Investigation of transverse dental changes following modified asymmetric rapid palatal expansion (ARPE) based on cone-beam computed tomography (CBCT) records found modified ARPE may be beneficial for treatment of a unilateral CB.
Abstract
Asymmetric dental expansion is a preliminary goal in the treatment of a true unilateral crossbite (CB). The aim of this study was to investigate transverse dental changes following modified asymmetric rapid palatal expansion (ARPE) based on cone-beam computed tomography (CBCT) records. The dataset consisted of CBCT records obtained before and after treatment with a modified ARPE appliance in patients presenting with unilateral skeletal posterior CB and class I skeletal relationship. Eighteen linear and four angular measurements were analyzed based on CBCT images. The Shapiro–Wilk test, paired-samples t-test and Wilcoxon signed-rank test were used for statistical analyses. Maxillary interdental widths showed significant increments on both sides (p < 0.05). Maxillary posterior dental expansion was greater on the CB side compared to the non-crossbite (NCB) side. A significant increase was detected in the mandibular inter-first premolar width (p < 0.05). In addition, the inter-side difference in maxillary first molar inclination between the NCB and CB sides was also significant (p < 0.05). Modified ARPE may be beneficial for treatment of a unilateral CB.
This exploratory study aimed to evaluate the expansion effects of a customized elastodontic appliance (CEA) on maxillary and mandibular arches in mixed dentition children using cone-beam computed tomography (CBCT), and to clarify whether these effects are dental, dentoalveolar, or skeletal.
This retrospective study included 31 mixed dentition children (mean age 8.3 ± 1.2 years) who underwent CEA treatment for 8.2 ± 1.3 months. Pre- and post-treatment CBCT images were used to measure width changes at three levels: cusp, alveolar bone, and apical basal bone. Paired t-tests were used for comparisons.
Significant increases were observed at cusp and alveolar levels. At the cusp level, maxillary inter-canine width increased by 2.97 mm ± 1.31 mm (95% CI: 2.49–3.45,
P
< 0.001), and mandibular inter-canine width by 2.39 mm ± 1.32 mm (95% CI: 1.91–2.87,
P
< 0.001). Maxillary second primary molar buccal cusp width increased by 1.67 mm
±
0.85 mm (95% CI: 1.36–1.98,
P
< 0.001), and mandibular counterpart by 1.26 mm
±
1.11 mm (95% CI: 0.85–1.67,
P
< 0.001). At the alveolar bone level, maxillary alveolar crest width increased by 1.39 mm ± 1.09 mm (95% CI: 0.99–1.79,
P
< 0.001), whereas mandibular alveolar crest width showed a minimal increase of 0.38 mm ± 0.75 mm (95% CI: 0.10–0.66,
P
= 0.008). No significant changes were observed in apical basal bone width in either arch.
The findings suggest that CEA may expand maxillary and mandibular arches in mixed dentition children with maxillary transverse deficiency. The maxillary expansion effect primarily involves dental movement and adaptive dentoalveolar change, without significant deep basal bone changes. In the mandible, significant dental expansion was observed at the cusp level, while the alveolar bone changes were minimal and should be interpreted cautiously. These findings provide preliminary CBCT-based evidence for the transverse expansion effects of CEA in mixed dentition children.
Not applicable. This is a retrospective, anonymous observational study without prospective intervention or a clinical trial protocol.
Objective The skeletal pattern of a Class II malocclusion can increase the probability of problems with oronasal function. This study aimed to analyze the relationship between the clinical effects of dentofacial orthopedics and oral function in deficient mandibles with proclined maxillary incisors during puberty. Methods Of 120 randomized participants, 63 with complete records were included in the final analysis (median age 12 years; 38% females). Subjects were treated with the Sander bite jumping appliance (BJA; n = 34) or the twin block appliance (TB; n = 29) with a maxillary expansion jackscrew. The growth effect was monitored by comparisons with the findings in 63 historical untreated Class II cases. Palatal scans and cephalograms were analyzed before and at one-year intervals after treatment. Both the children and their parents reported oral symptoms and functional limitations (FLs). Results Palatal volume increased in both appliance groups (BJA 860.3 mm3 [95% confidence interval (CI) 481.6–1,150.1] and TB 958.9 mm3 [95% CI 555.1–1,446.3]) in comparison with the untreated group (287.0 mm3 [95% CI 193.4–426.5]; P < 0.001). However, the treatment did not affect airways. In comparison with the untreated group, the treated groups showed greater mandibular length and reduced overjet (P ≤ 0.002). No linear correlations were found between changes in dentofacial, palatal, or airway characteristics and changes in oral function. However, the palatal volume of the treated children who experienced improvement in FLs increased more than that of those who showed no FL improvement (1,220.6 mm3 [95% CI 772.6–1,616.4] and 760.5 mm3 [95% CI 491.6–1,002.1]; P = 0.035). Conclusions Both appliances promoted mandibular growth and increased oral space, but did not significantly influence the measured upper airway widths.
