Different Treatment Modalities for Atrophied Distal Extension Maxillary Ridges

Inclusion Criteria: The patients will be selected according to the following: * They have distal extension maxillary ridge with sinus pneumatization and remaining alveolar bone height 6- 8mm as verified by preoperative CBCT, have no previous denture experience. They are healthy, free from any systemic diseases relating to the bone resorption (diabetes - hyperparathyroidism). This can be achieved through medical history and clinical examination by a physician and laboratory investigations. * Posterior maxillary alveolar ridge deficient in height, width and covered with healthy firm mucosa. * Patients are less satisfied with conventional RPD. * Absence of maxillary sinus diseases. Exclusion Criteria: * Acute or chronic sinus pathology * History of a sinus augmentation in the past in the relevant sinus * Poor dental hygiene. Smoker. * Compromised general health (uncontrolled diabetes, bleeding disorder