Topographic Anatomy of the Lateral Pterygoid Muscle: Implications for Landmark-Guided Extraoral Interventions

This study aimed to define the topographic anatomy and morphometry of the lateral pterygoid muscle (LPM) and the lateral pterygoid plate (LPP) in relation to superficial facial landmarks. The objective was to enhance the anatomic foundation for safe and effective extraoral interventions in temporomandibular disorders (TMD), such as botulinum toxin and dry needling procedures. Dissections were performed on 30 hemifacial cadaver specimens (18 female and 12 male). The length and thickness of the superior and inferior heads of the LPM and their vertical and transverse distances to the angulus oris, tragus, and lateral canthus were measured. The orientation of the LPP relative to these landmarks and its angle with the maxillary tuberosity (pterygomaxillary angle) were also assessed and categorized. The inferior head of the LPM was significantly longer and thicker than the superior head ( P <0.001). It was positioned more laterally and inferiorly to key landmarks. The mean pterygomaxillary angle was 124.73±16.57 degrees, with type II (moderately obtuse) being most prevalent (63.3%). Sixteen statistically significant correlations among morphometric parameters (q<0.05) were found, indicating strong anatomic consistency. Consistent anatomic relationships between the LPM, LPP, and facial landmarks provide reliable reference points for extraoral procedures. The maxillary tuberosity is particularly useful in guiding insertion angle and orientation. The findings support the development of safer and more standardized extraoral injection techniques for managing temporomandibular disorders.