Treatment timing for rapid maxillary expansion

Skeletal and dental effects of function-generating bite appliance compared to rapid palatal expander and untreated controls

INTRODUCTION

Maxillary expansion is a fundamental interceptive orthodontic treatment, which can be achieved through either a rapid expansion protocol or functional devices. However, no data exist about the efficacy of functional devices in achieving skeletal expansion. Therefore, the aim of this study was to compare the effects of the rapid palatal expander (RPE) and the function-generating bite type M (FGB-M) on the transversal dimension of the maxilla, and on the maxillary and mandibular dental arch width.

METHODS

One hundred eighty-one skeletal Class I patients, aged between 6 and 12 years and with a cervical vertebral maturation stage II or III, with maxillary transversal deficiency were retrospectively enrolled; among these 55 were treated with FGB-M, 73 were treated with RPE and 51 were untreated subjects retrieved from historical databases. The pre-treatment (T0) and post-treatment (T1) frontal cephalograms were retrieved, and the maxillary and mandibular widths, and the distance between upper and lower first molars were measured. T1-T0 interval was of 17.3 months (RPE), 24.6 months (FGB-M) and 18.2 months (controls).

RESULTS

The statistical analysis showed that there were no statistically significant differences between the RPE and FGB-M groups regarding skeletal and dental expansion, while the untreated control group differed significantly from the other two groups.

CONCLUSION

The comparison between patients treated with RPE and FGB-M showed that there were no statistically significant differences between the RPE and FGB-M groups regarding the amount of skeletal expansion and dental arch width, suggesting that both appliances can be used to achieve similar results.

Individual dental and skeletal age assessment according to Demirjian and Baccetti: Updated norm values for Central-European patients

PURPOSE

Chronological age often differs from dental and skeletal age. With orthopantomograms and lateral cephalograms, dental and skeletal development can be determined according to the methods published by Demirjian et al. and Baccetti et al. However, gender and skeletal class as possible confounders were frequently not considered and available norm values are not up-to-date. This retrospective cross-sectional study thus aimed to evaluate effects of skeletal class and gender on dental and skeletal age of growing patients and to generate updated norm values for contemporary Central-European patients.

METHODS

A total of 551 patients were included in the dental and 733 in the skeletal age assessment, respectively. Dental analysis was based on tooth mineralisation stages in orthopantomograms (Demirjian) and skeletal age was defined by cervical vertebrae maturation stages (CVMS) in lateral cephalograms (Baccetti). Skeletal class was determined by the individualised ANB angle of Panagiotidis/Witt. With nonlinear regression analysis a formula for determining dental age was established. Effects of gender and skeletal class were evaluated and updated norm values generated.

RESULTS

Inter- and intrarater reliability tests revealed at least substantial measurement concordance for tooth mineralisation and CVMS. Demirjian stages and CVMS significantly depended on gender with girls developing earlier. Skeletal class significantly affected skeletal age only, but without clinical relevance. Updated norm values for dental age differed significantly from the original values of Demirjian and the values for skeletal age differed from those published by Baccetti.

CONCLUSION

Optimised norms, separated by gender, increase precision in determining individual dental and skeletal age during orthodontic treatment planning. Further studies analysing the effect of skeletal class on dental and skeletal development are needed.

Comparison of the short-term effects of tooth-bone-borne and tooth-borne rapid maxillary expansion in older adolescents

PURPOSE

To compare the short-term effects of tooth-bone-borne and tooth-borne rapid maxillary expansion (RME) devices on dentofacial structures in older adolescents.

METHODS

The retrospective study reviewed pre- and posttreatment lateral and posteroanterior cephalometric images and orthodontic model records of patients who underwent maxillary expansion. Two groups were formed, in which the same upper jaw expansion protocol was applied with two different maxillary expansion devices: the first group consisted of 15 individuals treated with tooth-bone-borne (hybrid) RME (HRME; 9 girls and 6 boys; mean age, 16.9 ± 0.42 years) and the second group consisted of 15 individuals treated with tooth-borne (conventional) RME (CRME; 8 girls and 7 boys; mean age, 16.74 ± 0.54 years). Cephalometric and orthodontic model measurements were conducted on the records taken before and after treatment.

RESULTS

Significant skeletal and dental expansions were observed in both groups (p < 0.05). However, the increase in nasal width measurements in the HRME group (2.24 ± 0.61 mm) was significantly higher than the increase in the CRME group (1.12 ± 0.25 mm; p < 0.01). Buccal tipping of the premolars was significantly less in the HRME group (0.46 ± 0.35°) than in the CRME group (2.46 ± 0.63°; p < 0.01). The amount of tipping of the molars was higher in the HRME group (4.76 ± 0.88°) compared to the CRME group (2.9 ± 1.03°; p < 0.01).

CONCLUSION

Although the HRME device increase the nasal width in older adolescents to a greater extent, more dental side effects were seen at the maxillary first molars.

Evaluation of different models of intrusive force application and temporary anchorage device (TAD) placement in total arch intrusion using clear aligners; a finite element analysis

INTRODUCTION

Present study aims to evaluate different models of total arch intrusion using clear aligners in a finite element setup, which might be helpful in gummy smile patients who seek this treatment modality.

METHODS

Four patterns of intrusive forces were applied on each side of the upper arch aligner model: (1) Distal to the lateral incisors (facial - 80 g) and distal to the first molar (palatal - 150 g). (2) Distal to the lateral incisors (facial - 80 g) and distal to the first molars (facial - 80 g and palatal - 80 g). (3) Distal to the canines (facial - 80 g) and distal to the first molars (facial - 150 g). (4) Distal to the lateral incisors (facial - 80 g) and mesial to the first molars (facial - 150 g). Vertical and horizontal movements of the teeth were measured.

RESULTS

Extrusion movements were solely detected at buccal cusps of the first and second molars in the first model. Palatal movements of posterior teeth were detected in this model. Model II showed a homogeneous intrusion in anterior and posterior teeth and the amount of palatal movements of posterior teeth was reduced compared to model I. In contrast to Model IV, Model III had more intrusion in the posterior compared to anterior teeth. Facial movements of posterior teeth were detected in the third and fourth models. Incisor teeth showed facial movements among all of the models except for the lateral incisor in the third model.

CONCLUSIONS

Each model of force application, causes different outcomes and side effects which is beneficial in certain clinical situations.

Accuracy of dental calcification stages for the identification of craniofacial pubertal growth spurt: proposal of referral parameters

PURPOSE

This study primarily aimed to assess the accuracy of radiographic dental calcification parameters for the identification of specific craniofacial growth stages.

METHODS

Permanent mandibular canines, premolars, and second molars of 288 patients, from 6 to 15 years old, were analysed on randomly selected panoramic radiographs, and categorised according to two calcification methods. Reproducibility analyses and data derived from panoramic records were correlated with the gold-standard method, as evaluated from lateral cephalometric teleradiographs. Accuracy tests were finally calculated, considering several cutoff points.

RESULTS

Dental calcification methods showed "strong" to "almost perfect" intra- and inter-examiner reproducibility. Significant, although weak correlations were observed for all parameters. Canine and first premolar calcification stage 8 and second premolar and second molar stage 7 showed higher sensitivity rates for identifying the pubertal growth spurt period, as well as the stage F for these teeth. Canine and first premolar stages 10 and H obtained higher specificity rates for identifying the absence of post-pubertal period.

CONCLUSIONS

The dental calcification parameters showed adequate reproducibility, in addition to significant correlations with cervical vertebrae stages. Radiographic dental calcification parameters used for the mandibular first premolar obtained high accuracy rates and were recommended for identifying specific craniofacial growth periods.

Does MARPE therapy have effects on intracranial pressure? a clinical study

Background

We aimed to evaluate possible intracranial pressure (ICP) changes caused by screw activations during active microimplant-assisted rapid palatal expansion (MARPE) therapy of post-pubertal individuals by measuring the optic nerve sheath diameter (ONSD) under ultrasonography (US) guidance.

Methods

This study’s participants comprised 15 patients (7 males, 8 females) with posterior crossbite and a mean age of 16.7 years (14.25–20.08 years). The Maxillary Skeletal Expander (MSE) appliance was used to perform MARPE in all patients. Their vital signs (heart rate, mean arterial pressure (MAP), and peripheral oxygen saturation (SpO₂)) were recorded. The ONSD was measured by US immediately before the first screw activation (T0), and the measurements were repeated 1 min (T1) and 10 min (T2) after the first activation. In the last session of active MARPE therapy, the same measurement protocol was performed as in the first activation session (T3, T4, and T5). The patients’ perceptions of pain during the screw activation were also noted at T1 and T4 using a four-category verbal rating scale (VRS-4). The significant differences among different time intervals performed with the Friedman test (for all tested variables; SpO2, MAP, Heart Rate, VRS-4 and ONSD). Spearman correlation test was used for VRS-4 and ONSD comparisons. The statistical significance level was accepted as p < 0.05.

