The dynamic nature of our specialty is a constant source of study to all of us as practitioners. We search unceasingly for methods and means of predicting, utilizing, or avoiding factors of human growth and development, particularly in the face and cranium. In this never-ending quest we employ static evidence to compile a dynamic record. Growth and development are self-implied dynamics, and our studies of them also have been dynamic. We have left no stone unturned, no cephalometric exposure untaken, in our desire to implement our diagnosis or treatment planning. It is expedient at this point in our specialty's evolution and development to consider the role of dynamics or function in the production of our final goal of “straight teeth”. What has been presented is in no way an excuse for poor orthodontic mechanics; for all of the occlusal grinding possible, we cannot replace the need for sound and practical orthodontics. Occlusal adjustment before, during, or after orthodontic treatment should not be the indolent man's appliance. It is merely a way to achieve a more harmonious occlusal relation, in function, which enhances the totality of the original and purposive orthodontic treatment. What has been presented here is not new. All orthodontists have observed these things and have practiced a philosophy which in most instances encompasses the concept of function. What I have presented here represents merely a possible physiologic background for the how and the why of this concept. Orthodontics at the present time is accelerating at a rapid pace to meet all of the many and varied problems that are encountered each day in our practices. The ultimate solution to our problem is not found in a single concept, in a single set of dictums, nor in the mind and teaching of one man; rather, we will find that the multiplicity of our problems requires a multipronged attack by many men, many concepts, and many dictums. If but one thought from this presentation remains with you, I hope and trust that all of you will remember that the teeth are primarily for function in speech, deglutition, and mastication and that in recognition of this we must pursue a course of treatment which improves not only esthetics but function as well.