Mirror-imaged correction of unilateral orbital deformation caused by a maxillary air cyst

Purpose: To describe a case of hyperpneumatization of the maxillary sinus along with orbito ethmoidal Haller's cells leading to progressive upward dislocation and proptosis of the right globe. Design: Interventional case study. Methods: Using a web-based simulation of surgical resection, along with a mirror-imaged reconstruction of the right orbit by a custom-made titanium implant, transconjunctival surgical intervention was planned and accomplished under general anesthesia. Clinical evaluations regarding proptosis and upward dislocation of the right globe were collected. The total preoperative, simulative-, and postoperative orbital volumes were measured using Simpson's method. Results: The orbital volume was significantly lower on the affected side than on the unaffected side. During simulation, approximations of the right and left orbital volumes were planned. Postoperatively, the right and left orbital volumes were effectively equal, but the simulative orbital volume was approximately 5 cm3 higher than computed tomographic measurements of the orbital volume. Conclusion: Hyperpneumatization of the maxillary sinus with orbital infliction is a rare event. Decompression along with a three-dimensional simulated alignment of the orbital volume to the healthy side leads to reproducible results and enhances intraoperative security. Keywords: Orbital deformation, Computer-aided design, Surgical simulation, Pneumosinus maxillaris dilatans, Exorbitism