Abstract
The viability of orthodontic traction of impacted teeth in adults is often questioned by a large percentage of orthodontists who would rather consider the extraction of these teeth. Although possible, orthodontic traction of impacted canines in adults takes longer than in younger patients, present a poorer prognosis that worsens with age. Because of the prevalence of periodontitis in adults versus children, periodontal inflammation must be identified and resolved in order to keep attachment loss from progressing during orthodontic care. Likewise mucogingival changes need to be predicted and managed. This article reports a successful case of impacted maxillary right canine traction in an adult female, associated with alveolar corticotomies and the use of skeletal anchorage. At the end of treatment, the canine was ideally positioned in the occlusion, presenting excellent esthetics, function, and healthy periodontal tissues.
Introduction
Impacted teeth are those with complete root development and delayed eruption time based on clinical and radiographic evaluations. They are not expected to completely erupt in the maxillary or mandibular arch without the aid of a dental professional. The most common causes of dental impactions are arch length/tooth size discrepancies, prolonged retention or early loss of deciduous teeth, abnormal position of the dental germ, , root dilaceration or ankylosis, cystic or neoplastic formations, endocrine deficiency and idiopathic origin.
The prevalence of impacted canines ranges from 1 to 3% of the world’s population and women are 2.3 to 3 times more affected than men. Canine impaction is more common in the maxilla and the palatal displacement is 2 to 3 times more frequent than the buccal. Furthermore, 8% of the individuals with impacted maxillary canines present this condition bilaterally. Some of the reported treatments for impacted canines include: surgical exposure and subsequent orthodontic traction to bring the tooth into occlusion; extraction of the impacted canine and space closure with orthodontic appliances; canine auto-transplantation; or long-term follow-up without any active intervention.
Computerized tomographies are indicated to assess both the quantitative and qualitative aspects of the case and are very important to help orthodontists decide what is the most adequate intervention for each patient. Furthermore, factors such as the relation between the impacted canines and the adjacent teeth, their angulation and the distance they must be moved until reaching their ideal position in the dental arch influence the prognosis of the orthodontic traction.
Early diagnosis and appropriate interceptive interventions may prevent the definitive canine impaction, thus avoiding further adverse consequences for the patient. Orthodontic procedures performed at the beginning of the canine impaction process are significantly less invasive than those required at the latter stages of the impaction. For instance, rapid maxillary expansion and early extraction of deciduous canines and molars often reverse the development of the impaction and result in the natural eruption of the canine. Unfortunately, not all patients have access to adequate Preventive Dentistry and adult patients may present to a dental office with impacted canines.
Although possible, orthodontic traction of impacted canines in adults presents a lower success rate than in younger patients, the prognosis worsens with age and it should be expected to take longer. Alveolar corticotomies have been suggested as an alternative to accelerate orthodontic treatment or to facilitate complex orthodontic tooth movements, for instance, reducing up to 33% of the time needed to traction impacted canines in adolescents.
This article aims to illustrate the successful treatment of an impacted maxillary canine in a 53-year-old female patient, assisted with alveolar corticotomies and skeletal anchorage.
Case report
A 53-year-old female patient sought for orthodontic treatment to improve the esthetics of her smile and her masticatory function that had been significantly compromised due to the premature loss of some permanent molars. She reported having several previous dental treatments, but no orthodontic therapy. Her medical history was within normal limits. When asked about osteoporosis in the skeleton, she replied that she had a DEXA scan with T score at the hip and spine of <1.5, which ruled out need for bone sparing medication. She reported that she is compliant with vitamin D supplementation and weight bearing exercise to prevent further skeletal bone loss.
Extraoral examination showed a symmetric face with normal facial height, straight profile, but absence of passive lip sealing. The smile esthetics were compromised due to the diastema between her maxillary central incisors, the uneven gingival margins of her maxillary anterior teeth and the absence of the maxillary right canine ( Fig. 1 ).
Intraoral evaluation revealed a mutilated dentition with the absence of teeth #3, 6, 14, 18, 19, 30 & 31. Less than 2 mm of keratinized tissue was present in the lower molar edentulous areas.Maxillary right deciduous canine was overretained. There was significant spacing on both arches. Periodontal inflammation was treated with deep scaling root planing, oral hygiene instruction and 3 month professional maintenance regimen. To manage the risk of progressing periodontitis, the patient was regulated to maintain less than 10% of sites with bleeding on probing. Mild gingival recession persisted on teeth #20 and 28, however these sites did not exhibit dentinal sensitivity and were not visible during smiling or function. In this way, they were not part of the patient’s complaint. Amalgam and composite restorations exhibited marginal breakdown and leakage; the patient mentioned she would like to replace them after the orthodontic treatment. ( Figs. 2 and 3 )
The panoramic radiograph showed that the maxillary right permanent canine was not absent, but rather impacted in a mesially angulated position, fully overlapping the lateral incisor root and up to 50% of the central incisor root. A mild overall bone loss was also observed ( Fig. 4 ). Computed tomographic images showed that tooth #6 was palatally impacted without damaging the adjacent teeth ( Fig. 5 ).
Two interdisciplinary treatment alternatives were offered to the patient. The first option included the surgical removal of the impacted canine and its implant-supported prosthetic replacement. The second option comprised the orthodontic-surgical treatment, which would involve opening the adequate space for attempting the canine traction, surgical exposure associated with alveolar corticotomies, insertion of a palatal temporary anchorage device (TAD) for skeletal anchorage and application of light-forces to bring the canine into its position in the dental arch. After evaluating the careful explanation of the advantages and disadvantages of both options, the patient understood that the first alternative would be the faster, but since orthodontic treatment would still be required to correct the other aspects of her malocclusion and because she would rather not have any other tooth extracted, she opted for trying to perform the canine traction into the maxillary arch.
Fixed orthodontic appliances (0.022 × 0.028-in Mini-master series, American Orthodontics, Sheboygan, WI) were bonded from second molar forward on both arches. Leveling and alignment were performed, adequate space for the impacted canine was opened with the mesial movement of both right lateral and central incisors, what also closed the anterior diastema.Surgical exposure of tooth #6 was completed under local anesthesia. A full-thickness flap was raised and a button into which a twisted steel-ligature wire was placed was bonded using self-etching primer (Transbond Plus Self-Etching Primer, 3M/Unitek, Monrovia, CA). After confirming that adequate bonding was achieved, alveolar corticotomies were performed in the direction the canine would be moved ( Fig. 6 A). The canine crown was recovered. Sutures were placed and a self-drilling TAD(1,5 × 8 mm, Morelli®, Sorocaba, SP, Brazil) was inserted between the roots of teeth #2 and 4. ( Figs. 6 B and 7 )
