Katharina Laudemann

Segmental stability of resorbable P(L/DL)LA-TMC osteosynthesis versus titanium miniplates in orthognatic surgery☆

After two decades of the use of resorbable miniplates, new polymer compositions for resorbable osteosynthesis are still being developed to make the handling and outcome of operations even more predictable and give higher stability to the repositioned segments. This study investigates a new resorbable osteosynthesis system in orthognathic patients. 50 patients were treated with P(L/DL)LA-TMC resorbable osteosynthesis and compared to a group of 50 patients treated with titanium miniplates. Segmental stability and relapse were measured comparing preoperative, postoperative and follow-up lateral cephalograms. Throughout this study, resorbables appeared to be as stable as titanium miniplates except in maxillary elongation and mandibular setback. Here, the titanium miniplates showed significantly higher stability than resorbable plates. P(L/DL)LA-TMC osteosynthesis seem to have less strength against compressive forces after maxillary elongation and they are less resistant to the forces the tongue exerts, pressing against the mandible after setback. It can therefore be concluded that the resorbable osteosynthesis can be used in the same situations as titanium miniplates except in maxillary elongation and mandibular setback.

Comparison of Bipartite Versus Tripartite Osteotomy for Maxillary Transversal Expansion Using 3-Dimensional Preoperative and Postexpansion Computed Tomography Data

PURPOSE To evaluate tripartite paramedian versus bipartite median osteotomy in surgically assisted rapid maxillary expansion. Tripartite osteotomy was performed between the lateral incisors and canines at the former premaxillary junction to avoid midline diastema, septal and columellar dislocation, and asymmetric expansion, minimizing high-distraction forces through bilateral doubled osteotomy on periodontia and thus reducing vestibular attachment loss and producing stable callus formation to avoid relapse. PATIENTS AND METHODS The preoperative and postexpansion computed tomography data from 50 patients were analyzed in multiplanar viewing for bodily segment movement, vestibular bone loss, and transverse skeletal and dental widening with predefined landmarks. Of the 50 patients, 22 had undergone tripartite and 28 had undergone bipartite osteotomy. RESULTS Using an independent t test, both osteotomies permitted adequate transverse skeletal expansion in the premolars, converging, however, in the molars. Bipartite osteotomy resulted in less symmetry in transverse skeletal widening, greater bodily segment movement in the first premolar/molar, and greater vestibular bone loss. Tripartite osteotomy resulted in greater overall expansion and less bone remodeling. On variance analysis, tripartite bone-borne distraction resulted in the greatest decrease of transverse expansion in patients older than 20 years. The tripartite osteotomy also provoked distractor- and age-independent outward segmental movement. Bipartite osteotomy resulted in distractor- and age-independent inward segmental movement. Bipartite osteotomy showed the greatest bone resorption in patients younger than 20 years old in the molars and tripartite osteotomy in patients older than 20 years in the premolars. CONCLUSIONS Tripartite paramedian osteotomy allowed greater overall symmetric expansion compared with bipartite median osteotomy, with, however, a decline in transverse widening to the posterior. Bipartite osteotomy should be preferred whenever good periodontal status permits greater vestibular bone loss and a midline diastema and asymmetric expansion and a midline shift will be tolerated by the patient. Tripartite osteotomy should be chosen whenever a midline diastema and shift, septal and columellar dislocation, asymmetric expansion, and larger distraction forces on the paradontia, resulting in vestibular attachment loss, are to be avoided.

Assessment of Surgically Assisted Rapid Maxillary Expansion Regarding Pterygomaxillary Disjunction Using Thin Volume-Rendering Technique: In Variance Analysis and in Reliability, Accuracy, and Validity

PURPOSE To assess surgically assisted rapid maxillary expansion (SARME) with or without pterygomaxillary disjunction using a thin volume-rendering technique in variance analysis and in reliability, accuracy, and validity. MATERIALS AND METHODS Thin volume-rendered images of 68 patients were evaluated preoperatively and 2.87 ± 1.59 months after expansion with respect to dentoskeletal effects. RESULTS Variance analysis of SARME with pterygomaxillary disjunction showed an important decrease in transverse widening and segmental outward inclination and an increase in vestibular bone plate thickness (premolars) in patients younger than 20 years with bone-borne devices; the greatest increase in transverse widening was in patients with 3-segment osteotomy and tooth-borne devices. Analysis of SARME without pterygomaxillary disjunction showed an important decrease in transverse widening and segmental inward inclination in patients older than 20 years with bone-borne devices; the greatest pterygoid lateral bending was in patients with 2-segment osteotomy and bone-borne devices. CONCLUSION The performance of pterygomaxillary disjunction should depend on patient age (ie, treatment with pterygomaxillary disjunction in those >20 years old; treatment without pterygomaxillary disjunction in those <20 years old). Patients with pterygomaxillary disjunction, 3-segment osteotomy, and tooth-borne devices tended to show an increase in transverse widening but at the price of greater attachment loss. Patients younger than 20 years with pterygomaxillary disjunction and bone-borne devices tended to show an increase in vestibular bone plate (premolars) but at the price of decrease in transverse widening.

Patients' preoperative expectations and postoperative satisfaction of dysgnathic patients operated on with resorbable osteosyntheses.

Background: This study evaluated whether personal expectations and satisfaction throughout orthognathic surgery were fulfilled. In addition, patients were interrogated about their experience of resorbable osteosynthesis. Methods: A total of 50 patients were interviewed 3 times each throughout the study by a mixed questionnaire of standard psychologic tests and a tailored itemized questionnaire regarding their expectations regarding resorbable osteofixation and their postoperative satisfaction. Results: A postoperative increase in self-esteem and approach to life were evident. An examination of Oral Health-Related Quality of Life showed constant quality of life; an examination of Oral Health Impact Profile-Germany) showed no postoperative difficulties in dental hygiene and nutrition. No statistically significant change in any of the tests could be expressly determined. Avoidance of secondary surgery motivated 94% to choose resorbable osteofixations, although a mere 66% had heard of them before; 90% of patients were satisfied with the operation result. Conclusions: Orthognathic surgery cannot change preexistent depression or a problematic social background. Mastication and oral health improved, and postoperative happiness and confidence increased. When given the choice between resorbable fixation and titanium osteofixation, patients generally preferred resorbable fixations.

Bone harvesting at the anterior iliac crest using piezoosteotomy versus conventional open harvesting: a pilot study

OBJECTIVE The objective of this study was to evaluate piezoosteotomy for bone harvesting at the iliac crest in a pilot collective. STUDY DESIGN Thirteen patients underwent anterior iliac crest bone graft harvesting using piezoosteotomy. These patients were compared to an age- and sex-matched retrospective cohort of 13 patients who underwent bone graft harvesting at the anterior iliac crest using conventional chisels and saws in an otherwise identical protocol. RESULTS Harvested bone volumes and operation times were comparable; hospitalization time was briefer and pain levels at the first 2 postoperative days less in the piezoosteotomy group; pain medication requirement was comparable. Spearmans-rho correlation showed a strong tie between pain medication requirement and harvested bone volume in the piezoosteotomy group and between harvested bone volume and operation time in the conventional surgery collective. CONCLUSIONS The correlation between required pain medication and harvested bone volume together with lower pain levels in the piezoosteotomy group indicate pain more exclusively related to local osseous damage than to correlated soft tissue lacerations. Conventional technique shows a correlation between operation time and harvested bone volume indicating a more time-effective procedure, although total operation time was comparable. Piezoosteotomy appears to have potential use in iliac crest bone harvesting.