Hana Cukaj Ademi, Alexei Zhurov, Maja Ovsenik et al.· The Korean Journal of Orthod...· 0 citations
Maxillary constriction in the mixed dentition is commonly associated with a narrow arch form, space deficiency, and impaired eruption guidance. Although the use of the Invisalign Palatal Expander has increased in growing patients, case-based evidence regarding its immediate skeletal, dentoalveolar, and dental effects remains limited. This case series aimed to evaluate immediate maxillary transverse changes after Invisalign Palatal Expander treatment in three patients with mixed dentition using cone-beam computed tomography. In all cases, Invisalign Palatal Expander treatment was performed using sequential removable expanders, with each active stage programmed to achieve 0.25 mm of expansion, followed by an 8-stage overcorrection phase. Post-treatment cone-beam computed tomography scans were obtained 1 month after completion of the expansion phase. Transverse changes were assessed at the skeletal, dentoalveolar, and dental levels. All three cases demonstrated transverse increases across the evaluated levels. Case 1 showed transverse increases across all three levels, with comparatively greater skeletal-level changes than the other two cases. Case 2 showed overall transverse increases, although the skeletal-level changes were relatively smaller than the dentoalveolar and dental-level changes within the same case. Case 3 demonstrated skeletal-level changes; however, larger absolute increases were observed at the dentoalveolar and dental levels than at the skeletal level. These findings suggest that the Invisalign Palatal Expander may contribute to immediate transverse changes with skeletal involvement in mixed-dentition patients. However, because the Invisalign Palatal Expander is removable, inadequate wear compliance may limit the full clinical expression of programmed expansion. Therefore, monitoring of appliance wear and occlusal changes is essential during treatment.
Ki-Tae Park, Yeonmi Yang, Jaegon Kim et al.· THE JOURNAL OF THE KOREAN AC...· 0 citations
INTRODUCTION
It is generally accepted that the optimal timing for functional orthodontic treatment in patients with Class II malocclusion and mandibular retrusion is during the circumpubertal growth period (cervical vertebral maturation stage [CS] 3-CS4). However, these patients often present with excessive overjet and a retrusive facial profile, which compromises esthetics and increases the risk of dental trauma. Early intervention during the mixed dentition period may reduce the risk of dental trauma and help safeguard children's psychological well-being. This study aimed to evaluate the therapeutic effects of rapid maxillary expansion (RME) and a modified Twin-block appliance-sagittal-guidance Twin-block (SGTB)-in mixed dentition patients and to compare the outcomes with an untreated Class II malocclusion control group.
METHODS
After matching cervical vertebral maturation stages and observation/treatment durations, 3 groups-RME, SGTB, and untreated controls-were compared. Linear and angular cephalometric variables related to mandibular morphology were analyzed. All variables followed a normal distribution. In addition, one-way analysis of variance was performed, followed by Tukey's post-hoc tests.
RESULTS
One-way analysis of variance of treatment-induced changes (T2 to T1) revealed statistically significant intergroup differences in vertical parameters, including FMA, posterior facial height (PFH), lower anterior facial height (LAFH), PFH/LAFH ratio, and mandibular ramus length, and sagittal parameters, including NSGn, total mandibular length (Co-Gn), and gonial angle. Tukey's post-hoc analysis revealed no statistically significant differences between the RME and control groups across all evaluated variables. In contrast, the SGTB group exhibited significant changes in vertical measurements (FMA, PFH, LAFH, and mandibular ramus length) and sagittal measurements (NSGn, Steiner analysis, Co-Gn, and Go-Gn) compared with controls. Annualized growth analysis demonstrated an additional Co-Gn increase of 4.53 mm/y in the SGTB group compared with the untreated controls.
