Adhesively bonded, fixed orthodontic appliances—so-called multibracket appliances—on buccal or lingual tooth surfaces can make oral hygiene difficult. This increases the risk of caries and gingivitis, and patients require closely monitored prophylactic care. Oral hygiene indices serve to assess the oral hygiene situation and evaluate oral health status. The currently available indices do not adequately meet the special requirements of patients with multibracket appliances, since they evaluate only the smooth surfaces and/or approximal spaces of the teeth in terms of plaque accumulation and signs of inflammation of the marginal gingiva. The Orthodontic Plaque Index (OPI) is a special index for patients with fixed orthdontic appliances. The OPI focuses on the tooth area in the immediate vicinity of the bracket, since additional and relatively inaccessible plaque niches arise at these sites. To record the OPI, the dentition is divided into sextants. Plaque scores (0 to 4) are assigned. The plaque accumulation on each tooth surface adjacent to the bracket base is evaluated (mesial, distal, occlusal/incisal, and cervical). In addition, signs of gingival inflammation are recorded. The highest score per sextant is entered into a sextant table. Increased risk of caries and gingivitis is assumed as of score 3. The OPI can be used for both buccal and lingual multibracket appliances. In patients with fixed orthodontic apppliances, the OPI assesses oral hygiene in the bracket vicinity and thus provides differential findings. As a result, the OPI is recommended for clinical use. ORTHODONTICS (CHIC) 2012;13:94–99.
Key words: brackets, oral hygiene control, oral hygiene index, oral hygiene instruction, Orthodontic Plaque Index, orthodontics, prevention