Table 3

Prevalence of fluorosis in different age groups and its prevalent degree in FNB and FSB areas

Prevalence rate (N/%)p Values
FNB areasFSB areas
Dental fluorosis
 Subjects (children)5485526931
 Age (year)
  84499 (41.97)722 (13.96)<0.001
  95050 (48.83)881 (16.92)<0.001
  105613 (52.12)1001 (18.92)<0.001
  115579 (53.20)1089 (20.55)<0.001
  126929 (55.26)1428 (23.03)<0.001
 Prevalent degrees
  Very mild9862 (17.98)2285 (8.48)<0.001
  Mild9959 (18.16)1777 (6.60)<0.001
  Moderate5999 (10.94)784 (2.91)<0.001
  Severe1849 (3.37)275 (1.02)<0.001
Clinical skeletal fluorosis
 Subjects (adults)406298188400
 Age (years)
  16–25780 (0.96)77 (0.22)<0.001
  26–352143 (3.15)225 (0.71)<0.001
  36–456949 (7.43)1192 (2.75)<0.001
  46–5510990 (15.93)2003 (5.96)<0.001
  56–6512374 (22.83)2714 (10.82)<0.001
  66–10704 (26.85)2871 (14.89)<0.001
 Prevalent degrees
  Mild26491 (6.52)5236 (2.78)<0.001
  Moderate13707 (3.37)3013 (1.60)<0.001
  Severe3742 (0.92)833 (0.44)<0.001
  • FSB areas: fluoride-safe drinking water supply schemes had been built; FNB areas: no fluoride-safe drinking water supply scheme is provided.