RESUMEN
AIM AND OBJECTIVE: To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. BACKGROUND: Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. CASE DESCRIPTION: A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. CONCLUSION: Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. CLINICAL SIGNIFICANCE: The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.
Asunto(s)
Acrocefalosindactilia , Mordida Abierta , Osteogénesis por Distracción , Acrocefalosindactilia/complicaciones , Acrocefalosindactilia/cirugía , Adolescente , Adulto , Cefalometría/métodos , Humanos , Lactante , Masculino , Mordida Abierta/etiología , Osteogénesis por Distracción/efectos adversos , Osteogénesis por Distracción/métodos , Osteotomía Le Fort/métodos , Adulto JovenRESUMEN
MSX1 is a causative gene for oligodontia in humans. Although conventional Msx1-deficient mice die neonatally, a mutant mouse lacking the C-terminus MH6 domain of MSX1 (Msx1ΔMH6/ΔMH6) showed two different phenotypes; newborn homozygotes with cleft palates died neonatally, whereas those with thin palates remained alive and had craniofacial dysplasia and growth retardation compared with wild-type mice, with most mice dying by the age of 4-5 weeks. In a previously reported case of human oligodontia caused by a heterozygous defect of the Msx1 MH6 domain, a small foramen was observed on the occipital bone. The aim of this study was to test the hypothesis that the Msx1 MH6 domain is involved in bone formation in vivo. In Msx1ΔMH6/ΔMH6 mice, cranial suture fusion was delayed at embryonic day 18.5, and the anteroposterior cranial diameter was smaller and long bone length was decreased at 3 weeks of age. The femoral epiphysis showed no change in the trabecular number, but decreased bone mass, bone density, and trabecular width in Msx1ΔMH6/ΔMH6 mice. In addition, cancellous bone mass was reduced and the cartilage layer in the growth plate was thinner in Msx1ΔMH6/ΔMH6 mice. The mRNA expression levels of major osteoblast and chondrocyte differentiation marker genes were decreased in Msx1ΔMH6/ΔMH6 mice compared with wild-type mice. These findings suggest that the C-terminal region including the MH6 domain of MSX1 plays important roles not only in tooth development and palatal fusion, but also in postnatal bone formation.