Implant Size Selection and Location of Anatomical Structures Prior to Implant Placement to Retain Mandibular Overdentures: Panoramic Radiographs vs Cone Beam Computed Tomography - Abstract
Objectives: We investigated the level of agreement amongst clinicians on the size of the implants planned to retain a two-implant mandibular overdenture based on panoramic radiographs and on Cone Beam Compute Tomography (CBCT) scans as well as their confidence in accurately locating various anatomical landmarks in the anterior mandible.
Materials and methods: To select the appropriate diameter and length of implants planned to retain an overdenture, panoramic radiographs and the associated putty replicas of the edentulous mandibles of 15 patients were given to a group of 20 dentists and radiologists. The assessors were also asked how accurately they could locate seven anatomical landmarks in the anterior mandible using a 5-point Likert scale. One week later, the same exercises were performed on the basis of the information provided by CBCT scans.
Results: The agreement between the selected implant length and diameter based on the panoramic radiographs and on the CBCT scans was poor. The length differed in approximately 50% of the cases (Cohen’s kappa = 0.26), and the diameter in 30% of the cases (Cohen’s kappa = 0.07 and 0.09). The assessors’ confidence in accurately locating anatomical structures, such as the incisive canal was significantly higher when CBCT scans were available (p<0.001).
Conclusions: Preoperative selection of the appropriate implant size for an overdenture may be enhanced by examining cross-sectional images. Based on the additional information provided by CBCT scans, narrower and shorter implants were selected by the clinicians. The availability of CBCT scans seemed to improve the visualization of important anatomical landmarks in the anterior mandible.