To assess the accuracy of the computer assessed guides in horizontal bone augmentation achieved at posterior mandible using guided modified ridge splitting technique versus free hand modified ridge splitting technique

The first treatment plan includes harvesting and fixing the bone graft in posterior mandibular area using a computer-modified surgical guide.

The second treatment plan includes manually harvesting and fixing the bone graft in posterior mandibular area without a surgical guide.

Inclusion Criteria:

• posterior mandible with horizontal deficient alveolar ridge that is from 2 to 4 mm measured from the crest of the alveolar ridge buccolingually
• Age range from 25-55 years. No sex predilection.
• Patients free from any systemic conditions and bone metabolism diseases that might interfere with the surgical intervention, soft tissue or hard tissue healing.
• Patients of adequate alveolar bone width.
• Both genders males and females will be included
• Normal vertical dimension with normal inter-arch space. The minimum number of missing teeth in the posterior mandible alveolar ridge is two adjacent anterior teeth

Exclusion Criteria:

• Intra-bony lesions (e.g. cysts) or infections (e.g. abscess) that may retard the osteotomy healing.
• Previous grafting procedures in the edentulous area.
• General contraindications to implant surgery.
• Subjected to irradiation in the head and neck area less than 1 year before implantation.
• Untreated periodontitis.
• Poor oral hygiene and motivation.
• Uncontrolled diabetes.
• Pregnant or nursing.
• Immunosuppressed or immunocompromised
• Heavy smokers
• Patients undergo medication interfere with bone healing