CONCLUSIONS
In mixed-dentition patients with Class II malocclusion and mandibular retrusion, RME alone does not significantly stimulate mandibular growth in the short term; its long-term effects require further investigation. SGTB significantly increased Co-Gn compared with the control group, primarily through enhanced vertical growth. However, given its limited vertical control, careful case selection is essential.
Rui Jiang, Jingcheng Chen, Weiying Zheng et al.· American Journal of Orthodon...· 0 citations
To describe changes in maxillofacial morphology observed during bone-anchored maxillary protraction (BAMP) treatment in children with cleft lip and palate (CLP). This prospective, single-arm observational study included 20 consecutively treated patients with CLP (60% male; mean age at baseline (T1), 11.7 ± 1.0 years) who underwent BAMP therapy as part of a treatment protocol. Lateral cephalograms were obtained at baseline (T1) and at the end of maxillary protraction (T2; mean age, 15.3 ± 1.6 years). Protraction was considered complete when a positive overjet with adequate incisor overlap had been achieved and judged stable by the treating orthodontist, or when no further sagittal improvement was observed over two consecutive annual reviews, after which the miniplates were removed. Skeletal and dental changes were assessed using cephalometric measurements. Method error was evaluated using intraclass correlation coefficients. Statistical analyses included paired comparisons and exploratory univariable regression analyses. Significant increases were observed in the SNPg angle, midfacial length, mandibular length, and maxillomandibular difference, accompanied by a significant reduction in the SN/GoMe angle. The SNA angle increased by 1.3° from T1 to T2; however, this change did not reach statistical significance (95% CI: -0.17 to 2.66). Exploratory univariable analyses suggested that baseline age and observation time were associated with selected skeletal changes; these analyses were hypothesis-generating only. BAMP therapy was not associated with a statistically significant change in maxillary sagittal position (SNA), and overall skeletal changes were modest; clinicians should therefore maintain realistic expectations regarding the extent of skeletal correction achievable. Because the primary outcome (SNA) was not statistically significant, these findings are hypothesis-generating; whether BAMP can stabilise maxillary position during growth in milder discrepancies, and thereby reduce the likelihood of later orthognathic surgery, requires confirmation in controlled studies. Because the study had no control group, the observed T1-T2 changes cannot be separated from normal growth, and no causal effect of BAMP can be inferred.
A. Brudnicki, Marcin Olek, Zbigniew Surowiec et al.· Scientific Reports· 0 citations
Background/Objectives: This retrospective cephalometric study evaluated skeletal, alveolar, and dentoalveolar changes following alternate rapid maxillary expansion and constriction using a two-hinged maxillary expander (Alt-RAMEC/2-HME) and rapid maxillary expansion with facemask therapy (RME/FM) in skeletal Class III patients with maxillary retrusion, using a Le Fort I osteotomy group as a surgical reference. Methods: Pre-treatment (T0) and post-treatment (T1) lateral cephalometric radiographs of 42 patients were analyzed. Patients were divided into three groups—Alt-RAMEC/2-HME (n = 14), RME/FM (n = 14), and Le Fort I osteotomy (n = 14)—representing late-growth adolescents, growing children, and mature adults, respectively. Sagittal and vertical landmark positions were measured using a Cartesian coordinate system. The primary outcome was sagittal A-point displacement between T0 and T1. Intergroup changes were compared using non-parametric tests (p < 0.05). Results: Sagittal A-point displacement increased significantly in all groups. A larger A-point displacement was observed in the Le Fort I osteotomy group than in the two orthopedic groups (p < 0.001), whereas no significant difference was observed between the Alt-RAMEC/2-HME and RME/FM groups. Greater dentoalveolar positional changes were observed in the RME/FM group, in the maxillary incisor and molar regions. Conclusions: Sagittal A-point displacement was observed following Alt-RAMEC/2-HME in late-growth skeletal Class III patients with maxillary retrusion. However, in the absence of an untreated age- and skeletal maturity-matched control group, the observed displacement cannot be distinguished definitively from the normal craniofacial growth trajectory. These findings should also be interpreted in light of the retrospective study design and baseline differences between groups.
N. Tanrısever, H. Gökalp· Diagnostics· 0 citations
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