[Radiographic study of the age for crown and root length completion stages of permanent teeth in male and female children].

Purpose: To determine the age medians for crown and root length completion stages of permanent teeth (except for the third molars) and to study gender differences in crown and root length completion stages by radiographic examinations.
Methods: The development of permanent teeth (except for the third molars) was evaluated from 3304 panoramic radiographs of children aged between 3 and 18 years by Haavikko's method. Statistical analysis was performed using SPSS 25.0 software package. Age medians for crown and root length completion stages of permanent teeth were calculated. Gender differences were analyzed by Mann-Whitney U test.
Results: There were no significant gender differences in crown completion stages of central incisor and first molar, of which P values were 0.143 (for maxillary central incisor), 0.122 (for maxillary first molar), 0.191 (for mandibular central incisor) and 0.558 (for mandibular first molar), while girls were found to be ahead of boys for crown completion stages of other teeth. In maxilla, girls were found to be ahead of boys for root length completion stages except for lateral incisor, second premolar and second molar, of which P values were 0.057, 0.130 and 0.294; in mandible, except for second premolar and second molar, girls were observed to be ahead of boys for root length completion stages, of which P values were 0.428 and 0.057.
Conclusions: It is concluded that girls are advanced than boys for crown and root length completion stages in most teeth. There is a similarity in gender differences for crown and root length completion stages between maxilla and mandible.