Arch Expansion Research Articles

Surgically Assisted Rapid Palatal Expansion and Mini-screw Assisted Rapid Palatal Expansion - A review

This review was undertaken to compare the effects of surgically assisted rapid palatal expansion (SARPE) and mini-screw assisted rapid palatal expansion (MARPE). Discrepancies in the transverse relation between maxillary and mandibular dentition can result in the development of posterior cross bite. For the correction of posterior cross bite, maxillary expansion is frequently undertaken. The conventional approach for maxillary expansion includes expansion screw being anchored to the maxillary teeth and is known and rapid palatal expansion (RPE) appliance. However, RPE can only be applied in growing individuals and is not as effective in late adolescents and adults. In such patients, surgically assisted rapid palatal expansion (SARPE) technique is used to expand the maxillary arch. As this procedure involves surgery, it deters many patients from choosing SARPE as a treatment option. Recently a non-surgical technique of expansion of maxillary arch has been introduced that can be applied to late adolescents and adults using palatal mini-screws. This technique is known as mini-screw assisted rapid palatal expansion (MARPE). In this review, the studies in the current literature regarding the SARPE and MARPE expansion techniques as compared to conventional RPE were included. It was observed that both SARPE and MARPE are effective methods for achieving maxillary expansion. With both techniques being effective, the advantage of MARPE over SARPE is the non-surgical approach which leads to higher patient acceptance and lower rate of complications.

Analysis of mining roadway with large deformation of broken soft coal and research on supporting technology: A case study in Xin’an coal mine, China

The safe mining of Xin'an Coal Mine was challenging because of several problems, including the soft roadway seams, fracture development, fracturing and deformation of the incompact surrounding rock, and the unreasonable support parameters. Through the investigation of these problems and the analysis of the influence of active and passive support on the stability of the roadway combined with the theory, we proposed a new support plan and conducted field tests. The obtained results were as follows: broken surrounding rock, low degradation strength, unreasonable support parameters, and uncoupling of support and surrounding rock were the main causes of roadway deformation. To a certain extent, the passive support could prevent the damage of the surrounding rock, prevent the attenuation of the stress of the rock around the anchor point, and enhance the effect of active support. The active support could pre-support the gravity of the broken surrounding rock, improve the stress environment of the surrounding rock, and increase the self-balancing ability of the surrounding rock structure. It also could control the damage zone of surrounding rock and the expansion of the stress arch to the depth, restrict the range of rock strata that the passive support system needed to control, and play a protective role. The active–passive coupling support scheme had an amplifying effect. In this regard, the active–passive coupling support scheme of “bolt, W steel belt” + “anchor cable, anchor cable beam” + “I-steel shed” was practiced, and the relevant support parameters were determined. The scheme was implemented in the 2301 mining roadway, and the displacement convergence deformation of the two walls and the roof and floor of the roadway was monitored. It was found that the deformation of the roadway surrounding rock was effectively controlled and the scheme could ensure the stability of the roadway. The research results could provide a basis for the stability analysis of large deformation of broken soft coal of mining roadway and also a basis for the optimization of support parameters.

Invisalign eighth-generation features for deep-bite correction and posterior arch expansion

Invisalign eighth-generation features for deep-bite correction and posterior arch expansion

Chinese guideline for the diagnosis and treatment of childhood obstructive sleep apnea (2020).

Chinese guideline for the diagnosis and treatment of childhood obstructive sleep apnea (2020).

Corticotomy–An Accelerated Orthodontic Procedure

Corticotomy found to be effective in accelerating orthodontic treatment. It involves selective alveolar decortication in the form of decortication lines and dots performed around the teeth that are to be moved. It is done to induce a state of increased tissue turnover and a transient osteopenia, which is followed by a faster rate of orthodontic tooth movement. This technique has several advantages, including faster tooth movement, shorter treatment time, safer expansion of constricted arches, enhanced post-orthodontic treatment stability and extended envelope of tooth movement.

