Comparative evaluation of three different methods for evaluating alveolar ridge dimension prior to implant placement: An in vivo study

Background: During treatment planning for dental implant placement, there is a need for assessment of alveolar bone. Bone evaluation limited to the use of panoramic and or periapical radiographs may be insufficient, as it provides only two-dimensional information about the implant sites. Computed tomography (CT) provides three-dimensional information. The measurement of alveolar ridge dimensions can be accomplished using ridge-mapping technique. This technique involves penetrating the buccal and lingual mucosa down to the alveolar bone (following the administration of local anesthetic) with calipers and measures the bucco-lingual width of the underlying bone. Purpose: The aim of the study is to compare the techniques, i.e. ridge mapping, direct surgical exposure, and CT scan, which are used to measure the alveolar ridge bone width, and determine their accuracy in the clinical application. Materials and Methods: The study was conducted on 20 patients who reported to the Out-patient Department (OPD) of Prosthodontics and Crown and Bridge, PGIDS, Rohtak (Haryana) for replacement of edentulous span with dental implant. Width of alveolar ridge was studied by three techniques, i.e. CT scan procedure, ridge mapping, and direct surgical exposure at two points (3 mm from the crest of ridge and 6 mm from the crest of ridge), and then taking measurements of surgical exposure as the control group, the measurements obtained from the other two techniques were compared and then accuracy of these methods was assessed. The mean, standard deviation, standard error of mean, and degree of freedom were calculated and subjected to statistical analysis using Student's unpaired t test. Results: Results suggested that there is no significant difference in the measurements obtained by direct surgical exposure technique, ridge-mapping technique, and CT technique. Conclusion: Use of ridge-mapping technique along with panoramic and intraoral radiograph is adequate in cases where the pattern of resorption appears more regular and where mucosa is of more even thickness. It is suggested to use CT scan technique in situations where the alveolar ridges are resorbed, there is presence of maxillary anterior ridge concavities, vestibular depth is inadequate, and ridge mapping is not feasible.