We have discussed the maintenance system and its relationship to occlusal dynamics and occlusion function. The premise has been set forth that to avoid untoward sequelae post-orthodontically in the areas of relapse of tooth positions, occlusal wear, periodontal disease, and temporomandibular pain-dysfunction, it is best to have an occlusion free from centric and excursive interferences. The practical approach to the desired goal for the orthodontist lies in an understanding and familiarity of occlusal dynamics that allows him to look at detailing of tooth positions with insight into their ramifications from a functional standpoint. The insight can only be gained by hard work and self-discipline in the study of occlusion. A knowledge of these concepts will alert the orthodontist ot the true severity of the cases he is treating, allow him to position teeth so as not to create problems and , lastly, to be able to competently handle those cases that do develop posttreatment problems.