Father Zimmermann and Dentist Zimmerman
Father Zimmerman is the priest for whom Sister Irma is substitute teaching. He is also the person who revokes her permission to take art lessons, presumably after reading Jean's letter encouraging her to dedicate herself to her art.
The other Zimmerman is Jean's dentist, the guy who removes eight of his teeth. Both men represent Jean's seeming lack of control over his own life before his second epiphany.