Maxillary Expansion Appliance Research Articles

Early Orthodontic Intervention in Cleft Lip-Palate and Noncleft Children with Developing Class III Malocclusion: A Clinical Study.

Orthopedic correction of skeletal class III malocclusion in a growing patient is crucial as it can circumvent future surgical procedures. The aim of the study is to evaluate the dental and skeletal effects of early orthodontic intervention of developing class III malocclusion. A final sample of 38 children in the age-group of 6-14 years having skeletal class III malocclusion was selected. Subjects were divided into two groups; group I-included 18 children (male-10, female-8) with surgically repaired cleft lip and palate and group II-20 children (male-14, female-6) without any cleft lip and palate. Cemented rapid maxillary expansion (RME) appliances with 11 mm hyrax screws were used in all patients. Elastic traction forces were applied to the reverse-pull headgear worn by the patients. Both pre- and posttreatment records along with lateral cephalograms were taken. The pre- and posttreatment mean and standard deviation measurements of the angular and linear observations were statistically analyzed with Statistical Package for the Social Sciences (SPSS) software (version 13) and were correlated through independent t-test and paired t-test. Following headgear therapy, improvement was greater in the cleft group than noncleft group with greater advancement of maxilla along with clockwise rotation of mandible in clefts. Protraction mechanics with expansion can be employed successfully in repaired cleft lip and palate and noncleft prepubertal children having developing class III malocclusion, showing concave profile, and retrusive maxilla. Accurate diagnosis and understanding of the individual growth pattern are crucial in the early interception of a class III malocclusion to achieve a more favorable facial profile. Sahoo SS, Dash JK, Sahoo PK, et al. Early Orthodontic Intervention in Cleft Lip-Palate and Noncleft Children with Developing Class III Malocclusion: A Clinical Study. Int J Clin Pediatr Dent 2023;16(5):716-723.

3D occlusal changes of upper first molars after rapid maxillary expansion on permanent versus deciduous teeth: a retrospective multicenter CBCT study

BackgroundThe purpose of this study was to compare the three-dimensional dental changes for the maxillary first molars and the overall skeletal effects achieved after expansion between the rapid maxillary expansion (RME) appliance attached to two different anchor units, the maxillary deciduous molars and the maxillary permanent first molars.MethodsPatients were retrospectively selected according to the anchorage unit used for RME: deciduous upper second molars (RME-E group; 10 M, 10 F; mean age 8.4 ± 1.1 years) and first upper permanent molars (RME-6 group; 10 M, 10 F; mean age 12.6 ± 1.8 years). CBCT scans were obtained before treatment start (T1) and after retention and removal of the expander (T2). Images were analyzed using a new three-dimensional intra-hemi-maxillary reference system. 3D landmarks were marked to calculate all changes on maxillary first permanent molars; mesio-distal and buccal-lingual inclination and rotation, as well as intermolar and interforaminal distances were calculated. The Wilcoxon test was used to compare within-group changes, whereas the Mann–Whitney test was used to compare between-group differences, with the significance level set at 0.05.ResultsIn the RME-E group, significant distorotation and lingual inclination of the first permanent molars at T2 were observed (p < 0.01); in the RME-6 group, only the buccolingual inclination of the crossbite side after RME was resulted statistically significant (p < 0.01). In both groups, intermolar and interforaminal values increased significantly (p < 0.01). Intergroup analysis showed a significantly higher distorotation and reduced buccal inclination of maxillary first permanent molars in the RME-E group after RME (p < 0.01).ConclusionsRME is effective in treating maxillary transverse hypoplasia; RME anchored too deciduous teeth spontaneously reduces buccal inclination and increases distorotation of maxillary first permanent molars, whereas anchorage to permanent molars is associated with increased buccal inclination, albeit with little clinical significance.

Evaluation of dental and skeletal effects of the asymmetric rapid maxillary expansion appliance: A three-dimensional finite element study.

