Measurement of Distance Between the Mental Foramina using Cone-Beam Computed Tomography: A Pilot Study with a Possible Method for Planning Mandibular Implants

ABSTRACT

Objective: To identify the average number of dental implants that can be placed in the lower anterior region to support a fixed mandibular prosthesis based on the distance between the mental foramina, using a cone beam computed tomography (CBCT) scan through a new method of measurement. Material and Methods: Eighty-two CT scans from a total sample of 1,465 exams were selected. The method to measure the space between the foramina was developed using the BlueSky Plan3 software in Dicom format and the axial reconstruction views were chosen for measurements. Descriptive analysis of data was conducted categorical variables were compared using the χ2 test (p <0.05). Results: The mean age of individuals who underwent the scans was 63.51 ± 9.49 years old with a minimum and maximum age of 40 and 86 years old, respectively. The mean linear measurement between the foramina was 40.52 ± 3.92mm. In males the mean distance was 41.93 ± 3.98 mm, and for females it was 39.99 ± 3.80mm, with a significant difference between the means (p = 0.043). There was no positive association between the presence of the anterior loop and gender (p = 0.719). The results showed that the vast majority of subjects (n = 80) could be rehabilitated using a protocol with 4 implants of 3.3mm diameters. Conclusion: Seventy-seven patients would be able to receive protocols of 4 implants with diameters of 3.75 or 4.0mm, and only 4 subjects would be able to be rehabilitated with 6 implants with diameters of 3.75 mm according to the protocol originally described by Brånemark.