Brown lines running across teeth

[ouch321]

Hoping someone in the dental profession might see this.

On my front four bottom teeth, specifically the centre two, and to a lesser extent the adjacent on either side, I have have two brown lines running horizontally across my teeth.

I do not, nor have I ever, smoked and I do not touch coffee. I drink tea though milky.

Can anyone explain these odd lines? I have no brown marks on the other teeth just these bottom 4.It's not even patchy - they are just brown streaky lines going across those teeth.

The hygienist has removed them previously but they just always come back and I can't figure out what is causing them.

TIA

If the hygienist can remove them it's just staining. The surface of our teeth isn't perfectly smooth so can pick up staining from things like you mentioned like tea coffee nicotine strong coloured foods and drinks etc. Maybe get yourself an electric toothbrush if you don't already have one and use a smokers toothpaste once a month or so - wouldn't recommend to use every day as they can be quite abrasive