Transverse maxillary deficiency is one of the most common skeletal anomalies. The incidence of posterior crossbite caused by maxillary deficiency is between 2.7% and 23.3%. Unilateral posterior crossbite is more common than bilateral crossbite. The most common treatment for skeletal posterior crossbite is rapid maxillary expansion (RME), in which the base of the maxillary bone is expanded by separating the midpalatal suture. This study compares the biomechanical effects of three different RME appliances, especially the effects on the midline, and evaluates the usability of the modified asymmetric RME (ARME) appliance for treating unilateral crossbites. Three scenarios were created with skull models using three different appliances: (1) conventional-bonded RME appliance; (2) full-cap splint RME appliance, with all teeth covered with acrylic; and (3) ARME, with all teeth on the right side and premolars and molars on the left side covered with acrylic. The finite element method was used to assess stress levels and displacements in all models after applying a 5-mm horizontal displacement to the RME screw. The lateral transverse movement of the first molars was greater with the conventional RME appliance than with the full-cap splint RME appliance. The lateral transverse movement of the first molar was greater on the left than on the right side with the ARME. The lateral transverse movement of the central incisors was greater with the full-cap splint RME appliance than with the conventional RME appliance. The lateral transverse movement of the central incisor was greater on the right than on the left side with the ARME. Asymmetrical RME appliance increases unilateral expansion compared to other appliances. Therefore, it should be used in cases of unilateral posterior crossbite. This appliance can also successfully treat posterior crossbite with upper midline deviation, since it corrects the shifted midline.

Effect of three different maxillary expansion appliances on root resorption

Aim: The study was to examine rapid maxillary expansion (RME), semi-rapid maxillary expansion (SRME), and slow maxillary expansion (SME) compare the root resorptions occurring in the supporting upper first premolar teeth during treatment by using micro-computed tomography (micro-CT). Methodology: Thirty individuals that required maxillary expansion and upper first premolar tooth extraction were divided into three groups consisting of 10 individuals for RME, SRME, and SME. RME group, first premolar and first molar teeth with hyrax screw were activated ¼ tour twice daily with the banded hyrax appliances. SRME group, acrylic-bonded hyrax appliances were activated ¼ tour per morning and night until the opening of the suture. Upon the opening of the suture, it was activated ¼ tour per every two days until sufficient maxillary expansion was gained. SEM group, quad helix appliances were activated every 20 days. After 12 weeks of the retention period, the upper first premolar teeth were extracted. The teeth were scanned with Micro-CT (SkyScan 1172, Kontich, Belgium), and images were analyzed with a Dell Precision T5500 to determine the resorption crater volumes. Results: In all samples, the resorption craters were concentrated on the buccal surfaces of the tooth roots. The highest resorption craters volume, the total resorption volume, was observed in the RME group, followed by the SRME group, and the least resorption crater volume was detected in the SME group. Conclusion: Since the supporting teeth were exposed to more force on the root surfaces, the most resorption was seen in the RME group. How to cite this article: Topal R, Gündüz Arslan S. Effect of three different maxillary expansion appliances on root resorption. Int Dent Res 2023; 13(1):19-26. https://doi.org/10.5577/idr.2023.vol13.no1.4 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Comparison of the effects of different rapid maxillary expansion techniques on craniofacial structures: a finite element analysis study

AimTo compare the effects of three different maxillary expansion appliances with five different types of expansion modalities on stress distribution and displacement on the maxilla and its adjacent craniofacial structures using the finite element method (FEM).Materials and methodsCone-beam computed tomography data of a patient with maxillary transverse deficiency were rendered into a three-dimensional model of craniomaxillary structures. The expansion appliances included tooth-borne, hybrid, and bone-borne expanders. Five different expansion modalities were applied to each expander [conventional Rapid Maxillary Expansion (RME) (type 1), midpalatal suture cortico-puncture-assisted RME (type 2), LeFort l cortico-puncture-assisted RME (type 3), surgically assisted RME (SARME) without pterygomaxillary junction (PMJ) separation (type 4), and SARME with bilateral PMJ separation (type 5)]. The numerical and visual data were analyzed.ResultsThe highest amount of stress accumulation on teeth was found in the tooth-borne and hybrid groups. On the other hand, more stress concentration on the maxilla was observed in the bone-borne group. SARME cuts with PMJ separation increased total movement by reducing the stress on the midpalatal suture in all groups. While types 1, 2, and 3 were similar in terms of the amounts of displacement, types 4 and 5 increased the total amount of displacement in all groups. The total amounts of displacements from the highest value to the lowest value for the anterior and posterior maxilla were in the bone-borne, tooth-borne, and hybrid groups.ConclusionsSARME cuts were effective in reducing stress on the teeth, but the cortico-puncture application affected neither the stress values on the teeth nor the transverse displacement in the tooth-borne expanders. Surgical procedures such as SARME and corticotomy should be used with bone-borne devices to improve the outcomes of maxillary expansion procedures.

