In partial fulfilment of the requirements for the degree of Master in Medical Research.

Abstract:
Background and Objectives:
There were lack of studies in Nepalese population evaluating the lateral wall thickness of maxillary sinus. The lateral wall thickness of maxillary sinus is one of the crucial parameters for implant placement specially in the aged population for posterior maxilla. Hence, this study was carried out to measure the lateral wall thickness of maxillary sinus and look for potential variations as per age, gender, and ethnicity in a tertiary care center of Nepal.

Methods:
A cross-sectional analytical prospective study was conducted on 110 patients (57 males and 53 females) over a period of 4 months who fulfilled the inclusion criteria using cone beam computed tomographic images. The sinus wall thickness was measured at 3mm, 6mm and 9mm from the base of maxillary sinus in four different teeth i.e., maxillary right first molar, maxillary right second premolar, maxillary left first molar, and maxillary left second premolar which are generally near maxillary sinus. The calculated values were analyzed for variations among different age groups, gender, and ethnic groups as per the Health Management Information System of Nepal.

Results:
The overall mean sinus lateral wall thickness (LWT) was found to be 1.52±0.76mm which was found to be greater in molar region (1.72±0.82mm) when compared with premolar region (1.32±0.64mm). The relation between the lateral wall thickness of maxillary sinus and age, gender and ethnicity were not statistically significant except for maxillary left premolar which was found to be increased with increasing age and in females.

Conclusion:
Within the limitations of this study, the pattern of lateral wall thickness of maxillary sinus seems to be favorable for direct sinus lift in Nepalese population provided that other factors affecting the sinus lift procedure are well evaluated.

Key words: Dental implant, Edentulism, Lateral wall thickness, Maxillary sinus, Nepal