• The korean journal of orthodontics
• /
• v.36 no.4
• /
• pp.308-320
• /
• 2006

Rapid canine retraction, first introduced by Liou, is a distraction osteogenesis applied to the periodontal ligament tissue. Rapid tooth movement was facilitated by establishing minimal bony resistance on the distal surface of the canine by socket preparation and by osteogenesis on the mesial side in response to the periodontal distraction. Since undesired buccal tipping or extrusion of the canine during retraction tends to occur, it is crucial to maintain the firm path of movement and the axis of the canine during retraction. In order to improve the predictability of the canine movement, lingually extended distraction screws with heavy labial guiding wires were designed. Prefabricated plastic canine models for the estimation of socket depth and miniscrew implants for anchorage reinforcement were also devised. Applying these devices to a female patient with Class II anterior protrusion, the whole treatment was effectively finished in 13 months. Loss of vitality or periodontal problems did not occur throughout treatment, and stable occlusion was maintained during 10 months of retention. This case report demonstrates that a predictable rapid canine retraction can be achieved through the use of this modified technique.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.49 no.4
• /
• pp.402-413
• /
• 2022

The aim of this study was to identify factors that affect the treatment duration and to predict the duration of forced eruption in impacted maxillary canines using panoramic radiographs and cone-beam computed tomography. This retrospective study was performed by reviewing medical records and radiographs of 73 patients (93 impacted maxillary canines) from the age of 8 to 18 years who were treated with surgical and orthodontic interventions on impacted maxillary canines from January 2012 to December 2020 in Ajou University Dental Hospital. Stepwise multiple regression analysis showed that the distance between the canine cusp tip and the occlusal plane, mesio-distal location, bucco-palatal location, patient's age, and use of rapid palatal expansion are significant factors with regard to the duration of forced eruption. There was a statistically significant correlation of the treatment duration with the angulation between the axis of the canine and the occlusal plane and unilateral or bilateral impaction. It can be concluded that the duration of forced eruption in impacted maxillary canines could be shorter when the impacted canine is closer to the occlusal plane and located in the lateral incisor or canine area, buccal or middle, the patient is younger and uses rapid palatal expansion.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.4
• /
• pp.473-481
• /
• 2010

Maxillary canine impaction is an anomaly often encountered in children. Although it has been reported that the incidence of palatally impacted canines is higher than that of labially impacted ones, it has been found that labial impaction of canines is more common than palatal impaction in Asian populations. In the cases presented here, maxillary canines were guided normally after rapid palatal expansion, followed by modification of root angulation of neighboring lateral incisors in 8-10-year-old children who had maxillary canines suspected of labial impaction. Consequently, the method of modifying the root angulation of the maxillary lateral incisor, combined with rapid palatal expansion, is effective in preventing impaction of an ectopically erupting maxillary canine without resorting to surgical methods.

• The korean journal of orthodontics
• /
• v.34 no.6 s.107
• /
• pp.526-536
• /
• 2004

This study was undertaken to determine the effect of a 2.2mg/Kg/day intraoral administration of NaF on the amount of root resorption and osteoclastic activity during or after a rapid maxillary expansion procedure. Ten puerile female dogs were divided into two groups: a control group and a NaF-treated group. A fixed type maxillary expansion device was delivered to all dogs. The appliance was activated twice daily throughout a 20-day period, causing a 5-mm expansion of maxillary bone. After the expansion procedure, the animals were sacrificed at days 0, 15, 30, 45, and 60 of the retention period. The buccal surface of the root of each maxillary canine was examined by means of a surface electron microscope (SEM). Using SEM, web-like resorption lacunae were observed on the bone or the tooth surface at the site of osteoclastic activity; these observations were verified by histological methods. No peculiar resorption lacunae were found in the apical tip of the roots of either the control group or the NaF-treated group animals. The NaF-treated retention group was found to have less resorption lacunae formation on day 45 and day 60. The preventative effect of NaF on resorption lacunae formation on the surface of the bone covering the anchor tooth was confirmed. Larger areas of resorption lacunae were found on the surface of the bone covering the canines in the control group animals, as compared to those of the NaF-treated group, especially on day 30 and day 60. Using SEM, the present study revealed a difference between the control group and the NaF-treated group in the prevalence and the size of the resorption lacunae formation on the cemental root surface. The preventative effect of NaF on bone resorption was confirmed. Further studies concerned with the optimum concentration of NaF that has an effect in vivo are necessary.