Definition, indication and outcome of miniscrew-assisted rapid palatal expansion

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

Mini-screw-assisted rapid palatal expansion (MARPE) has become a popular approach for arch expansion in cases with maxillary transverse deficiency. Minimal high-quality studies were found regarding MARPE. There was a great degree of heterogeneity among the studies with regards to age of use, expansion protocol, appliance design and mini-screw dimensions and placement. There is a suggestion that MARPE is best performed on those under the age of 30. The literature suggests the degree of buccal tipping of teeth is comparable to that of rapid maxillary expansion (RME) and surgically assisted rapid palatal expansion (SARPE). However, other side effects included root resorption, periodontal damage and loss of buccal alveolar bone height. Studies on upper airway volume suggested there may be a positive correlation between MARPE and upper airway volume, but future clinical studies are required to make more definitive conclusions about MARPE. CPD/Clinical Relevance: A review of the literature regarding mini-screw-assisted rapid palatal expansion is reported and includes design protocols and clinical considerations.

Maxillary transverse deficiency (MTD) is a common affliction among orthodontic patients, affecting 8%-17% of the population. Historically, MTDs have been treated using rapid palatal expanders (RPEs), typically anchored on molar and premolar teeth; however, their efficacy in achieving true skeletal expansion decreases dramatically during adolescence. For patients with mature sutures, a surgically assisted rapid palatal expansion (SARPE) was the only choice until the advent of miniscrew-assisted rapid palatal expansion (MARPE). In MARPE, the expansion screw is anchored on the basal bone through miniscrews. This provides a minimally invasive alternative to SARPE, while facilitating transverse maxillary expansion in older patients. There are many designs of MARPE in use. MARPE causes an increase in the width of the maxilla, with a more parallel separation of the midpalatal suture (MPS), with expansion effects reaching almost till the midfacial regions, minimal dentoalveolar effects, an increase in the airway, and effects are seen on the concomitant soft tissues. While the effects of MARPE have been well documented, the factors affecting its success are less understood. This position article on MARPE highlights the factors affecting the success and failure of MARPE. Procedures like corticopunctures and minimally invasive surgical and miniscrew-assisted rapid palatal expansion (MISMARPE) are being used to supplement MARPE and improve its success rate. Overall, MARPE is a highly successful procedure, well-accepted by patients and practitioners, and should be used when indicated, following the proper diagnosis of a true skeletal transverse deficiency of the maxilla.

Long-term effects of conventional and miniscrew-assisted rapid palatal expansion on root resorption

Long-term evaluation of soft-tissue changes after miniscrew-assisted and conventional rapid palatal expansion using voxel-based superimposition of cone-beam computed tomography scans

Introduction: Miniscrew-assisted rapid palatal expansion (MARPE) is an effective non-surgical alternative for managing transverse maxillary deficiency in late adolescents and young adults. While its skeletal effects are well documented, reports of clinical complications remain limited. This retrospective study presents a comprehensive case-based analysis of MARPE-related complications within a cohort, highlighting both management outcomes and preventive strategies.Materials and methods: A retrospective review was conducted of 24 consecutive MARPE cases (mean age 17.4 ± 1.3 years; 11 males, 13 females) treated between January and December 2024. Appliance designs included a two-screw hybrid MARPE (n = 16) and a four-screw maxillary skeletal expander (MSE) (n = 8), with miniscrews measuring 1.8-2.0 mm in diameter and 9-11 mm in length. Data were collected on demographics, appliance type, screw size, fabrication method (custom vs. prefabricated), complications, management, and treatment interruptions. In addition to summary statistics, six representative case studies of complications were described in detail.Results: Of the 24 patients, eight (33.3%) developed true complications, two (8.3%) experienced procedural delays due to screw-locking defects, and 14 (58.3%) had no adverse events. Mechanical complications (n = 6) included screw fracture, appliance arm breakage, and acrylic failure, while biological complications (n = 2) involved tongue irritation and peri-implant mucositis. When the complication and no-complication groups were compared, an independent t-test revealed no significant age difference (17.8 vs. 17.1 years, p = 0.21). Chi-square analysis revealed no significant gender effect, although males experienced more complications (54.5% vs. 30.8%, OR = 2.7, p = 0.064). Fisher’s exact test demonstrated that complications were confined to screws ≤10 mm, while none occurred with 11 mm or 2.0 × 10 mm screws (p = 0.03). Activation was interrupted for at least two weeks until the issue was resolved. Six detailed case reports illustrate the causes, management, and clinical precautions for these events.Conclusions: MARPE is an effective and minimally invasive alternative to surgically assisted rapid palatal expansion, but complications occur in nearly one-third of cases. These may arise with any appliance type and are often related to human or technical errors. Early recognition, implementation of preventive strategies, and adherence to standardized protocols are crucial for ensuring safe and predictable outcomes.