Combined Orthodontic and Surgical Management for Treatment of Severe Class III Malocclusion with Anterior and Posterior Crossbites

Severe class III malocclusion can be a great challenge, especially in adult patients. This case report describes an adult patient with severe skeletal class III malocclusion and with an obvious maxillary deficiency and mandibular excess causing both anterior and posterior crossbites in addition to a shift in the upper and lower midlines to the left concerning the facial midline. This was complicated by compensatory mechanisms such as the proclination of upper incisors and retroclination of lower incisors. Decompensation of the upper and lower arches was performed combined with upper arch expansion to relieve crowding in the upper arch and correct the posterior crossbite. This was followed by double jaw surgeries, including Le Fort I osteotomy in the maxilla and bilateral sagittal split osteotomy (BSSO) in the mandible. Orthodontic finishing procedures were then used to correct any other dental discrepancies. Remarkable esthetic and functional results were achieved with high patient satisfaction.

Impact of Orthodontic Forces on Plasma Levels of Markers of Bone Turnover and Inflammation in a Rat Model of Buccal Expansion.

Plasma levels of protein analytes might be markers to predict and monitor the kinetics of bone and tissue remodeling, including maximization of orthodontic treatment stability. They could help predict/prevent and/or diagnose possible adverse effects such as bone dehiscences, gingival recession, or root resorption. The objective of this study was to measure plasma levels of markers of bone turnover and inflammation during orthodontic force application in a rat model of orthodontic expansion. Two different orthodontic forces for bilateral buccal expansion of the maxillary arches around second and third molars were applied in 10 rats equally distributed in low-force (LF) or conventional force (CF) groups. Four rats served as the control group. Blood samples were collected at days 0, 1, 2, 3, 6, 13, 21, and 58. Longitudinal concentrations of osteoprotegerin (OPG), soluble receptor activator of nuclear factor kappaB ligand (sRANKL), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNF), and parathyroid hormone (PTH) were determined in blood samples by a multiplex immunoassay. CF and LF resulted in a significantly maxillary skeletal expansion while the CF group demonstrated significantly higher expansion than the LF group in the long term. Bone turnover demonstrated a two-phase response. During the “early phase” (up to 6 days of force application), LF resulted in more sRANKL expression and increased sRANKL/OPG ratio than the CF and control animals. There was a parallel increase in PTH levels in the early phase in response to LF. During the “late phase” (6–58 days), the markers of bone turnover were stable in both groups. IL-4, IL-6, and IL-10 levels did not significantly change the test groups throughout the study. These results suggest that maxillary expansion in response to different orthodontic forces follows different phases of bone turnover that may be force specific.

Timely Combination Therapy of Skeletal and Dental Class II malocclusion with Temporary Anchorage Device and Mesially Impacted Mandibular 2ndMolars: A Case-Report

Introduction: Patient is a 14 years old Chinese boy presented with skeletal Class II with incompetent lips, severe dental Class II malocclusion and severe crowding complicated with both sides mesio-angular impacted of mandibular 2nd molars.
 Treatment Plan: Growth modification using functional appliance for skeletal Class II correction with maxillary arch expansion and correction of mandibular plane angle by intrusion of maxillary molars. Extraction of lower 1st premolars and 2nd molars on both sides was carried out in conjunction with fixed orthodontic alignment and to facilitate of spontaneous eruption of lower third molar. Midline correction was followed by space closure and finishing and detailing.
 Results: Alignment of upper arch in the regained space with maxillary expansion without any extraction was done. Anterior maxillary dentitions were retracted using Temporary Skeletal Anchorage Devices (TSADs). In lower arch 1st molars were mesially protracted by using class II elastics. 3rd molars spontaneously erupted in the extraction space of 2nd molar. Midline corrected with good facial profile and competent lips.
 Conclusions: Timely execution of expert treatment plan can bring cost effective and time saving results with minimum loss. By proper counseling, patient compliance and confidence can be boosted which could have a positive effect on the treatment outcome.
 Bangladesh Journal of Medical Science Vol.20(3) 2021 p.682-690

Methods of maxillary arch expansion in orthodontics: A literature review

The expansion of the arch has been one of the oldest means of creating space in the dental arches. The correction of transverse maxillary deficiency can be an important component of an orthodontic treatment plan. For the correction of transverse maxillary deficiency, based on the duration of time taken to achieve the desired expansion, expansion devices can be classified as- Rapid maxillary expansion devices and slow expansion devices. This article focuses on the various appliances that can be used for the expansion of maxillary arch.

