Effetti dentoscheletrici di un dispositivo intraorale per la distalizzazione dei molari e confronto sistematico con apparecchi alternativi

Objective: The aim of the present study was to evaluate the dentoskeletal effects produced by an intraoral appliance for the unilateral or bilateral distalization of the upper first molars. Materials and methods: We analyzed the pre- and post-distalization cephalometric films of 17 patients (10 males and 7 females) with class II malocclusion treated with the First Class appliance. The mean age at the start of treatment was 13 years and 4 months. Bilateral class II molar relationships were corrected within 2.4 months on average. Results: Seventy percent of the space created anterior to the first molars was the result of maxillary molar distalization; the remaining 30% was due to reciprocal loss of anchorage by the maxillary second premolars. The maxillary first molars showed significant distalization of 4.0 mm, associated with a significant distal inclination of 4.6 degrees and a significant extrusion of 1.2 mm. As for loss of anchorage, the second premolars exhibited significant mesial movement of 1.7 mm and significant mesial inclination of 2.2 degrees. In the anterior region, significant mesial movement of the maxillary incisors of 1.3 mm was associated with significant incisor proclination (2.6 degrees) and a significant increase in the overjet (1.2 mm). No significant changes in either sagittal or vertical skeletal relationships were observed. Conclusions: The results suggest that the intraoral appliance can produce efficient distalization of the maxillary permanent first molars comparable to that offered by other intraoral distalization devices.