Orthognathic surgery is the surgical correction of skeletal abnormalities of the mandible, maxilla, or both with the primary goal to improve facial form and physiologic function (for example, mastication, swallowing, and speech). These skeletal abnormalities may be congenital, develop with growth, or result from trauma or systemic disease, and correction is frequently performed in combination with orthodontic treatment to optimize occlusion and functional outcomes. [[13]]
The American Association of Oral and Maxillofacial Surgeons (AAOMS) provides clinical guidance on measurable indications for orthognathic surgery, including anteroposterior, vertical, transverse deformities and significant asymmetries. Representative thresholds cited by AAOMS and adopted in this policy include: horizontal overjet of +5 mm or more (or zero to a negative value); molar anteroposterior discrepancy of 4 mm or more (norm 0–1 mm); vertical deformity or transverse discrepancy that is ≥ 2 standard deviations from published norms; posterior open bite > 2 mm; bilateral palatal cusp‑to‑fossa transverse discrepancy ≥ 4 mm (or unilateral ≥ 3 mm); and asymmetries > 3 mm with concomitant occlusal asymmetry. These verifiable clinical measurements are intended to identify significant skeletal deformities associated with masticatory malocclusion. [[19]]
Orthognathic surgery is intended to produce functional improvement rather than solely cosmetic change; for coverage as a reconstructive, medically necessary procedure the individual must also have one or more documented functional impairments related to the skeletal malocclusion (examples include inability to bite or chew solid foods, choking on incompletely masticated foods, damage to soft tissues during mastication, malnutrition, or documented speech impairment). Procedures performed solely for cosmetic purposes or that correct an anatomical anomaly without restoring physiologic function are considered not medically necessary under this policy. [[3]]
Systematic reviews and meta-analyses summarize expected functional gains and considerations for long‑term stability. A 2023 systematic review found that masticatory performance improves after orthognathic surgery, though it may not reach levels seen with normal occlusion and outcomes depend on severity of the deformity; orthodontic treatment alone also improves masticatory performance. Other reviews evaluating long-term dental and dentolabial stability report variable outcomes and note limitations in the evidence base, recommending further prospective, long-term studies. These findings support the combined surgical–orthodontic approach while highlighting the need for individualized planning and follow-up. [[14]] [[15]]
Operationally, reviewers may request medical records that fully support medical necessity. Documentation should be legible and include relevant medical history, physical examination findings, and results of pertinent diagnostic tests or imaging to corroborate the stated deformity, measured thresholds, and associated functional impairments. The addition of explicit medical record documentation expectations in the policy clarifies that complete records may be requested for claims or prior‑authorization review but does not change the clinical criteria for medical necessity. [[4]] [[22]]