Evaluation of the Socket Morphology of Mandibular Molars for Immediate Implant Placement Using Cone-Beam Computed Tomography (CBCT) Imaging

The aim of this retrospective study was to assess the dimensions of the mandibular molar socket for immediate implant placement, using cone-beam computed tomography (CBCT) imaging.

The CBCT images of 81 patients were selected based on the inclusion and exclusion criteria. In the OnDemand software, measurements were assessed by virtually positioning a regular Straumann implant (4.8 mm) in the regions of the first and second mandibular molars. The socket morphology, the buccolingual width of cancellous bone, the gap between the implant and the socket wall, the length of the root, the cross-sectional morphology of the mandible, and the height and thickness of the inter-radicular septum were all determined. The variables were compared using either the Student’s t-test or the Mann-Whitney U test.

Among the cross-sectional morphologies of the mandible, the undercut type (U) was found to be the most prevalent. The mean distance of the implant from the inferior alveolar nerve (IAN) was found to be 6.22 mm for the first molars and 5.17 mm for the second molars. Moreover, the mean horizontal distances from the implant to the mesial and distal socket walls were 2.01 and 2.30 mm for the first molars and 2.14 and 2.59 mm for the second molars, respectively. The width of the interradicular septum across various sections was found to have a significant correlation with the position of the tooth (P<0.05).

The majority of the samples exhibited the undercut (U type) morphology of the mandible. The interradicular septum in the second molar tooth was found to be insufficient. Overall, the assessment of pre-extraction CBCT scans and the virtual positioning of implants can be beneficial for surgical treatment planning. This approach can also aid in minimizing potential complications.