Contralateral coronoid process bone grafts for orbital floor reconstruction: An anatomic and clinical study

Purpose: This study compares the contour of the coronoid process with the orbital floor using skulls and shows the use of this bone as a graft for orbital floor reconstruction. Methods: Measurements and contour evaluations of the orbital floor and the contralateral mandibular coronoid process (12 right orbital:floors with the lateral surface of the left coronoid process and 12 left orbital floors with the lateral surface of the right coronoid processes) were made in 24 dried adult human skulls (age, race, gender unknown) to assess the feasibility of using the mandibular coronoid process for orbital floor reconstruction. Applying the findings of this study, eight patients who had sustained either an isolated orbital floor blowout fracture (n = 2) or orbital floor compromise with an associated zygomatic bone fracture (n = 6) were treated by using their contralateral coronoid process for repair of the orbital floor. Results: Anatomic Study: Measurements and contour comparisons of the right orbital floor with the left lateral cortex of the coronoid process in 12 skulls and the left orbital floor with the right lateral cortex of the coronoid process in the another 12 skulls showed a close match in contour and demension. Clinical Study: Although minimal trimming of the peripheral bony margins and medial coronoid cortical plate was needed, none of the grafts required recontouring of their lateral cortical surface in the eight patients. Postoperative radiographic studies showed a correct anatomic contour of the orbital floor. A 1-year follow-up of each patient showed no occurrence of diplopia, enophthalmia, muscle entrapment, or infection. All eight patients had transient (1 to 2 weeks) trismus. Conclusion: Based on the anatomic studies and clinical results, the coronoid process makes an excellent donor graft site for reconstruction of orbital floor deformities.