Results

The ONSD values ​​(T1 and T4) relatively increased within 1 min after screw activation but did not reach a statistically significant level (p > 0.05). There was also no significant difference between the initial (T0) and the final (T5) ONSD values ​​during the active MARPE therapy (p > 0.05).

Conclusion

There is no changes or alterations in intracranial pressure in late adolescents during active MARPE therapy.

Supplementary information

The online version contains supplementary material available at 10.1186/s12903-022-02482-x.

Influence of rapid maxillary expansion in the stability of anterior open bite treatment

OBJECTIVES

This study aimed to compare the stability of anterior open bite (AOB) in patients treated with and without rapid maxillary expansion (RME) before fixed palatal crib (PC) therapy in the mixed dentition.

MATERIAL AND METHODS

Expansion/palatal crib group (EPC) was comprised of 25 patients (10 male, 15 female, mean initial age of 7.8 years) with AOB treated with RME before PC therapy. Palatal crib group (PC) included 25 patients with AOB (10 male, 15 female, mean initial age of 8.0 years) treated only with PC therapy. Lateral cephalograms were analyzed at pre-treatment (T0), after PC therapy (T1), and 3 years after PC removal (T2) in both groups. AOB relapse was considered when a negative overbite was observed at T2. Intergroup comparisons of interphase changes were performed using t and Mann-Whitney tests (p < 0.05).

RESULTS

Treatment and post-treatment alterations showed similar changes in both groups for all cephalometric variables. Overall changes from T0 to T2 were similar between the groups except for the maxillary incisors that tipped lingually in PC group (1.PP =  - 3.37°) and labially in EPC group (1.PP = 1.76°). The frequency of AOB relapse was 8% and 4% in the EPC and PC groups, respectively. Treatment time in the EPC group (9.7 months) was shorter (p = 0.024) when compared to the PC group (11.0 months).

CONCLUSIONS

In the mixed dentition, stability of AOB treated with RME before fixed PC therapy was similar to PC therapy alone. However, treatment time with fixed PC was slightly shorter in the group treated with RME.

CLINICAL RELEVANCE

This study aims to understand if RME performed previously to fixed palatal crib contributes to the index of stability of AOB treatment in the mixed dentition.

Effect of Low-Level Laser Therapy on Bone Formation in Rapid Palatal Expansion: A Systematic Review

Introduction: Crossbite is a common malocclusion with a 7-23% prevalence rate. Treatment is based on the expansion of the mid-palatal suture (MPS) with Rapid Palatal Expansion(RPE) followed by a retention period to reach new bone maturation, enough to maintain the results stable. This systematic review was conducted to evaluate the effectiveness of low-level laser therapy (LLLT) in increasing bone formation in MPS. Methods: This article was written by the PRISMA checklist. Electronically, 3 databases, namely PubMed, Scopus, and Embase, were searched with the keywords selected based on PICO. Time (2010-2021) and language restrictions were performed. Results: 528 articles, out of which 374 studies were screened, were found, and 9 full-text articles were subsequently included considering these inclusion criteria: randomized clinical trial (RCT) that examines the efficacy of LLLT in rapid palatal expansion (RPE), age under 15 years, non-surgical RPE with a tooth-supported appliance, and low-intensity laser application. Finally, 4 articles were appraised by Cochrane version 5.2.0 with 7 domains. 3 of 4 articles showed LLLT has a significant impact on bone formation. One of them showed no significant difference in pain perception and bone density between the laser and non-laser groups. Conclusion: While many studies have assessed the effect of LLLT on bone formation in animal models, high-quality clinical trials are missing in this regard. The available clinical trials suggest a positive effect of LLLT on sutural bone formation after RPE.

Efficacy of Miniscrew-Assisted Rapid Palatal Expansion (MARPE) in late adolescents and adults with the Dutch Maxillary Expansion Device: a prospective clinical cohort study

OBJECTIVES

To provide a higher degree of evidence on the efficacy of Miniscrew-Assisted Rapid Palatal Expansion (MARPE) in late adolescents and adults, thereby applying the Dutch Maxillary Expansion Device (D-MED).

MATERIALS AND METHODS

D-MED was developed as an individualized, 3D-designed, and fabricated MARPE appliance supported by 4 palatal miniscrews. Patients from the age of 16 onwards with transverse maxillary deficiency were enrolled consecutively. Pre-expansion and immediate post-expansion CBCTs and intra-oral scans were acquired and measurements of skeletal, alveolar, and dental expansion as well as dental and periodontal side-effects were performed.

RESULTS

Thirty-four patients were enrolled (8 men, 26 women) with mean age 27.0 ± 9.4 years. A success rate of 94.1% was achieved (32/34 patients). The mean expansion duration, or mean observation time, was 31.7 ± 8.0 days. The mean expansion at the maxillary first molars (M1) and first premolars (P1) was 6.56 ± 1.70 mm and 4.19 ± 1.29 mm, respectively. The expansion was 60.4 ± 20.1% skeletal, 8.1 ± 27.6% alveolar, and 31.6 ± 20.1% dental at M1 and 92.2 ± 14.5% skeletal, 0.0 ± 18.6% alveolar, and 7.8 ± 17.7% dental at P1, which was both statistically (p < 0.001) and clinically significant. Buccal dental tipping (3.88 ± 3.92° M1; 2.29 ± 3.89° P1), clinical crown height increase (0.12 ± 0.31 mm M1; 0.04 ± 0.22 mm P1), and buccal bone thinning (- 0.31 ± 0.49 mm M1; - 0.01 ± 0.45 mm P1) were observed, while root resorption could not be evaluated.

CONCLUSIONS

MARPE by application of D-MED manifested its efficacy in a prospective clinical setting, delivering a high amount of skeletal expansion with limited side-effects in late adolescents and adults.

CLINICAL RELEVANCE

Higher quality evidence is supportive of MARPE as a safe and successful non-surgical treatment option for transverse maxillary deficiency.

Evaluation of Alkaline Phosphatase as Skeletal Maturity Indicator in Gingival Crevicular Fluid

Introduction

The aim of this study was a comparison of the mean alkaline phosphatase (ALP) levels in gingival crevicular fluid (GCF) at distinct phases of skeletal maturity with the use of a hand-wrist radiograph and to analyze if GCF ALP levels can be used as a non-invasive biomarker for evaluation of skeletal maturity in patients undergoing orthodontic treatment.

Materials and methods

In this study, a standardized volume of 5 μL was collected from the subjects in the preadolescent, adolescent, and postadolescent phases from the mesial and distal embrasures of maxillary and mandibular central incisors after which a hand-wrist radiograph was obtained. Eppendorf tubes with buffer solution were used to transfer GCF to the laboratory for estimation of ALP level.

Results

The data collected were analyzed using Kruskal–Wallis and Mann–Whitney U test to obtain the ALP levels. Gingival crevicular fluid ALP levels were significantly higher in the adolescent stage. The site-wise comparison in the three groups show that there is a statistically insignificant difference between maxilla and mandible or between males and females.

Conclusion

It was concluded that the mean ALP levels were significantly increased in the adolescent phase in contrast with the pre- and post-adolescent stages. Gingival crevicular fluid ALP can be considered a promising diagnostic tool as a non-invasive biomarker of an adolescence growth spurt.

How to cite this article

Trehan M, Patil C. Evaluation of Alkaline Phosphatase as Skeletal Maturity Indicator in Gingival Crevicular Fluid. Int J Clin Pediatr Dent 2021;14(4):512–517.

A CBCT Evaluation of Midpalatal Bone Density in Various Skeletal Patterns

The purpose of this study was to evaluate midpalatal bone density (BD) by using cone-beam computed tomography (CBCT) according to gender, age, and vertical and horizontal skeletal patterns. CBCT images from 126 subjects (64 females and 62 males) were reoriented and analyzed in order to attain BD values at the midpalatal suture. Four age groups were used for classification (adolescence, 10 ≤ early < 14 years, 14 ≤ middle ≤ 17 years, and 17 < late ≤ 21 years; adult > 21 years). Vertical skeletal pattern categories were differentiated by the Frankfort horizontal line to mandibular plane angle (hypodivergent < 22°, 22° ≤ normovergent ≤ 28°, and 28° < hyperdivergent). Horizontal skeletal pattern differentiation was defined by ANB angle (Class III < 0°, 0° ≤ Class I ≤ 4°, and 4° < Class II). Females showed significantly higher BD than males (p < 0.001). As age increased, BD increased significantly (p < 0.001). There were no significant differences between vertical skeletal patterns. Class II showed significantly less BD than Class III (p < 0.05). With this information, clinicians can better understand BD trends of the midpalatal suture and, thus, better understand our patient’s anatomy and potential hurdles in successful treatment.

Palatal vault morphometric analysis of the effects of two early orthodontic treatments in anterior open bite growing subjects: a controlled clinical study

Background

The purpose of this study was to evaluate the palatal morphological changes in Anterior Open Bite (AOB) pre-pubertal subjects treated with Rapid Maxillary Expansion and Bite-Block (RME/BB) or Quad Helix with crib (QH/C) when compared with a Control Group (CG) by using Geometric Morphometric Analysis (GMM).

