Pulpal and periodontal reactions of immature permanent teeth in the dog to intrusive trauma

Abstract

Pulpal and periodontal tissues of immature incisors of 10 dogs were radiographically and histopathologically evaluated immediately, 7, 15, 30 and 60 days after experimental intrusion induced by mechanical blows. Forty upper central and mesial lateral incisors showing incomplete root formation on radiographs were submitted to intrusive force. After the observation periods, the dogs were killed, two at a time. The hemi-maxilas were removed and processed for histopathologic examination. The traumatized teeth showed accelerated apical formation with reduced radicular length. Pulpal vitality was maintained and the subjacent tissues did not present irreversible changes. All traumatized teeth re-erupted spontaneously.

Histological evaluation of dog permanent teeth after traumatic intrusion of their primary predecessors

“…At the moment of the sacrifice of group 1, the animals were 80 days old and would have all the matrix deposited, except for a small portion in the cervical region, and would not have initiated the root resorption of the primary teeth. According to microscopical analysis, the stages of deposition and mineralization of the enamel and dentin matrices and the aspect of the cells that are responsible for these events agree with the histological literature (18–21). When the sacrifice of group 2 was performed, the animals were 100 days old, which would correspond to the mineralization of two‐thirds of the crown, and the primary teeth would be near to exfoliation.…”

“…The histological variations described here were considered to be pathological alterations, as they differed in appearance from what the literature shows to be normal in the odontogenesis of dogs (19–22). They may have occurred as a consequence of the induced traumatic intrusion.…”

Traumatic intrusion of permanent teeth. Part 2. A clinical study of the effect of preinjury and injury factors, such as sex, age, stage of root development, tooth location, and extent of injury including number of intruded teeth on 140 intruded permanent teeth

“…In that regard a problem exists in that only a few experimental studies have been reported concerning the histological events after intrusion. Studies have been made in rats (14,15) and dogs (16)(17)(18). Both animal models, however, are not that comparable in relation to a human situation, because of significant differences in anatomy.…”

Influence of surgical repositioning of mature permanent dog teeth following experimental intrusion: a histologic assessment

“…Soon after, the dogs were placed on an operating table, and their heads were immobilized in such way that the upper and lower lateral incisors could receive a mechanical impact in a longitudinal direction to cause intrusion. The force was applied through a device, described in a previous report (20), able to obtain an intrusion established between 4 and 6 mm.…”