Bone response to buccal tooth movements--with and without flapless alveolar decortication (original) (raw)
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Changes in alveolar bone thickness due to retraction of anterior teeth
American Journal of Orthodontics and Dentofacial Orthopedics, 2002
In cases of bimaxillary protrusion, extraction of 4 premolars and orthodontic treatment with retraction of the anterior teeth is a widely used approach. However, there is controversy over whether the changes that occur in the anterior alveolar bone always follow the direction and quantity of tooth movement. Nineteen patients with dentoalveolar bimaxillary protrusion treated by extracting the 4 first premolars were evaluated with lateral cephalograms and computed tomography (CT). Cephalograms and CT scans were made before treatment and 3 months after retraction of the incisors. The measurements of the cephalograms showed that maxillary and mandibular incisors were retracted primarily by controlled tipping of the teeth. For all maxillary and mandibular incisors, we assessed the labial and the lingual alveolar plates at crest level (S1), midroot level (S2), and apical level (S3) for bone-thickness changes during retraction of the maxillary and mandibular anterior segments. In the mandibular arch, the labial bone maintained its original thickness, except the S1 measurements, which showed a significant decrease in bone thickness (P Ͻ .001). In the maxillary arch, the labial bone thickness remained unchanged. There were statistically significant decreases in lingual bone width in both arches after retracting the incisors. Some of the patients demonstrated bone dehiscence that was not visible macroscopically or cephalometrically. When tooth movement is limited, forcing the tooth against the cortical bone may cause adverse sequelae. This type of approach must be carefully monitored to avoid negative iatrogenic effects. (Am J Orthod Dentofacial Orthop 2002;122:15-26)
Dental Press Journal of Orthodontics, 2017
The aim of this multi-center retrospective study was to quantify the changes in alveolar bone height and thickness after using two different rapid palatal expansion (RPE) activation protocols, and to determine whether a more rapid rate of expansion is likely to cause more adverse effects, such as alveolar tipping, dental tipping, fenestration and dehiscence of anchorage teeth. Methods: The sample consisted of pre-and post-expansion records from 40 subjects (age 8-15 years) who underwent RPE using a 4-banded Hyrax appliance as part of their orthodontic treatment to correct posterior buccal crossbites. Subjects were divided into two groups according to their RPE activation rates (0.5 mm/day and 0.8 mm/day; n = 20 each group). Three-dimensional images for all included subjects were evaluated using Dolphin Imaging Software 11.7 Premium. Maxillary base width, buccal and palatal cortical bone thickness, alveolar bone height, and root angulation and length were measured. Significance of the changes in the measurements was evaluated using Wilcoxon signed-rank test and comparisons between groups were done using ANOVA. Significance was defined at p ≤ 0.05. Results: RPE activation rates of 0.5 mm per day (Group 1) and 0.8 mm per day (Group 2) caused significant increase in arch width following treatment; however, Group 2 showed greater increases compared to Group 1 (p < 0.01). Buccal alveolar height and width decreased significantly in both groups. Both treatment protocols resulted in significant increases in buccal-lingual angulation of teeth; however, Group 2 showed greater increases compared to Group 1 (p < 0.01). Conclusion: Both activation rates are associated with significant increase in intra-arch widths. However, 0.8 mm/day resulted in greater increases. The 0.8 mm/day activation rate also resulted in more increased dental tipping and decreased buccal alveolar bone thickness over 0.5 mm/day.
Al-Azhar Journal of Dental Science
Aim of the study: This study was conducted to evaluate clinically as well as radiographically using cone beam computed tomography (CBCT) the effect of rapid maxillary expansion on the buccal alveolar bone. Material and Methods: The current study was conducted on a total sample of thirty young adult orthodontic patients (20 girls and 10 boys) presented with transverse maxillary deficiency with an age ranged from 11-15 with mean of 13.3 ±1.1Y.The patients were distributed randomly in to three equal groups according to the position of center of the expansion screw in relation to the palatal surface of the maxillary first permanent molars. The CBCT were taken before the start of the orthodontic expansion (T1), three months after the last activation immediately after removal of the expander (T2). All patients did not have brackets or wires placed in the maxillary arch until after the T2 records were taken. Results: Paired t-test used to statistically test the mean differences between pre-expansion and pos-expansion measurements within each group. One-way analysis of variance (ANOVA) was used to compare among the different three groups. Tukey's post-hoc test was used for pair-wise comparisons among the groups when ANOVA test was significant. The significance level was set at P ≤ 0.05. Conclusions: RME may have a deleterious effect on buccal alveolar bone of the anchor teeth at least in the first stages of RME leading to its decrease in thickness and height, while the palatal bone thickness showed marked increase in all groups.
