Tooth movement biology and laboratory experiments: How useful are they to orthodontic practitioners?

Orthodontists are aware of the intimate relationship between mechanical force-induced tooth movement and the responsive function of cells in and around teeth. Initially, orthodontics relied on the age tested observation that teeth can be moved to new positions when subjected to such forces. However, since the dawn of the 20th century, attention started to shift to the role of cells derived from various tissue systems, like the nervous, vascular, immune and skeletal systems, and in the tissue remodeling that facilitates tooth movement. At first, histology was the main investigative tool, but soon thereafter, as it became evident that valuable new information can be obtained from studies within the expanding fields of cellular and molecular biology, multiple studies were conducted, with the aim of deciphering the behavioral pattern of cells under mechanical duress, and adopting in the orthodontic clinic worthwhile findings from the basic science laboratory. This adoption of new biologic findings may enable the orthodontist to provide customized treatment plans, which fit the specific biological features and constraints of every individual patient. This constant, powerful flow of new information and increased knowledge provides the orthodontic specialist with an ever increasing list of opportunities to correct malocclusions in a biologically correct fashion. But, the concerns raised by most clinicians after evaluating this ever expanding body of information, belong to the elusive optimal orthodontic force, and to determination of the suitability of newly discovered adjunctive means and methods capable of accelerating the velocity of tooth movement, without any invasive surgical intervention. This review aims at highlighting clinically useful information on these areas after critical evaluation of existing research data on tooth movement biology research.