| The advent of high spatial resolution 3D volumetric imaging has led to significant progress in diagnosis, treatment planning, surgical planning and image-guided intervention, and studies of craniofacial anomalies developmental aspects. This dissertation substantiates data collection and quantitative assessment of 3D compensatory changes to skeletal discrepancies, that result from displacement and remodeling of diverse structural counterparts in the craniofacial complex.; The present work assessed the following alterations with Frankel Regulator-II (FR-II) therapy: (1) temporomandibular articular disc position and shape changes; (2) mandibular ramus growth response relative to its developmental equivalents in the craniofacial structure, as assessed in 2D cephalograms; (3) actual developmental and morphologic 3D interrelationships among craniofacial components; and (4) 3D growth vectors at skeletal landmarks.; The results of the first study showed that significant configurational changes toward a normal biconcave shape occurred in the temporomandibular joint discs of treated children with Class II malocclusion, a unique finding suggesting that FR-II therapy at the beginning of the pubertal growth spurt might help prevent internal derangements of TMJs. The second study found that the treated group presented a more forward rami alignment and increased rami vertical dimension relative to the middle cranial fossae and posterior nasomaxilla dimension, using Enlow's counterpart analysis in 2D cephalograms. The third study showed striking statistically significant differences in the graphical display of relative 3D skeletal growth directions when we compared treated to untreated controls with Class II malocclusion and normal occlusion children. The group comparisons in the fourth study revealed highly significant differences of the 3D growth displacement vectors of gonion and pterygomaxillary relative to the other skeletal landmarks.; The novel and generalizable modeling techniques applied in this prospective and systematically controlled study facilitated assessment of differential craniofacial growth and response to treatment. When examining treatment effects, high resolution 3D imaging techniques significantly enhance the biological understanding of how the face actually grows by the regional anatomic structures that directly produce growth. Further applications of such techniques can lead to enormous advances in our diagnostic assessment of patient parameters in craniofacial biology. |
