Chief University of Cincinnati Medical Center Cincinnati, Ohio, United States
Disclosure(s):
Soroush Samimi, DMD: No financial relationships to disclose
Abstract: Statement of the problem: The likelihood of hardware failure following orthognathic surgery depends on various factors such as the type and location of the hardware, the patient's age and health, and adherence to post-operative instructions. This project aims to investigate hardware failure associated with commonly performed orthognathic procedures at the University of Cincinnati Medical Center (UCMC) from 2008-2020. We specifically focused on Bilateral Sagittal Split Mandibular Osteotomy (BSSO), Lefort I maxillary Osteotomy, and Genioplasty. Materials and methods: This was a retrospective chart review to assess the rates and risk factors associated with orthognathic hardware failure. This investigation audited procedures performed by one surgeon in the Division of Oral and Maxillofacial Surgery (OMS) at UCMC between August 2008 and December 2020. OMS patients whose procedure notes did not include the primary surgeon, patients who underwent non-elective procedures, and procedures that were not orthognathic were excluded from the population sample. Methods of data analysis: We constructed a univariate distribution of three commonly performed orthognathic procedures to demonstrate the frequently occurring failure types. A similar distribution of the failures was constructed to assess for relationship to patients’ age. All statistical analyses were carried out in STATA/MP version 14.2.
Results: Our sample consisted of 229 females and 144 males (N=373), with a median age at the time of procedure 20.0 years. Procedure types were categorically combined into seven procedure types: 89 (23.86%) BSSO, 73(19.57%) Lefort I, 174 (46.65%) BSSO + Lefort I, 37 (9.92%) combination procedures with Genioplasty involvement. BSSO (p-value < 0.007), Lefort 1 (p-value < 0.001), Genioplasty (p-value 0.026), and the combination of BSSO + Lefort 1 (p-value 0.005) showed significance for failure. When analyzing failure rates between mandible and maxilla hardware, failure rates for the mandible was higher at 12.6% compared to just 2.14%. Age groups were stratified into five categories: 10-19, 20-29, 30-39, 40-49, and 50+. Failures were seen to be more frequently observed in the 10-19 group (48.26%).
Conclusions: These findings support our hypothesis that mandibular hardware, subject to more stress and movement, is more likely to fail than maxillary hardware.
