Early smoking onset and temporomandibular disorder symptoms later in life.

OBJECTIVES

To investigate the association between early smoking onset (SO) and TMD symptoms among adults, and assess whether smoking intensity mediates this association.

METHODS

This secondary analysis used data from the Brazilian Longitudinal Study of Ageing (ELSI-Brazil). TMD symptoms were assessed using the Fonseca Anamnestic Index. Inverse probability weighting balanced early-life confounders and estimated risk differences (RD) and risk ratios (RR). Robustness was evaluated using positive (POC) and negative (NOC) outcome controls outcomes and E-values. Mediation analysis was conducted among smokers.

RESULTS

7,103 individuals were assessed. The RD comparing initiation before age 15 with never smoking was 0.06 (95% CI: 0.01, 0.11), corresponding to an RR of 1.37 (95% CI: 1.08, 1.72). POC, NOC, and E-values suggested residual confounding was unlikely to explain findings. No mediation via smoking intensity was observed.

CONCLUSION

Early SO is associated with higher TMD risk overall. Preventing early initiation, especially before age 15, may reduce TMD burden.