Groups Skeletal malocclusion, N (%) P-value
Class I Class II Class III
Without tooth agenesis 199 (62.4) 87 (27.3) 33 (10.3) Reference
All types of tooth agenesis 20 (71.4) 3 (10.7) 5 (17.9) 0.11
Type of congenitally missing tooth
Premolar agenesis 8 (61.5) 1 (7.7) 4 (30.8) 0.039a
Upper lateral incisor agenesis 9 (69.2) 2 (15.4) 2 (15.4) 0.597
Others tooth agenesis 4 (100) 0 (0) 0 (0) 0.302
Affected arch
Maxillary tooth agenesis 15 (68.2) 3 (13.6) 4 (18.2) 0.256
Mandible tooth agenesis 7 (63.6) 1 (9.1) 3 (27.3) 0.127

aStatistically significance difference (P < 0.05), Chi-square test.
N = number.
All comparisons were performed with the group without tooth agenesis. Others tooth agenesis was represented by two cases of molar agenesis and two cases of lower incisor agenesis.