[Light microscopic studies of pulp morphology following orthodontic therapy]

The authors studied the dental pulp morphology and distribution of acid and neutral mucopolysaccharides in teeth subjected to orthodontic therapy. The teeth were moved with a fixed appliance using forces of 60-200 g. Changes in the histological structure of the dental pulp followed the therapy. The number of collagen fibres increased; they were densely packed and formed thick bundles. A certain degree of hyalinization was also observed. The dental pulp cavity was narrowed by apposition of hard tissue deposits along the canal wall. Pulp stones and diffuse calcification were often encountered. The reaction of acid mucopolysaccharides was found to be very weak, sometimes even negative. The reaction of neutral mucopolysaccharides was not affected so markedly. The results of the paper suggest that changes induced in the dental pulp with fixed orthodontic appliances are irreversible and correspond to those of aging. These premature changes together with rapid hard tissue formation, may negatively influence endodontic treatment in the future.