Gender Differences in Dental Anxiety and Medical Fear in Croatian Adolescents.

OBJECTIVES: The aim of this study was to differentiate anxious from nonanxious adolescents and evaluate gender differences in anxiety with respect to previous negative dental and medical experiences. The purpose was also to evaluate a causative relationship between child medical fear and dental anxiety. STUDY DESIGN: This study sampled 113 Croatian adolescents from 15 to18 years of age. Children's Fear Survey Schedule - Dental Subscale (CFSS-DS) was used for the assessment of child dental anxiety regarding visits to the dentist and receiving dental treatment. A modified version of Child Medical Fear Questionnaire (CMFQ-M) was used for evaluation of child medical fear related to medical treatment and doctors in general. RESULTS AND CONCLUSION: The results showed significantly higher dental anxiety (CFSS-DS) and medical fear (CMFQ-M) in adolscent girls (p<0,001) as compared to adolescent boys. A significantly strong correlation between medical fear and dental anxiety in adolescent girls was proved by Pearson's correlation coefficient (p < 0,01). In this study, CMFQ-M and CFSS-DS questionnaires were standardized in the Croatian adolescent population and proved reliable in the estimation of anxious behaviour with respect to specific medical and dental situations.

Transforming Growth Factor-ß3 Therapy Delays Postoperative Reossification and Improves Craniofacial Growth in Craniosynostotic Rabbits.

Postoperative reossification is a common clinical correlate following surgery. It has been suggested that an underexpression of transforming growth factor-ß3 (TGF-ß3) may be related to craniosynostosis and postoperative reossification. Adding TGF-ß3 may delay reossification and improve postoperative growth. The present study was designed to test this hypothesis. Thirty 10-day-old New Zealand white rabbits with hereditary coronal suture synostosis were divided into three groups: (1) suturectomy controls (n = 14), (2) suturectomy treated with bovine serum albumin (n = 8), and (3) suturectomy treated with TGF-ß3 protein (n = 8). At 10 days of age, a 3-mm × 15-mm coronal suturectomy was performed, and serial three-dimensional (3D) computed tomography (CT) scans and cephalographs were taken at 10, 25, 42, and 84 days of age. Calvaria were harvested at 84 days of age for histomorphometric analysis. Mean differences were analyzed using a group by age analysis of variance. Analysis of the 3D CT scan data revealed that sites treated with TGF-ß3 had significantly (P < .05) greater defect areas and significantly (P < .05) greater intracranial volumes through 84 days of age compared with controls. Histomorphometry showed that sites treated with TGF-ß3 had patent suturectomy sites and significantly (P < .001) less new bone in the suturectomy site compared with controls. Serial radiograph data revealed significant (P < .05) differences in craniofacial growth from 25 to 84 days in TGF-ß3-treated rabbits compared with controls. Data show that TGF-ß3 administration delayed reossification and improved craniofacial growth in this rabbit model. These findings also suggest that this molecular-based therapy may have potential clinical use.

Indicators of dental anxiety in children just prior to treatment.

OBJECTIVES: We evaluated the relationship between child dental anxiety and selected child and parental characteristics. STUDY DESIGN: Children and their parents were interviewed at the New York University, College of Dentistry, Pediatric Dentistry Clinic. The Children's Fear Survey Schedule - Dental Subscale (CFSS-DS) evaluated child self-reported anxiety; the Modified Dental Anxiety Scale (MDAS) measured self-reported parental anxiety when the parent received dental treatment. RESULTS: Ninety-three children and their parents completed the questionnaires. Mean CFSS-DS scores were higher for girls than boys (32.5 vs. 26.3, p=0.003) and for children whose accompanying parents had MDAS scores of 11+ vs. ≥ 11 (32.8 vs. 26.6, p=0.001). There was little difference in mean CFSS-DS scores among those aged 6-10 yrs. vs. 11-14 yrs. (30.1 vs. 29.3). Significant correlations were found between CFSS-DS and both gender (Spearman's rho, rs=0.31) and MDAS scores (rs=0.33), but not between CFSS-DS and child age (rs=-0.05). Controlling simultaneously for gender, MDAS score and child age, a high CFSS-DS score (38+ vs. ≥ 38) was positively associated with girls (ORadj=3.76, 95% CI: 1.13-12.54) and an MDAS score of ≤ 15 vs. ≥ 11 (ORadj=2.50, 0.73-8.54), but weakly and inversely associated with age (ORadj=0.80, 0.25-2.52). CONCLUSION: Child gender and parental anxiety are indicators of child dental anxiety.

Use of fissure sealant retention as an outcome measure in a dental school setting.

The purpose of this study was to describe and assess the use of fissure sealant retention as a quality measure of the delivery system for pediatric dentistry. The Pediatric Dentistry Section at the Ohio State University College of Dentistry adopted Sealant retention as a measure of quality. Sealant retention in first and second molars was evaluated at each six-month recall appointment. Sealants were categorized as satisfactory or unsatisfactory. Two hundred five sealants were evaluated between March 1998 and March 1999. The mean age of the patients at the time of sealant evaluation was 14.0 +/- 2.9. Mean sealant retention period was 29.8 +/- 23.2 months, with a range of 0.9 to 148 months. Median sealant retention period was 23.2 months. Overall, 75.6 percent of the sealed teeth were classified as satisfactory. Use of this data in making improvements is discussed. Our results indicate that the use of sealant retention is a suitable measure for quality of care in pediatric dentistry.

Collagen gel delivery of Tgf-beta3 non-viral plasmid DNA in rat osteoblast and calvarial culture.

