A comparıson of anterior alveolar structures after extraction and nonextraction fixed orthodontic treatment

Objective: the aim of this study is to evaluate the thicknesses of the upper and lower alveolar regions after extraction and nonextraction fixed treatment. method: for this purpose, cephalometric films of 61 patients treated with four premolar extraction (n=31) and nonextraction (n=30) were evaluated. palatal and labial alveolar thicknesses of the incisor teeth were measured at the level of the apical and coronal third of the roots. the differences between the groups were assessed by mann-whitney tests or student‟s t test and intragroup differences were calculated by wilcoxon signed rank test or paired t test considering whether normal or abnormal distributed data. palatal side of the alveolar bone thickness in both groups. the alveolar bone palatal to the upper incisors were decreased, while the lingual side of the lower incisors did not change in nonextraction group. results: the bone thickness labial to the upper anterior incisors did not change while the palatal side of the incisors were decreased significantly at the coronal and apical levels after both treatment procedures. maxillary bone thickness decreased significantly in only nonextraction group. the alveolar bone thickness lingual to the lower incisor teeth decreased significantly at the coronal and apical levels in extraction group, while lingual bone decreased at the apical level in nonextraction group. the alveolar bone thickness labial to the lower incisors did not change in both extraction and nonextraction groups. b-b' width which is the narrowest region of the symphysis region decreased in only extraction group. discussion: all anterior alveolar thicknesses decreased or remained stable after extraction and nonextraction treatment. similar changes were observed in especially.