Analysis of the anatomy of the maxillary sinus septum using 3-dimensional computed tomography.
ABSTRACT Maxillary posterior teeth exhibit a high incidence of periodontal bone and tooth loss. After tooth loss, the edentulous alveolar process of the posterior maxilla is often affected by resorption, which results in loss of vertical bone volume. Moreover, progressive sinus pneumatization leads to a decrease in the alveolar process from the cranial side. The sinus elevation and augmentation surgical technique opened a new way of anchoring endosseous implants despite discernible bone reduction. However, the surgical interventions require in-depth knowledge of maxillary sinus anatomy such as sinus septum and potential variations. The purpose of this study was to investigate the prevalence, location, height, morphology, and orientation of maxillary sinus septa by use of computed tomography (CT) and 3-dimensional imaging.
Two hundred patients undergoing implant treatment at the Yonsei University College of Dentistry, Seoul, South Korea, were randomly selected for analysis of maxillary sinus septa. CT and DentaScan (GE Medical Systems, Milwaukee, WI)-reformatted data from 400 sinuses were analyzed with the Preview program (Infinitt, Seoul, South Korea). Three-dimensional images were rendered for measurement by use of the Accurex program (CyberMed, Seoul, South Korea).
We found 111 septa in 400 maxillary sinuses (27.7%). This corresponded to 37% of the patients. Among total septa, 25 sinus septa (22.5%) were located in the anterior, 51 (45.9%) in the middle, and 35 (31.5%) in the posterior regions. The directional orientation analyses showed that 106 septa were buccopalatal, 4 were sagittal, and 1 was transverse type. The mean septal heights were 7.78 ± 2.99 and 7.89 ± 3.09 mm in the right and left sinuses, respectively.
Three-dimensional CT image analyses may provide useful information that can avoid unnecessary complications during sinus augmentation procedures by facilitating adequate, timely identification of the anatomic structures inherent to the maxillary sinus.
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ABSTRACT: Posterior maxillary region is considered to be the most challenging area for dental implant placement. Lateral window opening is the gold standard procedure for maxillary sinus augmentation in this area. The purpose of this study is to evaluate lateral wall thickness of the maxillary sinus for sinus augmentation using computed tomography (CT) in edentulous patients. Computed tomography images of 302 patients were analysed. Using the maxillary sinus floor as the reference point in edentulous regions, lateral wall thickness was measured on CT scans. After drawing a tangent line at the lowest point of the sinus floor, another perpendicular line to the tangent line was drawn at the same point of the sinus floor. Thickness of the lateral wall of the maxillary sinus was measured using 10DR implant software at 3 (R1), 10 (R2) and 15 mm (R3) from the sinus floor. The mean thickness of the lateral wall of the maxillary sinus from the first premolar to second molar was 1·69 ± 0·71, 1·50 ± 0·72, 1·77 ± 0·78 and 1·89 ± 0·85 mm, respectively. The thickness differed significantly at the R2 and R3 points. Women had thinner lateral walls at the R1 and R2 points at the premolars than did men. At the R2 and R3 points at the second premolar, the mean thickness of smokers was larger than that of non-smokers. There were no significant differences on age or reasons for tooth loss. The changes in the thickness of the lateral wall at different reference points were observed, and CT examinations may help make lateral window without membrane perforation.Journal of Oral Rehabilitation 04/2012; 39(6):421-8. · 2.34 Impact Factor
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ABSTRACT: The aims of this study were to measure the distance of the intraosseous vascular anastomosis in the anterolateral wall of the maxillary sinus from different reference points, and to correlate the location of the intraosseous vascular anastomosis with the tooth position and the residual bone height of the maxilla. Computed tomography (CT) images were taken from 283 patients undergoing dental implants placement in the posterior maxilla. Three horizontal lines were drawn at the ridge crest, maxillary sinus floor, and the position of the anastomosis. A vertical second line at the center of each tooth was drawn perpendicular to the horizontal lines. The distance from the ridge crest to the maxillary sinus floor and the distance from the maxillary sinus floor to the bony canal were measured from the intersections of the horizontal and vertical lines. The residual alveolar bone height was used to categorize three groups: group 1,<4 mm; group 2, between 4 and 8 mm; and group 3, >8 mm. The residual bone height values of different tooth positions were significantly different (P=0.0002). The distance from the maxillary sinus floor to the intraosseous vascular anastomosis was significantly different between groups 1 and 3 (P=0.0039). At the molar sites, a moderate negative correlation was found between the residual bone height and the distance from the maxillary sinus floor to the intraosseous anastomosis. The distances of the alveolar ridge crest and the maxillary sinus from the intraosseous vascular anastomosis were not significantly different between sexes. Within the limitations of this study, sites with a higher residual bone height in the molar regions were at a relatively high risk of artery damage during window osteotomy preparation; therefore, we recommend taking more precautions when using a lateral approach for sinus elevation.Journal of periodontal & implant science 04/2014; 44(2):50-6.
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ABSTRACT: To gain further insights and resolve conflicting results in the literature regarding prevalence, predominant location and morphologic variability of maxillary sinus septa. Electronic and hand searching of English literature identified 33 investigations published from 1995 to 2011. Septa were defined as at least 2-4 mm in height. Septa were present in 28.4% of 8923 sinuses investigated (95% confidence interval: 24.3-32.5%). Prevalence was significantly higher in atrophic sinuses compared with dentate maxillae (p < 0.001). Septa were located in premolar, molar and retromolar regions in 24.4%, 54.6% and 21.0% respectively. Orientation of septa was transverse in 87.6%, sagittal in 11.1% and horizontal in 1.3% of cases. Septa height measured 7.5 mm on average. Complete septa (dividing the sinus into two separate cavities) were found in only 0.3%. Other rare conditions included multiple septa in one sinus (4.2%) and bilateral septa (17.2%). Septa diagnosis using panoramic radiographs yielded incorrect results in 29% of cases. In view of their high overall prevalence and significant morphologic variability, 3D radiographic imaging prior to sinus floor augmentation may help to reduce complication rates in the presence of maxillary sinus septa.Journal Of Clinical Periodontology 04/2012; 39(8):769-73. · 3.69 Impact Factor