Bilateral Buccal Fat Pad Flap in Primary Palatoplasty: Palatal Index-based Indication Criteria and Impact on Oronasal Fistula Rate.

BACKGROUND: Oronasal fistula (ONF) remains a common complication following primary palatoplasty, particularly in wide clefts. The use of pedicled bilateral buccal fat pad flaps (BFPFs) has shown promise in reducing ONF incidence, but clear indication criteria are lacking. This study evaluates the efficacy of BFPF interposition in primary palatoplasty and explored the use of the palatal index (PI) as a quantitative tool for flap indication. METHODS: A systematic literature review following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines identified studies reporting bilateral BFPF use during primary palatoplasty. Additionally, a retrospective cohort analysis was conducted on 139 patients undergoing primary cleft palate repair (2017-2024) at a single institution. Following a protocol revision in 2021, BFPF was selectively used based on intraoperative assessment. In the post-2021 cohort, PI and cleft width were measured to determine their association with BFPF use and ONF incidence. RESULTS: The systematic review revealed limited studies with inconsistent reporting on cleft severity and BFPF indication. In the institutional cohort, ONF incidence dropped significantly from 15.5% (group A) to 2.5% (group B; P = 0.005). BFPFs were used in 46.9% of post-2021 cases, primarily in severe clefts (PI ≥ 0.43). PI was significantly higher in patients receiving BFPF (P < 0.001), and no ONFs occurred above the 0.43 PI threshold. CONCLUSIONS: Bilateral BFPF interposition significantly reduces ONF incidence in primary palatoplasty. The PI is a useful, objective criterion to guide its use, with a PI value of 0.43 or higher proposed as an effective threshold. These findings support incorporating BFPF into standardized protocols for primary palatoplasty.