The frequency of dental anomalies in this sample was similar to other cleft populations. As surgical trauma has been suggested to damage forming teeth, the results of this study indicated that ESGAP has no detrimental influence on subsequent dental development.
The structural integrity of microfilaments has been shown to be necessary for the signal transduction of mechanical stimuli within osteoblasts. Qualitative and quantitative changes within the cytoskeleton of osteoblasts may therefore be crucial components of the signal transduction processes of these cells in response to mechanical stimulation. Avian osteoblasts were strained with a device that deforms a flexible, cell-laden membrane at a defined frequency and intensity in a uniform biaxial manner. We examined the effects of mechanical strain on the accumulation of protein and the expression of the major cytoskeletal elements and specific integrin-binding (arginine-glycine-aspartic acid) proteins of these cells. Mechanical strain increased the level of total extracellular matrix-accumulated fibronectin by approximately 150% and decreased that of osteopontin by approximately 60% but had no quantifiable effect on the accumulation of beta1 integrin subunit or collagen type I. An examination of the major elements of the cytoskeleton demonstrated that neither the level of actin nor that of the intermediate filament protein vimentin changed; however, the amount of tubulin decreased by approximately 75% and the amount of vinculin, a major protein of focal adhesion complexes, increased by approximately 250%. An analysis of protein synthesis by two-dimensional gel electrophoresis of [35S]methionine-labeled cytoskeletal proteins demonstrated that the changes in the accumulation of vinculin and tubulin resulted from their altered synthesis. Messenger RNA analysis confirmed that the changes in accumulation and protein synthesis observed for vinculin, fibronectin, and osteopontin were controlled at a pretranslational level. Immunofluorescent microscopy demonstrated that mechanical strain led to increased formation and thickening of actin stress fibers, with a commensurate dissociation in microtubules and a clear increase in levels of vinculin at the peripheral edges of the cells. In conclusion, the elevated rate of synthesis and the increased accumulation of vinculin and fibronectin, as well as the increase in the number and size of stress fibers and focal adhesion complexes, suggest that mechanical strain leads to a coordinated change both in the cytoskeleton and in extracellular matrix proteins that will facilitate tighter adhesion of an osteoblast to its extracellular matrix.
Early secondary gingivoalveoloplasty seems to allow for adequate ossification in both the alveolar and the nasal regions. Permanent tooth eruption occurs at a normal rate. None of the patients has required a secondary alveolar bone graft.
This is a longitudinal cephalometric study of patients with craniofacial synostosis (Crouzon's and Apert's) syndromes who underwent Le Fort III advancement during early childhood. The objectives of the study were to quantify presurgical growth, surgical results, and surgical stability as well as long-term postsurgical growth. Of the 31 patients operated on during their growth period (less than 10 years of age), 17 had sufficient records to be included in the study: at infancy, before the Le Fort III osteotomy (average age=7.3 years, range: 4.8-10 years), and immediately after surgery. Ten of the patients were followed radiographically long term for an average of 6.1+/-2.7 years (range: 4.5-10.8 years). The presurgical abnormal midfacial vertical growth pattern was accurately described with a progressive class III discrepancy and an increasing exophthalmos. Remarkable postoperative stability of the maxillary segment was observed. After surgery, growth of the midface was measured, together with minimal, if any, anterior growth, similar to the presurgical growth pattern and rate. No actual detrimental or beneficial effect of surgery on subsequent growth was seen. This study quantitatively confirms that the standard Le Fort III osteotomy is a stable and effective but generally not definitive procedure in childhood. This study might also serve as a control sample to compare with groups of patients undergoing distraction osteogenesis to verify the actual advantages and shortcomings of this alternative technique.
Although this is not a long-term study, at this time none of the patients operated with this technique have needed secondary columella lengthening. On the other hand, although certainly improved, the nasal anatomy obtained is far from normal.
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