▁groups , ▁with ▁group ▁ 5 ▁having ▁the ▁most ▁severe ▁disease . ▁ ▁There ▁was ▁an ▁apparent ▁increase ▁from ▁ 1 % ▁to ▁ 2 % ▁to ▁ 3 % ▁over ▁the ▁three ▁study ▁periods , ▁which ▁may ▁have ▁been ▁due ▁to ▁an ▁increase ▁of ▁dent ate ▁subjects ▁in ▁the ▁older ▁age ▁groups . ▁ ▁Sus in ▁ 2 0 0 4 ▁exam ined ▁a ▁representative ▁sample ▁of ▁ 8 5 3 ▁dent ate ▁individuals ▁in ▁Brazil ▁who ▁were ▁selected ▁by ▁a ▁mult ist age ▁probability ▁sampling ▁method . ▁ ▁They ▁had ▁a ▁full - mouth ▁clin ical ▁exam ination ▁of ▁six ▁sites ▁per ▁to oth ▁and ▁answered ▁a ▁struct ured ▁written ▁question naire . ▁ ▁Se vent y - n ine ▁percent ▁( 7 9 %) ▁and ▁ 5 2 % ▁of ▁the ▁subjects ▁and ▁ 3 6 % ▁and ▁ 1 6 % ▁of ▁the ▁teeth ▁per ▁subject ▁had ▁C AL ▁> 5 ▁and ▁> 7 mm , ▁respectively . ▁ ▁Oliver ▁ 1 9 9 8 ▁ ▁Bour ge ois ▁ 2 0 0 7 ▁found ▁that ▁the ▁pre val ence ▁of ▁deep ▁po ckets ▁( > ▁ 5 mm ) ▁is ▁low ▁( 1 0 . 2 1 %) ▁in ▁a ▁cross - section al ▁study . ▁ ▁B ael um ▁ 1 9 9 6 ▁re calcul ated ▁their ▁previous ▁data ▁from ▁Ken yan ▁and ▁Chinese ▁populations ▁to ▁conform ▁to ▁the ▁methods ▁of ▁exam ination ▁and ▁data ▁presentation ▁util ized ▁in ▁six ▁other ▁surve ys . ▁ ▁They