Buccal bone plate thickness after rapid maxillary expansion in mixed and permanent dentitions
Introduction: Rapid maxillary expansion (RME) might cause buccal displacement of anchor teeth. Dislocation of teeth outside their alveolar process can damage the periodontium; for this reason, maxillary expansion using deciduous teeth as anchorage in the mixed dentition might be suggested. The aim of this study was to compare changes of buccal bone plate thickness on the maxillary permanent first molars after RME in the mixed and permanent dentitions with different types of anchorage. Methods: Two groups of patients were evaluated with cone-beam computed tomography before and after RME. Group E (21 patients) underwent RME using deciduous teeth as anchorage; group 6 (16 patients) underwent RME using permanent teeth as anchorage. The Wilcoxon test was used to compare changes between the time points in the same groups, and the Mann-Whitney U test was used to compare differences between the groups. Results: In group E, generally, no statistically significant reduction was found in buccal bone plate thickness between the time points. In group 6, most measurements showed significant reductions in buccal bone plate thickness (P \0.05) between the time points, with a maximum decrease of 1.25 mm. Conclusions: RME in the mixed dentition with the appliance anchored to deciduous teeth did not reduce the buccal bone plate thickness of the maxillary permanent first molars, except for the mesial roots on both sides. RME in the permanent dentition caused a reduction of the buccal bone plate thickness of the maxillary permanent first molars when they were used as anchorage in the permanent dentition. (Am J Orthod Dentofacial Orthop 2019;155:198-206)
Factors affecting buccal bone changes of maxillary posterior teeth after rapid maxillary expansion
American Journal of Orthodontics and Dentofacial Orthopedics, 2007
The purpose of this study was to use cone-beam computed tomography (CBCT) images to determine the factors that might affect buccal bone changes of maxillary posterior teeth after rapid maxillary expansion (RME). Methods: Thirty consecutive patients (17 boys, 13 girls; mean age, 13.8 Ϯ 1.7 years) who required RME as part of their orthodontic treatment and had the pre-RME (T1) and post-RME (T2) CBCT images available were included in the study. The T1 and T2 measurements of interdental distance, interdental angle (IA), buccal bone thickness (BBT), and buccal marginal bone levels (BMBL) of the first premolar (P1), the second premolar (P2), and the first molar (M1) were compared with the Friedman and the Wilcoxon signed rank tests. To determine which variables were associated with the changes in IA, BBT, and BMBL, the Spearman rank correlation analysis was performed (␣ ϭ .05). Results and Conclusions: The results suggest that buccal crown tipping, and reduction of BBT and BMBL of the maxillary posterior teeth are the expected immediate effects of RME. There were no significant differences in dental expansion among P1, P2, and M1 (P Ͼ.05). P2 had clinically more buccal crown tipping (P ϭ .116) but statistically less reduction in BBT and BMBL (P Ͻ.0001 and P ϭ .001) than P1 and M1. Buccal bone changes and dental tipping on P2 were not affected by any other variables. Factors that showed significant correlation to buccal bone changes and dental tipping on P1 and M1 were age, appliance expansion, initial buccal bone thickness, and differential expansion (P Ͻ.05), but rate of expansion and retention time had no significant association (P Ͼ.05).
A cone-beam computed tomography evaluation of buccal bone thickness following maxillary expansion
Imaging Science in Dentistry, 2013
Purpose: This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Materials and Methods: Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p⁄0.05. Results: The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p⁄0.05) and between T1 and T3 (p⁄0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. Conclusion: RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone. (Imaging Sci Dent 2013; 43: 85-90
Meandros Medical and Dental Journal
Objective: The aim of this retrospective study was to evaluate the changes in alveolar bone height (ABH) and buccal bone thickness (BBT) of the maxillary teeth after surgically assisted rapid maxillary expansion (SARME) using cone-beam computed tomography (CBCT). Materials and Methods: A total of 9 patients with preoperative and postoperative CBCT records were included in this study. All patients underwent SARME and all of them received a modified acrylic bonded appliance as a maxillary expander. CBCT images were taken before SARME (T1) and after a consolidation period of 3 to 4 months (T2). ABH was determined by measuring the distance from the cemento-enamel junction to the alveolar crest on CBCT images. To evaluate BBT, two different points were identified along the root surface. Results: Alveolar bone loss (ABL) detected between T1 and T2 ABH measurements was statistically significant at all sites of each tooth. There was a statistically significant decrease in BBT at all measured points of each tooth between the T1 and T2 measurements. Conclusion: SARME with modified acrylic-bonded appliances causes ABL and a decrease in BBT, which increases the risk of tooth loss and gingival recession. Öz Amaç: Bu retrospektif çalışmanın amacı, cerrahi destekli hızlı üst çene genişletmesi (CDHÜG) sonrasında maksiller dişlerin alveolar kemik yüksekliğindeki ve bukkal kemik kalınlığındaki (BKK) değişiklikleri konik ışınlı bilgisayarlı tomografi (KIBT) kullanarak değerlendirmektir. Gereç ve Yöntemler: Operasyon öncesi ve operasyon sonrası KIBT kayıtları olan toplam 9 hasta çalışmaya dahil edildi. Bütün hastalara CDHÜG yapıldı ve tamamına üst çene genişletici olarak modifiye akrilik bonded apareyi uygulandı. KIBT görüntüleri, CDHÜG öncesi (T1) ve 3-4 aylık bir konsolidasyon süreci sonrası (T2) alındı. Alveolar kemik yüksekliği, KIBT görüntülerinde mine-sement hududu ile alveolar kret tepesi arasındaki mesafenin ölçülmesiyle tespit edildi. BKK'yi değerlendirmek için kök yüzeyi boyunca iki farklı nokta tespit edildi. Bulgular: T1 ve T2 alveolar kemik yüksekliği ölçümleri arasındaki farkla tespit edilen alveolar kemik kaybı (AKK) tüm dişlerin tüm yüzeylerinde istatistiksel olarak anlamlıydı. T1 ve T2 ölçümleri arasında her dişin her yüzeyinde BKK'de istatistiksel bir azalma vardı. Sonuç: Modifiye akrilik bonded apareylerle yapılan CDHÜG, diş kaybı ve dişeti çekilmesi riskini artıran AKK'ye ve BKK'de bir azalmaya neden olur.
