Sinus graft is a surgery performed to add bone to help replace a missing back tooth in the upper jaw. Tooth loss may lead to shrinkage of jaw bone in the maxillary sinus floor. A dental implant surgery requires enough bone volume to hold the implant. Sinus graft is a complex surgery where a lateral opening is made and the soft skin of the maxillary sinus is separated from the bone in order to build the bone using substitute material. The process requires exceptional skills from the dentist.