Methods

AOB group (AOBG) included 30 subjects (20 females, 10 males, mean age 8.1 ± 0.8ys) with dentoskeletal AOB. AOBG was divided in two subgroups according to the treatment strategy: RME/BB group (RME/BBg) included 15 subjects (10 females, 5 males, QH/C group (QH/Cg) comprised 15 subjects (10 females, 5 males). The two subgroups were compared with a CG of 15 subjects (10 females, 5 males) matched for sex, age, vertical pattern, and observation period. Digital upper dental casts were collected before treatment (T1) and at the end of the active treatment (T2). Landmarks and semilandmarks were digitized on dental casts and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed.

Results

At T2, RME/BBg when compared with QH/Cg evidenced no statistically significant differences. Instead, RME/BBg showed an increased maxillary transverse dimension and a decreased palatal depth when compared with CG. The comparison QH/Cg vs. CG demonstrated a slight transversal maxillary expansion.

Conclusions

RME/BBg showed significant changes in the transversal and vertical dimensions with a clear maxillary expansion and a decrease of the palatal depth when compared with QH/Cg and CG. QH/Cg showed a significant slight maxillary expansion and no variation in vertical and sagittal planes when compared with CG.

Three-dimensional zygomatic changes after rapid maxillary expansion in growing patients

PURPOSE

To assess the effects of rapid maxillary expansion (RME) treatment on the zygomatic bone complex (ZBC).

METHODS

In this single-center retrospective study, pre- and posttreatment cone-beam computed tomography (CBCT) images of 38 patients treated with RME were analyzed to investigate changes in the coordinates of the ZBC landmarks. At the start of treatment (T0), the patients' mean age was 11.1 ± 3.8 years (range 8.3-14.9 years). Cohen's d test was used to evaluate statistical differences.

RESULTS

There were statistically significant differences between T0 and T1 (P < 0.01) in the measurement values for the maxillary transverse width (ΔT: 3.18 ± 2.58, d: 1.23), frontozygomatic sutures (ΔT: 1.09 ± 0.56, d: 0.43), lowest point of the zygomaticomaxillary sutures (ΔT: 3.16 ± 1.78, d: 0.78), frontomaxillary angular parameter (right side ΔT: 2.81 ± 1.63, d: 1.73; left side ΔT: 2.52 ± 1.20, d: 2.10), frontozygomatic angular parameter (right side ΔT: 2.81 ± 1.63 d: 1.07; left side ΔT: 2.21 ± 2.79, d: 0.61), anterior intermaxillary distance (ΔT: 2.11 ± 1.42, d: 0.99), interzygomaticotemporal distance (ΔT: 2.00 ± 2.42, d: 0.99), and zygomatic angular parameter (right side ΔT: 2.06 ± 1.29, d: 1.6; left side ΔT: 2.02 ± 1.86, d: 1.09).

CONCLUSIONS

After RME in growing patients, the zygomatic bone showed pyramidal expansion in the coronal plane and parallel palatal expansion in the axial plane. In addition, significant lateral relocation of the zygomatic bone occurred. The zygomatic bone tended to rotate outward in conjunction with the maxilla, with a typical center of rotation close to the superior side of the frontozygomatic suture. These results shed light on the patterns of skeletal expansion in the zygomatic bone associated with RME in growing patients.

Effects of rapid maxillary expansion or alternating rapid maxillary expansion and constriction on nasal mucociliary clearance : A randomized clinical trial

PURPOSE

This parallel trial aimed to evaluate the changes in nasal mucociliary clearance (MCC) after a rapid maxillary expansion (RME) protocol or an alternating rapid maxillary expansion and constriction (Alt-RAMEC) protocol in orthodontic patients.

METHODS

This trial included 36 patients with a mean age of 14.38 years, with a narrow maxillary arch, bilateral posterior crossbite, no narrowing of the mandibular arch, no previous orthodontic treatment, and no nasal or systemic disease. Patients were randomly distributed into two groups (n = 18 each)-one group was treated with the RME protocol and the other group was treated with the Alt-RAMEC protocol. MCC was evaluated using the saccharine transit time (STT) test, which was measured for each individual before expansion (T0), after expansion (T1), and after a 4-month retention phase (T2). The study was single blinded, and blinding was applied only to the outcome assessor. The primary objective was to evaluate the effect of the Alt-RAMEC and RME protocols on MCC. The secondary objective was to determine the relationship between age, sex, and MCC. The χ ² test and independent samples t‑test were used to evaluate the data.

RESULTS

The STT decreased after expansion and retention in the RME group. In the Alt-RAMEC group, the STT decreased after expansion and slightly increased after retention. When the RME and Alt-RAMEC groups were compared, the STT showed a significant difference after expansion and retention (p < 0.05). No significant relationship was observed between age and sex and STT (p > 0.05).

CONCLUSION

This study demonstrated that the Alt-RAMEC protocol improved MCC and had a positive effect on nasal physiology by increasing the nasal volume more than that achieved by RME.

Long-term effect on adenoid dimensions and craniocervical angulation after maxillary expansion with fixed or functional appliances

Background

Maxillary expansion is a common orthodontic procedure that could have a positive effect also on airway patency. The aim of the present study was to evaluate the long-term effects of rapid maxillary expansion (RME) on nasopharyngeal area and cranio-cervical angulation in growing patients, compared to controls treated with a function-generating bite appliance (FGB).

Material and Methods

Sixty patients aged 6-14 consecutively treated with RME or FGB were selected retrospectively and divided into two groups. Lateral cephalograms taken before and after treatment were retrieved, and the nasopharyngeal area, delimited superiorly by a sella-posterior nasal spine (PNS) line and inferiorly by a basion-PNS line, and the cranio-cervical angulation were measured.

Results

The mean observation time was 17.6 ± 8 months. No differences were present between the two groups regarding age and gender. The nasopharyngeal area increased significantly in both groups after treatment, but with no statistically significant difference between them. The cranio-cervical angulation showed no differences within or between groups.

Conclusions

Maxillary deficiency treatment with either RME or FGB was followed by a comparable increase in nasopharyngeal area.

Key words:Rapid maxillary expansion, Airway, Nasopharyngeal area, Adenoid.

Skeletal width changes after mini-implant-assisted rapid maxillary expansion (MARME) in young adults

OBJECTIVES

To observe skeletal width changes after mini-implant-assisted rapid maxillary expansion (MARME) and determine the possible factors that may affect the postexpansion changes using cone-beam computed tomography (CBCT) in young adults.

MATERIALS AND METHODS

Thirty-one patients (mean age 22.14 ± 4.76 years) who were treated with MARME over 1 year were enrolled. Four mini-implants were inserted in the midpalatal region, and the number of activations ranged from 40 to 60 turns (0.13 per turn). CBCT was performed before MARME (T0), after activation (T1), and after 1 year of retention (T2). The mean period between T1 and T0 was 6 ± 1.9 months and between T2 and T1 was 13 ± 2.18 months. A paired t-test was performed to compare T0, T1, and T2. The correlations between the postexpansion changes and possible contributing factors were analyzed by Pearson correlation analysis.

RESULTS

The widths increased significantly after T1. After T2, the palatal suture width decreased from 2.50 mm to 0.75 mm. From T1 to T2, decreases recorded among skeletal variables varied from 0.13 mm to 0.41 mm. This decrease accounted for 5.75% of the total expansion (2.26 mm) in nasal width (N-N) and 19.75% at the lateral pterygoid plate. A significant correlation was found between postexpansion change and palatal cortical bone thickness and inclination of the palatal plane (ANS-PNS/SN; P < .05).

CONCLUSIONS

Expanded skeletal width was generally stable after MARME. However, some amount of relapse occurred over time. Patients with thicker cortical bone of the palate and/or flatter palatal planes seemed to demonstrate better stability.

Long-term effects of mini-screw-assisted rapid palatal expansion on airway

OBJECTIVES

To evaluate the long-term effects on airway in patients with mini-screw-assisted rapid palatal expansion (MARPE), rapid palatal expansion (RPE), and controls with three-dimensional cone-beam computed tomography (CBCT) analysis.

MATERIALS AND METHODS

A total of 180 CBCTs of 60 patients were analyzed at different time points, such as pretreatment, postexpansion, and posttreatment. Patients were divided into three groups: mini-screw assisted rapid palatal expansion (MARPE), rapid palatal expansion (RPE), and controls. The nasal cavity, nasopharyngeal, oropharyngeal, and laryngopharyngeal airway volume and area were measured. Changes in total airway volume, total airway area, minimal cross-sectional area, maxillary intermolar width, external maxillary width, and palatal width were also evaluated.

RESULTS

Both MARPE and RPE caused a statistically significant increase in the airway after expansion as compared with the control group, but there was no statistically significant difference in the change in airway between MARPE, RPE, and the control group at posttreatment, except for nasopharyngeal volume, which was significantly increased in the MARPE group. There was no correlation between the amount of expansion and increase in total airway volume.

