Intentional ankylosis of the deciduous canines to enhance maxillary protraction. A prospective cephalometric analysis

Omar Gabriel da SILVA FILHO, Terumi Okada OZAWA, Celeste Hiromi OKADA, Helena Yuko OKADA, Luciana DAHMEN

Aim: the current article analyses the effects of maxillary protraction associated to the intentional ankylosis of the deciduous canines on the basis of cephalometric measurements. Methods: the treatment protocol included: 1) intentional ankylosis of the upper deciduous canines; 2) rapid palatal expansion and 3) maxillary protraction performed immediately after the end of the expansion. The sample was comprised of 18 patients equally divided according to gender, in the primary and mixed dentition. The mean treatment time with maxillary protraction was 1 year. The lateral radiographs were taken in the beginning of the treatment and after correction of the Class III malocclusion. Results and Conclusion: the results show that the facial convexity angles - NAP and ANB - increased from 0º to 6.6º and 3.5º, respectively. This means that the patients’ profile changed from straight or concave, which is typical in the Class III malocclusion, to convex, which is typical in normal occlusion. Such an improvement in the facial convexity is due to the maxillary advancement, evidenced both in the dentoalveolar (SNA angle and Nperp-A measurement) and in the basal areas (SN.ANS angle). The maxilla was anteriorly displaced while the reduction of the SNB angle from 80.56º to 79.61º demonstrated a mandibular retropositioning. Besides the sagittal alterations, the mandible presented a clockwise rotation, with increase in the SN.GoGn and SN.Gn angles. Dental compensation was also noticed, represented by the buccal inclination of the upper incisors.

Keywords: Angle Class III malocclusion. Maxilla. Cephalometry.

Saturday, December 28, 2024 23:05