Alveolar Bone Thickness Changes Research Articles

Morphological changes in alveolar bone thickness and height after orthodontic proclination or labial movement combined with autogenous soft tissue grafting: a CBCT evaluation

BackgroundAutogenous soft tissue grafting is indicated in thin gingival biotypes before orthodontic proclination or labial movements to increase the keratinized gingiva and prevent gingival recession. However, its effect on local alveolar bone remodeling is unclear. The aim of this study was to investigate the effects of autogenous soft tissue grafting on local alveolar bone after orthodontic proclination or labial movements.MethodsSixteen patients with a thin scalloped gingival biotype, narrow keratinized gingiva, or thin cortical bone requiring orthodontic proclination or labial movement of teeth were included. Cone-beam computed tomography (CBCT) images were obtained before grafting and at least 6 months after surgery. Sixty mandibular teeth were included, and the vertical bone level and horizontal labial bone thickness were measured. The results were compared using paired t-tests or Wilcoxon signed-rank test.ResultsThe horizontal labial bone thickness increased, especially at 6 mm below the cementoenamel junction (CEJ) in the mandibular central and lateral incisors (P < 0.05). The total alveolar bone area of the canines, first premolars, and second premolars increased at 3, 6, and 9 mm below the CEJ, respectively, and the differences were statistically significant (P < 0.05). Additionally, vertical bone height increased minimally on the labial side, but the differences were not statistically significant (P > 0.05).ConclusionsNew bone regeneration was observed on the labial (pressure) side after autogenous soft tissue grafting, which may represent a mechanism to effectively prevent gingival recession and maintain periodontal health.IRB approvalAll the experimental procedures involving humans in this study were approved by the Medical Ethics Committee of Xiangya Stomatological Hospital, Central South University ( No. 20190048).

Labial and palatal alveolar bone changes during maxillary incisor retraction at the Universitas Sumatera Utara Dental Hospital

Background: The fundamental concept of tooth movement during orthodontic treatment is the occurrence of bone remodelling accompanied by tooth movement in equal proportions. The thickness of the alveolar bone, which supports incisors, is important in estimating the direction of tooth movement. Purpose: The study aimed to measure labial and palatal alveolar bone thickness changes after maxillary incisor retraction using lateral cephalograms. Methods: Cephalograms of 40 patients (18.58 ± 4.2 years) with skeletal Class I bimaxillary protrusion after maxillary first premolar extraction for insisivus retraction had been taken before (T0) and after (T1) orthodontic treatment. Changes in alveolar bone thickness were measured in linear and angular directions and then analysed with Spearman correlative analysis. Then the samples were separated into two groups based on the type of tooth movement (tipping and torque), and then the data were analysed using Wilcoxon analysis to see differences in the bone thickness (p&lt;0.05). Results: There was a significant difference in the apical palate (p&lt;0.05) and a relationship between retraction and alveolar bone thickness in the midroot area. In the angular direction, there was no significant difference and relationship; however, there was a significant difference in the labial crestal in the tipping group. In the torque group, the difference in bone thickness occurred in the crestal and apical palatal areas. Conclusion: The retraction and the type of tooth movement difference influence the alveolar bone thickness.

Alveolar bone changes around upper incisors in Class I non extraction patient after orthodontic treatment using cone beam computed tomography

Introduction: The position and movement of incisors play important role in orthodontics. Efficient tooth movement and stable position cannot be ensured without adequate alveolar bone support. The bone loss estimated by traditional radiograph is always less than real bone loss so CBCT is currently best to evaluate bone changes. The purpose of this study was to use CBCT to evaluate and compare changes in alveolar bone thickness and Vertical alveolar bone height around maxillary anterior teeth of Class I malocclusion patient after orthodontic treatment. Materials and Method: Forty patients with Class I occlusion between ages of 12 to 18 years were selected. The cone beam computed tomography (CBCT) and lateral cephalograms were taken before treatment (T0) and after treatment (T1). The lateral cephalograms were used to assess the change in tooth inclination whereas CBCT was used to assess the alveolar bone change. All the data were statistically analyzed using paired sample t-test and independent sample test. Result: Significant changes in alveolar bone thickness and vertical bone height were found on the palatal surface of the anterior teeth compared to that of labial surface with significant change in tooth inclination. Conclusion: Based on the results, we can conclude that the palatal alveolar bone loss and vertical bone loss was greater than that of the labial alveolar bone.

