Trephine Osteotomy in Lateral Sinus Lift

Inclusion Criteria: * Patients of both genders requiring implant placement in the posterior maxilla. * Age between 20-50 years. * Tooth extractions at the implant sites were performed at least 4 months before surgery. * Residual bone height between the alveolar bone crest and the sinus floor ranges from 4 to 6 mm. * Patients who are willing and fully capable to comply with the study protocol Exclusion Criteria: * Maxillary sinus pathologies (sinusitis, long standing nasal obstruction) * Any disease contraindicating surgery (e.g. uncontrolled diabetes) * Heavy smokers * Acute oral infections * Poor oral hygiene * A history of radiotherapy or chemotherapy of the head and neck region