Immediate dentoskeletal and periodontal effects of miniscrew-assisted rapid palatal expansion: Comparison between young vs middle-aged adults

Rationale:Neuropathic pain in the orofacial region, although relatively uncommon, can occur after dental procedures performed in trigeminally innervated areas. Miniscrew-assisted rapid palatal expansion (MARPE) is widely adopted to correct maxillary transverse deficiency in adults and is generally safe; however, neurosensory complications are rarely documented. This case highlights infraorbital neuropathy following MARPE, underscoring the need for clinical vigilance.Patient concerns:A healthy 28-year-old female presented with numbness and tenderness on the left midface approximately 5 weeks after MARPE appliance placement. Her symptoms included hypesthesia in the zygomatic, upper lip, philtral, and palatal regions, and palpation-induced pain in the buccal mucosa and lower lip. The discomfort was described as dull and throbbing, partially numb, provoked by touch but not by thermal stimuli, with a visual analog scale score of 2 to 3.Diagnoses:Clinical examination revealed normal oral function and painless maximal opening. Sensory testing demonstrated marked asymmetry: reduced direction discrimination (30% vs 100%), abnormal 2-point discrimination (perceiving 1 point as 2), elevated pressure pain threshold (60 g vs 30 g), and diminished cold perception, while contact threshold remained symmetrical. Standard panoramic and Waters’ radiographs showed no bony abnormalities. A provisional diagnosis of left maxillary trigeminal neuropathy, localized to the infraorbital nerve distribution, was made.Interventions:Pharmacological treatment was initiated with gabapentin titrated to 300 mg 3 times daily, a short course of oral prednisolone, and subsequent introduction of low-dose amitriptyline for enhanced neuropathic pain control. Medication was well tolerated except for mild oral dryness and drowsiness, which resolved with tapering.Outcomes:Serial follow-up over 5 months demonstrated progressive reduction in neurosensory deficits, with near-complete resolution by the third month and full recovery without recurrence at the fifth month.Lessons:This case illustrates that MARPE, while effective and generally safe, can occasionally induce neuropathic complications extending beyond palatal branches to involve the infraorbital pathway. Mechanical stress redistribution in skeletally mature patients likely contributes to this outcome. Careful monitoring for atypical sensory changes, early recognition, and timely pharmacological intervention are essential to optimize prognosis. Further research is warranted to clarify biomechanical mechanisms and risk factors for trigeminal nerve injury during orthodontic maxillary expansion.

This study aimed to assess how the anteroposterior position of the miniscrew-assisted rapid palatal expansion (MARPE) appliance influences maxillary skeletal expansion and to propose a reference point for optimal placement. Thirty-two skeletally mature patients treated with MARPE were retrospectively assigned to an anterior group (anterior miniscrews ≥ 5 mm anterior to the centre of the maxilla (CM)) or a posterior group (≤ 2 mm from or posterior to CM). Pre- and post-expansion cone-beam computed tomography scans were used to measure skeletal, dental, and paramaxillary changes. Independent t-tests following data normality, linear regression with validated model assumptions, and Bayesian mediation analyses evaluated direct and indirect effects of appliance position and bicortical engagement. The anteroposterior appliance position significantly affected expansion outcomes. Posterior placement yielded greater skeletal expansion and a more parallel pattern (p = 0.008), especially in the posterior maxilla (p = 0.001). Anterior positioning produced reduced skeletal effects and a V-shaped expansion (p = 0.001). Molar tipping increased both directly with anterior positioning (p = 0.002) and indirectly through reduced bicortical engagements. Miniscrew movement, indicating activation loss, was likewise indirectly mediated by fewer bicortical engagements (95% highest density interval: [-0.140, -0.009]). The posterior group exhibited significantly greater paramaxillary expansion, especially in the posterior regions of the jugale and zygoma (p = 0.011). Anteroposterior MARPE position significantly impacts skeletal expansion results. Positioning near or posterior to the centre of the maxilla point enhances parallel skeletal expansion and minimizes undesirable dental effects. This reference point can serve as a practical reference to optimize MARPE placement for mature patients.

