Faculty Bibliography

The hedgehog family of morphogens (sonic [Shh], Indian, and desert hedgehog) are central regulators of embryologic growth and tissue patterning. Although recent work implicates Shh in postnatal tissue repair and development, conclusive evidence is lacking. Here, we demonstrated the importance of Shh in wound repair, by examining the effects of cyclopamine, a specific inhibitor of the Shh signaling cascade, on tissue repair. Using a murine-splinted excisional wound model, which attenuates wound contraction in this loose-skinned rodent, we established that, by all measures (wound closure, epithelialization, granulation formation, vascularity, and proliferation), wound healing was profoundly impaired when Shh signaling was disrupted. Because embryonic disruption of Shh is associated with distinct phenotypic defects, our findings invite investigation of the potential role of Shh signaling under postnatal conditions associated with disregulated wound healing

BACKGROUND: The application of distraction osteogenesis is an effective treatment for mandibular deficiencies. A priori, a horizontal vector of distraction was hypothesized to produce horizontal movement of the mandible and a vertical vector of distraction to produce primarily downward vertical elongation of the ramus. This study was designed to test this hypothesis. METHODS: A retrospective clinical and radiographic review was conducted of all patients who underwent bilateral, uniplanar distraction with an external device at the New York University Medical Center between October of 1990 and February of 2004 (n = 185). A subset of 15 patients was identified who satisfied inclusion criteria and had adequate predistraction and postdistraction lateral cephalograms. Cephalometric tracings were made and multiple landmarks were assessed before and after distraction. RESULTS: A strong correlation was noted between the vector of distraction and rotation of the symphyseal plane, movement of the mandibular symphysis, and change in interocclusal angle. A horizontal vector of distraction resulted in minimal counterclockwise rotation of the symphyseal plane, greater downward vertical translation of the mandibular symphysis, and minimal closure of an anterior open bite. In contrast, a vertical vector resulted in greater counterclockwise rotation of the symphyseal plane, greater horizontal projection of the mandibular symphysis, and greater closure of an anterior open bite. Mathematical formulas were derived to correlate the distraction vector and mandibular movements. CONCLUSIONS: Successful distraction is dependent on accurate prediction of outcomes. This study demonstrates that the vector of distraction predictably affects the mandibular response during bilateral distraction osteogenesis but contradicts the a priori hypothesis

BACKGROUND: Bilateral cleft lip-cleft palate is associated with nasal deformities typified by a short columella. The authors compared nasal outcomes of cleft patients treated with banked fork flaps to those of patients who underwent nasoalveolar molding and primary retrograde nasal reconstruction. METHODS: A retrospective review of 26 consecutive patients with bilateral cleft lip-cleft palate was performed. Group 1 patients (n = 13) had a cleft lip repair and nasal correction with banked fork flaps. Group 2 patients (n = 13) had nonsurgical columellar elongation with nasoalveolar molding followed by cleft lip closure and primary retrograde nasal correction. Group 3 patients (n = 13) were age-matched controls. Columellar length was measured at presentation and at 3 years of age. The number of nasal operations was recorded to 9 years. The Kruskal-Wallis and Tukey-Kramer tests were used for statistical analysis. RESULTS: Initial columellar length was 0.49 +/- 0.37 mm in group 1 and 0.42 +/- 0.62 mm in group 2. Post-nasoalveolar molding columellar length was 4.5 +/- 0.76 mm in group 2. By 3 years of age, columellar length was 3.03 +/- 1.47 mm in group 1, 5.98 +/- 1.09 mm in group 2, and 6.35 +/- 0.99 mm in group 3. Group 2 columellar length was significantly greater (p < 0.001) than that of group 1 and not statistically different from that of group 3 (p > 0.05). All group 1 patients (13 of 13) needed secondary nasal surgery. No nasoalveolar molding patients (zero of 13, group 2) required secondary nasal surgery. CONCLUSION: Nonsurgical columellar elongation with nasoalveolar molding followed by primary retrograde nasal reconstruction restored columellar length to normal by 3 years and significantly reduced the need for secondary nasal surgery.

The bony biochemical environment is a complex system that permits and promotes cellular functions that lead to matrix production and ossification. In Part I of this review, we discussed the important actions of signaling molecules, including hormones, cytokines, and growth factors. Here, we review other constituents of the extracellular matrix, including minerals, fibrinous and nonfibrinous proteins, and enzymes such as the matrix metalloproteinases. We conclude with a discussion of the role of biochemical modulation in endogenous and exogenous tissue engineering