In the last decade, the application of distraction osteogenesis to the craniofacial skeleton has grown to include not only deformities of the mandible, but of the midface, palate, dentoalveolar region, and calvarium. A major advantage of distraction osteogenesis lies in the simultaneous soft tissue histogenesis that accompanies the bony distraction process, allowing for potentially lower relapse rates and improved cosmesis. Although this may seem appropriately suited to irradiation-induced deformities of both hard and soft tissues, there is little in the literature as to the efficacy of this technique in patients who have received radiotherapy. To introduce an effective application of this technology, and highlight some advantages and disadvantages of its application in the irradiated craniofacial skeleton, we present a case of distraction osteogenesis of the orbitozygomatic complex in a patient with radiation induced orbitozygomatic hypoplasia.

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RS Grover, J Mainprize, E Ing, OM Antonyshyn. Graves' exophthalmos: Volumetric assessment of orbital expansion. Can J Plast Surg 2003;11(4):191-197. INTRODUCTION: Graves' ophthalmopathy is characterized by an increase in the volume of orbital soft tissue contents and an associated increase in intraorbital pressure. Surgical expansion of bony orbital volume is therefore an effective method of treating moderate to severe exophthalmos. Numerous correlations between specific decompression procedures and reduction of proptosis have been made. The main emphasis of the majority of these studies, however, appears to be of a qualitative nature rather than quantitative. OBJECTIVES: To quantitatively examine the consequences of surgical orbital decompression in the treatment of severe Graves' exophthalmos, with respect to changes in ocular globe projection and orbital soft tissue and bony volume. MATERIAL AND METHODS: A series of three patients (five orbits) with severe exophthalmos were evaluated. All patients were operated on by a single surgeon using a standard technique of orbitozygmatic osteotomy in conjunction with three-wall orbital decompression and release of periorbita. Data obtained from standardized preoperative and three-month postoperative computed tomography scans were transferred to an offline computer workstation. Scalar and volumetric parameters were quantitatively analyzed to determine changes in globe projection in relation to intraorbital volume differences. RESULTS: Following surgery, mean globe retrodisplacement from the lateral orbital rim and from the optic foramen were 6.7 mm and 3.3 mm, respectively. Osteotomy and decompression were effective in producing an 18.6% increase in bony orbital volume. However, the volume of intraorbital soft tissues increased substantially following surgery, with a 23.4% increase in orbital fat volume and a 12.2% increase in neurovascular tissue volume. CONCLUSIONS: The degree of globe retrodisplacement achieved by surgical expansion of the bony orbital cavity in patients with Graves' ophthalmopathy may be less than anticipated, due to a postoperative increase in the intraorbital soft tissue volumes.