Evaluation of the relationship between roots of first and second maxillary molars and floor of maxillary sinus using cone-beam computed tomography

Maxillary sinus gradually extends laterally and inferiorly during pneumatization, and lamina dura of molar and premolar teeth can make a part of sinus floor. Knowledge about this anatomic relationship is essential to prevent complications paticularly iatrogenic perforation of sinus floor. Limitations of periapical and panoramic radiographs to visualization of this relationship led to the usage of cone-beam computed tomography (CBCT). This study was aimed to evaluate the vertical and horizontal relationship between roots of maxillary molars and sinus floor in CBCT images.

In this descriptive cross sectional study, ninety-five samples were selected of patients in Department of oral and maxillofacial radiology in Tabriz, Iran using simple randomization. Mean age of patients was 32.5 years old. Images were made by VGi cone beam Newtom and reconstructed by NNT viewer version 2.17. The vertical and horizontal relationship between roots of 139 maxillary first and 126 second molar teeth and floor of sinus evaluated.

Type 2 was the most common relationship among the first and second molars, vertically (the inferior wall of the sinus located below the level connecting the buccal and palatal root apices,without an apical protrusion) and horizontally (the alveolar recess of the inferior wall of the sinus located between the buccal and palatal roots). There was a significant relationship between the type of tooth and sinus floor (P<0.05).

Most of the maxillary molar roots were in contact with sinus floor and sinus floor was extended mostly between buccal and palatal roots vertically and horizontally, respectively. Attention to sinus involvement possibility during interventions in maxillary molar region is important.