CONCLUSIONS

There was a significant increase in total airway volume, total airway area, and minimal cross-sectional area with MARPE and RPE immediately after expansion, but at posttreatment, the changes in the MARPE and RPE groups were similar to the change in the control group. However, MARPE led to a significant long-term increase in nasopharyngeal volume. The amount of expansion did not correlate with the increase in pharyngeal airway volume.

Comparison of skeletal maxillary transverse deficiency treated by microimplant-assisted rapid palatal expansion and tooth-borne expansion during the post-pubertal growth spurt stage

OBJECTIVE

To investigate the efficacy of microimplant-assisted rapid palatal expansion (MARPE) to treat skeletal maxillary discrepancies during the post-pubertal growth spurt stage.

MATERIALS AND METHODS

Sixty patients with skeletal maxillary transverse deficiency during the post-pubertal growth spurt stage were randomly divided into MARPE and Hyrax groups. Thirty patients (mean age: 15.1 ± 1.6 years) were treated using the four-point MARPE appliance; 30 patients (mean age, 14.8 ± 1.5 years) were treated using the Hyrax expander. Cone beam computed tomography scans and dental casts were obtained before and after expansion. The data were analyzed using paired t-tests and independent t-tests.

RESULTS

The success rates of midpalatal suture separation were 100% and 86.7% for MARPE and Hyrax groups, respectively. Palatal expansion and skeletal to dental ratio at the first molar level were greater in the MARPE group (3.82 mm and 61.4%, respectively) than in the Hyrax group (2.20 mm and 32.3%, respectively) (P < .01). Reductions in buccal alveolar bone height and buccal tipping of the first molars were less in the MARPE group than in the Hyrax group (P < .01).

CONCLUSIONS

MARPE enabled more predictable and greater skeletal expansion, as well as less buccal tipping and alveolar height loss on anchorage teeth. Thus, MARPE is a better alternative for patients with skeletal maxillary deficiency during the post-pubertal growth spurt stage.

Short-term and long-term effects of rapid maxillary expansion on the nasal soft and hard tissue

OBJECTIVES

To evaluate nasal soft and hard tissue changes immediately post-rapid maxillary expansion (RME) and to assess the stability of these changes using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 35 treatment group (TG) patients (18 girls, 17 boys; 9.39 ± 1.4) had a pre-RME CBCT and a post-RME CBCT approximately 66 days after expansion, and 25 patients had a follow-up CBCT 2.84 years later. A total of 28 control group (CG; no RME) patients (16 girls, 12 boys; 8.81 ± 1.6) had an initial CBCT and a CBCT an average of 2.25 years later. Soft and hard tissue nasal landmarks were measured in transverse, sagittal, and coronal planes of space on CBCT scans. Differences within the same group were evaluated by paired t-tests or Wilcoxon signed-rank tests. Long-term comparisons between TG and CG were evaluated by independent-sample t-tests or Wilcoxon rank-sum tests.

RESULTS

Immediately post-RME, there were statistically significant mean increases of 1.6 mm of alar base width, 1.77 mm of pyriform height, and 3.57 mm of pyriform width (P < .05). CG showed the significant increases over 2.25 years (P < .001). Compared with CG, the long-term evaluation of TG demonstrated only pyriform height and pyriform width showed a statistically significant difference (P < .01).

CONCLUSIONS

Although RME produced some significant increase on the nasal soft tissue immediately after expansion, it regressed to the mean of normal growth and development over time. However, long-term evaluation of TG compared with CG showed only pyriform height and pyriform width to be affected by RME.

Buccal Bone Changes Around First Permanent Molars and Second Primary Molars after Maxillary Expansion with a Low Compliance Ni-Ti Leaf Spring Expander

Background: Vestibular bone thickness changes and dento-alveolar buccal tipping of second primary molars and of first molars after maxillary expansion performed with a slow maxillary expansion protocol was investigated. Methods: Twenty patients (mean age 7.3 ± 0.9 years old; 9 male and 11 female) were treated according to the Leaf Expander protocol. Buccal alveolar bone thickness (BT), buccal alveolar bone height (BH), inter-dental angle (TIP), and inter-molar width (IW) regarding first molars and second primary molars were calculated before and after expansion on cone beam computed tomography (CBCT) images. Descriptive statistics and paired t-tests were used to assess changes between the pre-treatment and post-treatment measurements. Results: Bone thickness vestibular to second primary molars and intermolar width of both teeth were the only variables that showed statistically significant changes. Conclusions: It appears that buccal bone thickness vestibular to first molars was not significantly reduced after maxillary expansion with the Leaf Expander. The clinical use of a slow maxillary expander with Ni-Ti springs appears efficient and safe in in the correction of maxillary hypoplasia during mixed dentition.

Changes in nasal septum morphology after rapid maxillary expansion: a Cone-Beam Computed Tomography study in pre-pubertal patient

Introduction:

Nasal septum deviation (NSD) is the most common structural cause of nasal obstruction, affecting around 65-80% of the adult population. Rapid maxillary expansion (RME) is currently used for treatment of maxillary transverse deficiency, but can also influence nasal cavity geometry.

Objective:

The present study aimed at evaluating the changes in NSD by using Cone-Beam Computed Tomography (CBCT) scans in pre-pubertal patients treated with RME.

Methods:

This retrospective exploratory study evaluated 20 pre-pubertal patients (mean age 10 ± 2 years) who were treated for transverse maxillary constriction with RME and presented mild/moderate NSD as an incidental finding. The outcome measures were NSD tortuosity and area. These measures were obtained from transverse and coronal views of records taken before and after RME treatment. Intra-rater reliability was also assessed with intraclass correlation coefficient.

Results:

NSD was mild in thirteen patients (65%) and moderate in seven (35%). NSD tortuosity index did not significantly change over time (mean difference 0.002 mm/year, 95% CI; p = 0.58). NSD area did not significantly change over time (mean difference 2.103 mm²/year, 95% CI; p = 0.38). Intraclass correlation coefficient was 0.73 (95% CI) for NSD tortuosity and 0.84 (95% CI) for NSD area.

Conclusions:

NSD tortuosity and area suggested potential changes in NSD with small clinical relevance in pre-pubertal patients who were treated with RME. Additional studies using CBCT scans in larger samples are required to clarify the role of RME in NSD treatment.

CBCT and CAD-CAM technology to design a minimally invasive maxillary expander

Background

A large number of articles in recent years studying the effects of non-surgically assisted tooth- versus bone-borne maxillary expanders in growing patients have found no significant differences in mid-palatal suture disjunction or even dentoalveolar changes. This suggests the need for new criteria and better use of current technology to make more effective devices and enhance the benefits of conventional treatments. This article describes a titanium grade V computer-aided design/computer-aided manufacturing (CAD/CAM) maxillary expander supported by two miniscrews, along with a 3D printed surgical guide.

Methods

The first step was to obtain a digitized model of the patient’s upper maxilla. To simplify the process and ensure the placement of the device in a high-quality bone area, the patients’ digital dental cast was superimposed with a cone beam computed tomography (CBCT) scan. Improved resistance to expansion forces was secured through the use of 2 mm-wide miniscrews, long enough for bicortical anchorage. Placement site and direction were assessed individually in order to achieve primary stability. We chose a site between the second premolars and first molars, while the inclination followed the natural contour of the palate vault. A 3D-printed, polyamide surgical guide was designed to ensure the correct placement of the device with a manual straight driver.

Results

Favorable clinical results were presented with 3D images. We confirmed a mid-palatal suture parallel separation of 3.63 mm, along with a higher palatal volume, as well as increased intercanine and intermolar distance. Segmentation of the facial soft tissue showed an expansion of nasal airways and changes in nasal morphology.

Conclusions

Digital models, CBCT and CAD/CAM technology, are essential to accomplish the goals proposed in this article. Further studies are necessary to establish safer miniscrew placement sites and insertion angles so as to achieve greater in-treatment stability. Both the clinician and the patient can benefit from the use of current technology, creating new devices and updating traditional orthodontic procedures.

Pulp blood flow and sensibility in patients with a history of dental trauma undergoing maxillary expansion

OBJECTIVES

To assess changes in pulp blood flow (PBF) and pulp sensibility (PS) in teeth of patients with a history of dental trauma undergoing maxillary expansion.

MATERIALS AND METHODS

Twenty-five patients requiring rapid maxillary expansion (RME) had the pulp status of their maxillary anterior teeth assessed using laser Doppler flowmetry, electric pulp testing, and thermal testing (CO2 snow). Each patient was tested at T1 (prior to expansion), T2 (2 weeks after rapid expansion), and T3 (3 months after expansion). Relationships between PBF, time interval, and history of trauma were evaluated using linear mixed modelling.

RESULTS

Within the Trauma group, PBF was significantly lower (P ≤ .05) at T2 and T3 in comparison to T1 and significantly lower (P ≤ .05) at T2 in comparison to T3. In the Non-trauma group, PBF at T2 was significantly lower (P ≤ .05) than PBF at T1 and T3; however, no significant difference (P > .05) in PBF was observed when comparing PBF at T1 and T3. In both groups, PS was maintained in almost all teeth (>90%).

