No description available.

Many of the undesirable side effects that occur during orthodontic treatment can be attributed directly to a lack of understanding of the physics involved in a given adjustment of an orthodontic appliance. A large number of variables in orthodontic treatment are not within our control, such as growth and tissue response to appliances. However, the force placed on the tooth should be a controllable variable (1), and careful study of the physics underlying our clinical application, can help in reducing those undesirable side effects. If researchers and clinicians can quantify the force systems applied to the teeth, they can better understand clinical and histologic responses. Orthodontic force systems used in everyday orthodontic mechanics are considered indeterminate force systems, in other words, there are too many unknowns to determine the different components of these force systems. Until recently, much of the literature was restricted to experimental two-dimensional analyses of the biomechanical aspects of orthodontic force systems, and computer modeling of three-dimensional analyses. Very little evidence exists in the literature regarding three dimensional experimental measurement and analysis of orthodontic force systems (2). Force system measurements were made on one or two tooth models, however in order for us to understand the orthodontic force systems we need to simultaneously, measure in 3D, the forces being applied on every tooth in the dental arch. With the very recent technological advances in force/torque sensors technology, data acquisition and data representation, it became possible to measure those forces and reveal the force systems we are applying to the dentition. The purpose of this PhD research study is the design and construction of an experimental device that is capable of revealing the details of the force systems used in modern day orthodontic mechano-therapy of continuous arch technique. / Orthodontics

Nitric oxide (NO) plays a role in regulating the rate of orthodontic tooth movement (OTM) in rat models; however, in humans this role remains less clear. In this study, samples of gingival crevicular fluid (GCF) were collected from each maxillary central incisor and first and second molar immediately before (T0), 1 hour after (T1), and 3-4 days after (T2) application of light orthodontic forces in thirteen male participants (ages 11-18 years) undergoing orthodontic therapy. NO levels were measured in each GCF sample, and significantly higher NO levels (p<0.05) were found at T1 at the buccal surfaces of the central incisors when compared to the posterior teeth. The results indicate a possible role for NO in OTM at the pressure sites of incisors at early time points. Further studies are required to determine whether NO levels in the PDL of human teeth are affected by the magnitude of an applied force.

Nitric oxide (NO) plays a role in regulating the rate of orthodontic tooth movement (OTM) in rat models; however, in humans this role remains less clear. In this study, samples of gingival crevicular fluid (GCF) were collected from each maxillary central incisor and first and second molar immediately before (T0), 1 hour after (T1), and 3-4 days after (T2) application of light orthodontic forces in thirteen male participants (ages 11-18 years) undergoing orthodontic therapy. NO levels were measured in each GCF sample, and significantly higher NO levels (p<0.05) were found at T1 at the buccal surfaces of the central incisors when compared to the posterior teeth. The results indicate a possible role for NO in OTM at the pressure sites of incisors at early time points. Further studies are required to determine whether NO levels in the PDL of human teeth are affected by the magnitude of an applied force.