I have treatment planned a case for installation of an implant in the maxillary first premolar area. Radiography shows an alveolar ridge bucco-lingual dimension of 4.5mm. There is 11mm between the maxillary alveolar ridge height and the floor of the maxillary sinus. Can I place a 3.3mm diameter implant and attempt to install just under or just barely against the sinus wall? Should I engage both cortices for bi-cortical stabilization? There is about 7-8mm mesiodistal space between the maxillary canine and second premolar. Patient declines sinus lift and bone graft. What do you recommend?