CONCLUSIONS

RME in healthy teeth causes reduction of PBF before reestablishment of pretreatment values. RME in traumatized teeth causes reduction of PBF without PBF being reestablished to pretreatment levels. Teeth with a history of compromise may have reduced adaptive capacity under insults such as RME, which should be appreciated during the informed consent process.

Differential assessment of skeletal, alveolar, and dental components induced by microimplant-supported midfacial skeletal expander (MSE), utilizing novel angular measurements from the fulcrum

Background

In order to assess skeletal expansion, alveolar bone bending, and dental tipping after maxillary expansion, linear and angular measurements have been performed utilizing different craniofacial references. Since the expansion with midfacial skeletal expander (MSE) is archial in nature, the aim of this paper is to quantify the differential components of MSE expansion by calculating the fulcrum locations and applying a novel angular measurement system.

Methods

Thirty-nine subjects with a mean age of 18.2 ± 4.2 years were treated with MSE. Pre- and post-expansion CBCT records were superimposed and compared. The rotational fulcrum of the zygomaticomaxillary complex was identified by localizing the interfrontal distance and modified interfrontal distance. Based on the fulcrum, a novel angular measurement method is presented and compared with a conventional linear method to assess changes of the zygomaticomaxillary complex, dentoalveolar bone, and maxillary first molars.

Results

From 39 patients, 20 subjects have the rotational fulcrum of the zygomaticomaxillary complex at the most distant points of the interfrontal distance (101.6 ± 4.7 mm) and 19 subjects at the most distant points of the modified interfrontal distance (98.9 ± 5.7 mm). Linear measurements accounted for 60.16% and 56.83% of skeletal expansion, 16.15% and 16.55% of alveolar bone bending, and 23.69% and 26.62% of dental tipping for right and left side. Angular measurements showed 96.58% and 95.44% of skeletal expansion, 0.34% and 0.33% alveolar bone bending, and 3.08% and 4.23% of dental tipping for the right and left sides. The frontozygomatic, frontoalveolar, and frontodental angles were not significant different (P > 0.05).

Conclusions

In the coronal plane, the center of rotation for the zygomaticomaxillary complex was located at the most external and inferior point of the zygomatic process of the frontal bone or slightly above and parallel to the interfrontal distance. Due to the rotational displacement of the zygomaticomaxillary complex, angular measurements should be a preferred method for assessing the expansion effects, instead of the traditional linear measurement method.

Impact of rapid palatal expansion on the internal nasal valve and obstructive nasal symptoms in children

OBJECTIVE

The aim of this study is to evaluate the impact of rapid palatal expansion (RPE) on the nasal airway subjectively by utilizing patient-reported outcome measures (PROM) and objectively by evaluating validated internal nasal valve (INV) measurements obtained from cone beam computed tomography (CBCT) in pediatrics.

MATERIALS AND METHODS

In this retrospective cohort study, subjects who underwent RPE from March to December 2018 with cone beam CT and Nasal Obstruction Symptom Evaluation (NOSE) scores were included. Exclusion criteria included craniofacial deformity, allergies, asthma, recent nasal trauma, or surgery. INV measurements (angle and cross-sectional area), diastema, midpalatal suture opening, and NOSE scores were evaluated.

RESULTS

Fifty-one subjects met the inclusion criteria with a mean age of 10.1 ± 2.6. Pre-expansion mean NOSE score was 32.55 (moderate) while post-expansion was 13.92 (mild). Mean NOSE score improved significantly by an average of 18.63 following post-expansion (P < 0.0001). The patients' right and left INV angles increased significantly by a mean of 2.42° and 2.65° respectively (P < 0.0001). Right and left INV cross-sectional areas increased significantly by an average of 14.35 mm² (P < 0.0001) and 14.17 mm² (P < 0.0001) respectively. An average expansion of the diastema and the suture was 1.60 mm and 3.05 mm respectively (P < 0.0001), with an average of 6.29 mm of expansion. We found the amount of diastema expansion to correlate with change in NOSE score (R = - 0.32, P = 0.022). Age and diastema showed a negative correlation (R = - 0.44, P = 0.0019), while INV angle and diastema showed a statistically significant positive correlation (R = 0.28, P = 0.048).

CONCLUSIONS

RPE showed improvement in both NOSE scores and objective measures of the INV. This may show the possibility of considering RPE in managing resistant pediatric nasal airways. Future studies should include collaboration with pediatric otolaryngologists, with the inclusion of pediatric patients with persistent nasal obstruction.

Complex clinical case with Class III and open bite: stability after seven years

A healthy 15-year-old boy with anterior open bite, edge-to-edge transverse discrepancy, and Class III skeletal relationship sought a nonsurgical orthodontic treatment. The patient was treated with premolars extraction, a Hyrax expander and intrusion mechanics with vertical elastics. This mechanics allowed for excellent facial and occlusal results. The final occlusion presented Class I molar and canine relationships, ideal overjet and overbite, and straight facial profile. Analysis of the posttreatment and follow-up radiographs showed that the treatment outcomes remained stable seven years after active orthodontic treatment. Thus, although combined orthodontic and surgical treatment should be considered for patients with this skeletal malocclusion, this case report proves that well controlled orthodontic movement with the patient's cooperation can be a valid alternative treatment, with good and stable outcomes for patients who refuse surgery.

Transverse maxillary deficiency: treatment alternatives in face of early skeletal maturation

Transverse deficiencies should be a priority in orthodontic treatment, and should be corrected as soon as diagnosed, to restore the correct transverse relationship between maxilla and mandible and, consequently, normal maxillary growth. Corrections may be performed at the skeletal level, by opening the midpalatal suture, or by dentoalveolar expansion. The choice of a treatment alternative depends on certain factors, such as age, sex, degree of maxillary hypoplasia and maturation of the midpalatal suture. Thus, the present study discusses different treatment approaches to correct maxillary hypoplasia in patients with advanced skeletal maturation.

Evaluation of Growth and Development of Late Mixed Dentition Upper Dental Arch with Normal Occlusion Using 3-Dimensional Digital Models

Objective

The purpose of this study was to observe the three-dimensional growth and development of the maxillary arch in 10-year-olds with normal occlusion during the late mixed dentition stage.

Methods

Forty-four 10-year-old students (22 males and 22 females) who had normal occlusion during late mixed dentition were selected from an elementary school in Beijing, China. Once per year for three consecutive years, a dental cast was obtained from each subject, and the cast was scanned with a 3D digital scanner (R700 3D). The three-dimensional measurements of the maxillary dental arch and the inclination of the bilateral maxillary first molars were obtained from the digital model.

Results

The upper anterior arch length (UAAL), upper total arch length (UTAL), upper inter primary or permanent canine width (UICW), upper intermolar width (UIMW), and upper dental arch length (UDAL) increased by 0.959 mm, 0.583 mm, 0.955 mm, 1.462 mm, and 2.46 mm, respectively, over the two years (P < 0.001). UR6BL and UL6BL decreased by 4.416° and 7.133°, respectively, over the two years (P < 0.001). The values of the UICW and UIMW were 1.67 mm and 1.86 mm, respectively, larger in males than in females at 12 years old (P < 0.01). The change in the UTAL was 0.431 mm greater in males than in females over the 2 years (P < 0.05).

Conclusion

The UAAL, UTAL, UICW, UIMW, and UDAL in 10- to 12-year-olds with normal occlusion increased with age. The buccolingual inclination of the bilateral maxillary first molars inclined to the palatal side with age. The UICW and UIMW were larger in males than in females at 12 years old. The male UTAL increased more than the female UTAL over the 2 years.

Molar inclination and surrounding alveolar bone change relative to the design of bone-borne maxillary expanders: A CBCT study

OBJECTIVE

To evaluate the molar inclination and skeletal and alveolar bone changes when comparing tooth bone-borne (MSE) and tissue bone-borne type maxillary expanders (C-expander) using cone-beam computed tomography (CBCT) in late adolescence.

MATERIALS AND METHODS

A sample of 48 late-adolescent patients were divided into two groups according to the type of expander: MSE group (n = 24, age = 19.2 ± 5.9 years) and C-expander group (n = 24, age = 18.1 ± 4.5 years). CBCT scans were taken before treatment and 3 months after expansion. Transverse skeletal and dental expansion, alveolar inclination, tooth axis, buccal alveolar bone height, thickness, dehiscence, and fenestration were evaluated on the maxillary first molar. Paired t-test, independent t-test, Pearson's chi-square test, and Spearman correlation analysis were performed.

RESULTS

The MSE group produced greater dental expansion (P < .05), whereas skeletal expansion was similar in both groups (P = .859). The C expander group had more alveolar bone inclination change (P < .01), and the MSE group had more buccal tipping of the anchorage teeth (P < .01 or .001). Buccal alveolar bone height loss and thickness changes were greater in the MSE group (P < .01 or <.001). Formation of dehiscences was more frequent in the MSE group (P < .001), whereas for fenestrations, there were no significant differences between the two groups. Buccal bone height loss in the MSE group had a negative correlation with initial buccal bone thickness.

