Introduction
The intrauterine development of paranasal sinuses commences in the form of mucosal invaginations in the 3rd and 4th months. 1There are four paranasal sinuses named after the bone they are associated with: maxillary, ethmoid, sphenoid, and frontal. The ethmoid sinuses are between the orbits. They are formed as labyrinths and vary in number from 3 to 18. The maxillary sinuses are the largest of the paranasal sinuses, located bilaterally in the maxilla. The frontal sinuses are in the frontal bone superior to the orbits and vary in size. The  sphenoidal sinuses are in the body of the sphenoid bone and open into the posterior wall of the sphenoid-ethmoidal recess.2
The maxillomandibular complex is often affected by developmental problems and growth problems, and unilateral, bilateral, horizontal, vertical and / or transverse deficiencies are observed. Treatment of this complex is often performed by surgical intervention involving one or both jaws. In surgeries involving the maxilla, maxillary sinuses are affected by the surgery and affect the course of surgery and precise knowledge of such structures with variable anatomy will be important.3,4 Paranasal sinuses are also very important structures for closely related endoscopic sinus surgeries, endoscopic skull-base interventions like pituitary adenomas, anterior and middle skull-base meningiomas, craniopharyngiomas, surgical repair of (cerebro-spinal fluid) CSF fistulas and osteotomies involving the maxilla such as Le Fort osteotomies.3 Detailed preoperative investigation is crucial for patient selection and hence desired outcome.5
The present study aims to compare ethmoid, sphenoid and maxillary sinus volumes and the presence of Onodi cells in patients with maxillary deficiency requiring Le Fort osteotomy compared to healthy patients, by employing computed tomography imaging. No accessible information could be found on this subject during literature search. The authors believe anatomical knowledge of these structures in patients with maxillary deficiency will influence all branches performing surgeries in these areas.