Effect of the computer-aided static navigation technique on the accuracy of bicortical mini-implants placement site for maxillary skeletal expansion appliances: an in vitro study

The objective of the present study was to evaluate and compare the effect of the computer-aided static navigation technique on the accuracy of the maxillary skeletal expansion (MSE) appliances. Material and Methods: Forty orthodontic self-drilling mini-implants were placed in ten anatomically based standardized polyurethane models of a completely edentulous upper maxilla, manufactured using a 3D impression procedure. The four orthodontic self-drilling mini-implants for anchoring the MSE appliance were digitally planned on 3D planning software, based on preoperative cone-beam computed tomography (CBCT) scan and a 3D extraoral surface scan. Afterwards, the surgical templates were virtually planned and manufactured using stereolithography. Subsequently, the orthodontic self-drilling mini-implants were placed an postoperative CBCT scans were performed. Finally, coronal entry-point, apical end-point and angular deviations were calculated using a t-test for independent samples or a non-parametric Signed Rank test. Results: Statistically significant differences were not shown at coronal entry-point (p = 0.13), apical end-point (p = 0.41) and angular deviations (p = 0.27) between the planned and performed orthodontic self-drilling mini-implants. Conclusions: Computer-aided static navigation technique enables accurate orthodontic mini-implant placement for the MSE appliances.

Slow expansion in orthodontics -A review article

One of the most common problems faced by an orthodontist while treating young as well as adult patients is the constricted maxillary arch. Expansion of the maxillary arch has been a topic of debate since centuries. The commonly used methods for constricted arch include slow maxillary expansion, rapid maxillary expansion and surgically assisted rapid palatal expansion (SARPE). Slow palatal expansion is a procedure to expand the maxillary arch in transverse dimension to correct the constricted maxillary arch with light forces. The following review article provides detailed information of various slow maxillary expansion appliances with their implications in orthodontics.

Evaluation and comparison of stresses and displacements generated by four different types of asymmetric maxillary expansion appliances in true unilateral crossbite using finite element method

True unilateral posterior crossbite can be efficiently treated by using asymmetric expansion appliances that essentially exert unilateral expansion forces thereby minimizing iatrogenic overexpansion of the normal pretreatment side. To evaluate and compare the stresses and displacements generated by four different types of asymmetric maxillary expansion appliances in true unilateral crossbite using the finite element method. A CBCT image of the skull was obtained from a 12-year-old female patient with a true unilateral posterior crossbite on the right side, for the FEM study. Asymmetrically split acrylic plate with jackscrew (ASAPJ), NORD crossbite expander, Asymmetric Maxillary Expansion appliance (AMEX), Asymmetrical Rapid Maxillary Expansion (ARME) appliances were simulated with a given force specific to the appliance. Von Mises stresses, displacements in the x, y, z-axis, and changes in the axial inclination were evaluated and compared on the selected skeletal and dental landmarks. Overall ARME seemed to generate the highest asymmetric von Misses stress on skeletal landmarks followed by NORD; ASAPJ and lowest by the AMEX. ARME also produced the highest asymmetric expansion followed by AMEX; NORD and lowest with the ASAPJ. NORD produced the minimum extrusion and buccal tipping of the canine and 1st molar followed by ASAPJ; AMEX and maximum by the ARME. Each of the four appliances expanded the maxillary arch more on the crossbite side as compared to the non-crossbite side, but the pattern of stress distribution, displacement and change in the axial inclination were unique for each appliance.

Polygraphic evaluation of the effects of different rapid maxillary expansion appliances on sleep quality: A randomized clinical trial.

