Bone-borne Expansion Research Articles

Three-dimensional analysis of miniscrew position changes during bone-borne expansion in young and late adolescent patients

IntroductionMaxillary expansion in patients at the end of their growth relies on the possibility to use miniscrew supported expanders to apply expansion forces directly to the midpalatal suture. Although miniscrews provide a stable anchorage unit, several studies have reported that they do not remain in exactly the same position during treatment. The aim of the present study was to analyze miniscrew position changes after the expansion using bone-borne appliances in late adolescent patients.MethodsNineteen patients (13 females, 6 males), with a mean age of 17.81 (SD = 4.66), were treated with a Bone-Borne Expander Device. The appliance was designed with 4 miniscrews: 2 in the anterior palatal area, at the third rugae level; 2 in the posterior area. A CBCT and an intraoral scan were obtained before treatment (T0), and then, a second CBCT was obtained after the expansion (T1). Data on peri-suture bone thickness were collected at T0, then the CBCTs were superimposed, and changes between mini-screws position on T0 and T1 were evaluated, both by linear and angular displacements.ResultsSignificant longitudinal differences were found in the distance of the head and the tip of miniscrews measured at the occlusal plane, as well as angular changes. Correlations between displacement measurements and peri-suture bone thickness and height measurements were found as well.ConclusionsWhile acting as bone anchor units, miniscrews do not remain in the same position during bone-borne expansion. The amount of displacement was related to peri-sutural total bone height and cortical thickness, especially in the anterior area of the naso-frontal maxillary complex.

Orthodontic treatment for posterior crossbites.

Orthodontic treatment for posterior crossbites.

Comparison of the surgically assisted orthodontic rehabilitation techniques of patients with transversal maxillary defficiency

The article considers comparison of the outcomes of surgically assisted rapid palatal expansion with the use of tooth-borne and bone-borne expansion appliances in patients with transversal maxillary deficiency. 76 computed tomography scans of 38 patients (24 with bone-borne anchorage, 14 with tooth-borne ones) were studied. Examination of the expansion was performed before the treatment onset and after the activation of the screw of the distraction apparatus. Expansion was evaluated in the areas of canines, premolars and first molars. The maximal amount of the vestibular tooth crown inclination was revealed in premolars with tooth-borne appliances. The use of bone-borne appliances allows to achieve the greatest effect of tooth body shift in a vestibular direction.

Bone-Borne Maxillary Expansion and Traditional Rapid Maxillary Expansion: A Systematic Review and Meta-Analysis

Introduction: The aim of this study was to perform a systematic review and meta-analysis to compare the effect of bone-borne expansion (BBE) and tooth-borne expansion (TBE) in patients with maxillary constriction. Methods: Electronic databases, including MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, were searched up to February 2019. Eligible clinical trials and cohort studies that studied the effects of bone-borne and tooth-borne expansion appliances on patients with constricted maxilla were selected. The study selection, data extraction, and risk of bias assessment were independently performed by two authors. Then, the random-effects meta-analysis and post-hoc heterogeneity tests were performed. Results: In the end, four studies were included in the present meta-analysis (i.e., a randomized clinical trial, two prospective controlled clinical trials, and a cohort study) that collected data from 117 patients. The mean differences between TBE and BBE were 0.38 mm and -0.28 mm for premolar and molar apices, 0.67 mm and 1.18 mm for premolar and molar crowns, 0.19 mm and 0.17 mm for alveolar bone in premolar and molar areas, and -0.61 mm and 0.02 mm for nasal and maxillary bones, respectively. Moreover, the differences between TBE and BBE for dental angulation were 3.84◦ and 1.52◦ for left and right molars, as well as 4.85◦ and 3.46◦ for left and right premolars, respectively. Conclusion: The BBE appliances do not have any advantages over tooth-borne devices with regard to the amount of skeletal or dental expansion; however, it seems to produce less tipping in posterior teeth.

Retrospective CBCT analysis of airway volume changes after bone-borne vs tooth-borne rapid maxillary expansion.

