The Dental Aesthetic Index (DAI) is an orthodontic index based on socially defined aesthetic standards. It is useful in both epidemiological surveys to identify unmet need for orthodontic treatment and as a screening device to determine priority for subsidized orthodontic treatment. An earlier study established the score of 36 on the DAI scale to identify handicapping malocclusions. The purpose of the present study was to determine decision points on the DAI scale that identify malocclusion severity levels less severe than handicapping. Two sources of data were used: 1) The frequency distribution of DAI scores on a probability sample of 1306 study models representing the untreated occlusions found in half a million adolescents. 2) The percent distribution of US youths aged 12-17 by specified case severity reported in an assessment of the occlusion of youths by the National Center for Health Statistics (NCHS). The decision points separating specific case severities on the DAI scale were determined by relating the proportions of the NCHS population with specified case severities to the cumulative percentages of the frequency distribution of DAI scores on the 1306 models. The NCHS report found 45.8 percent of the sample to have normal or minor malocclusion with no need or slight need for treatment. DAI scores 25 and below corresponded to that proportion of the sample. The NCHS report found 25.2 percent of the sample to have definite malocclusion with treatment being elective. DAI scores between 26 and 30 corresponded to that proportion of the sample. The NCHS report found 13 percent of the population to have severe malocclusion with treatment highly desirable. Fifteen percent were included in this category. DAI scores 31 to 35 corresponded to that proportion of the sample.

To be truly useful, an index must be applicable universally without modification. The data presented in this article support the use of the standard DAI without modification to assess need for orthodontic treatment in both developing and industrialized countries. When students from Thailand, Australia, the German Democratic Republic, and Native Americans residing on Indian reservations rated the same 25 occlusal stimuli (photographs of dental configurations) for dental aesthetics, their ratings of these stimuli when arranged in rank order were highly correlated with those of US students. These 25 occlusal stimuli were a subset of the original 200 occlusal stimuli used in deriving the standard DAI regression equation. This article presents data indicating that when a Native American DAI was derived based on Native American ratings of the same 200 occlusal stimuli used in deriving the standard DAI, the Native American DAI and the standard DAI had the same ten components (orthodontic measurements) and strikingly similar regression coefficients (weights). Further analysis indicated that the two equations were sufficiently similar to justify using the standard DAI to obtain DAI scores on Native Americans and to estimate the relative social acceptability of their dental aesthetics. If ratings for dental aesthetics for the full set of 200 stimuli were available for each of the countries where only 25 were rated, we expect that, as in the case of Native Americans, a country-specific DAI, if computed, would be sufficiently similar to the standard DAI that no modification would be needed to allow use of the standard DAI in that country.(ABSTRACT TRUNCATED AT 250 WORDS)

The aims of this study were to measure the distribution, prevalence and the severity of malocclusion and treatment need amongst randomly selected (n = 703) rural and urban Nigerian children aged 12-18 years (mean 14.0 +/- 1.84) using the dental aesthetic index (DAI), and to assess whether malocclusion was affected by age, gender and socio-economic background. Data were collected according to the method recommended by WHO. Most of the children (77.4 per cent) had a dental appearance which required no orthodontic treatment. Over 13 per cent fell into the group where treatment for malocclusion is considered to be 'elective'. However, a substantial proportion (9.2 per cent) of the population had severe to handicapping malocclusion where treatment is 'highly desirable' or 'mandatory'. There were no statistically significant differences (P > 0.05) in DAI scores between age groups, gender and socio-economic background. This study also found that Nigerian adolescents had better dental appearance and less orthodontic treatment need compared with the Caucasian and Oriental populations.

In the past decade, the utility of cone beam computed tomography (CBCT) images in oral and maxillofacial surgery has seen continuous increase. However, CBCT images are not always able to replace other imaging modalities. Based on the current published knowledge, this paper discusses advantages and limitations of CBCT images in the diagnosis and surgical planning of dentoalveolar procedures, odontogenic cysts, benign and malignant tumours, inflammatory changes, orthognathic surgery, maxillofacial trauma, sinus disorders, and systemic and osseous conditions that manifest in the maxillofacial area. This paper also suggests alternative imaging modalities when CBCT images are not adequate for surgical planning.Keywords: Dental radiography, oral surgery.Abbreviations and acronyms: BRONJ = bisphosphonate-related osteonecrosis of the jaws; CBCT = cone beam computed tomography; MDCT = multi-detector CTs; MRI = magnetic resonance imaging; OMS = oral and maxillofacial surgery.

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