Introduction: the total volume of maxillary sinus is important for maxillofacial reconstruction, plastic surgeries and prosthetic rehabilitation. It is important to diagnose sinus hypoplasia secondary to craniofacial syndromes, sinus obliteration caused by infections or blood dyscrasis.
Aim of the study: The aim of this study was to assess the accuracy of CBCT volumetric measurements of maxillary sinus using the geometric rule of pyramid volume based on CBCT linear measurements versus real skull measurements.
Materials and methods: fourteen skulls were scanned using Planmeca Promax 3D MID and the maxillary sinus pyramid height, length and width were measured in cm. The volume of 24 sinuses were calculated from pyramid volume (cm3) = 1/3 Height × Length × Width. The CBCT volumes and the reference standard were analyzed for error assessment using Dahelberg error and Relative Dahelberg Error.
Results: 4.3- 4.7% was the error obtained from CBCT volumetric measurements using the rule of pyramid volume. 0.9 correlation was detected between the CBCT volume and the reference standard, between the observers and within the same observer.
Conclusion: the geometric rule of pyramid volume based on CBCT linear measurements can be used to assess maxillary sinus volume.