Accuracy of predicting the upper arch expansion using the ClinCheck software

BACKGROUND: Among the anomalies of the dentoalveolar system, narrowing of the upper dental arches in a permanent bite occurs in 57% of the cases examined. Aligners are a preferable method for correcting the position of the teeth and expanding dental arches. Planning and modeling treatment outcomes when using clear aligners are essential parts, since it is the quantitative assessment of treatment outcomes that improves clinical practice. The ClinCheck software allows making an almost fully automated design and manufacturing of Invisalign.
 AIM: This study aimed to assess the accuracy of predicting the expansion of the upper arch using the ClinCheck software.
 MATERIAL AND METHODS: A prospective clinical study included 19 patients with dentoalveolar anomalies whose dental arch parameters were measured before and after treatment with Invisalign Full and Invisalign Teen. Evaluation of the accuracy of predicted expansion using ClinCheck was carried out by comparing the simulated parameters and actual outcomes. To assess the achieved results, individual tooth from the original ClinCheck model was superimposed on the digital model from the post-treatment scan. For the studied parameters, the arithmetic mean was calculated, and significant differences were established at a significance level of p 0.05.
 RESULTS: As regards treatment result, patients showed a significant expansion of the upper dental arch in the premolar and molar region as well as protrusion of the incisors. Data showed a high accuracy of prediction using ClinCheck, since no significant differences were found between the mean values obtained as a result of treatment and those predicted using ClinCheck.
 CONCLUSIONS: 1) Invisalign technology is effective in widening the upper arch. Following treatment, patients showed significant differences in the width for the first premolars at 4.030.24 mm, for the second premolars at 3.610.25 mm, for the first molars at 2.110.31 (p 0.05), as well as clinically significant incisor protrusion of 6.531.41 (p 0.05). 2) Differences between the mean values obtained following treatment and simulated in the ClinCheck program were as follows: expansion along the canines, 0.050.11 mm (p 0.05); expansion along the first premolars, 0.040.23 mm (p 0.05); expansion along the second premolars, 0.0030.14 mm (p 0.05); expansion along the first molars, 0.0020.13 mm (p 0.05), and incisor protrusion, 0.120.92 (p 0.05).

Accuracy of predicting the upper arch expansion using the ClinCheck software

BACKGROUND: Among the anomalies of the dentoalveolar system, narrowing of the upper dental arches in a permanent bite occurs in 57% of the cases examined. Aligners are a preferable method for correcting the position of the teeth and expanding dental arches. Planning and modeling treatment outcomes when using clear aligners are essential parts, since it is the quantitative assessment of treatment outcomes that improves clinical practice. The ClinCheck software allows making an almost fully automated design and manufacturing of Invisalign.
 AIM: This study aimed to assess the accuracy of predicting the expansion of the upper arch using the ClinCheck software.
 MATERIAL AND METHODS: A prospective clinical study included 19 patients with dentoalveolar anomalies whose dental arch parameters were measured before and after treatment with Invisalign Full and Invisalign Teen. Evaluation of the accuracy of predicted expansion using ClinCheck was carried out by comparing the simulated parameters and actual outcomes. To assess the achieved results, individual tooth from the original ClinCheck model was superimposed on the digital model from the post-treatment scan. For the studied parameters, the arithmetic mean was calculated, and significant differences were established at a significance level of p 0.05.
 RESULTS: As regards treatment result, patients showed a significant expansion of the upper dental arch in the premolar and molar region as well as protrusion of the incisors. Data showed a high accuracy of prediction using ClinCheck, since no significant differences were found between the mean values obtained as a result of treatment and those predicted using ClinCheck.
 CONCLUSIONS: 1) Invisalign technology is effective in widening the upper arch. Following treatment, patients showed significant differences in the width for the first premolars at 4.030.24 mm, for the second premolars at 3.610.25 mm, for the first molars at 2.110.31 (p 0.05), as well as clinically significant incisor protrusion of 6.531.41 (p 0.05). 2) Differences between the mean values obtained following treatment and simulated in the ClinCheck program were as follows: expansion along the canines, 0.050.11 mm (p 0.05); expansion along the first premolars, 0.040.23 mm (p 0.05); expansion along the second premolars, 0.0030.14 mm (p 0.05); expansion along the first molars, 0.0020.13 mm (p 0.05), and incisor protrusion, 0.120.92 (p 0.05).

