Maxillary tuberosity dimensions and tooth movement magnitude during distalisation using mini-implants: a preliminary tomographic study

Abstract

Purpose The aim of this study is to determine whether changes in the dimensions of the maxillary tuberosity influence the distalisation of maxillary teeth using mini-implants. Materials and Methods Ten young orthodontic patients requiring mild to moderate proclination of the maxillary anterior teeth were studied. Distalisation of the maxillary teeth was achieved using a retractive force of 200 grams applied bilaterally to a 0.018“x0.022” stainless steel wire, with mini-implants located at the mucogingival junction. The dimensions of the maxillary tuberosity namely mesiodistal length, vertical height, and buccolingual width were measured using CBCT. The maxillary incisor proclination was measured on lateral cephalograms at T1 (before distalisation) and T2 (six months later). Statistical analysis included Spearman rank correlation analysis and Wilcoxon signed-rank tests. Results At T2, the mesiodistal length and the vertical height of the maxillary tuberosity showed a statistically significant decrease in dimension. The change in buccolingual width and the amount of anterior teeth retraction and distalisation of the first molar showed a statistically significant positive correlation suggesting that an increased remodelling of the maxillary tuberosity in the buccolingual dimension was associated with a greater magnitude of distalisation of the maxillary dentition. A positive correlation existed between the mesiodistal length at T1 and the amount of anterior retraction, suggesting that a greater mesiodistal length of the maxillary tuberosity at T1 corresponds to a greater amount of anterior retraction. Conclusion The dimensions of the maxillary tuberosity appear to influence the distalisation of the maxillary teeth with mini-implants.