Table 3 : Distribution of closed root apices of permanent incisors and first
molars among 8-11.99 years children by sex.


Tooth Closed Root Apices Chi-Square p-Value
Male Female

11 35 (60.3%) 47 (61.0%) 0.007 0.935
12 28 (59.9%) 39 (57.4%) 0.071 0.790
21 33 (60.0%) 51 (64.6%) 0.288 0.592
22 33 (62.3%) 46 (63.9%) 0.035 0.852
16 Mesial root 36 (69.2%) 30 (46.9%) 5.847 0.016
16 Distal root 34 (68.0%) 27 (46.6%) 5.025 0.025
26 Mesial root 42 (72.4%) 49 (66.2%) 0.583 0.445
26 Distal root 39 (73.6%) 44 (64.7%) 1.090 0.296
31 52 (82.5%) 65 (85.2%) 0.185 0.667
32 43 (71.7%) 43 (78.2%) 0.024 0.878
41 53 (84.1%) 67 (84.8%) 0.012 0.911
42 45 (76.3%) 55 (73.3%) 0.151 0.698
36 Mesial root 34 (68.0%) 27 (46.6%) 0.475 0.491
36 Distal root 39 (73.6%) 44 (64.7%) 0.113 0.737
46 Mesial root 44 (66.8%) 53 (66.2%) 0.208 0.648
46 Distal root 44 (71.0%) 52 (65.8%) 0.423 0.515

*FDI world dental federation notation: 11-maxillary right central incisor,
12-maxillary right lateral incisor, 21-maxillary left central incisor,
22-maxilla left lateral incisor, 16-maxillary right first molar,
26-maxillary left first molar, 31-mandibular left central incisor,
32-mandibular left lateral incisor, 41-mandibular right central incisor,
42-mandibular right lateral incisor, 36-mandibular left first molar,
46-mandibular right first molar.

Mugonzibwa et al.Oral Biology and Dentistry  2018 6:1DOI : 10.7243/2053-5775-6-1