1. A dental or orthopedic densitometry modeling method, which comprises the steps of: building an initial patient-specific densitometry model; obtaining current densitometry data on said patient; performing with a computer time-lapse, automated digital comparisons of said initial and current patient-specific densitometry data, said comparisons identifying dental or orthopedic densitometry changes in the dental or orthopedic structures of individual patients; updating said initial patient-specific densitometry model; gathering with said computer a general population baseline database of patient dental or orthopedic densitometry data including variables for age and gender; performing with said computer automated digital comparisons of said identified dental or orthopedic densitometry changes with said general population baseline data; building a predictive densitometry model for a patient based on information from said database; providing an energy or field source; providing a sensor for energy or a field emitted by said source; placing said source and sensor on opposite sides of a patient's dental or orthopedic structure to be modeled; emitting energy or a field from said source, passing same through said patient's structure; and sensing said energy or field with said sensor; identifying a localized dental or orthopedic structure area as a watch area based on densitometry model changes with respect to the patient; directing said energy or field source towards the localized dental or orthopedic structure watch area; and obtaining specific, localized densitometry information concerning the densitometry model of said area.