Anterior Labial Alveolar Bone Thickness after Orthodontic Retraction of Anterior Teeth

Introduction: Correction of skeletal Class II malocclusion generally requires extraction of the premolars, followed by retraction of the anterior teeth to reduce overjet. Morphometric evaluation of alveolar bone can be used to study the limitation of tooth movement to avoid adverse effects. The purpose of this study is to measure the changes in the bone thickness of the maxillary incisors in skeletal Class II malocclusion patients after retraction and determine the relationship between changes in bone thickness and the amount of retractions using lateral cephalometric radiographs. Materials and Methods: This study was designed to determine the cross-sectional changes in bone thickness in linear directions after retraction, and the relationship between changes in bone thickness and the amount of retraction. Bone thickness in the linear directions was measured using digital cephalometric radiographs. Results: The measurement results from tracing 43 lateral cephalometric before and after anterior retraction treatment showed a difference in alveolar bone thickness at the 9mm level from the CEJ in a linear direction on the anterior retraction of skeletal Class II malocclusion maxillary incisors (p &lt;0.05); however, there was no difference observed in alveolar bone thickness at levels 3 and 6 mm from CEJ in the linear direction and in the angular direction (p&gt; 0.05). Changes in alveolar bone thickness did not correlate with the amount of incisor retraction (p&gt; 0.05). Conclusion: The results showed the change in labial alveolar bone thickness was not significantly correlate with the amount of retraction.

Buccal alveolar bone changes following rapid maxillary expansion and fixed appliance therapy.

To assess factors that may be associated with buccal bone changes adjacent to maxillary first molars after rapid maxillary expansion (RME) and fixed appliance therapy. Pretreatment (T1) and posttreatment (T2) cone-beam computed tomography scans were obtained from 45 patients treated with RME and preadjusted edgewise appliances. Buccal alveolar bone thickness was measured adjacent to the mesiobuccal root of the maxillary first molar 4 mm, 6 mm, and 8 mm apical to the cementoenamel junction, and anatomic defects were recorded. Paired and unpaired t-tests were used to compare alveolar bone thickness at T1 and T2 and to determine whether teeth with posttreatment anatomic defects had thinner initial bone. Correlation analyses were used to examine relationships between buccal alveolar bone thickness changes and amount of expansion, initial bone thickness, age at T1, postexpansion retention time, and treatment time. There was a statistically significant reduction in buccal alveolar bone thickness from T1 to T2. Approximately half (47.7%) of the teeth developed anatomic defects from T1 to T2. These teeth had significantly thinner buccal bone at T1. Reduction in alveolar bone thickness was correlated with only one tested variable: initial bone thickness. RME and fixed-appliance therapy can be associated with significant reduction in buccal alveolar bone thickness and an increase in anatomic defects adjacent to the expander anchor teeth. Anchor teeth with greater initial buccal bone thickness have less reduction in buccal bone thickness and are less likely to develop posttreatment anatomic defects of buccal bone.

A study on the morphologic change of palatal alveolar bone shape after intrusion and retraction of maxillary incisors

The purpose of this study is to evaluate the changes in the palatal alveolar bone thickness and find the factors related to the resorption of the palatal alveolar bone caused by tooth movement after the maxillary incisors were retracted and intruded during orthodontic treatment. The study group comprised of 33 skeletal Class II malocclusion patients who underwent extraction for orthodontic treatment. Palatal alveolar bone thickness changes and resorption factors were identified and analyzed. The changes of maxillary central incisors and palatal alveolar bone thickness were measured, and the corresponding sample t test was performed using SPSS (IBM SPSS version 22). The amount of palatal alveolar bone resorption was measured and various parameters were analyzed to determine which factors affected it. Correlation analysis adopting the amount of palatal alveolar bone resorption as a dependent variable demonstrated that the SNB, mandibular plane angle, and the inclination of the maxillary central incisor were significantly correlated with before treatment. On the other hand, mandibular plane angle, angle of convexity, the inclination of the upper incisor, and the occlusal plane (UOP, POP) were significantly correlated with post-treatment. In addition, the variables related to palatal contour (PP to PAS, SN to PAS, palatal surface angle) and occlusal planes (UOP/POP) were significantly correlated with the difference in palatal bone resorption. During initial diagnosis, high angle class II with normal upper incisor inclination can be signs of high-risk factors. In addition, maintaining the occlusal plane during treatment helps to prevent palatal bone loss.

