Background: Orbital dysmorphology and midface retrusion are the hallmarks of Crouzon and Apert syndromes. The precise nature of this deficiency is not known.
Methods: Untreated Crouzon and Apert syndrome patients and age- and sex-matched controls were included. Computed tomographic scans were digitized and reconstructed. Craniometric and volumetric data relating to the orbit were collected.
Results: Thirty-one scans were included (control, n = 12; Crouzon; n = 9; Apert, n = 10). The mean age of the Apert group was 5.31 ± 5 years; Crouzon, 5.77 ± 2.7 years; and control, 6.4 ± 3.6 years. The bony orbit length was 12 percent shorter in Apert (p = 0.004) and 17 percent shorter in the Crouzon group when compared to controls (p < 0.0001). The bony orbital volume was 21 percent smaller in the Apert children (p = 0.0006) and 23 percent smaller in Crouzon when compared to controls (p = 0.003). Globe volume was 15 percent larger in Apert (p = 0.008) and 36 percent larger in the Crouzon group when compared to controls (p < 0.0001). Orbital soft-tissue volume was 19 percent less in the Apert group (p = 0.004) and 29 percent less in the Crouzon group (p = 0.001) when compared to controls.
Conclusions: A shortened bony orbit, decreased orbital and orbital soft-tissue volumes, and an increased volume of the globe were found in both conditions. Despite normal volume of the overall orbital contents, the contents are altered, and the bony orbit is shorter and holds less volume.