Temporalis muscle innervation patterns are generally conserved across subjects

Abstract

The temporalis muscle is structurally complex; its muscular architecture is often misrepresented and its innervation pattern is not well characterized. In this study we digitized and mapped the 3D extramuscular and intramuscular mandibular nerve course from foramen ovale to its terminal branches in the temporalis muscle belly in four formalin embalmed cadaveric specimens. The muscle mass was dissected and digitized in layers to map its volume. The digitized nerve and muscle volume data were reconstructed into a 3D model using Maya® for visualization. Lateral 2D views were then manually registered to a common geometrical template using linear and non‐linear transformation techniques in Adobe Photoshop CS5. The extramuscular innervation consisted of three deep temporal nerves corresponding to anterior, middle and posterior portions of the muscle, masseteric and buccal nerves. Intramuscularly, the extent of muscle mass innervated by each of the nerves differed depending on the number of terminal branches. The spatial distribution of registered nerve branches was generally conserved suggesting that the degree of terminal branching was indicative of neurogenic control. We noted abundant intramuscular nerve fiber anastomosis from the anterior to posterior extent of the muscle in individuals. This work was supported by the American Association of Anatomists Visiting Scholarship.