Table 1.

Groups 1–7 based on the Hellman’s classification of dental development

Group	Hellman’s stage	Characteristics
1	IIA	Completion of primary occlusion
2	IIC	Eruptive phase of permanent first molar or incisor
3	IIIA	Eruption of permanent first molar or incisor completed
4	IIIB	Exchange phase of lateral teeth
5	IIIC	Eruptive phase of permanent second molar
6	IVA	Eruption of permanent second molar completed
7	IV C et V A	Eruptive phase or eruption of permanent third molar completed