The Study Of The Bone Thickness Changes Around Teeth During Orthodontic Treatment Between Different Periodontal Biotype

Objective : To compare buccal-lingual thickness of alveolar bone for orthodontic treated patient with mild to moderate chronic periodontitis before and after leveling and aligning, discussing the alveolar bone thickness differences in different periodontal biological type patients.Method : Randomly select 20 female adult orthodontic patients and equally divide into periodontal disease group (group A) and no periodontal disease group (group B).Subdivide each group into thin gingiva group (type Ⅰ), thick gingiva (type Ⅱ), labial movement (group 1), lingual movement (group2). Group A was treated with orthodontic combined periodontal treatment, group B was treated with standard orthodontic treatment. 120 teeth of 20 patients before (T0) and after leveling and aligning (T1) were measured for labial-lingual alveolar bone thickness at different distance point below CEJ. Data were processed with SPSS22.0 software.Results : (1) Labial and lingual alveolar thickness in both group A and B decreased,with labial absorption at apex > mid point of root > cervical point of root. (2) Alveolar bone thickness in both group Ⅰ and Ⅱ decreased, with AⅠ2 group more significant than AⅡ2 at labial side of cervical point, (labial side of cervical point: group AI2:3.39±2.42mm,group AⅡ2: 0.58±0.62mm AⅠ2>AⅡ2), differences has statistical significance(P<0.05 ).(3) The labial thickness at cervical point of group AⅠ1 decreased more significantly when compared with group B (labial side of cervical point: group AⅠ1: 2.43±1.85mm,group BⅠ1: 0.35±0.35mm,AⅠ1>BⅠ1), with statistical difference(P<0.05). (4) The labial thickness at cervical and mid point of group AⅠ2 decreased more significantly when compared with group BⅠ2 (labial side of cervical point: group AⅠ2: 3.39 ± 2,42mm,group BⅠ2: 0.78 ± 0.46mm; labial side of mid point: group AⅠ:2.35±1.79mm,group BⅠ: 0.29±0.12mm,AⅠ2>BⅠ2),differences has statistical significance (P<0.05) . (5) The lingual thickness at cervical, mid and apex point of group AII2 decreased more significant when compared to BⅡ2 (lingual side of cervical point: group AⅡ2: 2.09 ±1.47mm, group BⅡ2: 0.82 ± 0.69mm; lingual side of mid point:group AⅡ2: 3.77± 1.58mm,group BⅡ2: 1.33 ± 1.28mm; lingual side of apex point:group AⅡ2: 4.25±1.67mm,group: BⅡ2.07±1.34mm, AⅡ2>BⅡ2) , differences has statistical significance (P < 0.05)Conclusion: 1. More alveolar thickness decrease was seen in patients with periodontal disease than with no periodontal disease after leveling and aligning phase. The alveolar bone presented with mainly absorption with limited growth ability. 2.Lingual:movement in periodontal disease with thin gingiva biological type cause more thickness decrease of alveolar bone when compared with thick gingiva biological type:3. Lingual movement cause more thickness decrease of alveolar bone than labial movement, with higher risk of alveolar bone absorption.