ABSTRACT
Research in the field of cellular and molecular biology is relatively lagging in comparison to mechanical advances in the field of orthodontics. Even though the mechanical advances are used quite carefully during orthodontic tooth movement, traumatic effects on the periodontium have not been totally prevented. This may be because of a lack of complete understanding of the cellular complexities. Proper understanding of cellular and molecular biology will help design mechanics that will produce maximum benefits during tooth movement with minimal tissue damage. The rate of tooth movement depends on the rate at which bone remodels and hence, better knowledge of specific biochemical pathways in individual patients will provide a key to predicting how well teeth respond to mechanical forces. This in turn will provide for better tooth movement and faster treatment procedures. The pressure tension theory as well as the bioelectric theory have been discussed in detail along with various chemical mediators with the lipo-oxygensase pathway as well as they cyclooxygenase pathway. Role of neurotransmitters and vasoactive amines along with mechano-transduction has been discussed in the review. These predictors, however, need further work to validate reliability.