The Alveolar Bone and Its Limits
Craniofacial 3D Imaging, 2019
The alveolar bone has always been a factor in the decision-making process of the orthodontists, and there has recently been an increasing interest in the dental profession for evaluating the effects of orthodontic treatment on the alveolar bone. Both medical computed tomography (CT) and cone-beam computed tomography (CBCT) have made such evaluations possible under circumstances where direct observation was not practical or feasible. CBCTs provide accurate imaging of the alveolar bone and other anatomical structures surrounding the teeth. Unlike on conventional 2D radiographs, both the facial and the lingual surfaces of the alveolar bone can be observed and measured on CBCT images. This yields much needed data for clinical in-vivo studies that intend to evaluate alveolar bone changes during and after orthodontic treatment. Several studies have been completed assessing bone changes both in the anterior and posterior segments, as well as in the presence or absence of expansion devices, and in the presence or absence of extractions. Along with these studies, methods have been developed for the purpose of measuring facial and lingual alveolar bone.
Clinical Oral Implants Research, 2013
To study bony and soft tissue changes at implants installed in alveolar bony ridges of different widths. In 6 Labrador dogs, the mandibular premolars and first molars were extracted, and a buccal defect was created in the left side at the third and fourth premolars by removing the buccal bone and the inter-radicular and interdental septa. Three months after tooth extraction, full-thickness mucoperiosteal flaps were elevated, and implants were installed, two at the reduced (test) and two at the regular-sized ridges (control). Narrow or wide abutments were affixed to the implants. After 3 months, biopsies were harvested, and ground sections prepared for histological evaluation. A higher vertical buccal bony crest resorption was found at the test (1.5 ± 0.7 mm and 1.0 ± 0.7 mm) compared to the control implants (1.0 ± 0.5 mm and 0.7 ± 0.4 mm), for both wide and narrow abutment sites. A higher horizontal alveolar resorption was identified at the control compared to the test implants. The difference was significant for narrow abutment sites. The peri-implant mucosa was more coronally positioned at the narrow abutment, in the test sites, while for the control sites, the mucosal adaptation was more coronal at the wide abutment sites. These differences, however, did not reach statistical significance. Implants installed in regular-sized alveolar ridges had a higher horizontal, but a lower vertical buccal bony crest resorption compared to implants installed in reduced alveolar ridges. Narrow abutments in reduced ridges as well as wide abutments in regular-sized ridges yielded less soft tissue recession compared to their counterparts.
Clinical Oral Implants Research, 2006
Objective: To determine whether the reduction of the alveolar ridge that occurs following tooth extraction and implant placement is influenced by the size of the hard tissue walls of the socket. Material and methods: Six beagle dogs were used. The third premolar and first molar in both quadrants of the mandible were used. Mucoperiostal flaps were elevated and the distal roots were removed. Implants were installed in the fresh extraction socket in one side of the mandible. The flaps were replaced to allow a semi-submerged healing. The procedure was repeated in the contra later side of the mandible after 2 months. The animals were sacrificed 1 month after the final implant installation. The mandibles were dissected, and each implant site was removed and processed for ground sectioning. Results: Marked hard tissue alterations occurred during healing following tooth extraction and implant installation in the socket. The marginal gap that was present between the implant and the walls of the socket at implantation disappeared as a result of bone fill and resorption of the bone crest. The modeling in the marginal defect region was accompanied by marked attenuation of the dimensions of both the delicate buccal and the wider lingual bone wall. Bone loss at molar sites was more pronounced than at the premolar locations. Conclusion: Implant placement failed to preserve the hard tissue dimension of the ridge following tooth extraction. The buccal as well as the lingual bone walls were resorbed. At the buccal aspect, this resulted in some marginal loss of osseointegration.