Size and shape of the pterygopalatine fossa of the skull of a child aged 3–5 years based on the analysis of computed tomography scans
Authors: Prokofiev Aleksandr S. , Makeeva Ekaterina A. , Mitrokhina Eugenia О. , Chukbar Aleksandr V. 
Published: September 2024

BACKGROUND: Endoscopic microsurgical techniques are used for sparing operations to remove foreign bodies of the pterygopalatine fossa, as well as neoplasms invading into it or growing out of it. These surgeries are performed not only in adults, but also in children as young as one month. For these surgeries, understanding the detailed structure and morphometric characteristics of the pterygopalatine fossa is crucial. However, detailed descriptions specific to children are lacking in the literature.
AIM: This study aimed to examine the size and shape of the pterygopalatine fossa and the relative location of nerve foramina in children aged 3 to 5 years (the period of primary dentition) using computed tomography data.
MATERIALS AND METHODS: To study the size and shape of pterygopalatine fossa, we analyzed anonymous archival frontal and axial computed tomograms of 12 children (24 pterygopalatine fossae) aged 3 to 5 years, obtained for examination of the underlying disease (brain pathology). All computed tomography scans were obtained using a helical computed tomograph (Somatom Sensation 64; Siemens, Germany) with an effective current of 63, 120 kV, a slice thickness of 0.5 mm, a reconstruction step of 0.7 mm, a collimation of 12×0.6 mm, Kernel U 70, a window width of 450 HU and a window center of 50 HU in University Clinic of Russian University of Medicine. The measurements were performed in the Cdviewer software after the preliminary measurements had determined sufficiently constant points on the contours of the pterygopalatine fossa of scans. On axial sections passing through the pterygoid canal, where the measurements had the greatest values, the following were studied: the largest width of the pterygoid canal (the distance between the anterior opening of the pterygoid canal and the orbital process of the palatine bone), the width of the medial wall and separately the width of the sphenopalatine foramen and the sphenoidal process of palate bone, the angle of deviation the medial wall from the sagittal plane, the width of the anterior wall (the distance between the most posteriorly protruding point of the anterior wall of the pterygopalatine fossa to the orbital process of the palatine bone), the greatest depth of the pterygopalatine fossa (posterior wall width) and the width of the pterygomaxillary fissure. The distance from the level of the orifice of the greater palatine canal to the anterior opening of the pterygoid canal and to the round foramen were measured on the frontal sections. According to axial tomograms, the spatial ratios between the orifice of the greater palatine canal and the round foramen and the anterior opening of the pterygoid canal, between these openings and the sphenopalatine foramen, between the round foramen and the anterior opening of the pterygoid canal were assessed.
RESULTS: The study found that the shape of the pterygopalatine fossa differs from the pyramid-like structure, featuring four distinct parts: the main one adjacent to the sphenopalatine foramen, and funnel-shaped constrictions at the vestibule of the pterygoid canal, greater palatine canal, and pterygomaxillary fissure. The data indicated minor individual differences in the size of the pterygopalatine fossa and the uniformity of its shape in children aged 3 to 5 years. The spatial relationships of the orifice of the greater palatine canal, the anterior opening of the pterygoid canal, the round foramen, and the sphenopalatine foramen openings determining the position of the nerves in the pterygopalatine fossa were clarified.
CONCLUSIONS: Pterygopalatine fossa in children aged 3 to 5 years (period of formed primary dentition) is characterized by a complex cavity structure, suggesting a different position of the pterygopalatine ganglion in it than is commonly believed. This circumstance, as well as for the first time the sizes of the pterygopalatine fossa determined by us, should be considered when developing surgical access to the pterygopalatine fossa and the pterygopalatine ganglion.