Comparison of treatment effects during en‐masse retraction of upper anterior teeth placed using mini‐implants placed at infrazygomatic crest and interradicular sites: A randomized controlled trial
Swapna Sreenivasagan, Aravind Kumar Subramanian, Jong‐Moon Chae
Abstract
INTRODUCTION: The objective of this prospective study was to examine the efficacy of posterior interradicular and infrazygomatic crest mini-implants for en-masse anterior retraction. METHODS: The 22 patients were divided into two groups. In group 1 (IZC n = 11), mini-implants were placed in the infrazygomatic crests and in group 2 (IR, n = 11), mini-implants were placed in the molar-premolar interradicular sites. Soft tissue, skeletal, and dental treatment effects between two groups were compared using lateral cephalometric measurements. RESULTS: The average angle between the cranial base and A point was 1.01 degrees (P = .004), and the linear distance between the upper incisor and A point was 2.67 to 5.2 millimetres (P = .00). In IZC group the maxillary incisor to the palatal plane moved upward by a mean of -5.20 mm (P = .059), whereas in IR group the incisor movement changed by -2.67 mm (P = .068). There was no significant difference between groups IZC and IR while comparing overall treatment changes on upper incisor position change, angle, and overjet. CONCLUSIONS: Mini-implants placed in between the molar and premolar as well as the infrazygomatic crest can withstand the deepening of the bite during retraction. Mini-implants in IZC are capable of causing intrusion of the anterior teeth and preventing intrusion of the molars, thereby providing absolute anchoring in all planes. Placement of the mini-implants in the infrazygomatic crest resulted in more linear retraction.