Toothache-related queries and their respective RSV for each country.

<p>Terms with RSV = 0 were not considered.</p

Association of the variation of annual means of observed and fitted RSV toothache values with national statistics of toothache (U.S.) or urgent dental treatments (U.K.).

<p>Association of the variation of annual means of observed and fitted RSV toothache values with national statistics of toothache (U.S.) or urgent dental treatments (U.K.).</p

Flowchart summarizing the development of query strategies to assess the RSV toothache values in the U.S., U.K., Australia and Brazil.

<p>Flowchart summarizing the development of query strategies to assess the RSV toothache values in the U.S., U.K., Australia and Brazil.</p

Autocorrelation and partial autocorrelation plots for the monthly variation of RSV toothache values.

<p>(A) U.S., (B) U.K., (C) Australia, and (D) Brazil.</p

Predictive charts demonstrate the variation of RSV toothache values in the U.S., U.K., Australia and Brazil from January 2004 through April 2017.

<p>Note that RSVs presented after April 2016 (black line) represent 12-month predictive values. Observe the increase of the interest of Google users on toothache in all countries.</p

Seasonality of the interests of Google users on toothache.

<p>It was estimated by fitting a generalized additive model (GAM) to the detrended Google Trends data (lag-1 difference). Note that the scales vary from negative to positive values, since they represent the variation of values of the RSV of a month minus the RSV of the previous month. For instance, the detrended value of December 2004 is represented by the difference of its RSV in relation to the RSV of November 2004. GAM values using monthly RSV as a predictive variable for Google data are represented in the heat map.</p

Distribution of the main toothache-related queries according to distinct categories.

<p>Distribution of the main toothache-related queries according to distinct categories.</p

ARIMA model fit statistics.

<p>ARIMA model fit statistics.</p