Search

The Standard DAI is an orthodontic index based on perceptions of dental aesthetics in the USA. The Standard DAI is a regression equation linking perceptions of the social acceptability of dental aesthetics with the objective intraoral measurements of ten occlusal traits. Since the Standard DAI is based on perceptions of dental aesthetics in the USA it can be used without modification only where perceptions of dental aesthetics are similar to those in the USA. This study was designed to determine whether perceptions of dental aesthetics of students in eleven diverse ethnic groups are similar to those of students in the USA. The same 25 stimuli (photographs of dental configurations, a subset of the 200 stimuli used in deriving the Standard DAI equation) were rated for dental aesthetics by Australian, Chinese, German, Japanese, Korean, Latvian, Native American, Singaporean Chinese, Singaporean Indian, Singaporean Malay, and Thai students. Their ratings were compared with the ratings of the same 25 stimuli by students in the USA. Spearman rank-order correlations ranged from 0.84 to 0.94. These correlations are sufficiently high to show that perceptions of dental aesthetics in all eleven ethnic groups are very similar to the perceptions of USA students. Therefore the Standard DAI can be used without modification in all eleven ethnic groups.

The Standard DAI is an orthodontic index based on public perceptions of dental aesthetics in the USA and is a regression equation linking the relative social acceptability of dental appearance and the objective, physical measurements of ten occlusal traits. It can be used in surveys of need for orthodontic treatment and as a screening tool in public programmes providing orthodontic care. To determine if the Standard DAI could be used internationally, 200 stimuli (photographs of dental configurations) were rated for dental aesthetics by 413 Chinese students, 418 Latvian students and 428 Native Americans. To develop ethnic group-specific DAI equations these ratings were linked by regression procedures to the occlusal trait measurements available for each of the 200 stimuli. Using these equations, group-specific DAI scores were calculated for the 200 stimuli. At all levels on the DAI scale the percentage agreements, sensitivities and specificities ranged from 73 to 100 per cent indicating that the Standard DA can be used without modification to calculate DAI scores among Chinese, Latvians and Native Americans.

The Dental Aesthetic Index (DAI) was used to evaluate malocclusion in Japanese high school students (n = 409, ages 15-18 yr). The purpose of this study was to obtain basic data concerning malocclusion in Japanese high school students. This study used a sample of students from randomly selected urban and rural high schools in Japan's Kyushu district. The DAI scores for urban and rural high school students, as well as the total DAI scores from these two areas were significantly higher than that of American high school students. These results showed that the number of students with an acceptable dental appearance among Japanese high school students is significantly lower than among American high school students. This indicates a higher need for orthodontic treatment among Japanese high school students.

The Dental Aesthetic Index (DAI) is an orthodontic index based on socially defined aesthetic standards. The DAI is useful in both epidemiological surveys to identify unmet need for orthodontic treatment as shown by its use by WHO in ICS-II and as a screening device to determine priority for subsidised orthodontic treatment. The purpose of this study was to determine a decision point on the DAI scale that predicts the clinical judgments of orthodontists in separating handicapping from non-handicapping malocclusion. Orthodontists' decisions were available on a sample of 1306 models representing untreated occlusions found in half a million children. DAI scores were calculated for each model. By correlating orthodontists' decisions with DAI scores a cut-off point was established. Agreements between DAI scores and orthodontists' decisions were best at the 86th percentile on the DAI scale. The DAI score of 36 at the 86th percentile yielded an 88 per cent agreement, a specificity of 93 per cent and a sensitivity of 54 per cent. Cases with scores of 36 and higher would be considered handicapping according to the DAI.

Preliminary findings on the distribution of occlusal traits (COCSTOC-MOT) have been presented as measured on 1337 orthodontic models. These models were made from a sample representing more than 400 000 children ages 15 to 18 in Upstate New York (all of New York State with the exception of New York City). Some of the findings for occlusal traits in this survey are comparable to those from a representative sample of younger children representing the US population ages 6--11 years. For comparable traits differences between the findings in New York State and for the United States were: Openbite--1 per cent higher in the US sample. Overjet 6 mm or more--5.7 per cent higher in the US sample. Neutro-occlusion--7 per cent more in the US sample. Disto-occlusion--8 per cent more in the US sample. Mesio-occlusion--8 per cent more in the US sample. Differences in findings between these surveys are assumed to be largely due to the fact that the current survey measured occlusal traits in the permanent dentition; whereas, the US survey measured those traits in the mixed dentition. Some of the traits found in the mixed dentition are believed to be self-correcting. Statistically determined means and medians for some of the occlusal traits of COCSTOC indicate that there is considerable variation from ideal occlusion found in a large population.

An instrument developed by Jenny et al. (1980) for rating the public's perceptions of the social acceptability of a wide variety of occlusal configurations was administered to children and adults in Australia, the German Democratic Republic and the United States of America and also to US orthodontists. Mean scores for the 7 groups of subjects from the 3 countries were arranged in rank order from the least socially acceptable to the most socially acceptable and compared. The results indicate that use of the social acceptability scale of occlusal conditions (SASOC) is a highly reliable method for scoring and rank-ordering the aesthetic acceptability of occlusal morphologies. Spearman rank-order correlation coefficients between the ranking of SASOC stimuli by all 7 groups of subjects from the 3 countries ranged from 0.85 to 0.97. The probability of such correlations occurring by chance is less than 1 in 10000 (P less than 0.0001). SASOC proved capable of rank-ordering a wide range of occlusal morphologies for aesthetics with excellent consistency along the entire spectrum from the least acceptable to the most socially acceptable in all 3 countries. The data indicate that norms for socially acceptable dental appearance are essentially the same in Australia, the German Democratic Republic and the United States of America.