Orthodontic Treatment Time in Class IIMalocclusions Treated with 2 and 4-premolar-extraction Protocols

Objective:To compare the treatment times of complete Class Ⅱmalocclusions treated with 2 and 4-premolar-extraction protocols.Methods:76 patients were selected and divided into 2 groups,according to the 2 extraction criteria.Group A,treated with 2 maxillary premolar extractions,consisted of 38 patients(17 male,21 female) with a mean age of 14.25 years.Group B,treated with 4 premolar extractions,consisted of 38 patients(16 male,22 female)with a mean age of 13.86 years.Treatment times of the groups were compared with the t test.Results:Treatment times were significantly shorter with the 2-premolar-extraction protocol compared with the 4-premolar-extraction protocol.Conclusion:Treatment time will be shorter and the occlusal results more predictable with a 2-premolar-extraction protocol compared with 4-premolar-extraction.