M Beerens

WSL ASSESSED ON CLINICAL PHOTOGRAPHY AND BY QLF 2 25 INTRODUCTION Enamel demineralisation and white spot lesions (WSL) occur often during orthodontic full fixed appliance treatment and can remain after treatment (Artun and Brobakken, 1986; O’Reilly and Featherstone, 1987; Willmot, 2004; Murphy et al. , 2007). Prolonged exposure to bacterial plaque caused by deficient/inadequate oral hygiene is an important causal factor (Adams, 1967; Sakamaki and Bahn, 1968). There seems to be a difference in progression rate between non-orthodontic caused caries formation and white spot lesions induced by deficient oral hygiene combined with fixed appliance treatment (O’Reilly and Featherstone, 1987; Øgaard et al. , 1988a; Øgaard et al. , 1988b; Øgaard and Ten Bosch, 1994). It has been shown that visible white spot lesions can develop within 4 weeks of the start of fixed appliance treatment. It is known that not all lesions progress to cavities (Ferreira Zandona et al. , 2012). Although orthodontic lesions may remineralise to some extent after appliances are removed, they remain as scars, influencing the aesthetical appearance of the teeth (Mattousch et al. , 2007). It is important for clinical decision-making not to focus just on detecting caries at one point in time, as this is of limited use without monitoring caries activity and optical behaviour of WSL over time (Topping et al. , 2009). Since 2005, The International Caries Detection and Assessment System (ICDAS) is the instrument generally used to score caries clinically (National Institute of Health, 2001). This scoring system was developed to define visual caries detection criteria at an early non-cavitated stage that could informondiagnosis, prognosis and clinical management. The ICDAS system enables detection of early non-cavitated (white spot) lesions and provides an opportunity to explore lesion changes after orthodontic fixed appliance treatment in order to determine the progression or regression over time in a standardized way. However with ICDAS, progression or regression can only be observed when lesions transfer to a different score. Given that most orthodontic related caries lesions remain visible as scars despite remineralisation (van der Veen et al. , 2007), such ICDAS transitions are expected to be rare. In orthodontic practice it is custom to capture oral photographs at the start, during and after orthodontic treatment and retention and these photographs offer the opportunity to monitor caries lesion development by comparison of photographs longitudinally in time.