Le Fort I osteotomy in cleft patients: Maxillary advancement and velopharyngeal function

BackgroundMaxillary advancement may affect speech in cleft patients.AimsTo evaluate whether the amount of maxillary advancement in Le Fort I osteotomy affects velopharyngeal function (VPF) in cleft patients.MethodsNinety-three non-syndromic cleft patients (51 females, 42 males) were evaluated retrospectively. All patients had undergone a Le Fort I or bimaxillary (n = 24) osteotomy at Helsinki Cleft Palate and Craniofacial Center.Preoperative and postoperative lateral cephalometric radiographs were digitized to measure the amount of maxillary advancement. Pre- and postoperative speech was assessed perceptually and instrumentally by experienced speech therapists. Student's t-test and Mann–Whitney's U-test were used in the statistical analyses. Kappa statistics were calculated to assess reliability.ResultsThe mean advancement of A point was 4.0 mm horizontally (range: −2.8–11.3) and 3.9 mm vertically (range −14.2–3.9). Although there was a negative change in VPF, the amount of maxillary horizontal or vertical movement did not significantly influence the VPF. There was no difference between the patients with maxillary and bimaxillary osteotomy.ConclusionsThe amount of maxillary advancement does not affect the velopharyngeal function in cleft patients.     

Long-term skeletal stability after maxillary advancement with distraction osteogenesis in cleft lip and palate patients: A systematic review

Objective:To systematically review the long-term skeletal stability after maxillary advancement with distraction osteogenesis (DO) in cleft lip and palate (CLP) patients.Materials and Methods:Electronic databases, grey literature, and reference list searches were conducted. The inclusion criteria were stability of maxillary advancement with distraction osteogenesis assessed at the posttreatment follow-up ≥ 1 year in CLP patients. Full articles were retrieved from abstracts or titles that appear to meet the inclusion criteria or lacked sufficient detail for immediate exclusion. Once full articles were collected, they were again reviewed considering more detailed inclusion criteria for a final selection decision. A methodologic quality assessment tool was utilized.Results:Thirty abstracts/titles met the initial search criteria, and 13 articles were finally selected. Overall, methodologic quality scores were high in only one randomized clinical trial. After maxillary advancement with DO in CLP patients, the long-term horizontal relapse in A-point was less than 15% in eight studies and between 20% and 25% in four studies. The study that was judged as a high-quality study reported 8.2% horizontal relapse in A-point. The relapse rate was higher in DO with external distracter device than DO with internal distracter device.Conclusions:Current evidence suggests maxillary advancement with DO has good stability in CLP patients with moderate and severe maxillary hypoplasia.     

Maxillary distraction versus orthognathic surgery in cleft lip and palate patients: effects on speech and velopharyngeal function

This clinical randomized controlled trial was performed to compare the effects of distraction osteogenesis (DO) and conventional orthognathic surgery (CO) on velopharyngeal function and speech outcomes in cleft lip and palate (CLP) patients. Twenty-one CLP patients who required maxillary advancement ranging from 4 to 10 mm were recruited and randomly assigned to either CO or DO. Evaluation of resonance and nasal emission, nasoendoscopic velopharyngeal assessment and nasometry were performed preoperatively and at a minimum of two postoperative times: 3–8 months (mean 4 months) and 12–29 months (mean 17 months). Results showed no significant differences in speech and velopharyngeal function changes between the two groups. No correlation was found between the amount of advancement and the outcome measures. It was concluded that DO has no advantage over CO for the purpose of preventing velopharyngeal incompetence and speech disturbance in moderate cleft maxillary advancement.     

Velopharyngeal changes after maxillary advancement in cleft patients with distraction osteogenesis using a rigid external distraction device: a 1-year cephalometric follow-up