To compare changes in upper airway volume after maxillary expansion with bone- and tooth-borne appliances in adolescents and to evaluate the dentoskeletal effects of each expansion modality. This retrospective study included 36 adolescents who had bilateral maxillary crossbite and received bone-borne maxillary expansion (average age: 14.7 years) or tooth-borne maxillary expansion (average age: 14.4 years). Subjects had two cone beam computed tomography images acquired, one before expansion (T1) and a second after a 3-month retention period (T2). Images were oriented, and three-dimensional airway volume and dentoskeletal expansion were measured. Analysis of variance was used to test for differences between the two expansion methods for pretreatment, posttreatment, and prepost changes. Paired t-tests were used to test for significance of prepost changes within each method. Both groups showed significant increase only in nasal cavity and nasopharynx volume (P < .05), but not oropharynx and maxillary sinus volumes. Intermolar and maxillary width increased significantly in both groups (P < .05); however, the buccal inclination of maxillary molars increased significantly only in the tooth-borne group (P < .05). There was no significant difference between tooth- and bone-borne expansion groups, except for the significantly larger increase in buccal inclination of the maxillary right first molar after tooth-borne expansion. In adolescents, both tooth- and bone-borne RME resulted in an increase in nasal cavity and nasopharynx volume, as well as expansion in maxillary intermolar and skeletal widths. However, only tooth-borne expanders caused significant buccal tipping of maxillary molars.

Evaluation of miniscrew-supported rapid maxillary expansion in adolescents: A prospective randomized clinical trial.

To evaluate and compare the dental and skeletal changes with conventional and miniscrew-supported maxillary expansion appliances in adolescents. Forty patients were divided into two groups, with one group receiving a tooth-borne expander and the other group receiving an expander supported by four miniscrews (bone-borne). Multiplanar coronal and axial slices obtained from cone-beam computed tomography images were used to measure the changes in transverse skeletal widths, buccal bone thickness, tooth inclination, and root length. Paired t-tests and independent-sample t-tests were used to compare the two expansion methods. Bone-borne expansion increased the maxillary suture opening more than 2.5 times than tooth-borne expansion both anteriorly and posteriorly. Between the maxillary first premolars, sutural expansion accounted for 28% and 70% of the total transverse width increase in the tooth-borne and bone-borne expander groups, respectively. Similarly, 26% and 68% of the total expansion was of skeletal nature in the tooth-borne and bone-borne expander groups between the maxillary first molars. The pattern of expansion was variable, with most of the patients in both groups demonstrating a triangular-shaped sutural opening that was wider anteriorly. Subjects in the conventional group experienced significantly more buccal bone reduction and greater buccal inclination of the teeth. No significant differences were observed for root length measurements between the two groups. Use of bone-borne expansion in the adolescent population increased the extent of skeletal changes in the range of 1.5 to 2.8 times that of tooth-borne expansion and did not result in any dental side effects.

Is there an optimal initial amount of activation for midpalatal suture expansion?

Accelerated bone-borne expansion protocols on sutural separation and sutural bone formation were evaluated via histomorphometry and immunohistochemistry to determine the optimal initial activation without disruption of bone formation. Sixteen New Zealand white rabbits were randomly divided into fourgroups. Modified Hyrax expanders were placed across the midsagittal sutures and secured with miniscrew implants with the following activations: group1 (control), 0.5 mm expansion/day for 12days; group2, 1 mm instant expansion followed by 0.5 mm expansion/day for 10days; group3, 2.5 mm instant expansion followed by 0.5 mm expansion/day for 7days; and group4, 4 mm instant expansion followed by 0.5 mm expansion/day for 4days. After 6weeks, sutural expansion and new bone formation were evaluated histomorphometrically. Statistical analysis was performed using Kruskal-Wallis/Mann-WhitneyU tests and Spearman's rho correlation (p < 0.05). The smallest median sutural separation was observed in group1 (3.05 mm) and the greatest in group4 (4.57 mm). The lowest and highest amount of bone formation were observed in group4 (55.82%) and in group3 (66.93%), respectively. Immunohistochemical analysis revealed significant differences in median levels of alkaline phosphatase and osteopontin expression between all experimental groups. The highest level of these proteins was attained in group3, followed by groups2, 1, and 4, respectively. Sutural appositional bone formation corresponded with the amount of initial expansion to apoint. When initial expansion was increased to 4 mm, sutural bone remodeling was disturbed and new bone formation was decreased. The most effective sutural expansion was achieved with 2.5 mm initial activation followed by 0.5 mm expansion/day for 7days.

