The crown-root morphology of central incisors in different skeletal malocclusions assessed with cone-beam computed tomography

Progress in Orthodontics

Table 2 The distribution of samples

Skeletal malocclusion		Criteria for sample classification	Number
Class I	Average angle	1° ≤ ANB ≤ 5°, − 3.6 mm ≤ Wits ≤ 0.7 mm	24 (10 male)
Class II		ANB > 5°, Wits > 2 mm	20 (7 male)
Class III		ANB < 1°, Wits < − 3.6 mm	22 (9 male)
Low angle	Class I	SN-MP < 27 °, FHI(S-Go/N-Me) > 68%	21 (9 male)
Average angle		27° ≤ SN-MP ≤ 37° , 62% ≤ FHI(S-Go/N-Me) ≤ 68%	24 (10 male)
High angle		SN-MP > 37°, FHI(S-Go/N-Me) < 62%	21 (10 male)

CA Collum angle, LSA labial surface angle, SD standard deviation, I Class I, II Class II, III Class III, L low angle, A average angle, H high angle