Impact of reduced bone mineral density and osteoporosis on outcomes of orthognathic surgery: A systematic review

Reduced Bone Mineral Density (BMD) can present significant surgical challenges. Conditions like obstructive sleep apnea syndrome (OSAS) can lead to decreased BMD. This is crucial as orthognathic surgery, notably Maxillomandibular Advancement (MMA), is a vital surgical treatment option for OSAS. A systematic review was conducted using PubMed, including studies published up to August 15, 2024, in accordance with PRISMA guidelines. The search focused on associations between orthognathic surgery, BMD, and the use of medications such as antiresorptive drugs. The quality of the included studies awas assessed by the JBI’s critical appraisal checklists. A two-step independent review process was implemented to select pertinent studies. After reviewing 277 articles, eight were included. Current literature indicates that patients with T-scores below -1 (diagnosed osteopenia, osteoporosis) measured by dual-energy x-ray absorptiometry (DEXA), exhibit reduced Hounsfield units (HU) at orthognathic osteotomy sites in cone-beam computed tomography (CBCT) scans. Furthermore, a 3D-infinite analysis indicates that low BMD at osteotomy sites increases stress values on titanium osteosynthesis plates and screws. Reported complications across the identified case reports/ series were generally minimal. However, a preliminary study suggests postoperative relapse tendency in patients with low BMD measured by DEXA. None of the included articles encountered MRONJ as a postoperative complication in patients receiving antiresorptive drugs (ARD). Orthognathic surgery may be feasible in patients with reduced BMD and those receiving antiresorptive therapy. However, reduced BMD at surgical sites may lead to increased stress on osteosynthesis hardware, indicating potential for complications. Further research is necessary to develop guidelines ensuring safe surgical outcomes for this population. • Decreased BMD at osteotomy sites linked to osteoporosis in MMA patients • Low BMD increases stress on titanium plates, indicating higher complication risk • Minimal complications observed; low BMD may lead to postoperative relapse • Further studies are needed to establish critical BMD levels for surgery