The effect of maxillary advancement on speech may have benefits on articulation improvement but compromises velopharyngeal (VP) closure by increasing the nasopharyngeal distance. The purpose of this study was to evaluate the static VP anatomic changes on lateral cephalograms in patients who underwent maxillary advancement through distraction osteogenesis (DO) with a rigid external distraction device and to correlate these changes with clinical speech data. Twenty-two patients (5 female and 17 male) underwent maxillary advancement through DO utilizing a rigid external distraction device (age, 5.2 to 25.7 years) with various diagnoses, including 13 unilateral cleft lip and palate (CLP) patients, 5 bilateral CLP patients, 1 isolated cleft palate patient, 2 facial cleft patients, and 1 patient with craniosynostosis. Lateral cephalograms of preoperative, immediate postdistraction, and 1-year postdistraction were obtained for analysis. Speech evaluation was performed preoperatively, immediate postdistraction, and then at 6-month intervals, and included assessment of air pressure flow, hypernasality, and articulation. With an average amount of 8.9 mm maxillary forward advancement, 14% of patients (3 of 21) presented deterioration in hypernasality. However, 57% of patients (12 of 21) demonstrated improvement in articulation. The cephalometric analysis demonstrated an increase in nasopharyngeal depth by 8.5 mm (1:1 ratio with bony movement) and velar angle by 14.1 deg. The length of the soft palate remained unchanged. The need ratio (intersection of palatal plane and posterior pharyngeal wall-posterior nasal spine/posterior nasal spine--tip of uvula) worsens after distraction. The deterioration of hypernasality was related to the amount of forward distraction, especially in patients without a preexisting pharyngeal flap (PF). Speech evaluation is an important aspect concerning treatment planning for maxillary distraction. The increase in nasopharyngeal depth may compromise VP closure. The increase in velar angle was considered to be part of the compensation in the VP mechanism. An adverse effect of a preexisting PF on maxillary distraction was not observed; however, it prevented postoperative hypernasality.     

Skeletal,dental and facial aesthetic changes following anterior maxillary segmental distraction by tooth-borne device in patients with cleft lip and palate

Maxillary skeletal deficiency secondary to cleft lip and palate (CLP) remains a significant challenge. The aim of this study was to present the comprehensive skeletal, dental and facial aesthetic outcomes of anterior maxillary segmental distraction osteogenesis (AMSDO) for treatment of maxillary hypoplasia in patients with CLP. Twelve patients with maxillary hypoplasia treated with AMSDO by a customized tooth-borne distractor were included. Three-dimensional changes of anterior maxillary segment, upper incisor and pharyngeal space were measured by three-dimensional reconstruction derived from cone beam computed tomography (CBCT) data. Length and width of dental arch during distraction were determined in dental casts. Nasolabial angle, soft-tissue convexity and patient’s subjective satisfaction were assessed to evaluate facial aesthetic improvements. Nasopharyngoscopic evaluation and speech assessment were also performed before and after distraction. All patients successfully received AMSDO without serious complications. Following AMSDO, the anterior maxillary segments moved forward 5.56 ± 0.28 mm and slightly upward 1.15 ± 0.13 mm. AMSDO significantly lengthened maxillary dental arch, generated new bone to relieve dental crowding and improved patients’ facial aesthetic without worsening velopharyngeal closure and speech quality. AMSDO by tooth-borne distractor is an effective surgical alternative for the advancement in patients with cleft maxillary hypoplasia.     

Velopharyngeal insufficiency after maxillary advancement in patients with cleft palate − a survey of risk assessment in the United Kingdom and Ireland

Patients with cleft lip and palate may require orthognathic surgery to correct severe impairments in midfacial growth. Maxillary advancement in this group, however, is linked to deterioration in velopharyngeal function (VPF), and it is not clear how cleft teams assess this risk. We therefore surveyed surgeons from 15 cleft units who provide orthognathic treatment, to gain an understanding of current practice in the UK and Ireland. A total of 16/21 surgeons from 14/15 units responded. While 14/16 surgeons agreed that these patients are at risk of a deterioration in VPF after maxillary advancement, two disagreed. Preoperative assessment of perceptual speech is required in all cases, but only 9/14 routinely did an instrumental assessment of VPF. One third of respondents thought that they could not identify “borderline” cases. There were differences in how surgeons obtained preoperative consent regarding deterioration in VPF, and whether surgical plans should be modified accordingly. There was considerable variation in current practice regarding risk, assessment, and management of potential changes in VPF after orthognathic surgery. A national forum for multidisciplinary discussion would allow for the standardisation of care across the UK and Ireland. Further study is needed to establish the effects of orthognathic surgery on VPF in this group, as well as the clinical benefits of instrumental assessments.     

