Oral rehabilitation by dental implants in the severely atrophic maxilla often represents a challenge. To overcome this difficulty, bone augmentation procedures such as sinus augmentation, guided bone regeneration (GBR), or distraction osteogenesis have been used to obtain adequate bone height and width for proper three-dimensional implant placement. To avoid surgical morbidity and shorten treatment length, alternative methods such as short or tilted implants, as well as zygomatic implants (ZIs),have been proposed and have shown promising outcomes.

Placement of dental implants in the pterygo-maxillary region provides adequate posterior bone support for the prosthesis which permits better distribution of masticatory forces without the need of sinus floor augmentation, onlay and inlay grafts, split crest technique, or osteogenic distraction. This allows rehabilitating patients with satisfactory full arch fixed maxillary prosthesis, which is usually spanned from second molar to contralateral second molar tooth.

The purpose of the present study is to compare the Reliability of all on four by 2 zygomatic implants with 2 conventional implant in anterior region versus all on four approach by conventional implant for the rehabilitation of the atrophied maxilla in terms of survival rates and improving the quality of patient's life and involved complication with maxillary sinus.

Inclusion Criteria:

1. Patients with severely atrophic edentulous upper arch (Cawood class IV, V, VI) that could not be restored with other type of treatment.
2. Patients who had at least 8-12 mm vertical bone height in anterior maxilla to allow installation of at least 2 conventional implants.

Exclusion Criteria:

1. Patients with any systemic disease that might interfere with dental implants placement and/or osseointegration e.g. uncontrolled diabetes, hypertension and osteoporosis, etc.
2. Heavy smoker (> 20 cigarettes daily) and patients with history para-functional habits (e.g. clenching or bruxism, etc.) were also excluded.
3. Intraoral pathological lesion, related to maxilla, maxillary sinus and zygoma.

data to be shared after publication of the study

after puplication

data will be share upon request from Colleges