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Updated: May 26, 2026

Precision of In Vivo Quantitative Tooth Wear Measurement Using Intra-Oral Scans
Published on: July 12, 2022
Number of natural teeth and oral impacts: a study on sri lankan adults
Roshnal Perera1, Lilani Ekanayake
1School of Dentistry and Oral Health, Griffith University, Gold Coast Campus, Gold Coast, QLD 4215, Australia.
Abstract:
The aim of the study was to determine the association between the number of natural teeth and oral impacts in Sri Lankan adults. The sample consisted of 476, 40-59 and 452, ≥60 year olds. Oral impacts were assessed using a validated Sinhalese translation of the Oral Health Impact Profile-14 scale. A receiver-operating characteristic (ROC) curve was plotted to determine the number of natural teeth that would best discriminate those with oral impacts from those without. Oral impacts were reported by 26% of the 40-59 year olds and 34% of the older individuals. In both groups there was a significant negative correlation between the number of teeth present and oral impacts. The ROC curve for the 40-59 year olds gave an area under the curve (AUC) of 0.758 (95% CI = 0.702-0.814; P < 0.001) with an optimal cut-off of 24/25 teeth while for the ≥60 year olds, the AUC of the ROC curve was 0.737 (95% CI = 0.684-0.790; P < 0.001) with an optimal cut-off of 18/19 teeth. Based on the ROC curves the optimal cutoffs of the number of natural teeth that best discriminated between those with and without oral impacts for 40-59 and ≥60 year olds were 24-25 and 18-19, respectively.
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