Morphological evaluation of changes in velopharyngeal function following maxillary distraction in patients with repaired cleft palate during mixed dentition.

OBJECTIVE: To describe the morphological changes of nasopharyngeal components after maxillary distraction and clarify whether the morphological characteristics are related to velopharyngeal function (VPF). DESIGN: Perceptual judgments of hypernasality and nasendoscopy were performed before and after treatment. Lateral cephalograms were obtained to describe the morphological changes. SETTING: Department of Oral and Maxillofacial Surgery, Miyazaki Medical College, Miyazaki, Japan. PARTICIPANTS: Nine patients with repaired cleft palate in the mixed dentition stage underwent maxillary distraction using a face mask and an intraoral fixed appliance system. OUTCOME MEASURES: The severity of hypernasality, velopharyngeal insufficiency, and measurements such as pharyngeal depth, velar length, and the rotation of the palatal plane were evaluated. RESULTS: Increase in pharyngeal depth was not always proportional to the amount of advancement. It depended on the posture of the posterior pharyngeal wall and the rotation of palatal plane. CONCLUSION: Cephalometric measurements of the nasopharynx before and after surgery confirmed subsequent changes in VPF. These were suggested to be useful in predicting future VPF. When performing maxillary distraction in patients with cleft palate in the mixed dentition stage, and when velopharyngeal closure is found to occur by velar contact against the hypertrophied adenoid, patients should be counseled about risks of subsequent deterioration in their speech before surgery.     

唇腭裂患者牵张成骨术后的侧貌变化

目的：通过对唇腭裂术后继发上颌骨发育不足患者进行口外支架式前牵张治疗术后6～24个月的随访,观察分析其侧貌变化,为合理使用牵张器提供参考。方法：选取1998—2002年间上海交通大学医学院附属第九人民医院进行牵张成骨治疗、按时随访的唇腭裂患者14例进行术后随访分析。随访期分别为术后3、6、12、24个月,分别拍摄头颅定位侧位片及照片,记录患者的侧貌变化。结果：14例患者在牵张成骨术后6个月,至术后24个月,3例表现为双颌前突畸形,3例仍表现为面中部凹陷,1例表现为前牙开。结论：牵张成骨术治疗唇腭裂术后上颌骨发育不足患者具有一定优势,但牵张方向及牵张量难以控制,术后侧貌时不尽满意。因此,唇腭裂患者继发上颌骨发育不足在行牵张成骨术治疗时,应综合考虑多种因素的影响。     

Velopharyngeal changes after maxillary distraction in cleft patients using a rigid external distraction device: A retrospective study

Objective:To evaluate early and late velopharyngeal changes in cleft lip and palate (CLP) patients after use of the Rigid External Distractor (RED) device and to correlate these changes to the amount of maxillary advancement.Materials and Methods:Thirty Class III CLP patients were included in the study. Maxillary advancement was performed using the RED device in combination with titanium miniplates and screws for anchorage. Lateral cephalograms, nasometer, and nasopharyngoscope records were taken before distraction, immediately after distraction, and 1 year after distraction. A paired t-test was used to detect differences at P < .05.Results:SNA angle and A point and ANS to Y axis were significantly increased after maxillary distraction (P  =  .0001). Statistically significant increases in nasopharyngeal and oropharyngeal depths, velar angle, and need ratio were also found (P  =  .0001). Nasalance scores showed a significant increase (P  =  .008 for nasal text and .044 for oral text). A significant positive correlation was observed between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality (P  =  .012 and .026, respectively).Conclusions:Nasopharyngeal function was deteriorated after maxillary advancement in CLP patients. There was a significant positive correlation between the amount of maxillary advancement and the increase in nasopharyngeal depth and hypernasality.     