Effects of monocortical and bicortical mini-implant anchorage on bone-borne palatal expansion using finite element analysis.

Bone-borne palatal expansion relies on mini-implant stability for successful orthopedic expansion. The large magnitude of applied force experienced by mini-implants during bone-borne expansion may lead to high failure rates. Use of bicortical mini-implant anchorage rather than monocortical anchorage may improve mini-implant stability. The aims of this study were to analyze and compare the effects of bicortical and monocortical anchorages on stress distribution and displacement during bone-borne palatal expansion using finite element analysis. Two skull models were constructed to represent expansion before and after midpalatal suture opening. Three clinical situations with varying mini-implant insertion depths were studied in each skull model: monocortical, 1-mm bicortical, and 2.5-mm bicortical. Finite element analysis simulations were performed for each clinical situation in both skull models. Von Mises stress distribution and transverse displacement were evaluated for all models. Peri-implant stress was greater in the monocortical anchorage model compared with both bicortical anchorage models. In addition, transverse displacement was greater and more parallel in the coronal plane for both bicortical models compared with the monocortical model. Minimal differences were observed between the 1-mm and the 2.5-mm bicortical models for both peri-implant stress and transverse displacement. Bicortical mini-implant anchorage results in improved mini-implant stability, decreased mini-implant deformation and fracture, more parallel expansion in the coronal plane, and increased expansion during bone-borne palatal expansion. However, the depth of bicortical mini-implant anchorage was not significant.

Stresses and Strains Analysis Using Different Palatal Expander Appliances in Upper Jaw and Midpalatal Suture.

Rapid maxillary expansion (RME) is the technique of increasing the transverse dimension of the upper jaw using lateral forces applied by palatal expander. Usually, this palatal appliance is anchored on posterior teeth. The purposes of this computer simulation study were to analyze the stress and strain distribution generated in the maxilla, mainly in midpalatal suture (MPS), during RME by tooth-borne and bone-borne expanders and to study the correlation between mechanical strain and Wolff's Law. The analysis was performed with finite element models developed based on Cone Beam computed tomography (CT). To simulate the expansion load, displacements were applied concerning one (0.125 mm) and three (0.375 mm) activations in the medial sides of the tooth-borne expander, and one activation (0.125 mm) for miniscrews (MSIs) in transverse and lateral direction. It was observed that to obtain approximately the same spacing in the MPS activating once the expander with bone support, three activations for the tooth-borne were necessary. However, the strain level caused by bone-borne expansion, when applying a single activation, reached 900 and 5000 μɛ, with peaks up to 20000 μɛ, in a region very close to the MSIs. Comparing the results, bone-borne appliance anchorage in the palatine bone is more effective than tooth-borne expander. Nevertheless, the stresses and strains increased significantly in the entire jaw when the bone-borne expander is used.

Transverse, vertical, and anteroposterior changes from bone-anchored maxillary expansion vs traditional rapid maxillary expansion: A randomized clinical trial