The aim of this systematic review and meta-analysis was to evaluate root resorption after maxillary expansion with conventional rapid palatal expansion (RPE) and mini-screw assisted rapid palatal expansion appliances (MARPE) using 2D and 3D radiographic methods and histologic methods of measuring root resorption. A search of PubMed/MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, Global Index Medicus, Dissertations & Theses Global, ClinicalTrials.gov registry, ISRCTN Registry, National Research Register, OpenGrey, and the Trip Database was performed. The studies that had analysed root resorption after RPE or MARPE were selected for the systematic review. The database research, elimination of duplicate studies, data extraction, and risk of bias were performed by the authors independently and in duplication. This systematic review included prospective studies to evaluate root resorption following RPE after tooth-borne (TB), tooth-tissue borne (TTB), bone-borne (BB), and tooth-bone borne (TBB) expansion appliances. A total of 13 prospective trials (six randomized clinical trials and seven non-randomized prospective clinical trials) were identified for inclusion in this systematic review. Histological studies revealed that most teeth experience root resorption on the buccal surfaces after maxillary expansion. MARPE designs with BB and TBB expansion appliances were found to lead to reduced volumetric root resorption than conventional RPE using micro-computed tomography. However, one study using cone beam computed tomography showed no difference in the root resorption with MARPE and RPE designs. Maxillary expansion with RPE can lead to root resorption of maxillary posterior teeth. Root resorption occurs more frequently on buccal surfaces on maxillary posterior teeth. Limited evidence suggests that MARPE may lead to reduced root resorption than RPE. This systematic review was conducted following the Cochrane handbook for systematic reviews and interventions and reported according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The protocol was registered at PROSPERO database (https://www.crd.york.ac.uk/prospero/; registration number: PROSPERO CRD42021271181).

Objectives: This systematic review aimed to evaluate the effectiveness of currently available methods for the diagnosis and monitoring of skeletal, dental, and soft tissue changes, as well as the adequacy of follow-up protocols, in adolescents and adults treated with miniscrew-assisted rapid palatal expansion (MARPE). Materials and Methods: This systematic review was conducted in accordance with the PRISMA guidelines. A comprehensive electronic literature search was performed across five databases (PubMed, Scopus, Embase, Cochrane, and Web of Science) to identify prospective and retrospective clinical studies evaluating dental, periodontal, and alveolar bone outcomes associated with MARPE in late adolescent and adult patients. Study selection, data extraction, and risk of bias assessment were independently performed by two reviewers. Risk of bias was assessed using the ROBINS-I tool for non-randomized studies and the RoB 2 tool for randomized studies. The certainty of the evidence was evaluated using the GRADE approach. Owing to substantial methodological heterogeneity and limited follow-up duration, a structured qualitative (narrative) synthesis of the results was performed. Results: A total of 20 studies were included in the systematic review. The reported adverse events primarily involved hard and soft tissues and were identified using cone-beam computed tomography (CBCT), clinical and periodontal examination, panoramic and cephalometric radiography, and digital dental casts. Dental effects, including dental tipping, were frequently reported across the included studies. Alveolar bone loss was reported in 11 studies, buccal alveolar bone dehiscence in 3 studies, and failure of palatal suture opening in 6 studies. In most of the included studies, follow-up was either not reported or limited. Conclusions: The MARPE technique appears to be potentially effective in achieving transverse maxillary expansion in late adolescent and adult patients. However, the included studies report possible adverse events affecting periodontal and alveolar bone tissues, such as alveolar bone thinning and gingival hypertrophy, the assessment of which requires an integrated diagnostic approach combining CBCT imaging with clinical and periodontal examination. Overall, the certainty of the available evidence was low to very low, mainly due to a high risk of bias, methodological heterogeneity, and limited or absent follow-up in most studies. Therefore, the results should be interpreted with caution. Well-designed prospective controlled studies with standardized protocols and long-term follow-up are needed to conclusively evaluate the safety and long-term clinical stability of the MARPE technique.