Soft Tissue Changes in Cleft Lip and Palate Patients: Anterior Maxillary Distraction versus Conventional Le-Fort I Osteotomy

The purpose of the study was to compare the soft tissue changes after maxillary advancement in patients with maxillary deficiency associated with cleft lip and palate (CLP) by two approaches—anterior maxillary distraction (AMD) and advancement LeFort I osteotomy (ALO). Twenty patients with maxillary hypoplasia associated with cleft lip and palate who had undergone either LeFort I osteotomy or distraction osteogenesis with maxillary advancement were included in this study. Lateral cephalogram taken at various intervals of time were used to evaluate soft tissue and hard tissue changes over time. In both groups, vertical as well as horizontal changes in pronasale was well observed. A substantial increase in nasal parameters was noted in case of AMD group in comparison to ALO. Though maxillary advancement was evident in both the groups, a significant and consistent change was observed in AMD. Significant vertical and horizontal changes were seen with respect to subnasale and labrale superius in AMD group. Soft tissue as well as hard tissue relapse was greater in ALO group than AMD group. Significant soft tissue and hard tissue changes were clearly observed in both the groups, but the treatment results were more consistent in cases treated with AMD. Hence AMD could be considered as a better treatment of choice in cases of maxillary hypoplasia associated with cleft lip and palate.     

Anterior maxillary segmental distraction for correction of maxillary hypoplasia and dental crowding in cleft palate patients: a preliminary report

To evaluate the feasibility of anterior maxillary segmental distraction (AMSD) to correct maxillary hypoplasia and severe dental crowding in cleft lip and palate (CLP) patients, 7 patients (average age 16.4 years) with maxillary hypoplasia, shortened maxillary dental arch length and severe anterior dental crowding secondary to CLP were selected for this study. After anterior maxillary segmental osteotomy, 3 patients were treated using bilateral internal distraction devices, and 4 patients were treated using rigid external distraction devices. Photographs and radiographs were taken to review the improvement in facial profile and occlusion after distraction. An average 10.25 mm anterior maxillary advancement was obtained in all patients after 10–23 days of distraction and 9–16 weeks of consolidation. The sella–nasion–point A (SNA) angle increased from 69.5° to 79.6°. Midface convexity was greatly improved and velopharyngeal competence was preserved. The maxillary dental arch length was greatly increased by 10.1 mm (P < 0.01). Dental crowding and malocclusion were corrected by orthodontic treatment. These results show that AMSD can effectively correct the hypoplastic maxilla and severe dental crowding associated with CLP by increasing the midface convexity and dental arch length while preserving velopharyngeal function, and dental crowding can be corrected without requiring tooth extraction.     

Maxillary distraction osteogenesis in cleft lip and palate patients with skeletal anchorage.

OBJECTIVE: Maxillary distraction osteogenesis with the rigid external distraction (RED) system has been used to treat cleft lip and palate (CLP) patients with severe maxillary hypoplasia. We introduce maxillary distraction osteogenesis for CLP patients with skeletal anchorage adapted on a stereolithographic model. PATIENTS: Six maxillary deficiency CLP patients treated according to our CLP treatment protocol had undergone maxillary distraction osteogenesis. METHOD: In all patients, computed tomography (CT) images were recorded preoperatively, and the data were transferred to a workstation. Three-dimensional skeletal structures were reconstructed with CT data sets, and a stereolithographic model was produced. On the stereolithographic model, miniplates were adapted to the surface of maxilla beside aperture piriforms. The operation performed involved a high Le Fort I osteotomy with pterygomaxillary disjunction. Miniplates were fixed to the maxillary segment with three or four screws and used for anchorage of the RED system. Retraction of the maxillary segment was initiated after 1 week. RESULTS: The accuracy of the stereolithographic models was enough to adapt the miniplates so that there was no need to readjust the plates during surgery. Postoperative cephalometric analysis showed that the direction of the retraction was almost parallel to the palatal plane, and dental compensation did not occur. CONCLUSIONS: We performed maxillary distraction osteogenesis with skeletal anchorage adapted on the stereolithographic models. Excellent esthetic outcome and skeletal advancement were achieved without dentoalveolar compensations.     

上颌前徙术后腭咽闭合功能的临床观察

目的　临床观察评价上颌前徙术后腭咽闭合功能变化。方法　对 7例上颌发育不全患者及 3例唇腭裂继发上颌发育不全患者行LeFortI型截骨术前移上颌骨 ,术前术后行鼻咽纤维镜及发“i”音时的头颅侧位片检查 ,结合术前术后语音的评价 ,对上颌前徙术后腭咽闭合及发音的改变进行观察分析。结果　经统计学分析 ,软腭动度、腭咽闭合程度、语音清晰度等指标术前术后比较差异均无显著性。结论　患者术前腭咽闭合功能良好时 ,上颌前徙术后腭咽闭合功能无明显变化     

Prediction of deterioration of velopharyngeal function associated with maxillary advancement using electromyography of levator veli palatini muscle.