The purpose of this clinical study was to assess the effects of different rapid maxillary expansion appliances on the severity of obstructive sleep apnea (OSA). Patients having a narrow maxilla and identified with OSA were divided randomly into three groups: tooth tissue-borne, tooth-borne, and bone-borne expanders. Changes in sleep parameters at baseline and 3-month follow-up detected by polygraphy were the primary outcome. Treatment of the crossbite was the secondary outcome. Dunn-Bonferroni tests, Kruskal-Wallis, and Wilcoxon analysis were applied for intra- and inter-group differences at p < 0.05 significance level. Among 46 patients randomized, apnea-hypopnea index (AHI) changed from baseline to follow-up in all groups (- 1.6, p = 0.280; 0.6, p = 0.691; - 0.45, p = 0.796, respectively), with no between-group difference (p = 0.631). Oxygen desaturation index (ODI) altered from baseline to follow-up in all groups (0.80, p = 0.977; 0.20, p = 0.932; and - 1.00, p = 0.379, respectively), with no between-group difference (p = 0.858). There was no significant difference in minimum oxygen saturation from baseline to follow-up in all groups (0.00, p = 0.401; - 2.00, p = 0.887; 0.50, p = 0.407, respectively). No significant changes were observed in supine AHI from baseline to follow-up in all groups (0.00, p = 0.581; - 1.00, p = 0.393; 0.00, p = 0.972, respectively). The upper intermolar width increased from baseline to follow-up in all groups (5.04, p = 0.000; 3.15, p = 0.001; 5.41, p = 0.00, respectively) with no between-group difference (p = 0.560). Maxillary width increased from baseline to follow-up in all groups (4.25, p = 0.001; 4.74, p = 0.00; 4.49, p = 0.001, respectively) with no inter-group difference (p = 0.963). The amount of skeletal and dental expansion obtained in the maxilla was similar in all groups. Rapid maxillary expansion was not found to be effective in OSA treatment. ClinicalTrials.gov Identifier: NCT04604392.

Changes in the nasal and pharyngeal airway volume with miniscrew-assisted rapid palatal expansion appliances

Objectives: The purpose of this study was to assess the volumetric changes in the nasal and pharyngeal airway volume in patients with maxillary transverse deficiency treated with miniscrew-assisted rapid palatal expansion (MARPE) appliances. Material and Methods: The pre- and post-treatment cone-beam computed tomography scans of 20 subjects who underwent treatment with the MARPE appliance as part of their orthodontic treatment were included in the study. Pre- and post-expansion airway volume measurements of the nasal cavity, nasopharynx, and oropharynx were measured. Linear measurements of the skeletal structures surrounding the nasal cavity were taken to assess the pattern of airway expansion. Paired t-tests were used to evaluate nasal and pharyngeal airway volume changes with expansion. Pearson correlation test was utilized to assess the relationship between nasal and pharyngeal volume changes. Results: A total of 17 out of 20 samples had a successful split of the mid-palatal sutures. A significant increase in nasal airway volume (12.0%) was found post-expansion. In addition, a significant increase in linear measurements of the nasal cavity base width in the frontal plane (7.1%) and both the anterior and posterior widths in the transverse dimension (9.4% and 3.4%, respectively) were found. Significant positive correlations were found between airway volumes and increase in width of the maxillary expansion appliance. Conclusion: The effects of maxillary expansion with a MARPE appliance include an increase in nasal cavity volume, but not the nasopharyngeal and the oropharyngeal airway volume. The nasal cavity expands in a triangular pattern in both the frontal and transverse dimensions following orthopedic expansion with the MARPE appliance. Increase in airway volume is a result of the increase in width of the maxillary expansion appliance.

PATIENT’S PERCEPTION OF PAIN AND DISCOMFORT DURING MAXILLARY ARCH EXPANSION USING TWO DIFFERENT APPLIANCES - A PILOT QUESTIONNAIRE SURVEY

Aim: &#x0D; To evaluate and compare perceived pain and discomfort levels experienced by subjects treated with tooth-borne (Hyrax) and bone-borne (MARPE) Maxillary expansion appliances.&#x0D; Materials and Methods:&#x0D; Ten subjects (7 boys and 3 girls) with a mean age of 15.8(+/- 2.8) years were randomized into two groups. Group A received a MARPE appliance anchored using mini-implants in the anterior palate and group B received a conventional Hyrax appliance. A self-assessment questionnaire on pain intensity, discomfort and analgesic consumption was given to subjects on the review visit and responses were collected. Descriptive statistics and Mann-Whitney U test was done to compare the mean of pain and discomfort levels between the two groups.&#x0D; Results: &#x0D; All 10 subjects answered the questionnaire. More pain was experienced in the posterior teeth region by subjects treated with MARPE (p&amp;lt;0.05). No significant intergroup difference in pain levels experienced in the anterior region, palatal vault and the head region and analgesic consumption was noted. (p&amp;gt;0.05)&#x0D; Conclusions:&#x0D; Although both Hyrax and MARPE were generally well tolerated there was a significantly higher pain experience in posterior teeth region for subjects treated with MARPE.

