Comparison of the effects of varying positions of mini-implants on intrusion of maxillary incisors-an In vivo study

Objective: To compare the amount and rate of maxillary incisor intrusion by varying position of mini-implants. Materials and Methods: Twenty four subjects having deep bite were randomly allocated to two groups: Group I where a single mini-implant was placed in the alveolar region between the roots of maxillary central incisors and a force of 60 grams was applied with elastic chain tied from mini-implant to wire. Group II where mini-implants were placed bilaterally in the alveolar region between thee roots of maxillary lateral incisors and canines and a force of 30 grams (total 60 grams) was applied on each side. Lateral cephalograms taken before intrusion and 4 months after intrusion. Data was analyzed by means of independent sample 't' test and paired 't' test. Results: The maxillary incisors showed a significant amount of intrusion in both groups but there was no significant difference in the amount and rate of intrusion between the two groups (P > 0.01). Minimal molar extrusion was seen in both the groups but the difference was not statistically significant. Conclusions: Both the methods for maxillary incisor intrusion are effective as there was no statistically significant difference but two mini-implants are preferred as they cause relatively less proclination of maxillary incisors