The aim of this systematic review and meta-analysis was to evaluate the density of the midpalatal suture (MPS) of individuals with maxillary expansion (rapid maxillary expansion, RME), surgically assisted rapid maxillary expansion (SARPE), and miniscrew-assisted rapid palatal expansion (MARPE) through computed tomography. An electronic search was performed in four databases, MEDLINE via PubMed, SCOPUS, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) in February 2023 and updated in April 2023, using previously established search strategies. Studies were retrieved without restrictions in terms of data, language, or publication status. The risk of bias assessment was based on a quality assessment tool for before-and-after studies. Ten studies were included in our systematic review, and nine studies were included for our quantitative analysis. The analyses were performed by subgroup according to the evaluation of the region, anterior, middle, and posterior, including the three types of treatment: RME, SARPE, and MARPE. Heterogeneity was high for the three regions (anterior 95%, medium 97%, and posterior 84%) and a statistical difference was found in two of the three regions (anterior p = 0.06, medium p = 0.031, and posterior p < 0.001). There is not enough evidence to state that the MPS density is different after 6 months of RME in the anterior and middle regions; the bone density values for SARPE and MARPE suggest that 6 or 7 months after expansion, there is still no bone density similar to the initial one in the three regions.

Why does maxillary skeletal expansion work with some adults and fail with Others?: A narrative review

To investigate the relationship between circummaxillary sutures and miniscrew-assisted rapid palatal expansion (MARPE) success in adult male patients and to evaluate the correlation between the width of the sutures and the maxilla expansion ratio. This retrospective study comprised 40 adult male patients treated with MARPE divided into a separation group (N = 20, mean age, 21.9 years) consisting of subjects with midpalatal suture opening and a nonseparation group (N = 20, mean age, 21.7 years) consisting of subjects with no midpalatal suture opening. Cone-beam computed tomography images were obtained before MARPE expansion for both groups and after expansion for the separation group. Vertical and horizontal skeletal relationships, palate length, and widths of 10 circummaxillary sutures before expansion were compared. The correlation between maxilla expansion ratio (jackscrew expansion to maxillary expansion ratio) and circummaxillary suture widths was also analyzed in the separation group. There were no significant differences in age, vertical and horizontal skeletal relationships, and palate length between the two groups. Zygomaticomaxillary, pterygomaxillary, midpalatal, and transverse palatine sutures showed significantly greater width in the separation group (P < .05). The zygomaticomaxillary suture showed the greatest difference (Δ = 0.36 mm) between the groups. The zygomaticomaxillary and pterygomaxillary sutures showed significant positive correlation with the maxilla expansion ratio (P < .01). In adult male patients, greater circummaxillary suture widths before MARPE expansion, especially zygomaticomaxillary and pterygomaxillary sutures, resulted in a better chance of successful suture separation and more maxillary expansion.

Rapid palatal expansion (RPE) is commonly used to correct transverse maxillary deficiencies and recognized as a reliable orthopedic procedure in children and adolescents. For adults, however, conventional RPE has been considered rarely successful and can produce undesirable dental effects. Along with the development of digital techniques and mini-implant anchorage, a novel method called miniscrew-assisted RPE (MARPE) has become available for the treatment of maxillary transverse deficiency in older patients recently. In this article, the biomechanical principles and indications of MARPE, the advances in device design, the clinical effects, the matters needing attention and limitations of this method, and the stability after expansion are discussed.