Radiographic evaluation of the symphysis menti as a donor site for an autologous bone graft in pre-implant surgery

Abstract

PurposeThis study was performed to obtain a quantitative evaluation of the cortical and cancellous bone graft harvestable from the mental and canine regions, and to evaluate the cortical vestibular thickness.Materials and MethodsThis study collected cone-beam computed tomographic (CBCT) images of 100 Italian patients. The limits of the mental region were established: 5 mm in front of the medial margin of each mental foramen, 5 mm under the apex of each tooth present, and above the inferior mandibular cortex. Cortical and cancellous bone volumes were evaluated using SimPlant software (SimPlant 3-D Pro, Materialize, Leuven, Belgium) tools. In addition, the cortical vestibular thickness (minimal and maximal values) was evaluated in 3 cross-sections corresponding to the right canine tooth (3R), the median section (M), and the left canine tooth (3L).ResultsThe cortical volume was 0.71±0.23 mL (0.27-1.96 mL) and the cancellous volume was 2.16±0.76 mL (0.86-6.28 mL). The minimal cortical vestibular thickness was 1.54±0.41 mm (0.61-3.25 mm), and the maximal cortical vestibular thickness was 3.14±0.75mm(1.01-5.83 mm).ConclusionThe use of the imaging software allowed a patient-specific assessment of mental and canine region bone availability. The proposed evaluation method might help the surgeon in the selection of the donor site by the comparison between bone availability in the donor site and the reconstructive exigency of the recipient site.

Clinical Anatomy and Significance of the Retromolar Foramina and Their Canals: A Literature Review

“…Retromolar autologous bone withdrawal is also associated with the lower risk of complication compared to branch sagittal osteotomy or osteogenic distraction technique. However, it is essential to have a thorough understanding of the posterior mandibular region in order to limit the possibility of injuring nerves and vasculature in the area, including the mandibular canal [ 11 , 49 ].…”

Three-dimensional evaluation of the mandibular symphyseal region in block graft harvesting for dental implants using cone-beam computed tomography

“…6 Additionally, intraoral areas may offer other advantages over extraoral donor sites, such as decreased morbidity from graft harvesting and the use of a transoral approach, which does not leave cutaneous scars. 7 To select an appropriate intraoral donor site, parameters such as the amount, geometry, and type of bone required for alveolar reconstruction, as well as the risk of intraoperative and postoperative complications, should be considered. 3 Within the mouth, the mandible tends to present more sources than the maxilla, and the anterior border of the ramus, the mandibular body, or the symphysis are almost always preferred as donor sites.…”

“…4 Other advantages include minimal resorption (5%-28%), 9,10 no need for hospitalization (and thus lower cost), 6 minimal discomfort, 11 no alteration in ambulation, and the absence of cutaneous scars. 7 Compared to other mandibular sites, the symphyseal area has advantages such as easy accessibility, the presence of both cortical and cancellous bone volume (with greater cancellous bone mass), and suitability for bone defects involving up to 1-6 teeth. 8 Evidence shows that autogenous bone blocks within the retromandibular region only offer 80% of the bone volume available in the chin region.…”

“… 6 Additionally, intraoral areas may offer other advantages over extraoral donor sites, such as decreased morbidity from graft harvesting and the use of a transoral approach, which does not leave cutaneous scars. 7 …”

“… 4 Other advantages include minimal resorption (5%–28%), 9 10 no need for hospitalization (and thus lower cost), 6 minimal discomfort, 11 no alteration in ambulation, and the absence of cutaneous scars. 7 …”