Malocclusion occurs with considerably high prevalence rates. More than 60% of the population is affected by this anomaly. It occupies the third place in problems of oral health in the world, with others difficulties related to the occlusion and the pain produced by these. Most of the oral alterations, and in particular the malocclusions, are not life-threatening but, because of their prevalence and incidence, they are considered a public health problem. Its importance is established not only by the number of people who present it, but also because of the harmful effects they can generate in the oral cavity.
Occlusion anomalies should be adequately assessed and measured, it is necessary to use occlusal index, basic instruments for malocclusion surveys in large populations. The most widely used and recommended in the scientific literature is the Dental Aesthetic Index (DAI), which since its development has proven to be reliable and valid, as well as simple and easy to be apply. It takes into account morphological, functional and aesthetic criteria, it is quantifiable and provides information on both, malocclusion severity and need for treatment, its categories can be ordered on an interval scale, it is directly applicable on the patient or on study models and it does not require the use of photographs or x-rays. However, the DAI has some limitations, taking into account that the measurements of the variables that are expressed in millimeters are made with a specially calibrated probe for this purpose, it is possible to accumulate small measurement errors that may affect the final score of the index, both the procedure and the object being measured are likely to experience various influences that can modify the resulting information.
The DAI evaluates the aesthetic and anatomical components, gives each of the characteristics of malocclusion a certain score, depending on the relative contribution that this characteristic has to the severity of the whole of the malocclusion, which also allows the analysis of each component or occlusal feature in and independently way, based on the clinical characteristics of each patient. It provides information on the morphological, functional and aesthetic aspects of the malocclusion categorized in degrees of severity determining the need for orthodontic treatment.