Abstract: Background Delaire-type facemask is still the appliance of choice for non surgical paediatric Class III treatment. However, it entails great aesthetical problems and is totally dependent on patient compliance. A new modified maxillary protractor was then designed: it is monomaxillary, fixed, implant-supported, aesthetically pleasing and it does not require patient compliance. The aims of this study were to evaluate the clinical use and analyse the effects of a new appliance called Fixed Maxillary Protractor. The device aims at obtaining a forward movement of the maxillary dento-alveolar component in non-compliant paediatric patients, when mandible retrusion cannot be pursued.
Case report A non-compliant patient aged 4 years 11 months with mild skeletal and predominant dento-alveolar Class III malocclusion with maxillary deficiency, anterior crossbite and complete deciduous dentition was treated for 10 months. The appliance, anchored by 2 micro-implants in the posterior palatal region, consisted of an acrylic plate, a lingual splint, 2 TMA springs that delivered a posterior-anterior force, 2 anterior security devices and 2 occlusal bite raising splints on the deciduous molars. The treatment yielded a slightly overcorrected Class I incisal relationship. Increase in SNA angle (2°) and a decrease in SNB angle (1°) resulted in an increase in ANB angle (3°). Increases in Wits appraisal of 4 mm and in overjet of 7 mm were obtained. A correction of the anterior crossbite the a posterior sliding of the mandible due to the crossbite correction were observed. An anticlockwise rotation of the maxilla and a mild increase in the anterior facial height were achieved: the treatment effects are similar to those obtained with the Delaire-type facemask, but the amount of postero-anterior correction is lower.
Discussion and conclusion The Fixed Maxillary Protractor is effective for the treatment of mild-moderate Class III malocclusion with maxillary deficiency in non-compliant paediatric patients.