Changes in Buccolingual Inclination of the Posterior Maxillary Teeth with Forces Applied from the Mini-Implants in the Sagittal and Vertical Direction-A non-Randomized Clinical Study

To compare the changes in the buccolingual inclination of the posterior teeth when forces are applied from mini-implants placed on the buccal side of the maxillary posterior teeth in both sagittal and vertical directions. Sixteen young patients requiring distal movement of the maxillary teeth with mini-implants and ten patients requiring intrusion of the posterior teeth with mini-implants were included in group 1(G1) and group 2(G2), respectively. In G1,200 grams of sagittal forces were applied bilaterally using NiTi coil springs from mini-implants placed between the maxillary second premolar and first permanent molar to attachments on a 0.018"X0.025" stainless steel wire in the anterior region. In G2,200 grams of vertical forces were applied bilaterally through an elastic thread from the mini-implants onto a 0.019"X0.025" stainless steel archwire. CBCT scans were taken before and towards the end of distalisation/intrusion. Paired t-tests and Independent t-tests were performed. There was statistically significant buccal tipping of the maxillary second premolar in G2 (p-value of .008) accompanied by mild buccal tipping in G1. However, not statistically significant, mild buccal tipping of the maxillary second molar was observed in both groups. The maxillary first molar though not statistically significant demonstrated lingual tipping in G1 while no changes in buccolingual inclination were noted in G2. There was a clinically significant buccal tipping of maxillary second molar and second premolar in G1 and G2, lingual tipping of the maxillary first molar in G1. Significant changes were observed in the buccolingual inclination of the maxillary second premolars and second molars when forces were applied in the sagittal and vertical direction in the buccal direction. Lingual tipping of the maxillary first molar was noted in the sagittal direction.