Anatomical Prevalence and Surgical Implications of the Ossified Pterygospinous and Pterygoalar Ligaments: A Systematic Review with Meta-Analysis.

Abstract

Background: The infratemporal fossa (ITF) houses critical neurovascular structures and is frequently accessed in skull base and craniofacial surgery. Ossification of the pterygospinous (PSL) and pterygoalar (PAL) ligaments-forming the pterygospinous (PSB) and pterygoalar (PAB) bars represents a clinically crucial ossified (morphological) variant that may alter surgical access and predispose to nerve entrapment.

Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA 2020 and Evidence-Based Anatomy guidelines. PubMed, Scopus, Web of Science, and Google Scholar were searched for studies reporting the prevalence and morphometry of ossified PSL and PAL. Data were synthesized using random-effects models in R software.

Results: Sixty-nine studies comprising 54,542 skull sides met the inclusion criteria. The pooled prevalence of PSB was 8.36%, with incomplete ossification (6.89%) more frequent than complete ossification (2.04%). The overall PAB prevalence was 7.85%, also dominated by incomplete forms (5.30%). The combined presence of PSB and PAB was identified in 1.32% of cases.

Conclusions: The ossification of the PSL and PAL represents a relatively common morphological variation with significant implications for skull base and trigeminal interventions. These ossified structures may impede cannulation of the foramen ovale, alter local anatomical relationships, and contribute to trigeminal or lingual nerve entrapment, which could lead to unsuccessful or complicated procedures. Routine preoperative imaging using computed tomography or cone beam computed tomography should be considered when approaching the FO to identify these variants. Additional anatomical and clinical research is warranted to optimize surgical strategies and enhance patient safety in cases involving PSB and PAB.