Beta-tricalcium phosphate patient-specific gap implants in bilateral sagittal split osteotomy: an innovative treatment method to enhance the mandibular border contour. Part 1: concept and workflow.

Abstract

Antegonial notching can occur after bilateral sagittal split osteotomy (BSSO) and may lead to unpleasant aesthetic outcomes in both young and older patients. This clinical study presents a new concept to potentially overcome this problem and describes the workflow. Beta-tricalcium phosphate patient-specific gap implants (β-TCP gap-PSIs) are biocompatible and resorbable bone grafts that are placed in the space of the osteotomy gap during orthognathic procedures; they are virtually planned and printed in 3D. Between July 9, 2017 and July 31, 2018, 14 patients received bilateral β-TCP gap-PSIs during BSSO procedures. Nine were female (64.3%) and five were male (35.7%); mean age at surgery was 32.4 ± 12.7 years and the mean sagittal advancement gap was 9.4 ± 1.74 mm. The immediate postoperative position of the β-TCP implants, as well as early and long-term complications were evaluated; the clinical follow-up was 5 years. Intraoperative placement of the β-TCP implants was achieved without early complications, and the mandibular border contour was rated as very good or good in 82.1% of sides. Two minor long-term complications occurred, resulting in a total grafting success rate of 92.9%. In conclusion, this initial study (part 1) showed the potential of the β-TCP gap-PSI concept in BSSO procedures to prevent antegonial notching, which is currently underestimated and underreported. However, further extensive quantitative assessment is mandatory and will be presented in part 2.