Distraction osteogenesis as followed by CT scan in Pierre Robin sequence

The aim: The aim of this work was to assess the multislice CT scan for analysis of the craniofacial anatomic changes in Pierre Robin sequence both predistraction and postdistraction, and to assess the use of unidirectional internal distractors in this patient group. Patients & methods: The study involved 11 patients. Their age at the time of distraction ranged from 2 to 7 months. Six were females and 5 were males. All had retromicrognathia, glossoptosis and obstructive sleep apnoea. All were diagnosed clinically and by CT scan. All were managed by distraction osteogenesis and were followed postoperatively by multislice CT. Results: The distance between the base of the tongue and the posterior pharyngeal wall increased by a mean of 141%, and the total mandibular length increased by a mean of 26%. The increase in the distance between the hyoid bone and the posterior pharyngeal wall increased by a mean of 42% The distance between the hyoid bone and the genoid process increased by a mean of 9%. Conclusion: Multislice CT scan was found to be a practical imaging technique to evaluate the morphologic changes in the airway and the mandible after distraction osteogenesis. It rules out the need for other traditional methods. Owing to the plasticity and malleability of the infant mandible that allow for sufficient bone remodelling, unidirectional internal distractors achieved a satisfactory maxillomandibular relationship which was tolerated by the infants and accepted by the parents. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.