Richard A. Riedel

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.

An evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention.

Pretreatment, end of treatment, 10-year postretention, and 20-year postretention records of 31 four premolar extraction cases were assessed to evaluate stability and relapse of mandibular anterior alignment. Crowding continued to increase during the 10- to 20-year postretention phase but to a lesser degree than from the end of retention to 10 years postretention. Only 10% of the cases were judged to have clinically acceptable mandibular alignment at the last stage of diagnostic records. Cases responded in a diverse unpredictable manner with no apparent predictors of future success when considering pretreatment records or the treated results.

Mandibular arch length increase during the mixed dentition: postretention evaluation of stability and relapse.

Increasing mandibular arch length to resolve crowding has long been debated as a treatment method. Twenty-six patients with records obtained before treatment, after treatment, and a minimum of 6 years out of retention were assessed. All the patients showed a loss of treatment arch length increase with only 6 of 26 patients showing any gain over pretreatment dimensions. Width constriction was a consistent finding, as was crowding of anterior teeth after retention. In 89% the postretention record demonstrated clinically unsatisfactory alignment. Lateral cephalometric superimposition of mandibles showed variable molar and incisor change after retention. As teeth erupted after treatment, mesial molar movement and lingual tipping of incisors were the most common cephalometric findings.

Long-term evaluation of root resorption occurring during orthodontic treatment

The present study was undertaken to evaluate the long-term status of teeth that had undergone root resorption during active orthodontic treatment. A total of 100 patients who exhibited root resorption during appliance therapy were recalled at a mean period of 14.1 years (SD 0.4) after treatment. At those examinations full-mouth sets of periapical radiographs were taken and tooth mobility evaluated. Pretreatment, posttreatment, and long-term periapical radiographs were examined and compared for changes in root length and contour with time. At each stage scores were given on a scale from 0 to 4, depending on the degree of resorption. The maxillary incisors were affected more frequently and to a greater degree than the rest of the teeth during active treatment. The long-term evaluation showed no apparent changes after appliance removal except remodeling of rough and sharp edges. Hypermobility was observed in only two instances.

A comparison of apical root resorption during orthodontic treatment in endodontically treated and vital teeth

The purpose of this study was to determine whether vital and endodontically treated incisors exhibit a similar severity of apical root resorption in response to orthodontic treatment. Forty-three patients who had one or more endodontically treated incisors before orthodontic treatment and who exhibited signs of apical root resorption after treatment were studied. In each patient the vital contralateral incisor served as a control. Vital incisors resorbed to a significantly greater degree than endodontically treated incisors (p less than or equal to 0.05). When patients were separated by gender, control teeth in males exhibited a statistically significant increase in resorption over control teeth in females. No significant differences were apparent between males and females when endodontically treated incisors were compared.

Postretention evaluation of stability and relapse—Mandibular arches with generalized spacing

Assessment of cases that had been out of retention a minimum of 10 years and had displayed generalized spacing of anterior teeth before treatment showed consistent reduction of arch length and intercanine width into adult years. Intercanine width constriction typically occurred while arch length decreased in every case, both width and length reduction being progressive with time. Crowding was minimal for the majority of cases; few demonstrated the severe crowding more typical of cases with pretreatment crowding.

Serial extraction of first premolars — postretention evaluation of stability and relapse

Case records were evaluated for 30 patients who had undergone serial extraction of deciduous teeth plus first premolars followed by comprehensive orthodontic treatment and retention. Diagnostic records were available for the following stages: pre-extraction, start of active treatment, end of active treatment, and a minimum of 10 years postretention. All cases were treated with standard edgewise mechanics and were judged clinically satisfactory by the end of active treatment. Twenty-two of the 30 cases (73%) demonstrated clinically unsatisfactory mandibular anterior alignment postretention. Intercanine width and arch length decreased in 29 of the 30 cases by the postretention stage. There was no difference between the serial extraction sample and a matched sample extracted and treated after full eruption.

Mandibular incisor extraction--postretention evaluation of stability and relapse.

Pretreatment, posttreatment and 10-year postretention dental cast and lateral cephalogram records of 42 patients were evaluated. Each patient had undergone edgewise orthodontic treatment following removal of one or two mandibular incisors and various maxillary teeth. Seven of 24 patients (29%) in the single-incisor extraction group and 10 of 18 (56%) patients in the two-incisor extraction group demonstrated unacceptable mandibular incisor alignment at the postretention stage. This result was considerably more favorable than the results of previously reported premolar extraction cases (70% unacceptable alignment at postretention). Intercanine width decreased during treatment and continued to decrease postretention in most cases. Overbite and overjet remained acceptable. No associations could be found to predict the amount of relapse.

Pont's index: a clinical evaluation.

Abstract No Abstract Available. From the Department of Orthodontics, School of Dentistry, University of Washington. This study was supported by Public Health Serviae Training Grant DE-00238-01.

Research on variation in dental occlusion: A “state of the art” workshop conducted by the Craniofacial Anomalies Program, the National Institute of Dental Research

The following report on assessing research on variation in dental occlusion was based in part on a workshop conducted by the National Institute of Dental Research at the initiative of Richard L. Christiansen, Chief, Craniofacial Anomalies Program. The meeting was planned and developed by Robert J. Isaacson, Chairman, Touro M. Graber, Richard A. Riedel, and Richard L. Christiansen. This report is designed to provide a review of the achievements, directions, and needs of research concerning variations in dental occlusion. The workshop was held at the National Institutes of Health, Bethesda, Maryland, on Nov 22 and 23, 1972. The material presented by the workshop participants has been summarized and incorporated in this report. The subject of research related to the field of malocclusion was discussed in an article published in the American Journal of Orthodontics in January, 1971.