ABSTRACT
BACKGROUND: A 9-year-old male showed severe defects in midface structures, which resulted in maxillary hypoplasia, ocular hypertelorism, relative mandibular prognathism, and syndactyly. He had been diagnosed as having Apert syndrome and received a surgery of frontal calvaria distraction osteotomy to treat the steep forehead at 6 months old, and a surgery of digital separation to treat severe syndactyly of both hands at 6 years old. Nevertheless, he still showed a turribrachycephalic cranial profile with proptosis, a horizontal groove above supraorbital ridge, and a short nose with bulbous tip. METHODS: Fundamental aberrant growth may be associated with the cranial base structure in radiological observation. RESULTS: The Apert syndrome patient had a shorter and thinner nasal septum in panthomogram, PA view, and Waters' view; shorter zygomatico-maxillary width (83.5 mm) in Waters' view; shorter length between the sella and nasion (63.7 mm) on cephalogram; and bigger zygomatic axis angle of the cranial base (118.2°) in basal cranial view than a normal 9-year-old male (94.8 mm, 72.5 mm, 98.1°, respectively). On the other hand, the Apert syndrome patient showed interdigitating calcification of coronal suture similar to that of a normal 30-year-old male in a skull PA view. CONCLUSION: Taken together, the Apert syndrome patient, 9 years old, showed retarded growth of the anterior cranial base affecting severe midface hypoplasia, which resulted in a hypoplastic nasal septum axis, retruded zygomatic axes, and retarded growth of the maxilla and palate even after frontal calvaria distraction osteotomy 8 years ago. Therefore, it was suggested that the severe midface hypoplasia and dysostotic facial profile of the present Apert syndrome case are closely relevant to the aberrant growth of the anterior cranial base supporting the whole oro-facial and forebrain development.
ABSTRACT
OBJECTIVE: To describe a newly developed three-dimensional (3D) digital superimposition method for quantitative evaluation of tooth wear that occurs during orthodontic treatment. MATERIALS AND METHODS: The sample consisted of dental casts obtained from 56 patients (23 male patients and 33 female patients; mean ± standard deviation age â=â 21.8 ± 5.1 years) who received orthodontic treatment with extraction of four premolars. The maxillary and mandibular dental casts taken before (T1) and after (T2) orthodontic treatments were scanned, and 3D images of the canines were constructed. The canines at T1 were superimposed with those at T2 with the best-fit method using the middle third of the labial and lingual surface as the reference area. To measure the volume of the canines, four boundary planes were constructed, and the differences in volume before and after orthodontic treatment were calculated. RESULTS: The mean volume of tooth wear of the 224 canines was 2.0 mm(3) after 35.5 months of orthodontic treatment. The volume of canine tooth wear was 2.3 ± 1.5 mm(3) in male subjects and 1.9 ± 1.2 mm(3) in female subjects. The mean wear of the upper right canines (2.4 ± 2.0 mm(3)) was significantly greater than that of the lower right canines (1.9 ± 2.6 mm(3)). CONCLUSIONS: Regional registration of teeth in 3D digital models is useful for quantitative evaluation of tooth wear in orthodontic patients. This method may also be used to assess treatment results in restorative dentistry.