Construction and application of substitutes for oral mucosa in cleft palate repair.

Contains fulltext : 77584.pdf (publisher's version ) (Open Access)RU Radboud Universiteit Nijmegen, 2 juni 2010Promotor : Kuijpers-Jagtman, A.M. Co-promotores : Hoff, J.W. Von den, Maltha, J.C.181 p

Implantation of tissue-engineered mucosal substitutes in the dog palate.

Contains fulltext : 69830.pdf (publisher's version ) (Closed access)Tissue shortage complicates the surgery of cleft palate (CP) anomalies. The healing of defects on the palate impairs growth of the dento-maxillary complex due to scar tissue formation. Implantation of grafts into the wound area might reduce this adverse effect of surgery. The aim of this study was to evaluate a cultured autologous mucosal substitute, which can be used as a graft material. Two different types of cultured mucosal substitutes composed of skin-derived substrates (unprocessed dermis and AlloDerm) and autologous oral keratinocytes were implanted in palatal wounds in six beagle dogs (1-1.5 years of age). The cultured substitutes were compared with a sham and a control group. The animals were sacrificed in pairs 1, 3, and 12 weeks after surgery. Epithelial regeneration, inflammatory response (leucocyte protein L1), ingrowth of (myo-) fibroblasts, collagen type III, and formation of a basal membrane (JM 403) were evaluated. The results demonstrated that all cultured substitutes possessed a multilayered epithelium, closely resembling normal palatal epithelium. After implantation, however, the epithelium was lost and an inflammatory response was observed in the first week. After 3 and 12 weeks, the implanted substitutes had completely disappeared and epithelial migration occurred from the wound margins. It is possible to culture an autologous epithelium on a skin-derived substrate and implant it as an oral mucosal substitute in palatal wounds. However, these substitutes do not improve the healing of palatal wounds. It is suggested that the revascularization of the wound area is too slow to allow survival and integration of the substitutes

Dental maturity in children with a complete bilateral cleft lip and palate.

OBJECTIVE: Dental age in children with a bilateral cleft lip and palate (BCLP) was assessed and compared with children without cleft. DESIGN: Dental age was estimated for 74 children with a complete BCLP (54 boys and 20 girls) from 364 orthopantomograms. Nonlinear regression curves were made between 5 and 14 years of age for boys and girls separately. A comparison was made with a sample of Dutch children (91 girls and 90 boys) without oral clefts for three different age groups, namely 5, 9.5, and 14 years of age. SETTING: Data collection was carried out at the Cleft Palate Center, University Medical Center Nijmegen (The Netherlands). A sample from the Nijmegen Growth Study was used as a normative sample. RESULTS: At 5 years of age, boys with a BCLP were significantly delayed in dental age compared to boys without cleft. After that age, no significant differences in dental age were found. For girls with a BCLP, no difference in dental age with the girls without cleft could be found. CONCLUSION: Dental age in BCLP showed a tendency to be delayed at 5 years of age. At the ages of 9.5 and 14 years of age, no differences were found. Further investigation on the development of individual teeth is suggested to gain more insight into the origin of this delay

Dentoalveolar development in beagle dogs after palatal repair with a dermal substitute.

Contains fulltext : 88305.pdf (publisher's version ) (Closed access)INTRODUCTION: Our aim was to compare the dentoalveolar development in beagle dogs after palatal repair according to the Von Langenbeck technique with and without implantation of a dermal substitute. METHODS: Nineteen beagles (age, 12 weeks) were assigned to 2 experimental groups and an untreated control group. Palatal surgery was performed with the Von Langenbeck technique in the 2 experimental groups. The dermal substitute Integra (Plainsboro, NJ, USA) was implanted in 1 experimental group, and the other served as sham group. Dental casts were made before surgery and at several times in all groups to measure dentoalveolar development. Transversal distances, arch depth, tipping, and rotation were determined. Histologic evaluations were performed at 3, 7, and 15 weeks after surgery. The degrees of reepithelialization and tissue organization were evaluated microscopically. RESULTS: All wounds healed without complications. Scar tissue attached to the bone was found in both experimental groups. Deposition of bone in the Integra occurred after implantation, indicating its osteoconductivity. Transversal dentoalveolar development was similar in both experimental groups, but it was significantly less than in the control group. CONCLUSIONS: Implantation of Integra after the Von Langenbeck procedure for palatal repair does not improve dentoalveolar development.1 juli 201

Effects of different types of palatal lateral excisions on growth and development of maxilla and dental arch

Objective: This study aimed to explore the effects of different types of palatal lateral excisions on the growth and development of the maxilla and dental arch, and to investigate the underlying mechanisms. Methods: A total of 112 3-week-old Sprague-Dawley (SD) male rats were randomly divided into a control and 3 experimental groups: the mucoperiosteal denudation group, the mucosal flap excision group, and the periosteum excision group. In the experimental groups, bilateral mucoperiosteal, mucosal flap and periosteum were excised respectively in the lateral one half of the palate. Four rats in each group were randomly chosen for sacrifice every two weeks. The maxilla was dissected following the excision. The widths of the maxilla and dental arch were measured and the histological phenomena were investigated at different phases. At the same time, 12 animals in each group were sequentially injected with calcein every two weeks. Three animals in each group, whose fluorescent labeling was used, were sacrificed for investigating bone formation at Week 8 following injection. Results: (1) Each experimental group presented the constriction of the maxilla and dental arch. The upper first molars in the experimental groups inclined medially. The mucoperiosteal denudation group showed the largest degree of effect followed by the periosteum excision group. The indices of the mucosal flap excision group, which retained the structures of the periosteum layer, had the most approximate values to the control group; (2) Different histological changes among the experimental groups were detected. The fibers penetrated into the palatal bone as Sharpey’s fibers in the mucoperiosteal denudation group. The pattern of bone deposition was the bundle type. Sharpey’s fibers were not found in the mucosal flap and periosteum excision groups and the depositions of palatal bone were the lamellar type as those in the control group; (3) The rates of bone deposition in the experimental groups decreased compared with the control group. The rates in different phases were the most approximate values to those of the control group in the mucosal flap excision group, which has the same structure of periosteum as the control group. Conclusion: There were different effects on the growth and development of the maxilla and dental arch in different types of palatal lateral excisions. Periosteum is important for bone formation and deposition pattern. The prevention of Sharpey’s fibers forming and attaching to the palatine can effectively avert the following malformation