Evaluation of the neurosensory disturbances after inferior alveolar nerve lateralization with and without isolation of the simultaneously placed implants using collagen membrane And measuring the stability of implants after placement .

Inclusion Criteria:

• Adult patients with with atrophied posterior mandibular ridge
• Both sexes.
• No intraoral soft and hard tissue pathology.
• No systemic condition that contraindicate implant placement.

Exclusion Criteria:

• Presence pathological lesions
• Heavy smokers more than 20 cigarettes per day .(24)
• Patients with systemic disease that may affect normal healing.
• Psychiatric problems
• Disorders to implant are related to history of radiation therapy to the head and neck neoplasia, or bone augmentation to implant site.