Expression of Cytokeratin in Experimentally Created Inflammatory Cyst in Vivo and in Vitro.

The purpose of this study was to investigate the behavior of epithelial lining derived from Malassez's epithelial rest (MER) cells in experimentally created inflammatory cysts in vivo and in vitro. Porcine MER cells were cultured in vitro with or without interleukin (IL)-1ß (1 ng/ml) or IL-6 (1 ng/ml). Cell proliferation was assessed and expression levels of CK19 and CK13 mRNA determined using RT-PCR. In vivo, a cavity was created in the first molar of Sprague-Dawley male rats and tissue repair observed using immunohistochemical methods. In vitro, treatment with IL-1ß or IL-6 increased proliferation of MER cells and decreased expression of CK19 mRNA, but increased CK13 mRNA at day 1 (p<0.05). In vivo, at 2 weeks, CK19-positive epithelial cells were observed adjacent to the cementum, in the cystic lesion, and in connective tissue. At 3 weeks, they were only detected in cells adjacent to the connective tissue. Cells positive for CK13 were observed throughout the epithelium, except in cells adjacent to connective tissue at weeks 2 and 3. Exposure to IL-1ß and/or IL-6 induced proliferation and differentiation of MER cells.

Treatment of Child with Four Lost Maxillary Incisors due to Traffic Injury.

Tooth injury is frequently encountered in pediatric clinical practice. A clinician may be requested to not only respond at the time of injury, but also properly diagnose how such injury will affect the teeth and dentition. Here, we present a case of a child who lost 4 bilateral maxillary incisors due to a traffic accident, and in whom marked mesial inclination of the bilateral maxillary canines and bilateral maxillary first premolars would subsequently occur. Dental management was provided over an extended period. The boy, aged 9 years 11 months, visited our department with the chief complaint of premature loss of 4 bilateral maxillary incisors and eating disturbance associated with the loss of these teeth. Initially, a denture was fitted. The bilateral maxillary canines subsequently demonstrated marked mesial inclination, however, and erupted from an area equivalent to that of the bilateral central incisors. The bilateral maxillary first premolars also showed mesial inclination and rotation. Taking esthetics into consideration, a Nance holding arch with resin buttons that extended to the maxillary incisors and attached to artificial teeth was used. This appliance was also equipped with a retracting hook, and the bilateral maxillary canines were moved downward and distally. Presently, the removable partial denture is worn for the purposes of retention, esthetics, and mastication. Long-term oral management will be necessary. Therefore, final prosthetic treatment for the missing maxillary incisors is planned for when the patient reaches adulthood.