Abstract

Assessment of Position and Symmetry of the Chin Following Reconstruction of Mandible with Autogenous Iliac Bone Grafts and Non Pre-Shaped Titanium Reconstruction Plates: A Comparative Pilot Study of Visual Perception and Computer Analyzed 2D Photo Image

Babatunde O Akinbami and Udeabor SE

Aim: To restore acceptable facial profile after avulsion or ablation, the missing portions of the mandible must be adequately reconstructed. The purpose of this study was to compare the perception of individuals on mandibular chin dimensions and computer analyzed images following reconstruction of the mandible in a Nigerian tertiary health center.

Method: Ten patients with tumors involving the anterior part of the mandible were included. There were 2 groups of assessors. Patients were seated on the dental chair with back rest reclined at 90 degrees. Position of the chin was assessed from the side and symmetry was assessed from the front. Images were transported to computer for analysis. The coronal images were segmented into two halves with a vertical midline. On both sides to the midline, a vertical line was drawn. For the sagittal images, a vertical line was drawn to pass through the nasal sill.

Result: From the objective analysis, 5 of the patients had their chin in normal or very close to normal positions, 4 had mild retrusions (≤ 2 mm) and 1 had moderate retrusion (≥ 2). When evaluations were compared, more clinicians graded more accurately than para-clinicians in all the patients. Objectively, 8 patients had less than 2 mm, 1 patient had 2.5 mm and one had 5.5 mm (severe asymmetry). When evaluations were compared, 5 or more assessors in both groups graded correctly in 6 patients.

Conclusion: Chin positions were normal based on objective evaluation in half of the cases, while symmetry was very close to normal in only one case.