Retração rápida de caninos associada ao levantamento do seio maxilar / Rapid canine retraction associated with maxillary sinus lifting

INTRODUÇÃO: a retração rápida de caninos por distração do ligamento periodontal é uma técnica de movimentação dentária que permite o fechamento de espaço da extração de primeiros pré-molares em um intervalo de 2 ou 3 semanas, proporcionando uma redução significativa no tempo do tratamento ortodôntico. A técnica cirúrgica para realização deste procedimento é relativamente simples, entretanto, nos casos onde o seio maxilar apresenta-se próximo ao ápice radicular de caninos e pré-molares, sempre há o risco de perfuração da membrana desta cavidade. OBJETIVO: o objetivo deste artigo é apresentar, através de um caso clínico, uma modificação na técnica original proposta por Liou e Huang, onde o levantamento do seio maxilar, executado de forma bastante simples, imprimiu maior controle e segurança ao ato cirúrgico necessário para a realização da retração rápida de caninos. CONCLUSÃO: a retração rápida de caninos é um procedimento exeqüível e o levantamento de seio maxilar pode auxiliar na execução do movimento dentário.

INTRODUCTION: Rapid canine distalization using distraction of the periodontal ligament is a tooth movement technique that allows to close the space of extraction of first premolars in about 2 or 3 weeks, reducing orthodontic treatment time considerably. The surgical technique for this procedure is reasonably simple, however, during surgery in the maxilla, always exists the risk of sinus injury when the sinus membrane is close to the apex of canines and first premolars. AIM: The aim of this study is to present a case report showing a modification of the original technique proposed by Liou and Huang, where the maxillary sinus membrane lifting procedure was undertaken in a simple way, leaving it intact, and permitting a safer and more controlled protocol to start the rapid canine retraction. CONCLUSION: Rapid canine retraction is a viable procedure and maxillary sinus lifting may be helpful in providing the tooth movement.

Pulp and periodontal tissue changes following rapid tooth retraction by periodontal distraction in young adult dogs / 대한치과교정학회지

OBJECTIVE: The aim of this study was to evaluate pulp and periodontal changes following rapid tooth retraction by periodontal distraction after bone undermining surgery in young adult dogs. METHODS: After extraction of second premolars, the interseptal bone mesial to the upper 3rd premolar was undermined. After activating the distraction appliance at 0.5 mm/day for six days, the dogs were sacrificed at 0, 1, 3, 5, 7, and 9 weeks during the consolidation period. Tissue changes of periodontium and pulp were evaluated radiologically, histologically, and immunohistochemically. RESULTS: Digital subtraction radiography showed active bone formation in the stretched periodontal ligament from 0 - 4 weeks. Resorption of the alveolar bone, appearance of osteoclasts, and infiltration of inflammatory cells were observed just after the activation period at the pressure side, and distinctive bone formation was seen in the tension side of the periodontal ligament from 1 week. New bone formation was active at 1 - 3 weeks. The expression of calcitonin gene-related peptide in the experimental group was increased at the alveolar bone and pulp, and periodontal ligament at the pressure side from 0 - 1 week, and it decreased after 5 weeks to become similar to that of the control group. CONCLUSIONS: The results showed that rapid tooth movement using periodontal distraction can be new form of orthodontic tooth movement for accelerating normal bone formation.

Rapid canine retraction in a Class II bialveolar protrusion case using a lingually extended distraction screw / 대한치과교정학회지

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.

Histological periodontal tissue reaction to rapid tooth movement by periodontal distraction in dogs / 대한치과교정학회지

The objective of this study was to evaluate the changes that occurred over time in the distracted periodontal ligament space following the rapid retraction of a tooth by periodontal distraction after bone undermining surgery had been conducted in the dogs. The upper second premolars were extracted on the left and right side in 4 male beagle dogs. Immediately after extraction, the interseptal bone distal to the upper first premolar was thinned and undermined by grooving to decrease the bone resistance. Activating an individualized distraction appliance at the rate of 0.225 mm twice a day, the upper first premolar was retracted rapidly toward the extraction socket. Periodontal distractions were performed for 5, 10, and 20 days, and 20-day-distraction cases were followed by maintenance periods of 0, 14, 28, and 56 days. After 20 days of rapid retraction, the average distal movement of the upper first premolar was 5.02 mm, and the average mesial movement of the upper third premolars serving as an anchorage unit was 0.58 mm. On histological examination, the regeneration of bone occurred in a highly organized pattern. Distracted periodontal ligament space was filled with newly formed bone oriented in the direction of the distraction, and this was followed by extensive bone remodeling. This result was similar to those observed in other bones after distraction osteogenesis. In the periodontal ligament, the relationship between collagen fibers and cementum began to be restored 2 weeks after the distraction was completed, and showed almost normal features 8 weeks after the completion of the periodontal distraction. However, on the alveolar side, the new bone formation was still in process and collagen fiber bundles and Sharpey's fibers were not present 8 weeks after the completion of the periodontal distraction. Reactions in the periodontal ligament of the anchorage tooth represented bone resorption on the compressed side and new bone deposition on the tension side as occurred in conventional orthodontic tooth movement. In conclusion, the results of this study showed that periodontal structures on the distracted side of the periodontal ligament were regenerated well histologically following rapid tooth movement.