Residents’ journal review

Reduced tooth movement in diabetes—rat-model

Arita K, Hotokezaka H, Hashimoto M, Nakano-Tajima T, Kurohama T, Kondo T, et al. Effects of diabetes on tooth movement and root resorption after orthodontic force application in rats. Orthod Craniofac Res 2016;19:83-92

Current studies have demonstrated a link between diabetes and alterations in bone metabolism. Because of the high incidence of diabetes and the increasing number of adults seeking orthodontic treatment, the orthodontic practitioner must have an understanding of systemic disease in relation to orthodontic tooth movement. The authors of this study investigated the effects of diabetes on orthodontic tooth movement and orthodontically induced root resorption in a rat model of streptozotocin-induced type 1 diabetes. Twenty-three 10-week-old male Sprague Dawley rats were divided into 3 groups: control (n = 7), diabetes (n = 9), and diabetes + insulin (n = 7). A nickel-titanium closed-coil spring of 10 g was applied for 2 weeks to the maxillary left first molar of all rats to induce tooth movement. Tooth movement was measured using microcomputed tomography images. Furthermore, the quantity of root resorption was computed with scanning electron and scanning laser microscopy. According to the findings, diabetes altered the biologic response to orthodontic force application. Both orthodontic tooth movement and orthodontically induced root resorption were lower in diabetic rats than in normal rats. However, additional studies are warranted to understand the effects of long-term orthodontic treatment to appropriately and safely manage the diabetic patient. Further studies should also differentiate between the effects of high glucose and insulin itself. An additional type 2 diabetic control in which mice are injected daily with high doses of insulin to induce diabetes would provide more information in this regard.

Reviewed by Diana Esshaki

Correction of incisors’ position and inclination in skeletal Class III malocclusions

Zou B, Zhou Y, Lowe AA, Li H, Pliska B. Changes in anteroposterior position and inclination of the maxillary incisors after surgical-orthodontic treatment of skeletal class III malocclusions. J Craniomaxillofac Surg 2015;43:1986-93

The anteroposterior position and inclination of the maxillary incisors are critical components of an esthetically pleasing smile, which is essential to facial attractiveness. The authors of this study aimed to compare the anteroposterior position and inclination of the maxillary incisors between patients with skeletal Class I and normal occlusions and those with skeletal Class III malocclusions. They also aimed to evaluate the anteroposterior position and inclination of the maxillary incisors in skeletal Class III subjects before and after surgical-orthodontic treatment. With these purposes, the records of 67 skeletal Class III patients (study group, 38 female, 29 male; mean age, 21.3 years) and 65 skeletal Class I subjects (control group, 35 female, 30 male; mean age, 21.8 years) with minor crowding and a normal profile were retrospectively analyzed. Six landmarks on the forehead, nose, and maxillary incisor were marked on lateral cephalograms and photographs, and these images were digitally superimposed using a new computer program. The authors found that compared with Class I subjects, Class III subjects had similarly inclined foreheads, but their maxillary incisors were significantly retruded and proclined. In skeletal Class III subjects, comparisons of pretreatment and posttreatment images yielded much more ideal positions and inclinations postoperatively. Class I subjects and posttreatment Class III subjects had similar anteroposterior positioning for the maxillary incisors. This study showed that surgical-orthodontic treatment of Class III subjects was effective in correcting maxillary incisor position and inclination. These findings should also be evaluated from the perspective of soft tissue response to both orthodontic treatment and surgery. Additionally, changes caused by relapse should be considered.

Reviewed by Jordan Seetner

Correction of incisors’ position and inclination in skeletal Class III malocclusions

Zou B, Zhou Y, Lowe AA, Li H, Pliska B. Changes in anteroposterior position and inclination of the maxillary incisors after surgical-orthodontic treatment of skeletal class III malocclusions. J Craniomaxillofac Surg 2015;43:1986-93

The anteroposterior position and inclination of the maxillary incisors are critical components of an esthetically pleasing smile, which is essential to facial attractiveness. The authors of this study aimed to compare the anteroposterior position and inclination of the maxillary incisors between patients with skeletal Class I and normal occlusions and those with skeletal Class III malocclusions. They also aimed to evaluate the anteroposterior position and inclination of the maxillary incisors in skeletal Class III subjects before and after surgical-orthodontic treatment. With these purposes, the records of 67 skeletal Class III patients (study group, 38 female, 29 male; mean age, 21.3 years) and 65 skeletal Class I subjects (control group, 35 female, 30 male; mean age, 21.8 years) with minor crowding and a normal profile were retrospectively analyzed. Six landmarks on the forehead, nose, and maxillary incisor were marked on lateral cephalograms and photographs, and these images were digitally superimposed using a new computer program. The authors found that compared with Class I subjects, Class III subjects had similarly inclined foreheads, but their maxillary incisors were significantly retruded and proclined. In skeletal Class III subjects, comparisons of pretreatment and posttreatment images yielded much more ideal positions and inclinations postoperatively. Class I subjects and posttreatment Class III subjects had similar anteroposterior positioning for the maxillary incisors. This study showed that surgical-orthodontic treatment of Class III subjects was effective in correcting maxillary incisor position and inclination. These findings should also be evaluated from the perspective of soft tissue response to both orthodontic treatment and surgery. Additionally, changes caused by relapse should be considered.

Reviewed by Jordan Seetner

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Apr 4, 2017 | Posted by in Orthodontics | Comments Off on Residents’ journal review
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