CONCLUSIONS

The incorporation of teeth into bone-borne expanders resulted in an increase in the severity of side effects. For patients in late adolescence, tissue bone-borne expanders offer comparable skeletal effects to tooth bone-borne expanders, with fewer dentoalveolar side effects.

Rapid maxillary expansion outcomes according to midpalatal suture maturation levels

BACKGROUND

This study aims to compare the relationship between skeletal and dental outcomes of rapid maxillary expansion (RME) treatment on cone beam computed tomography (CBCT) images between pre-pubertal peak (pre-peak) and post-pubertal peak (post-peak) patients. The null hypothesis was that there was no difference in the outcomes of RME treatment between the groups.

METHODS

Thirty-two patients who underwent RME treatment were classified according to midpalatal suture maturation levels and then divided into two groups as pre-peak and post-peak. Skeletal and dental measurements were performed on the CBCT images at T0 (pre-treatment stage) and at T1 (post-treatment stage). Paired sample t test was used to evaluate normally distributed data and P < 0.05 was taken as the significance level.

RESULTS

There were significant differences between T0 and T1 within the groups, but the changes between the pre-peak and post-peak patient groups were not statistically significant.

CONCLUSION

Non-significant changes were found between the two groups, and the null hypothesis was excepted.

Three-dimensional stereophotogrammetric analysis of nasolabial soft tissue effects of rapid maxillary expansion: a systematic review of clinical trials

The aim of this systematic review is to analyse the quality and clinical evidence in the literature analysing, through 3D stereophotogrammetry, the nasolabial soft tissue modifications that may occur after rapid maxillary expansion (RME). This systematic literature review was based on the PRISMA-P statement and was registered in the PROSPERO database with the following protocol ID: CRD42017079875. Pubmed, Cochrane, EBSCO, Scopus, Web of Science databases were searched with no restriction of year or publication status. Selection criteria were: randomised clinical trials, controlled clinical trials, cohort studies, cross-sectional studies, case-control studies on patients with unilateral/bilateral crossbite, transverse maxillary deficiency and crowding, treated with RME and monitored by 3D stereophotogrammetry. 652 articles were retrieved in the initial search. After the review process, 11 full-text articles met inclusion criteria. After the evaluation process, 4 publications were included for the present literature review. Due to the heterogeneous methodology meta-analysis was not possible; consequently, a systematic assessment of the studies and summary of the findings from the available evidence were used to answer the research question. The maximum widening of the alar cartilage is 1.41 ± 0.95 mm, whose clinical significance is open to question. The effect of RME on the mouth width remains controversial. In Altindis et al., the difference between pre-treatment and post-treatment mouth width (1.80 mm increment in the banded RME group) was statistically significant, while in Baysal 1.86 mm was considered a non-significant value. Inconsistencies and limitations in the study population and measurement protocols were detected between studies. These data underline the necessity for updated guidelines that allow to standardise, for this type of study, sample selection, measurement methods and collection of results.

Influence of changing various parameters in miniscrew-assisted rapid palatal expansion: A three-dimensional finite element analysis

Objective

This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM).

Methods

In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE.

Results

When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes.

Conclusions

The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

Mini-implant selection protocol applied to MARPE

Introduction:

Rapid maxillary expansion (RME) is the therapy of choice to correct skeletal transverse dimension in children and adolescents, associating orthopedic and dental effects. In an attempt to prevent the undesirable dentoalveolar effects and optimize the potential of skeletal expansion in individuals in advanced stages of skeletal maturation, the miniscrew-assisted rapid palatal expander (MARPE) was proposed by Lee et al. in 2010.

Objective:

This paper presents a systematized protocol for selection of miniscrews indicated for MARPE, by the evaluation of cone-beam computed tomographies (CBCT). Variables related with the bone and soft tissue thicknesses at the palatal regions of interest, as well as in relation to the fixation rings of miniscrews of the palatal expander are analyzed and discussed to provide better performance in the clinical practice.

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

OBJECTIVES

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Transverse Skeletal Effects of Rapid Maxillary Expansion in Pre and Post Pubertal Subjects: A Systematic Review

OBJECTIVE

The aim of this systematic review was to assess the transverse skeletal effects of rapid maxillary expansion (RME) in pre and post-pubertal subjects.

MATERIAL AND METHODS

Five databases were searched till May 2018; Pubmed, Cochrane, Scopus, Lilacs and Web of science in addition to the manual search of other sources. There were no language restrictions. Methodological Index for Non-Randomized Studies MINORS was used to assess the quality and risk of bias of the trials included.

RESULTS

Six studies were finally included in the qualitative analysis. A meta-analysis wasn't performed due to the heterogeneity of methodologies and outcomes. All of the included studies showed drawbacks in their structure yielding weak evidence. On the short term, RME caused an increase in the maxillary and lateral-nasal widths in pre-pubertal subjects by 3.4 mm and 3.3 mm, and by 2.8 and 2.2 mm respectively in post-pubertal subjects. Although statistically insignificant, the maxillary width increase was more than that of the post-pubertal subjects by 0.6 mm. Over the long term, expansion produced permanent increases in the transverse dimensions of both the dento-alveolar and skeletal components of the maxilla and circum-maxillary structures in pre-pubertal subjects. The post-pubertal subjects presented with a statistically significant increase only in the later-nasal width by 1.3 mm than the untreated controls with no permanent increase in the skeletal maxillary width.

CONCLUSION

The literature is very deficient regarding the use of skeletal age as a reference in the treatment of skeletal crossbites using RME. Only weak evidence exists supporting the increased maxillary and lateral-nasal widths after tooth-tissue borne RME in pre-pubertal subjects, with these effects being less in the post-pubertal ones.

Three-Dimensional Prospective Evaluation of Piezocision-Assisted and Conventional Rapid Maxillary Expansion: A Controlled Clinical Trial

BACKGROUND:

Piezocision-assisted orthodontics (PAO) is considered one of the modern techniques aiming at reducing the treatment time and overcoming some limitations of orthodontic treatment. The use of piezocision as an adjunct in the treatment of posterior crossbite is limited, so additional research in this area is required.

AIM:

To three-dimensionally compare the skeletal and dental effects produced by piezocision-assisted rapid maxillary expansion (PARME) and conventional rapid maxillary expansion (RME) using cone beam computed tomography (CBCT).

MATERIALS AND METHODS:

This prospective controlled study comprised 14 consecutive non-syndromic patients with posterior crossbite. In 7 patients (mean age = 16.1 ± 0.3 years), PARME was used to correct the crossbite; whereas in the remaining 7 (mean age = 15.9 ± 0.5 years), RME was done. Cone beam computed tomography (CBCT) scans were performed before expansion (T1) and 3 months later after expansion (T2) to compare the skeletal and dental effects produced by the two expansion techniques. Transverse skeletal, dentolinear, and dentoangular variables at the level of maxillary first and second premolars and maxillary first molars were measured and compared within and between groups using the appropriate statistical test.

RESULTS:

For the transverse skeletal variables, PARME showed a non-significant increase; whereas, RME showed a significant increase. Regarding the dentolinear measurements, a significant increase in coronal widths and an insignificant increase in apical widths was seen in PARME, whereas, the RME showed a non-significant increase for both coronal and apical widths. Non-significant decreases (protrusion of teeth) in the dentoangular measurements were seen in both groups. Between-group comparisons showed a non-significant difference except for the dentolinear coronal widths.

CONCLUSION:

PARME is effective in treating posterior crossbite. Because of the more dental expansion produced by PARME as compared to the conventional RME, PARME should be limited only to mild or moderate not severe forms of palatal constriction. The available evidence regarding the effectiveness of corticotomy- and/or piezocision-assisted maxillary expansion for correction of posterior crossbite is limited and inadequate.

Investigation of maxillary sinus volume relationships with nasal septal deviation, concha bullosa, and impacted or missing teeth using cone-beam computed tomography

OBJECTIVES

The aim of this retrospective study was to investigate the correlations of maxillary sinus volume with nasal septal deviation, concha bullosa, impacted teeth, and missing teeth in the maxillary posterior region on maxillary sinus volume using cone-beam computed tomography (CBCT) images.

METHODS

The study cohort comprised 252 CBCT images of 252 patients retrospectively selected from the records in our CBCT archive. All CBCT images were exported to 3D modeling software for calculation of maxillary sinus volumes. Nasal septal deviation cases were grouped as mild, moderate, and severe. Concha bullosa was classified as lamellar, bulbous, and extensive. Maxillary sinus volume differences were evaluated by comparing the bilateral sinus volumes in patients with nasal septal deviation, unilateral concha bullosa, and unilateral impacted or missing maxillary posterior teeth.

RESULTS

The findings revealed that males had a significantly higher mean sinus volume than females (p < 0.01) and that sinus volume tended to decrease with age (p < 0.05). In moderate and severe nasal septal deviation cases, the maxillary sinus volume was significantly smaller on the same side as the deviation than on the contralateral side (p < 0.05). There were no significant correlations between maxillary sinus volume and concha bullosa, unilateral impacted teeth, or unilateral missing teeth (p > 0.05).

