[Hypodontia: considerations on orthodontic therapy in agenesis of the permanent upper lateral incisor].

The authors have investigated different clinical cases having in common the agenesis of the permanent upper lateral incisors, to evaluate from a clinical and esthetic point of view the possibilities, results and the limits of the orthodontic treatment. These are nowadays increasingly associated with esthetic dentistry, prosthodontics, implantology and finally with dental transplantation. The patients presented the absence of one or both permanent upper lateral incisors or the agenesis of other teeth, sometimes associated with dental crowding or a not favourable intermaxillary relation. Most of the cases were treated with compensatory extraction of the other normal or hypoplastic permanent upper lateral incisor. The results were satisfactory but the mean treatment time was relatively long (56 months, including the retention phase), according to the difficulty of obtaining a good esthetic result in the smile line. The importance of a correct point of time of the interception for the choice of the most adequate therapy is emphasized. The possibility of correcting occlusal relation by means of the orthopedic treatment of the maxillary structures is limited to the end of the deciduous dentition. The diagnostic criteria for a correct and opportune interception of this anomaly are being stressed on. Finally the esthetic problems arising of the orthodontic space closure and the possible solutions were discussed.