Background: Alveolar bone height in the posterior maxillary region is very important
and critical for dental implant planning and placement.
Objectives: This study aimed to evaluate the anatomy of the maxillary sinus floor in relation to the
alveolar crest and to determine variations in the vertical measurements between the maxillary sinus
floor and the alveolar bone crest tip in the posterior edentulous maxilla with the use of cone beam
Methods: This analysis enrolled 234 retrospectively selected patients (123 males with mean age
52.95±11.74 (range 32-76 years) and 111 females with mean age 58.14±11.92 (range 32-75 years))
with edentulous posterior maxillary regions. The maxillary sinus floor was divided into three anatomical
segments (anterior, median and posterior) in relation to the transverse palatine suture. The
measurements were performed on 3D surface rendered volumetric images by using rotation and
translation of the views. Landmarks for measurement were specified by using a cursor driven
pointer. Vertical lines were marked on the cross-sectional images between the alveolar ridge and the
deepest point of the maxillary sinus floor for each of the three regions. P < 0.05 was regarded as
Results: The mean distance values between the sinus floor and the alveolar crest in the anterior,
median and posterior regions were 8.74±3.97 mm, 5.37±3.23 mm and 7.06±3.28 mm, respectively.
Measurements in the anterior region were found to be high in both total and gender groups compared
to other regions. Also, subsinus alveolar bone heights decreased with increasing age in both
genders in all three regions.
Conclusion: This study emphasizes that the mean subsinus alveolar bone height is highest in the
anterior segment of the edentulous posterior maxilla. These results may guide clinicians to make the
decision of implant placement area and lead to less invasive alternative surgery methods for edentulous