CONCLUSIONS

The present findings suggest that maxillary sinus volume is smaller on the same side as the deviation in moderate and severe septal deviation cases and that the maxillary sinus volume tends to decrease with increasing age.

Evaluation of a novel palatal suture maturation classification as assessed by cone-beam computed tomography imaging of a pre- and postexpansion treatment cohort

OBJECTIVES

To test the reliability and usefulness of the midpalatal suture maturation classification and methodology proposed in 2013 by Angelieri et al. for successful prediction of rapid maxillary expansion (RME) treatment results.

MATERIALS AND METHODS

Reliability testing focused on 16 patients aged 9.5-17 years with early mixed to full permanent dentition, representing all proposed palatal maturation stages, from available preexpansion cone-beam computed tomography (CBCT). A retrospective observational longitudinal (cohort) study evaluated 63 preadolescent and adolescent patients aged 11-17 years with full permanent dentition treated with tooth-borne RME appliances who had CBCT records taken at pre- (T₁) and postexpansion (T₂). CBCT three-dimensional landmarking produced skeletal and dental widths and dental angulations used to evaluate the extent of skeletal and/or dental expansion. A regression model was used to assess the prediction capability of the T1 palatal suture classification of each subject for dental and skeletal changes.

RESULTS

There was almost perfect intraexaminer agreement and slight to poor interexaminer agreement, differing from previously reported reliability, affected by necessary operator calibration and the degree of postacquisition image sharpness and clarity. Further exploration of its scientific basis suggested that the proposed classification was ill-founded. Results from the cohort study were also wholly unsupportive of efficacy of the proposed palatal suture maturation classification in predicting the magnitude of portrayed changes.

CONCLUSIONS

Clinicians should be cautious in applying this classification. Although it has merits, the palatal classification still needs much more research and validation.

Differential Benefit of Two Different Tooth-Borne Rapid Maxillary Expansion Appliances in Female Subjects

Objective

The aim of the present study was to evaluate the effects of tooth-borne acrylic-bonded rapid maxillary expansion (RME) appliances with or without the anterior teeth anchorage on the skeletal and dentoalveolar structures, as well as soft tissues.

Methods

This study included 44 patients who were treated with two different tooth-borne bonded acrylic RME appliances. Lateral cephalometric radiographs were taken before the treatment (T0) and in the post-retention (T1) phase of the RME treatment. The posterior-bonded RME appliance group and full-bonded RME appliance group were created as the two different groups of treatment. The following statistical analyses were performed: intra- and inter-group comparisons were made using the paired t-test, Wilcoxon test, independent t-test, and Mann-Whitney U-test for normal and non-normal distribution data.

Results

Significant increases were observed in R1-A, R1-ANS, R1-U1, R1-AR, R1-St, R1-Li, and R1-Pn in both groups. R1-PNS, R1-Ls, R1-Sn, and R1-B' were found to be significantly larger at T1 than at T0 in the posterior-bonded RME appliance group. R2-A, R2-ANS, R2-L1, R2-A', and R2-Pn were significantly larger at T1 than at T0 in the full-bonded RME appliance group. The R2-A' was significantly different between the groups.

Conclusion

The soft tissue A point appears to be the most important differing matter between the two different RME appliances, and a full acrylic-bonded RME appliance may be beneficial for subjects with a maxillary retrognathic profile.

Developing Class III malocclusions: challenges and solutions

Class III malocclusion represents a growth-related dentofacial deformity with mandibular prognathism in relation to the maxilla and/or cranial base. Its prevalence varies greatly among and within different races, ethnic groups, and geographic regions studied. Class III malocclusion has a multifactorial etiology, which is the expression of a moderate distortion of normal development as a result of interaction between innate factors or genetic hereditary with environmental factors. Various skeletal topographies of underlying Class III malocclusion are due to discrepancy in the maxillary and mandibular growth along with vertical and/or transverse problems apart from sagittal malformations. The spectrum of complications for Class III malocclusion ranges in gravity from dentoalveolar problems with functional anterior shift of the mandible to true skeletal problems with serious maxillomandibular discrepancies, which makes its diagnosis highly challenging in growing children. Concern regarding early treatment and the need for interceptive care in the case of Class III malocclusion has always been a dilemma, knowing that not all problems will be solved in these cases until maxillomandibular growth is further completed, and the long-term outcome of various treatment approaches may depend on the growth tendency of an individual. Interceptive treatment of Class III malocclusions should be undertaken if it prevents damage to the oral tissues and/or significantly reduces the amount or severity of future orthodontic and surgical interventions. This paper presents an overview of developing Class III malocclusion, with the emphasis on challenges and their solutions based on the best current available evidence.

Relationship between dental calcification and skeletal maturation in a Peruvian sample

Objective:

the objective of the study was to determine the relationship between dental calcification stages and skeletal maturation in a Peruvian sample.

Methods:

panoramic, cephalometric and carpal radiographs of 78 patients (34 girls and 44 boys) between 7 and 17 years old (9.90 ± 2.5 years) were evaluated. Stages of tooth calcification of the mandibular canine, first premolar, second premolar, and second molar and the skeletal maturation with a hand-wrist and a cervical vertebrae method were assessed. The relationships between the stages were assessed using Spearman's correlation coefficient. Additionally, the associations of mandibular and pubertal growth peak stages with tooth calcification were evaluated by Fisher's exact test.

Results:

all teeth showed positive and statistically significant correlations, the highest correlation was between the mandibular second molar calcification stages with hand-wrist maturation stages (r = 0.758, p < 0.001) and with vertebrae cervical maturation stages (r = 0.605, p < 0.001). The pubertal growth spurt was found in the G stage of calcification of the second mandibular molar, and the mandibular growth peak was found in the F stage of calcification of the second molar.

Conclusion:

there was a positive relationship between dental calcification stages and skeletal maturation stages by hand-wrist and cervical vertebrae methods in the sample studied. Dental calcification stages of the second mandibular molar showed the highest positive correlation with the hand-wrist and cervical vertebrae stages.

The cervical vertebral maturation method: A user's guide

The cervical vertebral maturation (CVM) method is used to determine the craniofacial skeletal maturational stage of an individual at a specific time point during the growth process. This diagnostic approach uses data derived from the second (C2), third (C3), and fourth (C4) cervical vertebrae, as visualized in a two-dimensional lateral cephalogram. Six maturational stages of those three cervical vertebrae can be determined, based on the morphology of their bodies. The first step is to evaluate the inferior border of these vertebral bodies, determining whether they are flat or concave (ie, presence of a visible notch). The second step in the analysis is to evaluate the shape of C3 and C4. These vertebral bodies change in shape in a typical sequence, progressing from trapezoidal to rectangular horizontal, to square, and to rectangular vertical. Typically, cervical stages (CSs) 1 and CS 2 are considered prepubertal, CS 3 and CS 4 circumpubertal, and CS 5 and CS 6 postpubertal. Criticism has been rendered as to the reproducibility of the CVM method. Diminished reliability may be observed at least in part due to the lack of a definitive description of the staging procedure in the literature. Based on the now nearly 20 years of experience in staging cervical vertebrae, this article was prepared as a "user's guide" that describes the CVM stages in detail in attempt to help the reader use this approach in everyday clinical practice.

Expansion of permanent first molars with rapid maxillary expansion appliance anchored on primary second molars

Background

To evaluate how the amount of expansion of the primary second molars, the patient’s age, and the skeletal maturation stage influence the amount of expansion at the level of the permanent first molars.

Material and Methods

Fifty-five patients aged between 6 and 11 years with a cervical vertebral maturation stage of CS1 or CS2 were retrospectively selected. The intermolar width was measured before and after expansion to evaluate the amount of expansion achieved at the level of the primary second molars and the permanent first molars. Stepwise multiple linear regression was used to evaluate how the amount of primary molars expansion, the patient’s age, and the cervical vertebral maturation stage predict the amount of permanent molar expansion.

Results

A significant regression equation was found, and for every 1 mm of primary molar expansion, 0.91 mm of permanent molar expansion can be expected. An age between 6 and 11 years and the CS1 or CS2 skeletal maturation stage were not significant predictors of permanent molar expansion.

Conclusions

A rapid maxillary expansion appliance anchored on primary second molars is effective in expanding the permanent molars to correct a transverse maxillary deficiency in prepubertal patients, transferring the risks associated with the large forces used to the primary teeth.

Key words:Maxillary expansion, transversal deficiency, primary molars.

Nasal septum changes in adolescent patients treated with rapid maxillary expansion

Objective:

To analyze cone-beam computed tomography (CBCT) scans to measure changes in nasal septal deviation (NSD) after rapid maxillary expansion (RME) treatment in adolescent patients.

Methods:

This retrospective study involved 33 patients presenting with moderate to severe nasal septum deviation as an incidental finding. Out of these 33 patients, 26 were treated for transverse maxillary constriction with RME and seven, who did not undergo RME treatment, were included in the study as control group. CBCT scans were taken before appliance insertion and after appliance removal. These images were analyzed to measure changes in nasal septum deviation (NSD). Analysis of variance for repeated measures (ANOVA) was used.

