The aim of this study was to assess the efficiency of the computer-guided interpositional sandwich osteotomy for the vertical bone gain and effects on vital structures (inferior dental nerve bundle) compared to free hand interpositional osteotomies.

in this research a full digital sandwich osteotomy protocol was conducted to be compared with the conventional protocol. the investigators were seeking to determine the significance of using surgical computer software in sandwich interpositional bone grafting at atrophied posterior mandibles and how efficiently can it affect this technique.

Inclusion Criteria:

• • Edentulous posterior mandibular ridge with vertical loss of alveolar bone with remaining bone height (4-7 mm) above the mandibular canal

  • Good oral hygiene
  • Highly motivated patients
  • Patients seeking fixed prosthesis at posterior mandibular region.
  • Patients willing for a surgical procedures follow-up with an informed consent
  • Age range 20-65 years

Exclusion Criteria:

• • Smokers

  • Individuals with dentulous posterior mandible ridge
  • Medically compromised patients
  • Patients with local pathosis at the surgical area suggested
  • Previously subjected to reconstructive procedures of the posterior mandible