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Grays, United Kingdom

Adali N.,University College London | Mars M.,North Thames Cleft Center | Petrie A.,University College London | Noar J.,UCL Eastman Dental Institute | Sommerlad B.,North Thames Cleft Center
Cleft Palate-Craniofacial Journal | Year: 2012

Objective: Evaluation of the effect of presurgical orthopedics on maxillary archform up to 6 months of age. Design: Retrospective, single-blinded, case-control study. Participants: Study model sets of 75 infants with consecutive, nonsyndromic, complete unilateral cleft lip and palate (excluding Simonart bands) from1995 to 2005. Interventions: All patients (PSO group, n = 14; non-PSO group, n = 61) received lip repair/vomer flap at 3 months and soft palate repair at 6 months by the same consultant surgeon. The two groups were comparable at birth (p > .01) in all archform variables. Main Outcome Measures: Sixteen variables were computed, following singleblinded analysis using the Reflex Microscope to describe the archform in the transverse, anteroposterior, and vertical dimensions and the arch circumference. Data were analyzed using a repeated-measures hierarchical analysis of variance with a significance level of 1%. Results: Repeatability studies showed good measurement precision. Presurgical orthopedics produced no statistically significant mean change in any archform variable when compared with the non-PSO group. The difference in the mean reduction in the alveolar cleft width between the groups was 0.69 mm (95% confidence interval, 20.89 to 2.28 mm, p = .52). Lip repair produced greater change in archform than did presurgical orthopedics, reducing the mean alveolar cleft width by 4.45 mm (95% confidence interval, 3.53 to 5.37 mm; p < .001). Conclusions: There was no evidence that presurgical orthopedics produced any significant effect on archform, raising questions for its continued use in this context. Lip repair had a greater impact on arch dimensions than did presurgical orthopedics. Source

Shah R.,UCL Eastman Dental Institute | Ready D.,Microbial Diseases | Knowles J.C.,UCL Eastman Dental Institute | Knowles J.C.,Dankook University | And 3 more authors.
Journal of Tissue Engineering and Regenerative Medicine | Year: 2014

Tissue engineering has the potential to overcome limitations associated with current management of skeletal muscle defects. This study aimed to sequentially identify a degradable phosphate glass scaffold for the restoration of muscle defects. A series of glass compositions were investigated for the potential to promote bacterial growth. Thereafter, the response of human craniofacial muscle-derived cells was determined. Glass compositions containing Fe4- and 5mol% did not promote greater Staphylococcus aureus and Staphylococcus epidermidis growth compared to the control (p>0.05). Following confirmation of myogenicity, further studies assessed the biocompatibility of glasses containing Fe5 mol%. Cells seeded on collagen-coated disks demonstrated comparable cellular metabolic activity to control. Upregulation of genes encoding for myogenic regulatory factors (MRFs) confirmed myofibre formation and there was expression of developmental MYH genes. The use of 3-D aligned fibre scaffolds supported unidirectional cell alignment and upregulation of MRF and developmental MYH genes. Compared to the 2-D disks, there was also expression of MYH2 and MYH7 genes, indicating further myofibre maturation on the 3-D scaffolds and confirming the importance of key biophysical cues. © 2012 John Wiley & Sons, Ltd. Source

Aljabo A.,UCL Eastman Dental Institute | Xia W.,UCL Eastman Dental Institute | Liaqat S.,UCL Eastman Dental Institute | Khan M.A.,UCL Eastman Dental Institute | And 3 more authors.
Dental Materials | Year: 2015

Objectives Cure, volumetric changes and mechanical properties were assessed for new dental composites containing chlorhexidine (CHX) and reactive calcium phosphate-containing (CaP) to reduce recurrent caries. Methods 20 wt.% of light curable urethane dimethacrylate based liquid was mixed with 80 wt.% glass filler containing 10 wt.% CHX and 0-40 wt.% CaP. Conversion versus depth with 20 or 40 s light exposure was assessed by FTIR. Solidification depth and polymerization shrinkage were determined using ISO 4049 and 17304, respectively. Subsequent volume expansion and biaxial flexural strength and modulus change upon water immersion were determined over 4 weeks. Hydroxyapatite precipitation in simulated body fluid was assessed at 1 week. Results Conversion decreased linearly with both depth and CaP content. Average solidification depths were 4.5, 3.9, 3.3, 2.9 and 5.0 with 0, 10, 20, and 40% CaP and a commercial composite, Z250, respectively. Conversions at these depths were 53 ± 2% for experimental materials but with Z250 only 32%. With Z250 more than 50% conversion was achieved only below 1.1 mm. Shrinkage was 3% and 2.5% for experimental materials and Z250, respectively. Early water sorption increased linearly, whilst strength and modulus decreased exponentially to final values when plotted versus square root of time. Maximum volumetric expansion increased linearly with CaP rise and balanced shrinkage at 10-20 wt.% CaP. Strength and modulus for Z250 decreased from 191 to 158 MPa and 3.2 to 2.5 GPa. Experimental composites initial strength and modulus decreased linearly from 169 to 139 MPa and 5.8 to 3.8 GPa with increasing CaP. Extrapolated final values decreased from 156 to 84 MPa and 4.1 to 1.7 GPa. All materials containing CaP promoted hydroxyapatite precipitation. Significance The lower surface of composite restorations should both be solid and have greater than 50% conversion. The results, therefore, suggest the experimental composite may be placed in much thicker layers than Z250 and have reduced unbounded cytotoxic monomer. Experimental materials with 10-20 wt.% additionally have volumetric expansion to compensate shrinkage, antibacterial and re-mineralizing components and competitive mechanical properties. © 2015 Academy of Dental Materials. Source

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