Aims: To investigate the efficacy of the anterior repositioning splint and the canine-protected splint in relieving the signs and symptoms of anterior disc displacement with reduction, and to evaluate the effects of both splints on disc position using a standardized magnetic resonance imaging measurement technique. Material and Methods: A sample of 18 adult subjects was studied. The joint disorder was dually diagnosed via pretreatment clinical examination and magnetic resonance imaging. The sample was randomly divided into two groups. In the first group, each subject received an anterior repositioning splint; in the second group, each subject received a canine-protected splint. The treatment lasted 3 months. A standardized magnetic resonance imaging 10-step procedure was developed. Posttreatment clinical examinations and magnetic resonance imagings were done. Pretreatment and posttreatment records were statistically compared. Results and Conclusions: Both types of splints were effective in eliminating pain and clicking. All magnetic resonance imaging measurements showed that the canine-protected splint was superior to the anterior repositioning splint, as it allowed the articular disc to resume its normal length and shape while moving in a posterior direction toward recapture. Disc recapture was demonstrated via magnetic resonance imaging in 25% of the subjects from the anterior repositioning splint group, in 40% of the subjects from the canine-protected splint group, and in 33.3% of the subjects from both groups. Thus, noninvasive treatment techniques (such as occlusal splint therapy) might be the treatment of choice for anterior disc displacement with reduction. World J Orthod 2004;5:133–140.