A Simple Methodology to Better Appreciate Structures in Mandibular Angle Fractures Using 3-Dimensional Reconstruction Software
Dr. Arjunan Kumaran,
5 Lower Kent Ridge Road, Singapore.
Introduction: In Singapore, fractures of the mandible are common and of which, 32% occur at its angle. Current Two-Dimensional (2D) imaging methods are lacking in accuracy, leading to increased surgical morbidity.
Aim: To determine the Length (L), Diameter (D), Width (W) and Height (H) measurements in fractured and non-fractured mandibles by using Three-Dimensional (3D) Computed Tomography (CT).
Materials and Methods: A single centre retrospective CT based study of 23 subjects (46 mandibular angles and M3s) was conducted and subjects below 16 years, conservatively managed fractures, mandibles without M3s and cases with inadequate CT scan data were excluded. Intraosseous M3 L and D and mandibular H and W were measured and ratios L/H and D/W were calculated.
Results: Average mean (Standard Deviation, SD) L, D, H and W was 8.58 (2.089), 11.63 (2.156), 29.17 (4.830) and 16.94 (1.967) mm respectively. Average mean L/H and D/W were 0.30 (0.070) and 0.69 (0.126) respectively. There was a trend towards greater osseous volume occupied horizontally in fractured mandibles. Measurements demonstrated good reliability (CA 0.999-1.000) and good intra and inter-observer variability (ICC 0.998-1.000, p<0.001).
Conclusion: A 3D reconstruction with OsiriX offers greater insight at little additional cost. However, this can be further streamlined and automated.