Malocclusion is difficult to define because individuals and cultures vary widely in their perceptions of what constitutes an occlusal problem. A number of occlusal indices have been devised but, probably because of this perceptual problem, none has ever emerged as a standard. Objective: The main objective was to review the use of the principal occlusal indices. Basic research design: The PUBMED database was searched for the main occlusal indices employed, journals with an impact in dentistry and specialist orthodontics journals. Results: The occlusal indices most frequently employed were IOTN (163 studies), PAR (132 studies), DAI (68 studies) and ICON (32 studies). The journals publishing the greatest number of studies using these occlusal indices are those specialising in orthodontics. Conclusions: In the high-impact scientific literature, the indices in greatest use are IOTN, followed by PAR, DAI and ICON. DAI and IOTN are mainly used in epidemiological or prevalence studies, while PAR is generally used for longitudinal studies. IOTN is used more in Europe. DAI is used worldwide; though least in Europe. Key words: occlusal indices, orthodontic treatment need, DAI, IOTN, ICON, PAR