Neither of my kids has ever been sent to the office though they both had one fairly major incident during their settling phase (in one case he misinterpreted the rules of the game because he thinks differently and forvthe younger he reacted violently to being teased) which were dealt with by the teacher. If I were the principal I would consider it a failure on the teacher's part to constantly send a kid to the office.

More than once a month would concern me, once a week would be a major concern.