Buccal alveolar bone thickness changes after rapid maxillary expansion with tooth-borne and bone-borne expanders

Buccal alveolar bone thickness changes after rapid maxillary expansion with tooth-borne and bone-borne expanders

Changes in the alveolar bone thickness of maxillary incisors after orthodontic treatment involving extractions - A systematic review and meta-analysis.

BackgroundOrthodontic treatment involving en-masse retraction of incisors following premolar extractions, may induce morphological alterations of the alveolar bone surrounding the anterior teeth.ObjectiveTo assess changes in alveolar bone thickness around the incisors of extraction patients measured with CBCT.Material and MethodsAn electronic search was conducted in PubMed, Scopus, Embase and Cochrane Library, using search terms, with no limitation on publication date, up to April 2018. The articles selected for analysis included randomized controlled trials, case-control studies and cohort studies of patients treated with fixed appliances and premolar extractions, which had measured alveolar bone thickness with CBCT before and after treatment. Changes in bone thickness were calculated and the heterogeneity of the studies was assessed using the I2 and Cochran’s Q tests.ResultsOf the 136 articles identified in the initial search, 19 were related to the review subject. After removing a further 14 that did not meet the inclusion criteria, 5 articles were selected for analysis. All five were retrospective studies of medium quality. The main changes in alveolar bone thickness were found in the labial cervical third of the central incisor, presenting increases of 0.4-0.64 mm. On the palatal side the results varied considerably.ConclusionsA significant increase in alveolar bone thickness occurs in the labial cervical third of the central incisor. These changes may be influenced by incisor position and inclination, the orthodontic technique and mechanics employed, the timing of the final CBCT scan and the bone remodeling capacity during en-masse retraction. Key words:Cone-beam computed tomography, alveolar bone, orthodontics.

Effect of orthodontic treatment on alveolar bone thickness in adults: a systematic review.

ABSTRACTObjectives: This review aimed at evaluating changes in alveolar bone thickness after completion of orthodontic treatment. Methods: Only prospective clinical studies that reported bone thickness in adult patients undergoing non-surgical orthodontic treatment were considered eligible. MEDLINE, EMBASE and LILACS databases were searched for articles published up to July 2018. Results: A total of 12 studies met the selected criteria. Most of the studies showed that orthodontic treatment produces a reduction in bone thickness of incisors, mainly at the palatal side. Conclusion: On patients undergoing different orthodontic treatment techniques, there was a significant bone thickness reduction, mainly on the palatal side. Clinical relevance: These findings are relevant and have to be considered in diagnosis and planning of tooth movement, in order to prevent the occurrence of dehiscence and fenestration in alveolar bone.

Proclination-induced changes in the labial cortical bone thickness of lower incisors.

We sought to objectivize the overall alveolar bone thickness changes in lower incisors after orthodontic intervention. The effect of orthodontic treatment on the cortical bone, specifically the clinical implications of proclination-induced change, have long been a matter of dispute. Cone-beam computed tomographs of 58 patients were obtained before and after treatment and labial cortical bone thickness and overall alveolus width were measured in sagittal sections in the distance of 3, 6, 9 and 12 mm apically from the cemento-enamel junction. A statistically significant decrease of the cortical bone thickness in all four incisors was found at the levels 3, 6 and 9 mm (p 0.05). Moreover, no correlation was found between bone thickness change and extent of the incisor movement. Our results point to a marked cortical bone loss after proclination of lower incisors, furnishing a sound basis for caution in treatment planning due to the considerable risk of alveolar defect development, especially in patients with low initial bone thickness (Tab. 6, Fig. 2, Ref. 25).

