Jolly 1971.

Methods	FLUOROSIS STUDY Country of study: India Geographic location: the Punjab Year of study: not stated Year of change in fluoridation status: NA Study design: cross‐sectional
Participants	Inclusion criteria: school children Exclusion criteria: none stated Other sources of fluoride: not stated Social class: not stated Ethnicity: not stated Residential history: not stated Other confounding factors: not stated
Interventions	All naturally fluoridated Group 1: 0.7 ppm Group 2: 1.4 ppm Group 3: 2.4 ppm Group 4: 2.4 ppm Group 5: 2.5 ppm Group 6: 3.0 ppm Group 7: 3.0 ppm Group 8: 3.3 ppm Group 9: 3.3 ppm Group 10: 3.6 ppm Group 11: 4.3 ppm Group 12: 5.0 ppm Group 13: 5.09 ppm Group 14: 5.49 ppm Group 15: 7.02 ppm Group 16: 8.5 ppm Group 17: 9.5 ppm
Outcomes	Mottled enamel Age at assessment: 5‐15 years
Funding	Not stated
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Sampling	Unclear risk	There was insufficient detail reported to determine how selection took place
Confounding	High risk	Did not account for the use of fluoride from other sources or SES
Blinding of outcome assessment (detection bias) All outcomes	High risk	Insufficient information
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Number of participants examined was not reported and the outcome was reported as a proportion
Selective reporting (reporting bias)	High risk	The outcome of interest was reported as a proportion; and without absolute numbers or the number of participants examined (n) it is unclear what the proportion represents. Data not in suitable format for analysis
Other bias	High risk	No mention of examiner calibration