Evaluation of the effects of different rapid maxillary expansion appliances on airway by acoustic rhinometry: A randomized clinical trial

ObjectiveThe purpose of this 3-arm parallel trial was to compare the effects of tooth tissue-borne (TTB), tooth-borne (TB) and bone-borne (BB) rapid maxillary expansion (RME) appliances on nasal airway with acoustic rhinometry (AR). Setting and sample populationForty-six 12- to 14-year-old patients with narrow maxilla were randomly allocated into 3 study groups accordingly the type of expander: TTB, TB and BB. The participants were recruited from the Department of Orthodontics, Izmir Katip Celebi University. Materials and methodsAll patients had RME with an initial activation of two-quarter turns a day (0.5 mm) for an average of 8 days followed by 1 quarter turns per day for an average of 10 days. Disguised group allocation using opaque sealed envelopes was made with a computer-generated randomization program. The primary outcome was changes on the minimal nasal cross-sectional area (MCA). Secondary outcome included the assessment of nasal cavity volume. AR measurements were obtained at baseline (T0), immediately after the expansion (T1), and at 3 months-follow-up (T2). One-way analysis of variance (ANOVA) and Bonferroni test were used for inter-group comparison and two-way ANOVA was used for intra-group evaluation. ResultsThere were significant increases in MCA 1, 2 and nasal Vol in all groups after the treatment (95% [CI], P < 0.05) whereas in inter-group comparisons; MCA 1, 2 and nasal Vol, the changes were found to be similar (95% [CI], P > 0.05). HarmsNo serious harm was observed except for mild gingivitis due to plaque accumulation. ConclusionsRME treatment increased minimal nasal cross-sectional areas and nasal volume irrespective of appliance design. Trial registrationThis trial was registered at Clinicaltrials.gov (Identifier NCT04529057). ProtocolThe protocol was not published. FundingThis trial was financed by Izmir Katip Celebi University, Scientific Research Projects Unit [grant number 2016-TDR-SABE-0024].

Stability of transversal correction with hybrid maxillary expansion appliance in bone and tegumental piriformis opening in relation to bone age and maturation of the midpalatal suture.

BackgroundTo evaluate the stability of the transverse correction with a hybrid maxillary expansion appliance in the bone and tegumental piriformis opening in relation to bone age and maturation of the midpalatal suture (MPS). Material and Methods15 patients with a mean initial age of 14.9 years (SD=1.50), 7 (46.7%) were female and 8 (53.3%) were male, treated with a hybrid maxillary expander. Cone beam computed tomographic (CBCT) images were collected in three phases: T1 (orthodontic records), T2 (21.33 days (SD=10.68) after the end of expansion screw activation) and T3 after 9.13 months (DP=2.41) after the expansion screw was activated. In CBCT, measurements were performed in the nasal cavity considering the tegumental piriform opening (sagittal-axial sections) and bone (sagittal-axial-coronal sections) and the stage of MPS maturation (sagittal-axial sections). Repeated measures ANOVA was used for continuous variables and Friedman’s ANOVA for the ordinal variable followed by Bonferroni’s tests for p<0.001, in relation to time. ResultsThere were significant differences between T1 and T2 (p=0.041), between T2 and T3 (p<0.001) and between T1 and T3 (p=0.041). Regarding bone age by cervical vertebrae maturation, 20% were in stage CS3, 40% in stage CS4, 26.7% in stage CS5 and 13.3% in stage CS6. There was a significant increase in tegumental piriformis opening between T1 (M=32.19, SD=3.79) and T2 (M=34.82, SD=2.81) (p=0.008), followed by a significant decrease in T3 (M=34.64, SD=2.73) (p=0.021), as well as in the opening of the bone piriform, between T1 (M=21.30, SD=2.47) and T2 (M=25.35, SD=2.21) (p<0.001), followed by a significant decrease in T3 (M=24.89, SD =2.30) (p=0.018). ConclusionsThe hybrid maxillary expansion appliance was effective in opening the midpalatal suture of all patients in the present study, without influence of the initial stage of MPS maturation and bone age. There was a relapse of the increase in the bone and tegumental piriform openings. Key words:Maxillary expansion, orthodontic anchorage procedures, nose.