Changes in alveolar bone support induced by the Herbst appliance: a tomographic evaluation.

ABSTRACTObjective: This study evaluated alveolar bone loss around mandibular incisors, induced by the Herbst appliance. Methods: The sample consisted of 23 patients (11 men, 12 women; mean age of 15.76 ± 1.75 years), Class II, Division 1 malocclusion, treated with the Herbst appliance. CBCT scans were obtained before treatment (T0) and after Herbst treatment (T1). Vertical alveolar bone level and alveolar bone thickness of mandibular incisors were assessed. Buccal (B), lingual (L) and total (T) bone thicknesses were assessed at crestal (1), midroot (2) and apical (3) levels of mandibular incisors. Student's t-test and Wilcoxon t-test were used to compare dependent samples in parametric and nonparametric cases, respectively. Pearson's and Spearman's rank correlation analyses were performed to determine the relationship of changes in alveolar bone thickness. Results were considered at a significance level of 5%. Results: Mandibular incisors showed no statistical significance for vertical alveolar bone level. Alveolar bone thickness of mandibular incisors significantly reduced after treatment at B1, B2, B3, T1 and significantly increased at L2. The magnitude of the statistically significant changes was less than 0.2 mm. The changes in alveolar bone thickness showed no statistical significance with incisor inclination degree. Conclusions: CBCT scans showed an association between the Herbst appliance and alveolar bone loss on the buccal surface of mandibular incisors; however, without clinical significance.

Changes of anterior maxillary alveolar bone thickness following incisor proclination and extrusion.

To investigate changes in maxillary alveolar bone thickness after maxillary incisor proclination and extrusion during anterior crossbite correction in a group of growing patients with Class III malocclusion. Maxillary incisors of 15 growing patients with anterior crossbite were proclined and extruded with 0.016″ beta-titanium advancing loops and Class III elastics. Lateral cephalograms were recorded before advancement (T0) and 4 months after a normal overjet and overbite were achieved (T1). Changes in alveolar bone thickness surrounding the maxillary incisors at the crestal (S1), midroot (S2), and apical (S3) levels were measured using cone-beam computed tomography (CBCT). Paired t-tests were used to determine the significance of the changes. A Spearman rank correlation analysis was performed to explore the relationship between thickness changes and the rate and amount of incisor movements. Although statistically significant decreases were observed in palatal and total bone thickness at the S2 and S3 level (P < .05), the amounts of these changes were clinically insignificant, ranging from 0.34 to 0.59 mm. Changes in labial bone thickness at all levels were not significant. Changes in palatal bone thickness at S3 were negatively correlated with changes in incisor inclination. (r = -0.71; P < .05). In a group of growing patients with Class III malocclusion undergoing anterior crossbite correction, controlled tipping mechanics accompanied by extrusive force may produce successful tooth movement with minimal iatrogenic detriment to the alveolar bone.

Assessment of Corticotomy Facilitated Tooth Movement and Changes in Alveolar Bone Thickness - A CT Scan Study.

Corticotomy is an effective method of accelerating the orthodontic treatment. The aim of this study was to compare the treatment time for the extraction space closure, between corticotomy assisted and conventional orthodontic tooth movement and to check the alveolar bone thickness before and after corticotomy procedure in the corticotomy group. Cross-sectional clinical study. Twenty patients (age>15 y) requiring orthodontic treatment with upper anterior retraction in the extraction space of 1(st) premolar were selected and were randomised into control and corticotomy group each group consisted of 10 subjects. Pre retraction, corticotomy was performed in the maxillary anterior segment. The pre and post retraction CT scans were recorded and the thickness of the alveolar plates were measured at crestal level (S1), mid root level (S2) and apical level (S3) PreTreatment (T1). The same measurements were repeated after incisor retraction was completed PostTreatment (T2). Student's t-test, Pearson correlation coefficient. There was a significant difference in retraction time (days) between control and corticotomy groups (p<0.001). Also, there were significant difference in total alveolar bone thickness at the crest region for all the four incisor teeth (p<0.05). A significant difference was observed in total alveolar bone thickness at the S2 and S3 level for 11, 21 and 11, 12 and 22 (p<0.05) respectively. Alveolar corticotomies not only accelerates the orthodontic treatment but, also provides the advantage of increased alveolar width to support the teeth and overlying structures.

