A study of young people undergoing orthodontic treatment has advanced knowledge of the impact of obesity on oral tissues.1

It is now recognised that obesity represents a state of chronic subclinical inflammation mediated through the presence of excess adipose tissue. In this investigation, the consequences of obesity for orthodontic tooth movement have been investigated.

Led by Professor Martyn Cobourne and Dr Guy Carpenter at King's College London Dental Institute, the study involved two cohorts of young people with an average age of 15 years. One group was of normal weight and the other was classified as obese based upon body mass index (BMI).

Taking samples of both saliva and gingival crevicular fluid, the researchers found that the obese young people had significantly increased inflammatory biomarkers in their periodontal tissues prior to treatment. This was associated with a significantly increased initial displacement of the teeth during the first week of treatment and a significantly increased rate of tooth movement over the alignment phase.

The British Orthodontic Society's (BOS') Director of External Relations, Richard George, commented that: 'This study provides evidence that increased BMI can have manifestations for orthodontic patients. Significantly, the patients with obesity had a pre-existing pro-inflammatory state in their periodontal tissues and this influenced how the teeth moved with fixed braces.'

Orthodontic tooth movement is mediated by an inflammatory response within the periodontal tissues following the application of orthodontic force. If obesity can affect how teeth respond to fixed braces, it might also potentially influence root resorption and long-term stability.

The two groups of patients in the study are still in treatment and the research team at King's are currently following them up to the completion of treatment.