Research progress on anterior alveolar bone changes after orthodontic treatment involving extractions / 口腔疾病防治

@#It has been traditionally believed that a 1:1 cortical bone remodeling/tooth movement ratio has been preserved during orthodontic treatment for tooth movement, with the alveolar bone on the tension side growing and the alveolar bone on the pressure side resorbing to maintain the balance of the alveolar bone. However, recent studies have shown that alveolar bone loss has been found in patients who have undergone orthodontic treatment, suggesting that the alveolar bone does not change as the teeth change over time. Whether the morphology of the alveolar bone will change when the anterior teeth are moved has been the clinical focus. The changes of anterior alveolar bone in patients who have undergone tooth extraction after orthodontic treatment were summerized by literature review in this paper. The results of the review showed that the alveolar bone at the lingual/palatal root-cervical site of the anterior root is more prone to bone loss after extensive movement of the anterior teeth. With the development of imaging technology, CBCT is now more commonly used for analysis instead of two-dimensional images for measurement, as its results are more accurate. However, there are few multifactorial studies in which CBCT has been used to assess the morphological changes in the alveolar bone. The focus of future research is to compare the long-term changes in the anterior alveolar bone of patients of different ages based on three-dimensional imaging, and to study the correlation between different skeletal features, tooth movement patterns and alveolar bone remodeling.

Clinical effect of platelet-rich fibrin combined with bone substitute in alveolar ridge preservation / 口腔疾病防治

Objective@#To study the clinical outcomes of implanting platelet rich fibrinogen (PRF) mixed with Bio-Oss® in the extraction socket for alveolar ridge preservation and to provide evidence for clinical application. @*Methods@#Thirty-six patients who underwent alveolar ridge preservation were enrolled. Thirty-six extraction sites were divided into two groups: PRF mixed with Bio-Oss® group (test group) and Bio-Oss® alone (control group). Bone dimensional changes in height and width were measured by CBCT before and 6 months after surgery, and early soft tissue healing and postoperative pain sensation were evaluated clinically 1 week after surgery.@* Results @# There was no significant difference in the alveolar bone height (-1.48 ± 0.40) mm between the test group and the control group. The difference in the alveolar bone width between the test group (-1.09 ± 0.42) mm and the control group (-1.35 ± 0.22) mm was statistically significant (z=-2.63, P=0.01). The postoperative pain score of the test group was 2.39 ± 1.20, and that of the control group was 3.39 ± 1.65, the difference was statistically significant (t=-2.083, P=0.045). There was no significant difference in soft tissue healing between the test group and the control group.@*Conclusion @#The use of PRF mixed with Bio-Oss ®in the alveolar ridge preservation procedure can reduce alveolar bone absorption and postoperative pain.

Effect of Xianling Gubao Capsule on alveolar bone mass in postmenopausal women with periodontitis: A cone-beam CT evaluation / 中国组织工程研究