Maxillary arch development with Invisalign system.

To evaluate tooth movements during maxillary arch expansion with clear aligner treatment. The study group included 28 subjects (16 females, 12 males, mean age 31.9 ± 5.4 years) collected prospectively from January 2018 to May 2019. Inclusion criteria were European ancestry, posterior transverse discrepancy of 3-6 mm, permanent dentition stage, presence of second permanent molars, mild or moderate crowding, and good compliance with aligners. Treatment protocol included nonextraction strategies, application of Invisalign clear aligner system, and no auxiliaries other than Invisalign attachments. Linear and angular measurements were performed before treatment (T1), at the end of treatment (T2), and on final virtual models (T2 ClinCheck). A paired t-test was used to compare T2-T1 and T2-T2 ClinCheck changes. The level of significance was set at 5%. Statistically significant differences were found for all measurements, except for ones at the upper second molars. The greatest increase in maxillary width was detected at the upper first and second premolars: +3.5 mm for the first premolar and +3.8 mm for the second premolar at T2. Comparison of T2-T1 angular outcomes showed statistically significant changes in the inclinations of all teeth except for the second permanent molars. T2-T2 ClinCheck showed significant differences for both linear and angular measurements for maxillary canines, resulting in poor predictability. Maxillary arch development revealed a progressive reduction of the expansion rate and buccal tipping in the anterior, lateral, and posterior regions, with the greatest net increase at the first and second premolars. Clinical attention should be paid to maxillary canine movements, and overcorrection should be planned for them during dentoalveolar expansion.

Effects of Fluoridated Tooth Paste on Medically Erosive Enamel in Banded Primary Teeth during Maxillary Arch Expansion in Cleft Palate Patients: An In Vitro Study

Effects of Fluoridated Tooth Paste on Medically Erosive Enamel in Banded Primary Teeth during Maxillary Arch Expansion in Cleft Palate Patients: An In Vitro Study

Effects of a ceramic active self-ligating bracket on retraction/tipping/rotation of canine, premolar mesialization, and transverse arch dimensions: A preliminary single-blind split-mouth randomized clinical trial

There is no clinical study on ceramic self-ligating brackets (SLBs). Therefore, this preliminary study was conducted for the first time to address its effects. This split-mouth randomized trial was performed on 32 quadrants in 16 orthodontic patients needing extraction of maxillary premolars and distalization of canines. In each blinded patient, right/left sides were randomized into control (ceramic bracket) and experimental (ceramic SLB) groups. Dental stone models were taken before canine retraction and 3 months into retraction. Models were digitized as three-dimensional models. Changes were measured on superimposed models. Groups were compared using Wilcoxon signed-rank test (α = 0.05, β = 0.1). Both bracket types caused significant changes after 3 months in terms of all assessed clinical outcomes (P ≤ 0.002). Compared to conventional ceramic brackets (control), ceramic SLBs reduced retraction rate (P = 0.001), canine rotation (P = 0.001), canine tipping (P = 0.002), and arch expansion at the canine site (P = 0.003). However, the extents of anchorage loss (P = 0.796) and arch constriction in the premolar area (P = 0.605) were not statistically different between the bracket types. Compared to conventional metal-lined ceramic brackets, active ceramic SLB can increase the duration of canine distalization, while reducing canine rotation and tipping (inducing more bodily movements). The loss of anchorage with ceramic SLB was similar to that of conventional ceramic bracket after 3 months of treatment (considering the lower rate of SLB canine retraction during that time). Both brackets similarly constricted the arch at the premolar site. In the canine area, they expanded the arch, with the SLB causing smaller extents of expansion.

