DR. HERBERT I. MARGOLIS LECTURESHIP
LYSLE E. JOHNSTON, JR., D.D.S., M.S., Ph.D., FDS RCS(E) Professor Emeritus and Former Chair, Orthodontics and Pediatric Dentistry, Michigan School of Dentistry
In orthodontics, everything works well enough to support a practice. Thus, it should come as no surprise that both the literature and the lecture circuit feature a bewildering array of salable strategies designed to prevent or correct Class II malocclusions. Many are merely practice management expedients masquerading as biology. Whatever the motivation, emphasis on the mandible is a central theme.
“Early” and “late” mesial shifts are said to be important factors in the development of a “Class I”; mandibular growth modification, the rational treatment for a Class II. By inference (or wishful thinking), it is argued that the maxilla is the wrong jaw; that the upper incisors are never protrusive; and, most commonly, that “extraction” and “backward-pushing” mechanics are bad.
Dr. Johnston disagrees. Based on an examination of literally thousands of Class II treatments and relevant literature, he will argue that some of our most basic ideas about cause and cure need are counter-productive and thus need to be re-examined. Specifically, he will argue that many Class II malocclusions are a result of a “perfect storm”—a convergence of ill-timed growth, the persistence of cusps, and dentoalveolar compensation—and that the maxillary dentition provides the most realistic therapeutic opportunity, both for prevention and for cure, regardless of method.
- Understand the cause of Class II malocclusions
- Understand common beliefs regarding the treatment of Class II malocclusions
- Learn the ideal methods of preventing or correcting Class II malocclusions