BACKGROUND: Xianling Gubao Capsule can reduce bone loss and promote the formation of osteoblasts. Its efficacy in osteoporosis and fracture has been preliminarily confirmed, but its efficacy in postmenopausal female periodontitis has not been clarified. OBJECTIVE: To assess the effect of Xianling Gubao Capsule on alveolar bone mass in postmenopausal women with periodontitis by cone-beam CT, providing an effective basis for its clinical use. METHODS: One hundred and thirty-five patients with periodontitis diagnosed and treated in the Department of Stomatology, First Affiliated Hospital of Guiyang College of Traditional Chinese Medicine from October 2015 to April 2017 were enrolled. All patents were randomly divided into blank group (basic treatment), control group (basic treatment+vitamin D) and experimental group (basic treatment+Xianling Gubao Capsule), with 45 patients in each group. All patients received oral hygiene and health education, and were guided to brush their teeth correctly and self-control plaques. Basic treatments for periodontal disease were performed to eliminate plaque and calculus by cleaning and curing the gums, and smoothing the root surface, once 3 months for 6 continuous months. The control group received oral Calci-D (600 mg of calcium and 125 U of vitamin D per tablet), one tablet per day, for 6 continuous months. The experimental group was orally given Xianling Gubao Capsule 1.0 g/time, 3 times per day, 3 months as a course of treatment, for two consecutive courses. Cone-beam CT was used to detect the changes of bone mineral density and height of alveolar bone defect in all patients before treatment, 3 and 6 months after treatment. Ethics approval was obtained from the First Affiliated Hospital of Guiyang College of Traditional Chinese Medicine on May 29, 2015 (approval No. K2015-186). RESULTS AND CONCLUSION: (1) Compared with the baseline, the alveolar bone defect height was significantly reduced in the experimental and control groups (P 0.05). The improvement of alveolar bone defect height and bone density was better in the experimental group than the control group (P 0.05). The alveolar bone defect height and bone mineral density of the patients older than 55 years had no changes (P > 0.05). (3) Alveolar bone defect height and bone mineral density were significantly improved in patients with mild and moderate periodontitis (P 0.05). To conclude, the treatment of periodontitis by Xianling Gubao Capsule can significantly improve the alveolar bone defect height and bone mineral density, and cone-beam CT can be used to evaluate its clinical efficacy.

CBCT study of the alveolar bone remodeling after retraction of the maxillary incisors assisting with micro-implant anchorage in maxillary protrusion adults / 口腔疾病防治

Objective@# To study the remodeling of alveolar bone after retraction of the maxillary incisors assisting with micro-implant anchorage in adult patients with maxillary protrusion by CBCT.@*Methods@#Forty patients who were treated with extraction of the maxillary first premolars with microimplant anchorage meeting the inclusion criteria were selected. The CBCT data before and after treatment were collected, and the Dolphin Imaging 3D measurement software was used to measure and analyze the height and thickness of the alveolar bone of the 80 upper central incisors and the 80 lateral incisors.@*Results @#After retraction of the incisors assisting with microimplant anchorage, the labial alveolar bone height of the maxillary central incisors decreased (0.11 ± 0.33) mm, and the lingual alveolar bone height of the maxillary central incisors decreased (0.85 ± 1.23) mm. The labial alveolar bone height of the maxillary lateral incisors decreased (0.18 ± 0.42) mm, and the lingual alveolar bone height of the maxillary lateral incisors decreased (1.13 ± 1.14 ) mm. The reduction in the lingual alveolar bone height was greater than that of the labial side, and the difference was statistically significant (P < 0.05). The labial alveolar bone thickness of the maxillary central incisors increased (the root cervix, the root media and the root apex), and the difference was statistically significant (P < 0.001). The labial alveolar bone thickness of the maxillary lateral incisors also increased (P < 0.05), while the lingual alveolar bone thickness and the total alveolar bone thickness of the maxillary central and lateral incisors decreased (P < 0.001). @*Conclusion@#In adults with maxillary protrusion, the microimplant was used to assist the reduction of the anterior teeth. The alveolar bone height of the maxillary incisors was reduced, and the palatal alveolar bone height decreased more than that of the labial side. The alveolar bone of the labrum was thickened, and the palatal alveolar bone thickness and the total alveolar bone thickness of the maxillary incisors were reduced after treatment.

Changes in alveolar bone height due to retraction of anterior teeth in adult patients / 实用口腔医学杂志

Objective:To investigate the alveolar bone height change before and after retraction of anterior teeth in adult patients. Methods:A total of 15 adult patients with angle class I bimaxillary protrusion had 4 first premolars extracted followed by othodontic treatment for retraction of anterior teeth with straight arch wire techniques.Cone beam computed tomography(CBCT)scans were made before and 3 months after retraction.The labial and the lingual alveolar bone height around central and lateral incisors was measured and analyzed before and after treatment.Results:Significant increase of labial alveolar bone height around anterior teeth was found in both maxilla and mandible(P ＜0.05),however,lingual alveolar bone height was decreased(P ＜0.05).Conclusion:For bimaxillary protrusion patients,the lingual alveolar bone height decreased due to obvious incisors retraction in adults which should be considered carefully in orthodontic clinic.