Results:

No significant changes were identified in NSD regardless of the application or not of RME treatment and irrespective of the baseline deviation degree.

Conclusion:

This study did not provide strong evidence to suggest that RME treatment has any effect on NSD in adolescent patients; however, the results should be interpreted with caution, due to the small sample size and large variation amongst individual patient characteristics.

Novel methodologies and technologies to assess mid-palatal suture maturation: a systematic review

INTRODUCTION

A reliable method to assess midpalatal suture maturation to drive clinical decision-making, towards non-surgical or surgical expansion, in adolescent and young adult patients is needed. The objectives were to systematically review and evaluate what is known regarding contemporary methodologies capable of assessing midpalatal suture maturation in humans.

METHODS

A computerized database search was conducted using Medline, PubMed, Embase and Scopus to search the literature up until October 5, 2016. A supplemental hand search was completed of references from retrieved articles that met the final inclusion criteria.

RESULTS

Twenty-nine abstracts met the initial inclusion criteria. Following assessment of full articles, only five met the final inclusion criteria. The number of subjects involved and quality of studies varied, ranging from an in-vitro study using autopsy material to prospective studies with in vivo human patients. Three types of evaluations were identified: quantitative, semi-quantitative and qualitative evaluations. Four of the five studies utilized computed tomography (CT), while the remaining study utilized non-invasive ultrasonography (US). No methodology was validated against a histological-based reference standard.

CONCLUSIONS

Weak limited evidence exists to support the newest technologies and proposed methodologies to assess midpalatal suture maturation. Due to the lack of reference standard validation, it is advised that clinicians still use a multitude of diagnostic criteria to subjectively assess palatal suture maturation and drive clinical decision-making.

Miniscrew-assisted rapid palatal expansion for managing arch perimeter in an adult patient

INTRODUCTION:

Etiology of dental crowding may be related to arch constriction in diverse dimensions, and an appropriate manipulation of arch perimeter by intervening in basal bone discrepancies cases, may be a key for crowding relief, especially when incisors movement is limited due to underlying pathology, periodontal issues or restrictions related to soft tissue profile.

OBJECTIVES:

This case report illustrates a 24-year old woman, with maxillary transverse deficiency, upper and lower arches crowding, Class II, division 1, subdivision right relationship, previous upper incisors traumatic episode and straight profile. A non-surgical and non-extraction treatment approach was feasible due to the miniscrew-assisted rapid palatal expansion technique (MARPE).

METHODS:

The MARPE appliance consisted of a conventional Hyrax expander supported by four orthodontic miniscrews. A slow expansion protocol was adopted, with an overall of 40 days of activation and a 3-month retention period. Intrusive traction miniscrew-anchored mechanics were used for correcting the Class II subdivision relationship, managing lower arch perimeter and midline deviation before including the upper central incisors.

RESULTS:

Post-treatment records show an intermolar width increase of 5 mm, bilateral Class I molar and canine relationships, upper and lower crowding resolution, coincident dental midlines and proper intercuspation.

CONCLUSIONS:

The MARPE is an effective treatment approach for managing arch-perimeter deficiencies related to maxillary transverse discrepancies in adult patients.

Assessment of midpalatal suture ossification using cone-beam computed tomography

BACKGROUND AND OBJECTIVE

The degree of ossification of the midpalatal suture is an important factor in the selection of treatment procedure, especially in young individuals. Considering the discrepancies in the results of studies on the exact time of the closure of this suture, the present study was undertaken to evaluate ossification and morphology of the suture with the use of CBCT.

METHODS

In the present cross-sectional study, the CBCT images of the maxilla in 144 Iranian subjects (72 males, 72 females) with an age range of 10 to 70 years, referring to a private radiology center in Sari, Iran, were evaluated. The CBCT images were evaluated in the axial cross-sectional slice at 1 mm intervals to determine morphology and the maturation stage of the suture and its degree of ossification. The six developmental stages that were observed were as follows: stage A, a direct line without disturbances; stage B, a scalloped appearance in the suture; stage C, two parallel lines with a scalloped appearance that were connected at some points; stage CD, the anterior portion was similar to stage C, and the posterior region was similar to stage D; stage D, ossification only in the palatine bone; stage E, complete ossification of the suture. The degree of ossification of the suture was calculated with the use of the ratio of the length of the ossified segment to the entire length of the suture. Data were analyzed with Spearman's correlation test, Chi-squared test, t-test, ANOVA, Mann-Whitney U, and Kruskal-Wallis test. Intra-observer agreement was calculated with the use of weighted kappa coefficient. Data were analyzed with SPSS 17.

RESULTS

There was a strong correlation between the age groups and the developmental stages of the midpalatal suture in both genders (r=0.681, p<0.001). The ossification process occurred in the posterior to anterior direction in 98% of the cases. There was a significant relationship between aging and the degree of ossification (p<0.001); however, the difference was not significant between the two genders (p=0.193).

CONCLUSION

Although the rate of suture closure increased with aging, age was not a reliable factor alone to determine the developmental stage of the suture. Use of CBCT is necessary in all the patients to determine the degree of ossification and morphology of the midpalatal suture.

Immediate impact of rapid maxillary expansion on upper airway dimensions and on the quality of life of mouth breathers

OBJECTIVE:

To assess short-term tomographic changes in the upper airway dimensions and quality of life of mouth breathers after rapid maxillary expansion (RME).

METHODS:

A total of 25 mouth breathers with maxillary atresia and a mean age of 10.5 years old were assessed by means of cone-beam computed tomography (CBCT) and a standardized quality of life questionnaire answered by patients' parents/legal guardians before and immediately after rapid maxillary expansion.

RESULTS:

Rapid maxillary expansion resulted in similar and significant expansion in the width of anterior (2.8 mm, p < 0.001) and posterior nasal floor (2.8 mm, p < 0.001). Although nasopharynx and nasal cavities airway volumes significantly increased (+1646.1 mm3, p < 0.001), oropharynx volume increase was not statistically significant (+1450.6 mm3, p = 0.066). The results of the quality of life questionnaire indicated that soon after rapid maxillary expansion, patients' respiratory symptoms significantly decreased in relation to their initial respiratory conditions.

CONCLUSIONS:

It is suggested that RME produces significant dimensional increase in the nasal cavity and nasopharynx. Additionally, it also positively impacts the quality of life of mouth-breathing patients with maxillary atresia.

Prediction of rapid maxillary expansion by assessing the maturation of the midpalatal suture on cone beam CT

Rapid maxillary expansion (RME) primarily involves the mechanical opening of the midpalatal suture of the maxillary and palatine bones. The fusion of the midpalatal suture determines the failure of RME, a common event in late adolescents and young adults. Recently, the assessment of the maturation of midpalatal suture as viewed using cone beam computed tomography (CBCT) has been introduced. Five maturational stages of the midpalatal suture have been presented: Stage A = straight high-density sutural line, with no or little interdigitation; Stage B = scalloped appearance of the high-density sutural line; Stage C = two parallel, scalloped, high-density lines that lie close to each other, separated in some areas by small low-density spaces; Stage D = fusion of the palatine bone where no evidence of a suture is present; and Stage E = complete fusion that extends also anteriorly in the maxilla. At Stage C, less skeletal response would be expected than at Stages A and B, as there are many bony bridges along the suture. For patients at Stages D and E, surgically assisted RME would be necessary, as the fusion of the midpalatal suture already has occurred either partially or totally. This diagnostic method can be used to estimate the prognosis of the RME, mainly for late adolescents and young adults for whom this procedure is unpredictable clinically.

Evaluation of the stiffness characteristics of rapid palatal expander screws

Background

The aim of this study is to evaluate the mechanical properties of the screws used for rapid expansion of the upper jaw.

Methods

Ten types of expansion screw were assessed, seven with four arms: Lancer Philosophy 1, Dentaurum Hyrax Click Medium, Forestadent Anatomic Expander type “S”, Forestadent Anatomic Expander type “S” for narrow palates, Forestadent Memory, Leone A 2620-10 with telescopic guide, and Leone A 0630-10 with orthogonal arms; and three with two arms: Dentaurum Variety S.P., Target Baby REP Veltri, and Leone A 362113. A test expander with the mean dimensions taken from measurements on a sample of 100 expanders was constructed for each screw. The test expanders were connected to the supports of an Instron 4467 (Instron Corp., USA) mechanical testing machine equipped with a 500 N load cell, and the compression force exerted after each activation was measured. The mean forces expressed by the two- and four-arm expanders were then compared.

Results

After five activations, the forces expressed by the two-arm devices were double than those expressed by the four-arm devices on average (224 ± 59.9 N vs. 103 ± 32.9 N), and such values remained high after subsequent activations.

Conclusions

The expanders tested demonstrated stiffness characteristics compatible with opening of the palatine sutures in pre-adolescent patients. The stiffness of such devices can be further increased during the construction phase.