Different forms of collagen as a carrier for naked plasmid DNA have shown potential as vehicles for therapeutic gene delivery and tissue engineering. The objective of this study was to determine the suitability of a dense collagen gel as a vehicle for sustained delivery of plasmid DNA in cell and organ culture. Plasmid DNA encoding Tgf-beta(3) was combined with collagen gel. DNA released into the media was measured by Pico-Green spectrophotometry. Results showed that DNA was released from the collagen gel at a gradual rate for up to 14 days. To evaluate collagen-mediated transfection in tissue, calvariae were exposed to collagen containing plasmid encoding GFP or DsRed. Transfection was visualized by fluorescence localized to tissue adjacent to the vehicle. To evaluate protein production, fetal rat calvarial osteoblasts were cultured with a collagen/Tgf-beta(3) plasmid mixture or in media containing plasmid alone. Media was collected at various time points to measure Tgf-beta(3) protein production. ELISA assays showed that collagen-transfected osteoblasts demonstrated an elevated Tgf-beta(3) protein production for up to 14 days. Therefore, collagen delivery of viable plasmid DNA created a sustained transient transfection of calvarial osteoblasts resulting in prolonged and elevated growth factor production. Together, these results suggest that use of collagen gel as a vehicle may provide a strategy to achieve localized and controlled, non-viral gene delivery in vivo.

Interactions between integrin receptors and fibronectin are required for calvarial osteoblast differentiation in vitro.

We previously showed that anti-fibronectin antibodies or soluble fibronectin fragments containing the central cell-binding domain inhibit formation of mineralized nodules by fetal calvarial osteoblasts in vitro. These findings suggest a critical role for fibronectin in osteoblast differentiation and morphogenesis. In this study we tested the hypothesis that fibronectin's effects on osteogenesis are mediated via direct interactions with integrin receptors for fibronectin on osteoblasts. Immunocytochemical analysis identified the integrin fibronectin receptor alpha5ss1 in fetal rat calvarial tissue and in cultured osteoblasts at all stages of differentiation. Three other integrins, alpha3ss1, alpha8ss1 and alphavss3, which can bind fibronectin, as well as other matrix components, were also identified in tissue and at all stages of cell culture. Immunoprecipitation data showed that alpha5ss1 levels are constant throughout osteoblast differentiation whereas levels of alpha3ss1 and alpha8ss1 decline in mature mineralized cultures. To determine whether integrin fibronectin receptors are required for osteoblast formation of mineralized nodules, we examined the extent of nodule formation in the presence and absence of function-perturbing anti-integrin antibodies. The antibodies were present continuously in cultures beginning at confluence (day 3), and nodule formation was measured at days 10 and 20. An anti-alpha5 integrin subunit antibody reduced nodule formation to less than 5% of control values at both time points. Inhibition of nodule formation was reversible and did not affect cell attachment and viability. Function-perturbing antibodies against alpha3ss1 and alpha8ss1 also reduced nodule formation, to less than 20% of control values. In contrast, function-perturbing antibodies to alphavss3 and alphavss5 did not affect nodule formation, indicating that the inhibitions noted were indeed specific. To determine the effect of antibody treatment on gene expression, steady-state mRNA expression was examined and found to be suppressed for osteoblast markers alkaline phosphatase and osteocalcin. Together, these results indicate that direct osteoblast interactions with the extracellular matrix are mediated by a select group of integrin receptors that includes alpha5ss1, alpha3ss1 and alpha8ss1. We further conclude that the specific alpha5ss1 fibronectin receptor mediates critical interactions between osteoblasts and fibronectin required for both bone morphogenesis and osteoblast differentiation.

Fibronectin regulates calvarial osteoblast differentiation.

The secretion of fibronectin by differentiating osteoblasts and its accumulation at sites of osteogenesis suggest that fibronectin participates in bone formation. To test this directly, we determined whether fibronectin-cell interactions regulate progressive differentiation of cultured fetal rat calvarial osteoblasts. Spatial distributions of alpha 5 integrin subunit, fibronectin, osteopontin (bone sialoprotein I) and osteocalcin (bone Gla-protein) were similar in fetal rat calvaria and mineralized, bone-like nodules formed by cultured osteoblasts. Addition of anti-fibronectin antibodies to cultures at confluence reduced subsequent formation of nodules to less than 10% of control values, showing that fibronectin is required for normal nodule morphogenesis. Anti-fibronectin antibodies selectively inhibited steady-state expression of mRNA for genes associated with osteoblast differentiation; mRNA levels for alkaline phosphatase and osteocalcin were suppressed, whereas fibronectin, type I collagen and osteopontin were unaffected. To identify functionally relevant domains of fibronectin, we treated cells with soluble fibronectin fragments and peptides. Cell-binding fibronectin fragments (type III repeats 6-10) containing the Arg-Gly-Asp (RGD) sequence blocked both nodule initiation and maturation, whether or not they contained a functional synergy site. In contrast, addition of the RGD-containing peptide GRGDSPK alone did not inhibit nodule initiation, although it did block nodule maturation. Thus, in addition to the RGD sequence, other features of the large cell-binding fragments contribute to the full osteogenic effects of fibronectin. Nodule formation and osteoblast differentiation resumed after anti-fibronectin antibodies or GRGDSPK peptides were omitted from the media, showing that the inhibition was reversible and the treatments were not cytotoxic. Outside the central cell-binding domain, peptides from the IIICS region and antibodies to the N terminus did not inhibit nodule formation. We conclude that osteoblasts interact with the central cell-binding domain of endogenously produced fibronectin during early stages of differentiation, and that these interactions regulate both normal morphogenesis and gene expression.