Background: The high-oblique sagittal osteotomy (HOSO) is an alternative to a bilateral sagittal split osteotomy (BSSO). Due to its novelty, there are no long-term studies which have focused on describing the incidence and type of complications encountered in the post-operative follow-up. The aim of this retrospective study is to analyze patients operated on with this surgical technique and the post-operative complications encountered.
Patient and methods: The electronic medical records of all patients treated with orthognathic surgery at the Department of Oral, Maxillofacial and Facial Plastic Surgery, University Hospital Frankfurt, Goethe University, Frankfurt, Germany, between the years 2009 and 2016 were retrospectively reviewed.
Results: A total of 116 patients fulfilled the inclusion criteria. The cases operated on with the standard osteosynthesis (X, Y, and straight) showed a complication rate of 36.37% (n = 4/11). The cases operated on with the HOSO-dedicated plates (HOSO-DP) showed, in total, a complication rate of 6.67% (n = 7/105). The most common post-operative complication resulting from both fixation methods was a reduction in mouth opening and TMJ pain for 4.3%. During the first years of performing the surgery (2009-211), a variety of standard plates had material failure causing non-union or pseudarthrosis. No cases of material failure were observed in the cases operated on with the HOSO-DP. The statistical results showed a highly significant dependence of a reduction in OP-time over the years, when the HOSO was performed without additional procedures (R2 > 0.83, P < 0.0015).
Conclusion: The rate of complications in the HOSO were shown to be comparable to the rate of complications from the BSSO reported in the literature. Moreover, the use of the ramus dedicated plate appears to provide enough stability to the bone segments, making the surgery safer.
Clinical relevance: The HOSO needs to be considered by surgeons as an alternative to BSSO. Once the use of the HOSO-DP was established, the rate of complications and the operation time reduced considerably.
Keywords: HOSO; High oblique sagittal osteotomy; Orthognathic surgery.