patients (2.8% of cases), in 15 cases due to infection and 5 cases for diverse reasons. The incidence of inferior alveolar nerve damage was increased when compared to a group of patients managed with intermaxillary fixation following advancement BSSO treated in the same unit. In 4 patients (0.6%) a lingual nerve dysaesthesia occurred. Screw loosening in the first postoperative week occurred in 4 patients and in 3 of these re-operation was necessary. Extra oral scar formation did not give rise to any significant problems.

Bone Screws↗
PubMed1994

Condylar resorption in orthognathic surgery. The role of intermaxillary fixation.

Condylar resorption that occurs after orthognathic surgery was investigated in a large sample of patients treated in the Department of Oral and Maxillofacial Surgery of the Free University in Amsterdam, the Netherlands. The findings correspond with previous publications on this subject. In a 1-year follow-up study the role of intermaxillary fixation was investigated radiologically. In a group of 158 patients prone to show occurrence of condylar resorption, 24 (26.4%) of the 91 patients treated with intermaxillary fixation showed signs of condylar resorption. In the group of 67 patients treated without intermaxillary fixation only eight (11.9%) of the patients showed signs of reduced volume of the condyle. Avoidance of intermaxillary fixation seems to reduce the incidence of condylar resorption after orthognathic surgery in patients with a mandibular deficiency with high mandibular plane angle.

Adolescent↗
PubMed1994

A comparative in vitro study on fixation of sagittal split osteotomies with Würzburg screws, Champy miniplates, and Biofix (biodegradable) rods.

A bilateral sagittal split osteotomy was performed on seven fresh cadaver mandibles. Three different systems of fixation were mechanically tested on 14 sites. Tensile diagrams were obtained in which the (offset-) yield point was measured. This resulted in mean yield stresses of 199 N for bi-cortical self-tapping screws (n = 6), 49 N for miniplates with monocortical screws (n = 5), and 113 N for bi-cortical biodegradable rods (n = 3).

Analysis of Variance↗
PubMed1993

Stability of the osteotomy site following bilateral sagittal split osteotomy: screw fixation v IMF.

In a group of patients with mandibular deficiency with a low to normal mandibular plane angle (mean 20.7 degrees, range 10-28 degrees) and deep bite, the position of the condylar segment relative to the mandibular body, following bilateral sagittal split osteotomy (BSSO) for mandibular advancement was assessed. Ten patients in whom intermaxillary fixation (IMF) was used for a 5-week period were compared to 10 patients where 2 mm diameter Wurzburg positional screws were used as internal fixation. Six patients who were known bruxists and underwent BSSO were also reviewed. No clinically significant changes were seen in any patient group and no significant differences were found in the relationship with time between the condylar and body segments, irrespective of the fixation method used.

Adolescent↗