Evaluation of an Alveolar Bone Graft for Cleft Patients

CLINICAL STUDY ON KOREAN POSTERIOR MAXILLAE RELATED TO DENTAL IMPLANT TREATMENT

Effects of lower third molar removal on attachment level and alveolar bone height of the adjacent second molar

The purpose of this study was to evaluate the periodontal status distal to the adjacent second molar following the extraction of a partially or fully impacted mandibular third molar at Klinik Pergigian Pakar Hospital Universiti Sains Malaysia (KPPHUSM) from April of 2008 until June of 2008.This was a prospective study which involved the clinical and radiological study of patients. In this study, convenience sampling method had been used. The sample size was 22 patients aged 18-32 years old with inclusion criteria. The outcomes measured in this study were periodontal pocket depth (PPD), clinical attachment level (CAL) and alveolar bone height (ABH). Subjects were examined at distal surface (disto-buccal, mid-distal and disto-lingual) of second molar for PPD and CAL before and 3 months after the impacted adjacent lower third molar extraction. OPG was taken each before and after the third molar removal. These data were analyzed using SPSS version 16 and Wilcoxon-signed-ranks test was used to compare the PPD, CAL and ABH pre and post operatively. All the results were not significant with p >0.05. For PPD, median = 3mm pre and post extraction. CAL median= 2mm pre and post operatively and ABH median of 3.10mm (before) and 2.8mm (after) the third molar removal. From our study, we concluded that there were no significant changes of PPD, CAL and ABH at distal side of second molar after 3 months of the adjacent impacted lower third molar removal.

A study about the change of locations of the center of resistance according to the decrease of alveolar bone heights and root lengths during anterior teeth retraction using the laser reflection technique / 대한치과교정학회지

Treatment mechanics should be individualized to be suitable for each patient`s personal teeth and anatomic environment to get a best treatment result with the least harmful effects to teeth and surrounding tissues. Especially, the change of biomechanical reaction associated with that of the centers of resistance of teeth should be considered when crown-to-root ratio changed due to problematic root resorption and/or periodontal disease during adult orthodontic treatment. At the present study in order to investigate patterns of initial displacements of anterior teeth under certain orthodontic force when crown-to-root ratio changed in not only normal periodontal condition but also abnormal periodontal and/or teeth condition, the changes of the centers of resistance for maxillary and mandibular 6 anterior teeth as a segment were studied using the laser reflection technique, the lever&pulley force applicator and the photodetector with these quantified variables reducing alveolar bone 2mm by 2mm for each of maxillary 6 anterior teeth until the total amount of 8mm and root 2mm for each of mandibular 6 anterior ones until the total amount of 6mm. The results were as follows: 1. Under unreduced condition, the center of resistance during initial displacement of maxillary 6 anterior teeth was located at the point of about 42.4% apically from cemento-enamel junction(CEJ) of the averaged tooth of them and kept shifting to about 76.7% with alveolar bone reduction. 2. The distance from the averaged alveolar crest level of maxillary 6 anterior teeth to the center of resistance for the averaged tooth of them kept decreasing with alveolar bone reduction, but the ratio to length of the averaged root embedded in the alveolar bone was stable at around 33% regardless of that. 3. Under unreduced condition, the center of resistance during initial displacement of mandibular 6 anterior teeth was located at the point of about 43% apically from CEJ of the averaged tooth of them and this ratio kept increasing tc about 54% with root reduction. Bur the distance from CEJ to the center of resistance decreased from around 5.3mm to around 3.3mm, that is to say, the center of resistance kept shifting toward CEJ with the shortening of root length. 4. A unit reduction of alveolar bone had greater effects on the change of the centers of resistance than that of root did during initial phase of each reduction. But both of them had similar effects at the middle region of whole length of the averaged root.