ISO system for primary dentition
Upper right quadrant (maxillary) - 5
Upper left quadrant (maxillary) - 6
Lower left quadrant (mandibular) - 7
Lower right quadrant (mandibular) - 8
Medial/ central incisors - 1
Lateral incisors - 2
Canines - 3
1st molars - 4
2nd molars - 5
For example, the lateral incisor in the lower left quadrant has a numbering of 72 (7 is for the lower left quadrant, while 2 refers to the lateral incisor as it is the second tooth from the midline of the jaw).