Orbitofrontal monobloc advancement for Crouzon syndrome.

INTRODUCTION: Usually, patients suffering from Crouzon syndrome have synostosis of coronal sutures, exophthalmia, hypertelorism, and hypoplasia of the middle third of face. Sometimes maxillary retrusion is absent, so these patients have class I or II relationship. In these cases, frontofacial monobloc advancement, which is the gold standard, increases the maxillo-mandibular dysmorphia. Therefore we propose orbitofrontal monobloc advancement minus dental arch, without splits of the pterygoid plates.

CASE REPORT: A 12-year-old girl with Crouzon syndrome had intracranial hypertension, exophthalmia, a middle third retrusion and a class II occlusion. We achieved orbitofrontal monobloc advancement which is frontofacial monobloc advancement minus maxillary dental arch. Four distractors KLS Martin were used. After 20 days of distraction, the final advancement was 10.2 mm for cranial distractors and 10.5 mm at fronto-zygomatic. Distractors were removed after 8 months.

DISCUSSION: We offer patients suffering from Crouzon syndrome with class I or II relationship a change from the classic frontofacial monobloc advancement leaving the maxillary dental arch in place, thus avoiding the worsening of the maxillo-mandibular dysmorphia related to surgery. The idea of associating Le Fort I osteotomy with a frontofacial monobloc advancement or Le Fort III osteotomy has already been described, mainly by Tessier and Obwegeser, however they probably achieved a complete Le Fort I osteotomy while we don't split the pterygoid plates. The patient's morphology and his surgical history determine the choice between Le Fort III and monobloc advancement. Dental occlusion needs to be taken into account for surgical indication.