Anatomic considerations for immediate implant placement in the mandibular posterior region –A systematic review and meta-analysis

To review anatomical considerations for immediate implant placement in the mandibular posterior region using Cone Beam Computed Tomography (CBCT). A systematic electronic literature search was conducted independently by two reviewers across PubMed, Web of Science, ProQuest, Scopus and Cochrane databases, supplemented by a manual search, to identify eligible clinical studies published from 2006 up to October 2024. Studies evaluating anatomical parameters relevant to implant placement were included. From 1,151 records,12 studies met the inclusion criteria, involving 1,834 patients who received immediate implants in the mandibular posterior region. The meta-analysis showed that the mean distance between the root apex and the inferior alveolar canal was 5.14 mm for premolars, 6.32 mm for first molars, and 4.65 mm for second molars. Undercut ridge morphology was most prevalent at the second molar site (73%), posing a higher risk for lingual plate perforation. Immediate implant placement in the mandibular posterior region requires careful anatomical assessment, with particular attention to the distance from the inferior alveolar canal and the potential risk of lingual plate perforation, to optimize treatment outcomes.