Comparison of the changes of alveolar bone thickness in maxillary incisor area in extraction and non-extraction cases: computerized tomography evaluation

To compare, through computed tomography, alveolar bone thickness changes at the maxillary incisors area during orthodontic treatment with and without tooth extraction. Twelve patients were evaluated. They were divided into 2 groups: G1--6 patients treated with extraction of right and left maxillary first premolars, with mean initial age of 15.83 years and mean treatment length of 2.53 years; G2--6 patients treated without extraction, with mean initial age of 18.26 years and mean treatment length of 2.39 years. Computed tomographies, lateral cephalograms and periapical radiographs were used at the beginning of the treatment (T1) and 18 months after the treatment had started (T2). Extraction space closure occurred in the extraction cases. Intragroup and intergroup comparisons were performed by dependent and independent t test, respectively. In G1, the central incisor was retracted and uprighted, while in G2 this tooth showed vestibularization. Additionally, G1 presented a higher increase of labial alveolar bone thickness at the cervical third in comparison with G2. The incidence of root resorption did not present significant differences between groups. There were no changes in alveolar bone thickness when extraction and nonextraction cases were compared, except for the labial alveolar bone thickness at the cervical third of maxillary incisors.

Changes in alveolar bone thickness due to retraction of anterior teeth during orthodontic treatment: A cephalometric and computed tomography comparative study

Evaluate the changes in alveolar bone as a result of maxillary and mandibular incisor retraction in patients with bimaxillary protrusion by means of using lateral cephalograms and computed tomography (CT) scans and to investigate any occurrence of bony defects like dehiscence and fenestration. Ten patients (age 15 ± 3 years) with bimaxillary protrusion treated by extraction of four first premolars were investigated by lateral cephalograms and CT scans during pre-treatment (T1) and after 3 months of completion of incisor retraction (T2). The labial and lingual cortex of all the incisors were assessed on the CT scan with measurements taken at site adjacent to widest point of the labiolingual root in three slices separated by 3 mm at crest level (S1), mid root level (S2), and apical level (S3). In the mandibular arch, after lingual movement of the incisors, the bone labial to the anterior teeth decreased in thickness at the coronal level of the left lateral and left central incisors. Left lateral incisor showed significant changes in all the three levels. In the maxilla the change in the labial bone thickness was not statistically significant. Lingual bone of all the incisors showed significant changes in S1 level and S3 levels. Few patients demonstrated bone dehiscence that was not visible macroscopically or cephalometrically. When incisors are retracted, the risk of adverse effect is present. This must be carefully monitored to avoid negative iatrogenic effects. This study needs follow up after 6 months or 1 year after completion of the orthodontic treatment to assess the long-term consequences.

Factors related to alveolar bone thickness during upper incisor retraction

To investigate the factors related to changes in alveolar bone thickness during upper incisor retraction. The subjects consisted of 23 ongoing orthodontic patients (mean age 20.4 ± 2.7 years) whose upper incisors were bound for retraction. Changes in alveolar bone thickness in the retracted area were assessed using preretraction (T0) and postretraction (T1) cone-beam computed tomography images. Labial bone thickness (LBT), palatal bone thickness (PBT), and total bone thickness (TBT) were assessed at the crestal, midroot, and apical levels of the retracted incisors. Paired t-tests were used to compare T0 and T1 bone thickness measurements. Spearman's rank correlation analysis was performed to determine the relationship of changes in alveolar bone thickness with the rate of tooth movement, change in inclination, initial alveolar bone thickness, and the extent of intrusion. As the upper incisors were retracted, the LBT at the crestal level and TBT at the apical level significantly increased (P < .005). Changes in alveolar bone thickness were significantly associated with the rate of tooth movement, change in inclination, and extent of intrusion (P < .05) but not initial alveolar bone thickness (P > .05). Rate of tooth movement, change in inclination, and extent of intrusion are significant factors that may influence alveolar bone thickness during upper incisor retraction. These factors must be carefully monitored to avoid the undesirable thickening of alveolar bone.