Muscle architecture, the arrangement of fibre bundles within the muscle volume, has important functional implications. Previous studies of infraspinatus (IS) muscle architecture have focused on dissection and photography of the superficial muscle layers rather than a volumetric analysis. The aim of this study was to develop a methodology to quantify the architectural parameters of the fibre bundles throughout the volume of IS. As a prototype, one formalin‐embalmed cadaveric specimen was used. The IS was exposed and each fibre bundle was meticulously dissected and digitized from end to end. The digitized data was imported and a 3D model of the fibre bundle architecture, as in situ, was constructed in Autodesk® Maya®2012. Architectural parameters including fibre bundle length (FBL), pennation angle (PA), and physiological cross sectional area (PCSA) were computed. Based on the architectural parameters, muscular partitioning was determined. This technique successfully captured IS architecture throughout its volume. The IS was found to consist of 2 architecturally distinct regions, superior and inferior. The average measures for the superior and inferior regions were respectively: FBL 115.3mm; PA 22.2°; PCSA 180.3mm2 and FBL 84.9 mm; PA 15.9°; PCSA 550.5 mm2. The results suggest that there is muscular partitioning of the IS. This methodology will form the basis of a continuing study to understand detailed IS architecture at the fibre bundle level.

Introduction The greater palatine canal route has been well‐described in adults for the purposes of anesthetizing the branches of the maxillary division of trigeminal nerve for the relief of sphenopalatine neuralgia [11]. The canal also provides direct access to the contents of the PPF [12]. A complex array of vascular and neural structures characterizes this posterior maxillary region where the GPC is located. Its surgical anatomy can get further complicated by any anatomic variations and identification of vital structures becomes difficult, especially when bleeding during surgery obscures the region. Accurate knowledge of normal anatomy and common anatomical variations therefore remain crucial in minimizing intraoperative and postoperative complications associated with invasive microsurgical approaches to this region. The aim of this study was to explore the architecture of the GPC for any anatomic variations. Material & Method In total, 30 adult dried and intact skull specimens were selected. The selection criteria included an intact hard palate with erupted 3rd molars and an intact lateral nasal wall on both sides. The exclusion criteria included any major craniofacial deformities, excessive bone resorption, very old specimens. The bony walls of the GPC were observed by passing a black wire. Findings 4 out of 30 specimens showed marked variations in the bony medial wall of the greater palatine canal (GPC). Partial to complete malfusion between the posterior surface of the maxilla and the perpendicular plate of palatine bone was observed. This might be the result of embryological malformation. Conclusion The present study provided information regarding the existence of some degree of anatomical variation in the bony architecture of greater palatine canal. Significance This might help surgeons visualize over the possibility of the existence of any such variation while performing any surgical procedure in the posterior maxillary area. In order to establish the embryological basis of these findings, investigation on a larger number of specimens is highly suggested by the authors.