Comparative Assessment of The Expansion of The Dentition Using Ligature and Passive Self-Ligating Braces in Combination with Pitts Broad and Early Elastics

Background: The study aimed to analyze the effectiveness of the use of the Pitts Broad and early elastics in the treatment of patients with narrowing and deformation of the dentition. Materials and methods: A comprehensive examination of 46 patients, aged 18 to 30 years, with narrowing and deformation of the dentition was performed. Patients were separated into two groups, depending on the algorithm of treatment: group 1 – using the brackets of passive self-ligation, the Pitts Broad and early short elastics; group 2 – using ligature brackets and archwires Orthos. Results: Biometric analysis of the diagnostic models of the 1st group after treatment showed a significant expansion of maxillary arch between the premolars and molars (a distance between premolars: 39,8±0,4mm, between molars: 48,3±0,5mm) and mandibular arch (a distance between premolars: 37,1±0,5mm, between molars: 46,3±0,6mm) compared to the data before treatment. Biometric analysis of the diagnostic models of the 2nd group showed that expansion between the molars was achieved on a much smaller extent on both jaws, compared with the 1st group (maxilla: a distance between premolars – 35,7±0,4mm, between molars – 43,5±0,5mm; mandible: a distance between premolars – 33,2±0,3mm, between molars – 42,3±0,5mm). Conclusions: As a result of the study, it was found that the passive self-ligation system in combination with a protocol of the Pitts Broad contributes to the expansion of dentition in aesthetically significant areas (distal regions) at the early stages of treatment. The use of early light elastics provides an early control of the premolars torque, and it allows us to achieve a balanced and wide smile at the end of treatment.

Tessier cleft type 5 craniofacial anomaly – A rare oblique facial cleft

One of the rarest types of craniofacial malformations is Tessier cleft type 5. These are oblique facial clefts with bony defect representing an alveolar cleft in the premolar region. This extends to the lateral surface of the maxilla up to the infraorbital rim and orbital floor. The cleft begins in the upper lip, just medial to the commissure, and extends up to the eyelid. They may also show deficient maxillary growth on the side of the cleft, clinically represented as constriction in the maxilla and occlusal cant. It becomes very challenging to treat such cases and requires a team approach. The goals of such cases include surgical repair of the lower eyelid and outer canthus, expansion of the arch and alignment, Bone grafting for the alveolar cleft, zygomatic region, and orbital rim to restore the continuity. The following is a case report of Tessier type 5 facial cleft describing the clinical features, diagnosis, and treatment approach for the case.

Correção da mordida cruzada posterior bilateral em paciente classe III por compensação dentoalveolar – relato de caso

The search for orthodontic treatment by adult patients has increased in the offices. Aesthetic demand is a contributing factor for this increase. When treating an adult patient, many types of occlusal problems can be found. As an example, we can mention the transverse deficiency of the maxilla. This clinical case is the compensatory treatment of a Pattern I patient with bilateral posterior crossbite, Class III molar relationship, upper arch atresia, and expansion of the lower arch. To perform the treatment self-ligating fixed appliance, Cooper NiTi wires with expanded diagram in the upper arch and conventional NiTi in the lower arch were used in conjunction with the bite lifters and the use of intermaxillary elastics (1/8 “) to uncross the bite. A satisfactory result was obtained by correcting the posterior crossbite ratio, obtaining a satisfactory Class I occlusion, improving the smile, overbite, and overjet within the standards, and resolving the patient’s complaint.

