Unilateral versus bilateral correction of unicoronal synostosis: an analysis of long-term results.

Introduction: Hollowing of the temporal region is a common problem after cranioplasty for unicoronal synostosis. In this study, first, the development of temporal hollowing pre- and postoperatively is evaluated. Second, the origin of temporal hollowing is investigated by comparing two operative techniques. Ultimately, the relation between timing of surgery and the development of hollowing is investigated.

Methods: From 1979 to 2010, 194 patients with unicoronal synostosis were operated at our center. Patients were treated with a unilateral or bilateral correction of the supraorbital rim. A total of 48 patients qualified for the present study. Mean age at follow-up was 7.5 years. Cephalic landmarks were identified on radiographs prior to and after surgery to determine the growth of the forehead. For visual analysis, two independent observers evaluated normal photographs for the presence and severity of temporal hollowing.

Results: Preoperative osseous asymmetry improved significantly after surgery. A total of 21 patients show an increase of temporal hollowing on photographs after surgery (46%). In 35 out of 48 patients, postoperative temporal hollowing was noted (73%). Bilaterally treated patients showed more severe temporal hollowing compared to unilaterally treated patients, though not significantly (23% vs. 6%, p = 0.229). Timing of surgery (before or after the age of 1 year) did not influence the occurrence of severe temporal hollowing.

Conclusions: Fronto-supraorbital advancement was unable to achieve normal growth in the temporal region in a large proportion of patients, although more symmetry was achieved. The operative technique itself did not seem to influence the occurrence of temporal hollowing, nor did the timing of surgery.