Slow maxillary expansion

Constricted maxillary arch is one of the most common problems faced by an Orthodontist while treating young as well as adult patients. Maxillary expansion occupies a unique niche in dentofacial therapy and it has been a topic of debate since centuries. Slow maxillary expansion, rapid maxillary expansion and surgically assisted rapid palatal expansion (SARPE) are the commonly used methods for maxillary expansion. Slow maxillary expansion is a procedure to expand the maxillary arch in transverse dimension to correct the constricted maxillary arch with light forces. This review article provides detailed information about various slow maxillary expansion appliances with their implications in orthodontics.

Comparative Evaluation of the Stress Distribution and Transverse Displacement of the Circummaxillary Sutural System by Four Different Designs of Rapid Maxillary Expansion Appliances Using 3D Finite Element model: A Study Protocol

Background: In adolescent patient’s Rapid maxillary skeletal expansion (RME) is used with predictable clinical results for correcting transverse maxillary skeletal contraction. During RME, heavy force is directed towards the maxillary skeletal base. These forces also have effect on the palatal bone, adjacent skeletal structures and dentition. Tooth supported RME apply significant pressure on the teeth leading to varying amount of buccal inclination of premolars and molars and dental expansion. Implant assisted expanders take skeletal anchorage thus minimizing or negating the effect of heavy pressure on the teeth and supporting structures. Finite Element Analysis is a form of computer simulation. It is a non-invasive, precise method for obtaining quantitative and comprehensive knowledge about the physiological responses that occur in tissues. It outperforms other experimental methods because it creates a three-dimensional model that allows for simulation and analysis of orthodontic force systems in all three dimensions.&#x0D; Objective: The present study intends to make an assessment of four different RME designs (Banded HYRAX, Banded MARPE, MSE expander, Orthoeasy PAL expander) in terms of distribution of stress in the circummaxillary Sutural system and resulting displacement of the bones in the craniofacial complex upon activation of the respective appliance.&#x0D; Methodology: CBCT scan data of an adolescent patient will be taken from archives of a reputed scan centre. 3D skull model will be generated using CBCT data and .stl/ DICOM format will be converted into Finite Element model. The different types of RME appliances will be designed over the FE model. The expanders will be activated and the stresses generated at the sites of interest would be studied.&#x0D; Results: The study is expected to permit a clinician to select the design of RME appliances, which will produce suitable stress and displacement that will help to increase transverse width of maxilla to correct the underlying skeletal discrepancy.&#x0D; Conclusion: This study will help to arrive at a conclusion about which designs of RME will best suit clinical application of mechanics for orthopaedic expansion in a particular case.

Comparison of Conventional Rapid Palatal Expansion with Bone Anchored and Tooth-Bone Anchored Rapid Palatal Expansion Appliances

In modern orthodontics, several types of designs for bone anchored expansion appliances have been developed with the objective to increase the amount of skeletal expansion with rapid palatal expansion. In the present review, the skeletal and dental effects of rapid palatal expansion have been evaluated immediately following expansion and in the long-standing interval following expansion. The effects of conventional rapid palatal expansion appliances are compared with bone anchored maxillary expansion appliances and tooth-bone anchored maxillary expansion appliances. Temporary Anchorage Devices (TADs), or mini-screws, or mini-implants are used for the insertion of bone anchored and tooth-bone anchored maxillary expansion appliances. These lead to higher forces on the bone while expansion is undertaken and consequently more orthopedic effects. This article will discuss how the modern bone anchored expansion appliance used in modern orthodontics compare to conventional rapid palatal expansion appliances.

Bone-anchored versus tooth-anchored expansion appliances: Long-term effects on the condyle–fossa relationship

The objective of this study was to evaluate the short-term and long-term effects of tooth-anchored and bone-anchored maxillary expansion appliances on the condyle-fossa relationship, compared to those in a matched control group. Another objective of the study was to evaluate whether the amount of dental and skeletal expansion is correlated with the condyle-fossa relationship. A total of 180 cone-beam computed tomography scans (CBCTs) for 60 subjects were analyzed for 3 groups: 1) bone-anchored maxillary expansion (BA; n=20); 2) tooth-anchored maxillary expansion (TA; n=21); and 3) controls (n=19) at pretreatment, post-expansion (T2), and post-treatment (T3). The posterior joint space (PJS), superior joint space (SJS), anterior joint space, angle of mandibular condyle, distance of the condyle to the mid-sagittal plane, the inter-molar cuspal width, and the skeletal maxillary width (SMW) were measured for all 3 groups. Both BA and TA led to a significant increase in inter-molar cuspal width, SMW, and TA led to a significant increase in PJS as compared to controls at T2. However, there was no significant difference in the joint spaces between the BA, TA, and control groups in the long term. Both the BA and TA groups showed a significant increase in SMW at T3 compared to the control group. Molar extrusion showed a weak correlation with PJS at T2 (r=0.46) and T3 (r=0.51), and a moderate correlation with SJS at T2 (r=0.61) and T3 (r=0.69). TA led to a significant increase in PJS, compared to a control group, at T2, but there was no long-term difference in the condyle-fossa relationship among the BA, TA, and control groups. Molar extrusion showed moderate correlation with SJS and PJS.