OBJECTIVE: The purpose of the present study was to examine the possibility that postoperative velopharyngeal function following maxillary advancement could be predicted using preoperative electromyography of the levator veli palatini. DESIGN: Levator muscle electromyography was recorded preoperatively during speech and blowing. Levator activity was expressed as a percentage relative to the maximum value observed throughout the experiment. Postoperative velopharyngeal function was evaluated by means of perceptual judgment and nasoendoscopy. PARTICIPANTS: The subjects were four patients with repaired cleft palates who underwent maxillary advancement, two by osteotomy and two by distraction osteogenesis. None of the subjects presented with preoperative hypernasality, and nasoendoscopy demonstrated complete velopharyngeal closure in all subjects prior to maxillary advancement. RESULTS: Preoperative levator activity for speech of two subjects was similar to that for normal speakers (< 60% of total range), and postoperative nasality and nasoendoscopic findings revealed no detectible changes. For the other two subjects, levator activity for speech exceeded 60% of the total range, similar to that of speakers with velopharyngeal incompetence. These subjects showed increased hypernasality and deteriorated velopharyngeal closure following maxillary advancement. CONCLUSION: The deterioration of velopharyngeal function associated with maxillary advancement was demonstrated for subjects whose levator activity was at higher levels during speech in comparison with maximal activity observed during blowing, regardless of the amount of maxillary advancement. Preoperative levator muscle electromyography could be a predictor in identifying patients at higher risk of postsurgical deterioration of velopharyngeal function.     

The effect of cranio-maxillofacial osteotomies and distraction osteogenesis on speech and velopharyngeal status: a critical review.

OBJECTIVES: To review the impact of maxillary advancement by orthognathic surgery and distraction osteogenesis on speech and velopharyngeal status based on the literature of the past 30+ years, to review the methods employed in previous studies to explain discrepancies in results, and to make recommendations for future studies. METHOD: Thirty-nine published articles on the effect of cranio-maxillofacial osteotomies and distraction osteogenesis on speech and velopharyngeal status were identified and were systematically analyzed. A total of 747 cases of cleft and noncleft patients were selected, including craniofacial deformities and syndromes mainly involving maxillary hypoplasia. RESULTS: Findings varied. Many studies found that surgery had no impact on speech and velopharyngeal status. Some reported worsening only in patients with preexisting velopharyngeal impairment or those with borderline velopharyngeal function before surgery. There was no clear difference in outcome between distraction and conventional osteotomy, although there have been few systematic comparisons. There was great variation among reviewed studies in the number of subjects, speech sample, number and type of listeners, speech outcome measures, and timing of postoperative assessment. Few studies employed reliability measures. CONCLUSION: None of the 39 reviewed studies compared conventional osteotomy and distraction by including both groups in a single study. Randomized controlled trials with adequate number of subjects and follow-up duration are needed.     

Class II functional orthopaedic treatment: a systematic review of systematic reviews

This Systematic Review (SR) aims to assess the quality of SRs and Meta‐Analyses (MAs) on functional orthopaedic treatment of Class II malocclusion and to summarise and rate the reported effects. Electronic and manual searches were conducted until June 2014. SRs and MAs focusing on the effects of functional orthopaedic treatment of Class II malocclusion in growing patients were included. The methodological quality of the included papers was assessed using the AMSTAR (Assessment of Multiple Systematic Reviews). The design of the primary studies included in each SR was assessed with Level of Research Design scoring. The evidence of the main outcomes was summarised and rated according to a scale of statements. 14 SRs fulfilled the inclusion criteria. The appliances evaluated were as follows: Activator (2 studies), Twin Block (4 studies), headgear (3 studies), Herbst (2 studies), Jasper Jumper (1 study), Bionator (1 study) and Fränkel‐2 (1 study). Four studies reviewed several functional appliances, as a group. The mean AMSTAR score was 6 (ranged 2–10). Six SRs included only controlled clinical trials (CCTs), three SRs included only randomised controlled trials (RCTs), four SRs included both CCTs and RCTs and one SR included also expert opinions. There was some evidence of reduction of the overjet, with different appliances except from headgear; there was some evidence of small maxillary growth restrain with Twin Block and headgear; there was some evidence of elongation of mandibular length, but the clinical relevance of this results is still questionable; there was insufficient evidence to determine an effect on soft tissues.     

