The aim of this study was to evaluate quantitatively sagittal, skeletal and dental changes occurring during and after Herbst treatment and relate these changes to alteration in the occlusion. Lateral roentgenograms in centric occlusion were analysed. The sample consisted of 40 Class II, division 1 cases treated with the Herbst appliance for an average period of 7 months. The subjects were reexamined 6 and 12 months post treatment. The results revealed the following: during the treatment period all subjects were treated to Class I or overcorrected Class I or Class III dental arch relationships. Overjet and sagittal molar relationship improved by an average of 6.9 mm and 6.3 mm respectively. This was a result of a 2.2 mm greater mandibular than maxillary growth, a 2.3 mm lingual movement of the maxillary incisors, a 2.4 mm labial movement of the mandibular incisors, a 2.0 mm distal movement of the maxillary molars and a 2.1 mm mesial movement of the mandibular molars. During the post treatment period of 12 months the occlusion settled into Class I in all subjects. Overjet and sagittal molar relationship relapsed by an average of 2.2 mm and 1.7 mm respectively. About 90 per cent of the occlusal relapse occurred during the first 6 months post treatment. In 58 per cent of the subjects the occlusal relapse was exclusively a result of tooth movements while unfavourable maxillary and mandibular jaw growth contributed to the relapse in 42 per cent of the subjects. As Herbst treatment is performed during a relatively short period, the dentition will be in a state of instability after the appliance is removed. Post treatment retention as well as interocclusal adjustments with an activator are therefore recommended.

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Objective: To evaluate morphologic stability and patient satisfaction at least 5 years after orthodontic treatment. Materials and Methods: Published literature was searched through the PubMed and Cochrane Library electronic databases from 1966 to January 2005. The search was performed by an information specialist at the Swedish Council on Technology Assessment in Health Care. The inclusion criteria consisted of a follow-up period of at least 5 years postretention; randomized clinical trials, prospective or retrospective clinical controlled studies, and cohort studies; and orthodontic treatment including fixed or removable appliances, selective grinding, or extractions. Two reviewers extracted the data independently and also assessed the quality of the studies. Results:The search strategy resulted in 1004 abstracts or full-text articles, of which 38 met the inclusion criteria. Treatment of crowding resulted in successful dental alignment. However, the mandibular arch length and width gradually decreased, and crowding of the lower anterior teeth reoccurred postretention. This condition was unpredictable at the individual level (limited evidence). Treatment of Angle Class II division 1 malocclusion with Herbst appliance normalized the occlusion. Relapse occurred but could not be predicted at the individual level (limited evidence). The scientific evidence was insufficient for conclusions on treatment of cross-bite, Angle Class III, open bite, and various other malocclusions as well as on patient satisfaction in a long-term perspective. Conclusions: This review has exposed the difficulties in drawing meaningful evidence-based conclusions often because of the inherent problems of retrospective and uncontrolled study design.

; Hans-Gö ran Grö ndahl d ABSTRACT Objective: To investigate the incidence and severity of root resorption during orthodontic treatment by means of cone beam computed tomography (CBCT) and to explore factors affecting orthodontically induced inflammatory root resorption (OIIRR). Materials and Methods: CBCT examinations were performed on 152 patients with Class I malocclusion. All roots from incisors to first molars were assessed on two or three occasions. Results: At treatment end, 94% of patients had $1 root with shortening .1 mm, and 6.6% had $1 tooth where it exceeded 4 mm. Among teeth, 56.3% of upper lateral incisors had root shortening .1 mm. Of upper incisors and the palatal root of upper premolars, 2.6% showed root shortenings .4 mm. Slanted surface resorptions of buccal and palatal surfaces were found in 15.1% of upper central and 11.5% of lateral incisors. Monthly root shortening was greater after 6-month control than before. Upper jaw teeth and anterior teeth were significantly associated with the degree of root shortening. Gender, root length at baseline, and treatment duration were not. Conclusion: Practically all patients and up to 91% of all teeth showed some degree of root shortening, but few patients and teeth had root shortenings .4 mm. Slanted root resorption was found on root surfaces that could be evaluated only by a tomographic technique. A CBCT technique can provide more valid and accurate information about root resorption. (Angle Orthod. 2012;82:480-487.)

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