Early Maxillary Expansion with the Ni-Ti Memory Leaf Expander-A Compliance-Free Fixed Slow Maxillary Expansion Screw: A Report of 2 Cases.

Transversal problems such as crowding and crossbite are one of the most common problems dealt with in early orthodontic treatments. Early correction of these problems may ease or even eliminate the future need for treatment. This paper presents the management of 2 cases with transverse discrepancy using the Ni-Ti Memory Leaf Expander--a new compliance-free slow maxillary expansion appliance. The total treatment time for both cases was 9 months. In both cases, the inter-canine, inter-premolar, and inter-molar distances, as well as the arch length, have all increased.

A postero-anterior cephalometric evaluation of different rapid maxillary expansion appliances

The purpose of the study was to evaluate dental and skeletal changes induced by tooth-bone-borne, tooth-tissue-borne, and tooth-borne rapid maxillary expansion (RME) appliances using postero-anterior (PA) cephalometric radiographs. A total of 54 patients' (25 boys, 29 girls) PA cephalometric radiographs who had bilateral posterior crossbite and RME treatment were included and divided into three groups according to the type of appliance used during treatment: tooth-bone-borne RME appliance (hybrid Hyrax) (7 boys, 11 girls, mean age 13.28 ± 1.20 years), tooth-tissue-borne RME appliance (TTB) (8 boys, 10 girls, mean age 13.08 ± 1.06 years) and tooth-borne RME appliance (Hyrax) (10 boys, 8 girls, mean age 12.05 ± 1.35 years). Pretreatment (T0) and posttreatment (T1) PA cephalometric radiographs were analyzed with Dolphin software v. 11.7 (Chatsworth, CA). The comparisons of the groups were performed with Two-way analysis of variance. P < 0.05 was considered statistically significant. Significant and equal increase of right molar relationship and upper intermolar molar widths occurred in all groups. Dental midline discrepancy showed significant increase in only hybrid Hyrax group between T0 and T1. Significant increases were reported for lateronasal width in hybrid Hyrax and tooth-tissue-borne groups (P < 0.05). Both skeletal and dental changes were observed after RME in all groups. However, the greatest skeletal changes were seen in hybrid Hyrax and tooth-tissue-borne groups.

Comparison of skeletal and dentoalveolar changes between pure bone-borne and hybrid tooth-borne and bone-borne maxillary rapid palatal expanders using cone-beam computed tomography

Objectives: The objectives of the study were to compare the skeletal, dentoalveolar, and periodontal changes between two types of microimplant-assisted rapid maxillary expansion appliances: The bone-anchored maxillary expanders (BAME) and the tooth-bone-anchored maxillary skeletal expander (MSE). Materials and Methods: Thirty-four patients with a transverse maxillary deficiency were divided into two groups; the first group (16 patients, average age 14.9 years) was treated with the MSE appliance, and the second group (18 patients, average age 13.8 years) was treated with the BAME appliance. Cone-beam computed tomography scans were taken at pre-treatment (T1) and immediately post-expansion (T2) to measure the changes in midpalatal suture opening, total expansion (TE), alveolar bone bending, dental tipping (DT), and buccal bone thickness. Data were analyzed using paired t-test and two-sample t-test. Results: Midpalatal suture separation was found in 100% of the patients in both groups. The TE at the first molar was 5.9 mm in the MSE group and 4.7 mm in the BAME group. The skeletal contributions were 56% and 83% of TE for the MSE and BAME groups, respectively. Significantly less dental buccal tipping and buccal bone loss were found with the BAME group. The midpalatal suture in both groups exhibited a parallel opening pattern in the axial plane. Conclusion: The use of BAME appliance resulted in greater skeletal effects, less dental tipping, and less buccal bone reduction compared to MSE appliance (immediately after maxillary expansion).