Pathologies of the orbital dystopia or orbital deformities include congenital anomalies, trauma and tumors. However, these conditions are rare and surgical planning in detail is always difficult. We herein report our limited experience in the treatment of orbital dystopia/deformity, and discuss pre-surgical planning as well as surgical techniques and post-operative considerations.
Materials:In the past 18 years, we treated 26 cases of orbital dystopia/deformity. There were 11 males and 15 females. There were 12 cases of post traumatic deformity comprising 4 cases of malunion of panfacial fractures and 8 cases of malunion of orbital fractures. Of those with congenital anomalies, 4 cases of anterior plagiocephaly, one of Apert syndrome and one of hypertelorism were treated. There were 3 cases of neurofibromatosis type 1 involving the orbital roof, 2 cases of fibrous dysplasia of the orbit, and 3 cases of post-ablative surgery for maxillary cancer.
Discussion:In the first step of surgical planning, CT scan, 3DCT and facial landmarks were combined to determine the facial midline. Vertical/horizontal orbital dystopia, orbital dimension and exophthalmos/enophthalmos were then evaluated on the CT image. A 3D model is a useful option for surgical simulation. The occlusal plane, pupil line and nasal bridge line are helpful landmarks, and the facial scale is the most reliable ruler to control bilateral orbits in cases of vertical orbital dystopia. Neurofibromatosis may involve the anterior cranial base connecting the cranial and orbital cavities, resulting in pulsatile proptosis. Surgery was focused on separating the two with titanium mesh, which was pre-bent to fit the bone defect on the 3D model. In the treatment of congenital pathologies, periodical follow-up is crucial as the two orbits may grow independently and lead to further surgery. Soft tissue deformities surrounding the orbit are treated when soft tissue swelling subsides after skeletal surgery. From our limited experience, vertical orbital dystopia was precisely treated as planned in accordance with pre-surgical computer simulations. However, horizontal movement of the orbit was less reflected by the amount of medial eye movement in cases of hypertelorism, which was approximately 70% of the amount of skeletal movement.
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