I don't know if it was meant or just a coincidence, but there's no crossover between the two shows :)

In WBL he worked under the former school doctor (sorry, it's been a while and I don't remember the names). Here in My tooth your love, he works under Bai Lang, the bar owner who is also the main character.

 Chelsea Black:

Thanks - in WBL the former doctor asks him to teach him to run a bar so it sounds like it's his own bar whereas here he works for Bai Ling and has that whole "overseas" vibe 

Thanks for answering. I know Taiwanese love a cross over :D 

Yes, Plus & minus taught us they really love crossovers ♡

It would have been interesting, since it's the same production studio, but I didn't get any hint towards it. I should probably check if Alex has a name in WBL to be 100% sure :) but as it is, I believe there's no crossover

Nah he's just known as bartender :D 

 Annarwen:

It might be cuz, in this past ep, Bai said Alex came with the bar.

I thought the same but in WBL he owned it and the bar set up was different.  I'll take the L on this one. It's not a match 

Taiwan's BLs do love a good crossover. But they also love a good open-to-interpretation cameo. As well as a good passive reference.

Even Plus & Minus's were up to interpretation because the couple from Be Loved In House were never named in the script, the credits, or in promo materials for their presence (unless I missed something somewhere, which is possible considering what they are called in the MDL cast list). 

And the main CP from HIStory 3 shows up everywhere - sometimes named as someone different, sometime unnamed (and thus open to interpretation).

In Be Loved in House, we get a character who's dialogue references the fact that he and the ML shared a previous drama together, despite the ML being a different character in Be Loved In House.

You can also often see BL posters from all over the world on the wall, in trashbins, etc. I think someone even spotted a BL poster from another Taiwanese BL once. But I cant remember what.

Eh, I see it more as making a nod to the industry - since it is so small. Like a respect/acknowledging thing. 

It also helps from a marketing/hype standpoint, because fans go crazy over it. It provides fuel for so much and different types of discussion, which keeps people talking about it for longer. Or even talking at all (a lot of people flat out mention that theyve watched dramas because of certain cameos). 

It also sends people back to previous BLs they may have missed. Because a lot of these references feel like references (as evidenced by people coming to comment sections saying things like "are they from something?")

So I wouldnt say it's as simple as authors re-using material.

 MiniiFoxx:

Actually plus and minus doesn’t have any crossover. Yes there are actors who play couples in it that play couples in other dramas but they aren’t the same couples. Also yes there is a character who plays a similar role to what he did in another drama but it isn’t a crossover.

For a while there, everyone was saying that it was a crossover with the Be Loved In House couple. Even MDL said it for a while. But yes, none of the Plus and Minus appearances were true crossovers.