Introduction The purpose of this study was to compare the transverse, vertical, and anteroposterior skeletal and dental changes in adolescents receiving expansion treatment with tooth-borne and bone-anchored expanders. Immediate and long-term changes were measured on cone-beam computed tomography (CBCT) images. Methods Sixty-two patients needing maxillary expansion were randomly allocated to 1 of 3 groups: traditional hyrax tooth-borne expander, bone-anchored expander, and control. CBCT images were taken at baseline, immediately after expansion, after removal of the appliance (6 months), and just before fixed bonding (12 months). Repeated measures multivariate analysis of variance (MANOVA) was applied to the distances and angles measured to determine the statistical significance in the immediate and long time periods. Bonferroni post-hoc tests were used to identify significant differences between the treatment groups. Results Immediately after expansion, the subjects in the tooth-borne expander group had significantly more expansion at the crown level of the maxillary first premolars (P = 0.003). Dental crown expansion was greater than apical expansion and skeletal expansion with both appliances. The control group showed little change (growth) over the 6-month interval. At 12 months, no group had a statistically significant difference in angle changes, suggesting symmetric expansion. Both treatment groups had significant long-term expansion at the level of the maxillary first molar crown and root apex, first premolar crown and root, alveolus in the first molar and premolar regions, and central incisor root. Tooth-borne expansion resulted in significantly more long-term expansion at the maxillary premolar crown and root than did bone-borne expansion. Conclusions Both expanders showed similar results. The greatest changes were seen in the transverse dimension; changes in the vertical and anteroposterior dimensions were negligible. Dental expansion was also greater than skeletal expansion. The purpose of this study was to compare the transverse, vertical, and anteroposterior skeletal and dental changes in adolescents receiving expansion treatment with tooth-borne and bone-anchored expanders. Immediate and long-term changes were measured on cone-beam computed tomography (CBCT) images. Sixty-two patients needing maxillary expansion were randomly allocated to 1 of 3 groups: traditional hyrax tooth-borne expander, bone-anchored expander, and control. CBCT images were taken at baseline, immediately after expansion, after removal of the appliance (6 months), and just before fixed bonding (12 months). Repeated measures multivariate analysis of variance (MANOVA) was applied to the distances and angles measured to determine the statistical significance in the immediate and long time periods. Bonferroni post-hoc tests were used to identify significant differences between the treatment groups. Immediately after expansion, the subjects in the tooth-borne expander group had significantly more expansion at the crown level of the maxillary first premolars (P = 0.003). Dental crown expansion was greater than apical expansion and skeletal expansion with both appliances. The control group showed little change (growth) over the 6-month interval. At 12 months, no group had a statistically significant difference in angle changes, suggesting symmetric expansion. Both treatment groups had significant long-term expansion at the level of the maxillary first molar crown and root apex, first premolar crown and root, alveolus in the first molar and premolar regions, and central incisor root. Tooth-borne expansion resulted in significantly more long-term expansion at the maxillary premolar crown and root than did bone-borne expansion. Both expanders showed similar results. The greatest changes were seen in the transverse dimension; changes in the vertical and anteroposterior dimensions were negligible. Dental expansion was also greater than skeletal expansion.

Minimally invasive rapid palatal expansion with an implant-supported hyrax screw / Minimalinvasive forcierte Gaumennahterweiterung mit einer implantatgetragenen Hyraxschraube

Rapid palatal expansion is indicated in the orthopedic treatment of transverse maxillary deficiency for correction of severe crossbite. The fixation of the appliance at the tooth crowns leads to more tipping connected with resorptions at the buccal cortical bone, fenestrations and gingival retraction. The aim of the present study was focused on the improvement of bodily movement and optimization of the surgical osteotomy (Glassman's technique) in adult patients with application of the Dresden Distractor (DD). In 18 patients, the new method with a special mechanism of adaptation involving minimized surgical intervention and direct fixation of the hyrax screw by one implant and one bone screw was tested. The implants were loaded directly by activation of the hyrax screw two times per day. CT scans were taken before and 6 months after insertion of the DD. In the horizontal and vertical planes there was a V-shaped opening of the suture in anterior and cranial direction, corroborating previous studies. Dental arch also showed this V-shape, indicating tooth protection. DD is a suitable minimally invasive tooth-independent bone-borne expansion method, protecting teeth and causing skeletal as well as dental effect with tipping reduced by 10 degrees.

Prostaglandin E2 levels in gingival crevicular fluid during tooth- and bone-borne expansion

The purpose of this study was to compare Prostaglandin E(2) (PGE(2)) levels in gingival crevicular fluid (GCF) of young adults with maxillary constriction during tooth- and bone-borne expansion. Thirty patients, 15 females and 15 males, with a mean age of 17.3 +/- 2.8 years were divided into three groups. Group I consisted of 10 patients, five females and five males, treated by transpalatal distraction (TPD) as a bone-borne device, group II 10 patients, five females and five males, with a Hyrax appliance as a tooth-borne device, and a control group of 10 patients, five females and five males, without any expansion appliances. GCF samples were collected with filter paper strips at six observation periods in order to evaluate the effect of heavy orthopaedic forces in both groups. In group II, the samples were additionally collected at two pre-treatment time points in order to evaluate the effect of the forces generated by the separators. An automated enzyme immunoassay was used to measure PGE(2) in the GCF. The differences within the groups were evaluated with a pairwise t-test and the differences between the groups were determined by the Mann-Whitney U-test. The mean PGE(2) level was significantly elevated on day 4 after placement of the separators in group II (P < 0.05). The PGE(2) values in group II were significantly different to those in group I and the controls at all observation periods. Lower PGE(2) levels were observed in group I compared with group II and the controls. Expansion using the TPD method could potentially enhance the prognosis of the teeth by inducing more skeletal dental changes when compared with the Hyrax appliance.

