At level 2 (TOOTH) there is a mean caries status for all the teeth (FIXED EFFECT), but each tooth has its own mean that differs from the mean value of all the teeth (RANDOM EFFECT).

At level 3 (MOUNTH) there is a mean caries status for all the mouths (FIXED EFFECT), but each mouth has its own mean that differs from the mean value of all the mouths (RANDOM EFFECT).

At level 4 (INDIVIDUAL) there is a mean caries status for all the individuals (FIXED EFFECT), but each individual has its own mean that differs from the mean value of all the individuals (RANDOM EFFECT).

At level 5 (PLACES) there is a mean caries status for all the places (FIXED EFFECT), but each place has its own mean that differs from the mean value of all the places (RANDOM EFFECT).