Effects of fluoridated tooth paste on medically erosive enamel in bonded primary teeth during maxillary arch expansion in cleft palate patient

AIMS:This study searched the effects of fluoridated toothpaste on the enamel surface of deciduous molars eroded by different pediatric liquid medicaments which were encircled by orthodontic bands by gravimetric analysis method.MATERIALS AND METHODS:A suitable orthodontic band was used to band each of the 110 non-carious exfoliated deciduous molars, and stored in artificial saliva. These teeth were divided randomly into fluoridated and non-fluoridated groups (50 teeth each), and 10 teeth were used as negative controls. The enamel surface of the fluoridated group was swabbed with fluoridated toothpaste for 5 minutes twice daily. Each group was subdivided into five clusters of 10 teeth each according to the type of medication used which included paracetamol, Adol, amoxicillin, Medazole (ME), and Viton (VI) according to a specific immersion cycle. The erosion induced in the enamel for all the teeth was evaluated by gravimetric analysis for different intervals.RESULTS:The results showed that the weight loss increased with increasing exposure to liquid medication for all groups, but this increase was smaller in the fluoridated group. The highest mean weight loss after 28 days was in VI, and the lowest was in ME (0.145 [0.005] mg; 0.08 [0.008] mg), respectively.CONCLUSION:The fluoridated toothpaste significantly reduced medically eroded enamel by oral medical syrups. The gravimetric method is valid for the detection of erosion on banded deciduous molars.

Modified Arnold expander: an alternative for mandibular arch expansion.

ABSTRACTIntroduction: Due to the anatomical constraints of the mandible, mandibular dental arch usually serves as a guideline to determine the required changes in the maxillary transverse dimension. The Schwarz appliance and the Lip Bumper are the traditional orthodontic appliances for mandibular arch expansion in patients with borderline amounts of crowding, and/or transverse discrepancy. However, they often require patient cooperation, which may be a concern for orthodontists in daily practice. Objectives: This article illustrates a simple fixed orthodontic device as an alternative to achieve mandibular arch expansion in patients with moderate tooth-size/arch-length discrepancy. The four reported cases refer to 8 to 10-year-old patients in the mixed dentition, with an Angle Class I or Class II malocclusion, transverse deficiency in both arches, moderate crowding and/or posterior crossbite, combined with compromised smile aesthetics. The patients were treated with rapid maxillary expansion (RME) using Hass expander appliance and the modified Arnold expander (MAE). Conclusion: This low-cost compliance-free orthodontic appliance provided dentoalveolar decompensation by means of uprighting the posterior teeth, with minimal or no adjustments during treatment. The final results were achieved in only three to four months, and fulfilled all treatment objectives, such as an increase in the arch perimeter and width, and a better teeth alignment.

Nasomaxillary effects of miniscrew-assisted rapid palatal expansion and two surgically assisted rapid palatal expansion approaches

This retrospective study was performed to evaluate nasomaxillary changes in 36 patients at an advanced stage of skeletal maturity who underwent miniscrew-assisted rapid palatal expansion (MARPE) or surgically assisted rapid palatal expansion (SARPE) with/without an alar base cinch. Cone beam computed tomography images taken before and after expansion were analysed. Changes in the width of the dental arch (D66S, D66I), maxillary base (MxMol), and nasal floor and nasal cavity in the molar and canine regions (NaFMol, NaFCan, NaCMol, NaCCan) were compared, as well as changes in the choanal aperture (CA) and nasal soft tissue (NW). The MARPE technique produced smaller dental changes (D66S; P=0.025) and greater nasomaxillary expansion (MxMol, P=0.010; NaCMol, P=0.016; NaCCan, P=0.017; NaFMol, P=0.001; CA, P=0.002) than both SARPE techniques. Changes in NW did not differ significantly between the groups (P=0.200). MARPE uniformly increased the anterior and posterior widths of the nasal cavity. SARPE expanded the nasal cavity in a ‘V-shape’ pattern. Changes in the nasal cavity and choanal aperture related to the amount of dental arch expansion were greater for MARPE than for SARPE. All three approaches increased the width of the nasal soft tissue, although the cinch in SARPE limited this increase.