The logic of modern retention procedures

similar concerns posed the problem of retention or its counterpart-relapse or treatment instability. This article intends to show that the problem has not been satisfactorily answered by the multiplicity of authoritative statements and opinions, nor by clinical and experimental studies made before and during the intervening decades. Despite this lack of definiteness of the studies to be reviewed, to achieve some clarity and understanding of the magnitude of the retention problem, it would seem to be not only an advantage but almost a prerequisite for the serious clinical orthodontist and the researcher to be familiar with the approaches and studies that have already been made. In doing so, he or she will better appreciate some of the variation in the treatment results2,“,‘7.45,62’119 that are being retained and the complex nature of the retention problem.” Moreover, the complexity of the retention problem is very often increased because the clinician, the researcher, and the patient can and do view retention in very different lights with almost endless gradation. For example, the problem will differ if the clinician has to make a choice for a particular patient in obtaining a more desirable facial result at the possible expense of optimal occlusal stability. On the other hand, the academic and more research-oriented orthodontist often gathers statistics and evaluates them without having to become involved with either the esthetic3.4s”2 or psychologic needss,54 of the patient. Also, the esthetic needs4 as far as tooth alignment and facial change are concerned, may be extremely variable within the needs and demands of the individual clinical patient. The psychologic needP are even more difficult to determine and after a half a century of further study we cannot wholly deny Hellman’s ( 1936)7 statement that “We are almost in complete ignorance of the factors which pertain to retention for the individual patient. ’ ’ At the present time, the orthodontist is very much aware that the study of occlusion,“” gnathology,” and temporomandibular joint dysfunction problems20’~202 has become increasingly important not only in his own specialty but in almost all areas of restorative dentistry. The dynamic approach to occlusion in graduate training and continued self-study throughout practice should enable the orthodontist to hold a key position on any dental team focused to address these problems.” As such, the orthodontist in his pursuit of desirable facial dental objectives must be prepared to explain and defend to dental colleagues, especially the periodontist,‘8 gnathologist, or the TMJ therapist (as well as the patient and the referring dentist) any compromise in an optimal functional occlusion in treatment results. For example, some compromise in posterior occlusion may be necessary to obtain anterior or posterior space closure and a minimum of midline deviation when the patient has exaggerated interor intraarch tooth size discrepancies or congenitally missing teeth. However, this compromise may be minimized by bonding and stripping techniques . ‘89*2’o On the other hand, it must also be understood by the dental profession as a whole that the orthodontist’s efforts to achieve and maintain functional and stable occlusal excellence’* for a patient is of merit if the facial aspects and the dental results are esthetically pleasing. Also, an excellent treatment result is desired by the adolescent patient, whether it is admitted or not, “not only at the end of active treatment but most certainly in the decade of the twenties”“’ and hopefully throughout life. In this same theme, both orthodontist and patient should know that although occlusal changes are to be expected at all ages,‘0,39,‘8’ it is noteworthy that in a time period paralleling the major portion of adolescent orthodontic treatment and retention, even the “non-orthodontic,” “ beautiful” occlusions of 12-yearold “smile winners” in a 9-year follow-up study”3 showed 50% “noticeable crowding of mandibular incisor teeth.” In addition, the orthodontist must fully realize that posttreatment facial-skeletal’3-‘5~‘39~‘s’ growth of this same patient, over which there may be little control, can be both a liabilty and an advantage. What about the retention needs of adult patients?