MAXILLARY SINUS MORPHOMETRY AND ITS SEPTA: AN ANATOMICAL, AND RADIOLOGICAL STUDY
Mohamed Atif Said Ahmed* and Ashraf H. Abd El-Hakem**
Anatomy Department, Faculty of Medicine, Zagazig University*,Assiut University**, Faculty of Medicine,King Khaled University, Abha, KSA.
As the maxillary sinus is the largest paranasal sinus, so its exact anatomical knowledge is very important for endoscopic sinus surgery and for a preoperative evaluation. Providing normative values for maxillary sinus could be helpful in evaluating the presence of any abnormality. Knowledge of the topography between the root apex of the maxillary teeth and the inferior wall of maxillary sinus is important for diagnosing and planning dental implantation, endodontic procedures, and orthodontic treatment.OBJECTIVES: First, to clarify the volume and dimensions of the maxillary sinus. Second, to determine the prevalence as regards of maxillary sinus septa, location, and morphology in dentate and partially dentate maxillary segments. Third, to identify the vertical relationship of maxillary sinus inferior wall with the roots of the maxillary teeth. METHODS: Maxillary sinus volume was quantified in 24 cadavers (48 sinuses) Maxillary sinus size was measured in cadavers using casts of the maxillary sinus made by using dental impression material. Volume of cast material was recorded and also the dimensions of the cast inside the sinus. Our study used also 30 dry skull bones from adults of both sexes. A retrospective study was performed using panoramic radiographs of 223 patients and cone beam CT of 47 patients. The distance between each root apex and the inferior wall of the maxillary sinus were measured.RESULTS: Antero-posterior length, height, width, and volume of the maxillary sinus (mean ± SD) were 30.9±6.35 mm, 33.6±6.91 mm, 25.9±6.11 mm, and 14.9±5.2 ml, respectively. The prevalence of one or more septa per sinus was found to be 26 % , 29% and 24.5% in the overall study population and the partially dentate and dentate maxillary segments, respectively. The incidences and classifications of the vertical relationship between the inferior wall of the maxillary sinus and the roots of the maxillary teeth were studied. Type I was most common in 1st molar and 2nd premolar, Type I and type IV were nearly the same number for 2nd molar. The less number for the 2nd premolar was found in the type V, while it was the type III for the 1st and 2nd molar. The apex of the roots of the 2nd molar, 1st molar and 2nd premolar were 2.1 mm, 3.1 mm 5.7 mm respectively away from the inferior wall of the maxillary sinus. Analysis of the projection lengths of the roots showed that the mean length of 1st and 2nd molar teeth roots superior to the sinus floor (2.90, 3.20 mm) was longer than that of the second premolars (1.80 mm). Maxillary 2nd molar roots were protruded into the sinus more frequently than the roots of other teeth (47.8%).CONCLUSIONS: Our results may be helpful in understanding normal volumetric values of the maxillary sinuses. There is a wide anatomical variations in the prevalence as regards of maxillary sinus septa, size, location, and morphology. This study demonstrated various anatomical characteristics and relationships between the inferior wall of the maxillary sinus, and its surrounding structures. The knowledge of the presented data may have clinical applications in the area of oral and maxillofacial diagnosis as well as in surgical procedures.