to determine the distances between the apices of the maxillary posterior teeth and the floor of the maxillary sinuses, and the thickness of the lateral bone covering these apices
n (patients): 38 Patients. n (Autopsy specimen): 12 specimens
Materials and Methods:
-Study sites were examined in three anatomic planes: sagittal, axial, and coronal
-Measurements were made by depositing one reference cursor at the root apex and another at the floor of the sinus
-The accuracy of the CT software measurements were compared with macroscopic in vitro measurements from 12 preserved autopsy specimens and no sig difference was noted -Results:
-The average distance from the maxillary molars and premolars to the floor of the maxillary sinus ranged from 0.83 mm for the MB root of the 2nd molar to 7.05 mm for the lingual root of the 1st premolar
-The thickness of buccal bone covering the apices ranged from 1.63 mm over the buccal root of the first
premolar to 4.45 mm over the MB root of the 2nd molar. The thickness of palatal bone covering the palatal roots of the 1st and 2nd molars and the 1st premolar was 7.01, 2.16, and 5.42 mm, respectively. 5% of the sample had roots that protruded into the sinus cavity Table.1.
on the basis of the thickness of bone, one could reason that the palatal roots of the first and second molars should be approached palatally whereas the palatal root of the first premolar should be approached buccally. However, other factors such as soft tissue reflection, control of hemorrhage, and visibility of the surgical field must also be considered.