Pericision: An aid to the reduction of rotational relapse in clinical practice? An assessment

An experimental study in dogs of transseptal fiber arrangement between teeth which have emerged in rotated or non-rotated positions

Transseptal fibers of the periodontal ligament are thought to play a role in relapse after orthodontic derotation. The aim of this study was to compare the location of the attachment site and the arrangement of the transseptal fibers in rotated emerged and non-rotated emerged teeth. In five dogs, unilaterally, the first upper premolars were replaced into a rotated position, before emergence. Histological evaluation showed that transseptal fibers developed in the experimental as well as in the control specimens. In all cases, transseptal fibers bridged the shortest distance between two adjacent teeth. It was concluded that the attachment site of the transseptal fibers was not determined by the tooth anatomy itself, but by the tooth position and its orientation in the dental arch during transseptal fiber development.

A long-term prospective evaluation of the circumferential supracrestal fiberotomy in alleviating orthodontic relapse

This prospective study conducted during a period of nearly 15 years initially involved 320 consecutively selected cases. The primary purpose of the investigation was to statistically evaluate the efficacy of the circumferential supracrestal fiberotomy (CSF) procedure in alleviating dental relapse following orthodontic treatment. The "Irregularity Index" method of Little for measuring the malposition of teeth was used to quantitatively record the relapse of the control and CSF cases at approximately 4 to 6 years after active treatment and again at 12 to 14 years after active treatment. The differences between the mean relapses of the control and the CSF cases were highly significant at both time intervals. The surgical procedure appeared to be somewhat more effective in alleviating pure rotational relapse than in labiolingual relapse. On a long-term basis, the CSF procedure was shown to be more successful in reducing relapse in the maxillary anterior segment than in the mandibular anterior segment. Nevertheless, a significant and unpredictable variation in individual tooth movement following orthodontic treatment was observed in both the control and CSF groups. No clinically significant increase in the periodontal sulcus depth nor decrease in the labially attached gingiva of the CSF teeth was observed at 1 and 6 months following the surgical procedure.

Stability and relapse of mandibular anterior alignment-first premolar extraction cases treated by traditional edgewise orthodontics

Assessment at least 10 years postretention of sixty-five cases previously treated in the permanent-dentition stage with first-premolar extractions, traditional edgewise mechanics, and retention revealed considerable variation among patients. The long-term response to mandibular anterior alignment was unpredictable; no variables, such as degree of initial crowding, age, sex, Angle classification, etc., were useful in establishing a prognosis. Typically, arch width and length decreased after retention, regardless of treatment expansion or constriction. Two thirds of the patients had unsatisfactory lower anterior alignment after retention. Cases that were minimally crowded before treatment usually became more crowded, while initially severe crowding cases usually moderated.

Clinical experiences with circumferential supracrestal fiberotomy

This article has reported on a survey of 1,000 randomly selected orthodontists in the United States to ascertain the incidence of use of the circumferential supracrestal fiberotomy technique to minimize rotational relapse. It was also the purpose of the study to determine whether any problems were associated with the procedure. While the surgical technique is not widely prescribed, there are regional differences. The result of this survey tend to indicate that the technique is reasonably problem-free and that its use probably will be increasing in the future. It should be emphasized that quantitative long-term studies of the effectiveness of the procedure and of possible periodontal sequelae have to date not been reported in the literature.