Hi, though I think this approach is the best, because in my opinion there should be a filter on the two first questions.
If "they never refuse to brush their teeth" the next two questions are obsolete.
If "this behaviour is not a problem" the third question is obsolete.
In an online questionnaire it's always better to ask question by question with a valid routing.
Nevertheless, I assume you want something like this.
Just merge the two workarounds for "dropdowns in matrix" and "matrix with others", which are described many times here.
And an example.
By the way: You may add more others just by adding more "Other questions" and adding the subquestions.
Joffm