The Change of Craniofacial Growth of Two Patients with Achondroplasia

Achondroplasia, one of the typical syndromes characterized by dwarfism, has marked chondrodystrophy in the craniofacial region like the one observed in the limbs. However, there have been only a few quantitative evaluation of the craniofacial morphology and, furthermore, no description of its growth pattern. We examined the craniofacial skeletal and the growth pattern of two patients with achondroplasia based on serial roentgen cephalometry. Cephalometric analysis clearly revealed the craniofacial dysmorphology of this syndrome, distinguished by the short posterior cranial base length, small-sized middle face depth and skeletal cross-bite due to the receded maxilla. Additionally, the mandible of both cases was characterized by the relatively large gonial angle which made the anterior facial height higher than the posterior facial height. Of special interests was the normal sized anterior cranial base of the two cases suggesting no early chondrodystrophy in the sphenoethmoidal synchondrosis, since the small sized anterior cranial base was one of the features in the previous reports. On the other hand, it was noteworthy that each craniofacial measurement including the neurocranium and splanchnocranium in the two cases demonstrated the normal growth increment ratio, despite of their decelerated physical growth. These findings on the craniofacial growth pattern seemed to be significantly useful to consider the orthodontic treatment and diagnosis for the patients with achondroplasia.