Prevention of Periodontal Deterioration/Damage

Abstract

This chapter emphasizes the reasons why lower incisors should generally not be proclined more than 2 mm since this orthodontic movement is associated with problems of health, function, stability, and esthetics. Facial movement of the teeth decreases the buccolingual thickness of the gingival tissue, which results in reduced height (recession) of the free gingival portion. In patients in whom the gingiva covering the labial of the lower incisors is thin and scalloped, orthodontic proclination of the lower incisors may cause not only gingival recession but also dehiscence. Both are examples of health problems associated with proclination of the incisors. An increase in the magnitude of the anterior open bite may occur in open-bite tendency malocclusions if lower incisors are moved labially and sometimes may even result in lip incompetence. These two are examples of functional problems associated with proclination of the incisors. There is evidence that post-retention stability of lower incisor alignment is compromised if the lower incisors were proclined during orthodontic treatment. Additionally, when the lower incisors are moved labially, facial esthetics could be compromised in pleasing facial profiles because as the teeth procline, the lips also move forward, while the chin stays back. An increase in lip protrusion could thus be associated with an undesirable appearance of a decreased chin projection and a diminished definition of the labiomental sulcus. Patient records are shown which illustrate the undesirable effects of lower incisor proclination. The contraindications for incisor proclination are discussed, and the orthodontic procedures recommended by the author to avoid incisor proclination in dentally crowded patients are shown.