Temporary Occlusal Modifications Cause Variations in Urinary Catecholamine Levels

Many patients report generalized discomfort and anxiety with onset of oral parafunctional activities during the early stages of orthodontic treatment when creation of an interproximal space with elastic separating modules (ESM) is needed for placing orthodontic bands. OBJECTIVE: To determine whether the increased nociceptive and mechanoreceptive stimuli caused by compression of the periodontal ligament might be inducing an excitatory response from the sympathetic nervous system, we measured the levels of urinary catecholamines (UC) before and after the placement of ESM. METHODS: Sixteen healthy subjects, age 29±6.3 years (mean±SD,) from the Orthodontics Department gave their informed consent for this study. A Hamilton's Anxiety Scale was obtained from each subject before the experiment to determine their predisposition to experience anxiety and thus marked variations in their levels of UC. A 24-hour urine sample was collected for each subject one day before and one day after placing ESM between all posterior teeth bilaterally in the upper and lower dental arches and analyzed with high performance liquid chromatography (HPLC) to assay the catecholamin content, and compared with a Paired t-test. A certified orthodontist placed the ESM. All subjects were asked to comply with the indications for the technique and to avoid stressful situations. RESULTS: The average score for the anxiety test was 11.9±5 (mean±SD), which according to the scale is considered as a low tendency to anxiety. All subjects reported the onset of teeth clenching and discomfort. There was an average increase of 313.3±231.2% in the UC levels that was statiscally significant (p<0.001) for the group of subjects; however, 48 hours after the ESM were retrieved the UC levels were significantly lower (p<0.001). CONCLUSION: These results provide further evidence of a catecholaminergic modulation by occlusal factors and indicate that the altering dental occlusion may evoke sympathetic responses that should be considered.