I feel that' irregular teeth' is an unusual collocation, but it makes sense; perhaps say 'uneven/crooked* teeth', or if possible say what's wrong - example 'My boss has a bad over-bite' (that's just an example - the condition may not apply).
Also 'have their teeth adjusted' is an unusual collocation, but makes sense. You could use 'fixed' or 'straightened', or the less specific 'don't want to have anything done about it'.
Finally, 'my colleague' is OK if your audience knows which one you're talking about. If not, say 'a colleague of mine' or just a paraphrase like 'someone I work with'.
PS* Unlike booked, hooked, looked and rooked, crooked has two syllables: /'krʊkɪd/ .
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