Expansion maxillaire rapide par appui osseux avec une vis Hyrax implanto-portée : le Dresden Distractor (DD) ou Disjoncteur de Dresde

Rapid palatal expansion is indicated in the orthopedic treatment of transverse maxillary deficiency for correction of severe crossbite. The fixation of the appliance at the teeth crowns leads to more tipping at the two halves of the maxilla than bodily transverse movement. Additional resorptions at the buccal cortical bone with fenestrations and gingival retraction were observed. The aim of the present study was focused on the improvement of bodily movement and optimization of the surgical osteotomy (Glassman's technique) in adult patients with application of the Dresden Distractor (DD). In 15 patients, the new method involving minimized surgical intervention and direct fixation of the hyrax screw by one implant and one bone screw was tested. The implants were loaded directly by activation of the screw two times per day. CT scans were taken before and six month after insertion of the DD. In the horizontal and the vertical planes there was a V-shaped opening of the suture in anterior, respective cranial direction, corroborating previous studies. Dental arch showed this V-shape as well, indicating tooth protection. If forces are transferred via teeth the progressive increase of skeletal resistance in anterior to posterior direction lead to dental tipping. DD is a suitable minimal invasive tooth-independent bone-borne expansion method, protecting teeth and causing skeletal as well as dental effect with 10 degree less tipping and as a precondition for stable post surgical occlusion.

Three-dimensional evaluation of surgically assisted implant bone-borne rapid maxillary expansion: A pilot study

The purpose of this study was to evaluate 3-dimensional changes in dental, alveolar, and skeletal structures caused by a bone-borne implant-supported rapid maxillary expansion device (Dresden distractor). Axial computed tomography scans of 10 patients (mean age, 25.3 years) treated with the Dresden distractor were examined. Scans were taken immediately before and 9 months after expansion. Distances in all 3 dimensions were calculated for 38 skeletal, alveolar, and dental landmarks with respect to the reference point ELSA (point equidistant to both foramina spinosa). In the transverse dimension, a V-shaped opening of the suture was shown; the greatest amount of opening was anteriorly directed, with convergence of the suture opening in the posterior aspect of the palate. The expansion of the maxillary dental arch showed a V pattern similar to the opening of the suture. In the frontal view, expansion caused a wedge-shaped opening with its base at the central incisors and the estimated center of rotation next to the frontonasal suture. The alveolar processes tipped buccally (9.9 degrees to 13.3 degrees) as did the molars (2.5 degrees to 3.5 degrees) and the premolars (3.0 degrees to 3.9 degrees). Less tipping of teeth compared with skeletal tipping (about 6 degrees to 9 degrees less) is related to the torque effect of the fixed appliance. The Dresden distractor is a minimally invasive bone-borne expansion appliance that protects teeth by inducing more skeletal than dental changes. This might be a precondition for stable postsurgical occlusion.

Transversal palatal expansion using a palatal distractor.

The method and first results of transversal expansion with a palatal distractor in adolescents and adults with transverse maxillary deficiencies are presented. In ten patients with a mean age of 25.8 years, a newly developed distractor was applied for bone-borne expansion of the two halves of the maxilla following osteotomy of the lateral walls of the maxillary sinuses and the midpalatal suture. After a 3-week distraction period, mean changes of 8.8 mm in intercanine distance (ICD), 8.6 mm in anterior dental arch width (ADA), and 8.3 mm in posterior dental arch width (PDA) were registered. 6 months after the subsequent multibracket appliance therapy, these values were found to be largely constant. Because of the short treatment period, the absence of relapses, and the handling simplicity for the patient, this method is recommended for clinical application.