Congenitally Missing Upper Lateral Incisors treated by space closure: aiming for excellence
The prevalence of congenitally missing teeth has been studied and reported by many Authors: a presence ranging between 6 to 10% was found in the population, with a prevalence of congenitally missing upper lateral incisors (CMLI) between 1 and 2%. Furthermore, it has been found that agenesis of both maxillary lateral incisors is more common than the single one. Patients with congenitally missing maxillary lateral incisors (CMLI) often need challenging interdisciplinary treatment and the replacement of CMLI offers three treatment options: canine substitution, tooth-supported restorations, or single implants. The ideal treatment must fulfill individual esthetics, functional requirements and periodontal health: not only at the end of the treatment, but also in the long-term. The rationale, effectiveness and advantage for space closure treatment have been widely discussed in previous articles, and this treatment finds its greatest application since CMLI is usually diagnosed at young age. Space closure offers indeed the possibility of completing treatment before adolescence and achieving a long-term stable outcome at a young age. Hence, it is possible to avoid a long lasting period with temporary restorations waiting for the final restorative procedures at the end of growth. Long-term investigations on periodontal, functional and esthetic stability have shown that space closure can lead to an acceptable functional occlusion with no difference in prevalence of TMJ signs or symptoms and to a better periodontal condition with minor tendency to accumulate plaque and develop gingivitis when compared to prosthetic replacement. Moreover, in the last 15 years, gradual improvement in orthodontic finishing, supported by careful and minimally invasive restorative procedures, has led to high quality esthetic results, almost indistinguishable from natural dentition. The purpose of this article is to show the considerable improvement that can be nowadays achieved with the space-closure alternative by combining techniques from esthetic dentistry with carefully detailed orthodontic treatment. In order to obtain an ideal smile, a detailed orthodontic treatment is mandatory and thus includes:
– Extrusion of canine and intrusion of first premolar to reach optimal leveling of the gingival margins. This also allows not to have to grind the palatine cusp of first bicuspid during final build-up
– Root palatal torque of extruded canines in order to maintain proper thickness of the
periodontal labial plate and prevent the risk of recessions.
– Proper torque of intruded first premolars considering root anatomy to allow minimally invasive restorations.
Premolar intrusion and canine extrusion themselves can remodel the periodontal profile and properly locate the gingival margins, so that an optimal esthetic result can be achieved. This means the gingival margin of the new canine (i.e. the intruded first premolar) is at the same level of the central incisor, while the gingival margin of the new lateral incisor (the extruded canine) is at a 2-3 mm lower level.
The intrusion of the first premolars was also performed in order to obtain a larger “canine” after the building-up of the generally short and small first premolars in the “normal” canine position.
About the difference in color between cuspid and bicuspid, cuspids are usually darker and/or more yellowish than the incisors, new home bleaching systems are available to achieve very good and stable results.
In order to explain how it is possible to achieve excellence in space closure, a case is shown step by step.
The treatment plan was done, as well as the entire orthodontic treatment, by Dr. Marco Rosa, to provide the malocclusion correction, space closure and proper control of cuspid and bicuspid positions.
Multidisciplinary treatment of upper missing lateral incisors is mandatory to provide a good esthetic and function in frontal area. In order to achieve this kind of results, especially in young patients, closure of the space could be the better choice. A major advantage of such an approach is the permanence of the finished result. The alveolar bone height is maintained by early mesial movement of the canine, and the need for removable or resin-bonded retainers until the implant insertion is avoided. Nevertheless, in order to obtain these kind of results using a combination of carefully performed orthodontic space closure and cosmetic build-ups of several teeth is necessary.
Special Thanks to Dr. Marco Rosa, for the orthodontic treatment and for the daily inspiration in the last 22 years in teamwork.
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