Three-Dimensional Evaluation of Autogenous Ramus Block Graft Donor Site and Its Relation to Mandibular Canal

Abstract

Sufficient bone volume is necessary for placing a dental implant in an ideal position. To restore severely insufficient bone volume, autogenous block graft procedures with various intra-oral donor sites are presented in the literature. The aims of this retrospective study are to present the dimensions and volume of the potential ramus block graft site, and to evaluate possible effect of mandibular canal diameter and its position in relation to mandibular ramus block graft volume. Two-hundred cone-beam computed tomography (CBCT) images were evaluated. The maximum length, width, height, and volume of the potential ramus block graft site, mandibular canal diameter, mandibular canal - mandibular basis distance, and mandibular canal - crest distance were measured. Mandibular canal diameter, mandibular canal - crest distance, and mandibular canal - mandibular basis distance were 3.139 ± 0.446 mm, 15.376 ± 2.562, and 7.834 ± 1.285 mm, respectively. In addition, the dimensions of the potential ramus block graft sites were measured 11.156 ± 2.297 mm x 10.390 ± 3.420 mm x 8.816 ± 1.720 mm (height x length x width). Moreover, the potential ramus bone block volume was calculated as 1.076 ± 0.398 cm3. While a positive correlation was detected between mandibular canal - crest distance and the potential ramus block graft volume (r = .160, P = .025), a negative correlation was found between mandibular canal - mandibular basis distance and the potential ramus block graft volume (r = -.020, P = .001). Mandibular ramus is one of the predictable intra-oral donor sites for bone augmentation procedures. However, ramus has some volumetric limitations related to its neighboring anatomic structures. It seems to be important to evaluate lower jaw in a 3-dimensional manner to prevent surgical complications.