the evaluation of patient satisfaction of All on-4 versus All on-3 implant treatment concepts rehabilitation of atrophied mandibular ridge.

Patients will be classified into 2 groups according to the implant treatment concept they received:

• Group 1 (control group); included patients who received All on 4 implant-supported fixed restoration. The patients received 2 inclined implants anterior to the mental foramina and 2 vertical implants in the lateral incisor/canine areas.
• Group 2 (test group); included patients who received All on 3 implant-supported fixed restoration. The patients received 2 inclined implants anterior to the mental foramina and 1 vertical implant in the midline of the mandible.

Inclusion Criteria:

• 1. All patients already have implants inserted in their mandibular ridges According to the All on 4 or All on 3 concepts.

  2. They were healthy, free from any systemic diseases relating to bone resorption such as uncontrolled diabetes or osteoporosis. This was achieved through medical history and clinical examination by the physician.

  3. All patients have sufficient inter-arch space. 4. All patients are of angle class I maxillo-mandibular relationships. 5. All patients had maxillary conventional complete dentures.

Exclusion Criteria:

1. Any neuromuscular disorders 2. Uncooperative patients

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