Our results suggest that the OMA orthopedic appliance can correct the mesial jaw relationship and negative incisal over jet. This appliance is effective for correcting skeletal Class III malocclusion with both midface deficiency and Mn prognathism in growing children.

The aim of this study was to investigate the treatment effects on the maxillofacial complex by maxillary protraction combined with chin cup therapy among growing children. An effective geometric morphometric assessment of cephalometric radiographs, using Procrustes analysis and thin-plate spline analysis, was applied to evaluate shape change in the craniofacial and midfacial configurations of a treated sample of 20 children with skeletal Class III malocclusion. This was compared with matched untreated skeletal Class III controls. Marked treatment induced change involved the maxilla and the mandible. Major deformation consisted of forward advancement of the maxillary complex with negligible rotation of the palatal plane and a forward direction of growth of the mandibular condyle associated with a restriction in sagittal advancement of the chin. Considerable dentoalveolar components contributed to the correction of anterior crossbite. Further detailed study of skeletofacial remodelling in response to maxillary protraction in other skeletal components, including the cranial base and the mandibular complex that contribute to Class III skeletal discrepancies, is warranted.

The purpose of this study was to provide more information about the morphological characteristics of the craniofacial complex in mandibular prognathism. Forty young adult males having mandibular prognathism were compared with 40 having normal occlusion. This was conducted to carry out geometric morphometric assessments to localize alterations, using Procrustes analysis and thin-plate spline analysis, in addition to conventional cephalometric techniques. Procrustes analysis indicated that the mean craniofacial, midfacial and mandibular morphology was significantly different in prognathic subjects compared with normal controls. This finding was corroborated by the multivariate Hotelling T(2)-test of cephalometric variables. Mandibular prognathism demonstrated a shorter and slightly retropositioned maxilla, a greater total length and anterior positioning of the mandible. Thin-plate spline analysis revealed a developmental diminution of the palatomaxillary region anteroposteriorly and a developmental elongation of the mandible anteroposteriorly, leading to the appearance of a prognathic mandibular profile. In conclusion, thin-plate spline analysis seems to provide a valuable supplement for conventional cephalometric analysis because the complex patterns of craniofacial shape change are visualized suggestive by means of grid deformations.

No abstract

There is insufficient evidence in conventional cephalometric analysis of the actual sites of putative maxillofacial change in Class II and Class III malocclusions. The purpose of this study was to provide more information about the morphological characteristics of the midfacial complex and mandible in children with Class II or III malocclusions. Seventy children with Class II, division 1 malocclusion and 70 children with Class III malocclusion were compared with 70 children with normal occlusion. This study was conducted to carry out geometric morphometric assessments to localize alterations using Procrustes analysis and thin-plate spline analysis. Procrustes analysis indicated the midfacial and mandibular morphologies differed between normal occlusion subjects and subjects with Class II or Class III malocclusion (P<0.0001). The deformations in subjects with Class II malocclusion may represent a developmental elongation of the palatomaxillary complex and a shortening of the mandible anteroposteriorly, which leads to the appearance of a protruding midface and retruding mandibular profile. In contrast, the deformations in subjects with Class III malocclusion may represent a developmental shortening of the palatomaxillary complex and elongation of the mandible anteroposteriorly, which leads to the appearance of a retrognathic midface and prognathic mandibular profile.