唇腭裂术后患者牵引成骨术X线头影测量分析

目的:通过对唇腭裂术后继发上颌骨发育不足患者进行口外支架式前牵引治疗术后6～24个月随访,探讨术后复发程度及可能存在的复发因素,并提出初步预防复发的办法。方法:1998～2002年我院进行牵引成骨治疗的39例唇腭裂患者中选出14例资料齐全者进行术后随访分析,随访期分别为术后3月、6月、1年、2年,分别将其头颅定位侧位片用CASSOS系统描迹、定点,进行矢状向和垂直向分析。结果:14例患者在牵引成骨术后6月内均有不同程度的复发,尤其是牵引器拆除后未进行正畸治疗者。而6月以后患者上颌骨在垂直向及矢状向基本无明显改变。结论:(1)唇腭裂术后上颌骨发育不足患者进行牵引成骨治疗后6月内较不稳定,尤其是未进行正畸治疗者;(2)6月后上颌骨矢状向和垂直向基本稳定。复发因素可能与局部疤痕、肌肉牵拉、软组织张力及适应性改建有关。     

A pilot study of the effects of transpalatal maxillary advancement on velopharyngeal closure in cleft palate patients

BACKGROUND AND AIMS: Impaired velopharyngeal closure function is sometimes a complication of a standard Le Fort I maxillary advancement in cleft palate patients. The transpalatal Le Fort I osteotomy has been suggested as an alternative technique that may avoid this problem. The aim of this pilot study was to examine the effects of the transpalatal approach on velopharyngeal function in a series of cleft palate patients. PATIENTS: Sixteen consecutive patients with a history of cleft palate exhibiting maxillary hypoplasia who underwent a transpalatal Le Fort I osteotomy. METHODS: All patients had a simultaneous audio/video speech recording and nasopharyngoscopy examination prior to maxillary advancement, followed by a repeat of the same examinations at least 1 year post-operatively. Velopharyngeal function was measured in two ways: by direct observation using nasopharyngoscopy, and indirectly by means of perceptual assessment. Reliability studies of the two measures were performed with satisfactory results. RESULTS: No statistically significant difference was found between the pre- and post-operative data in either the perceptual speech assessment or nasopharyngoscopy examination. CONCLUSION: These results indicate that maxillary advancement by transpalatal Le Fort I osteotomy does not adversely affect velopharyngeal closure function.     

Photometric Evaluation of Soft Tissue Changes in CLP Patients: Le Fort I Advancement Osteotomy (ALO) Versus Anterior Maxillary Distraction (AMD)

Aim

This paper is a comparative photometric evaluation of soft tissue changes in patients with CLP associated with maxillary deficiency treated with conventional Le Fort I advancement osteotomy (ALO) and anterior maxillary distraction (AMD).

Materials and Methods

Twenty patients with maxillary hypoplasia associated with cleft lip and palate who had undergone either LeFort I osteotomy or distraction osteogenesis with maxillary advancement were included in this study. Frontal and profile photographs were used to ascertain the changes post-surgically. Photographs were obtained before treatment and 1 year after surgical correction in both groups.

Results

Vertical as well as horizontal changes in pronasale was well observed in both groups. A substantial increase in nasal parameters was noted in case of AMD group in comparison to ALO group. Though maxillary advancement was quite evident in AMD and ALO groups, a significant and consistent change was observed in AMD group. Significant vertical and horizontal changes were seen with respect to subnasale and labrale superius in AMD group.

Conclusion

The hard and soft tissue changes produced by AMD by intra oral distractors were being evaluated so far. The results of the above studies have proved the excellence of AMD over conventional osteotomies. The present study goes hand in hand with the research outcomes till date.     

Dental and skeletal effects of palatal expansion techniques: a systematic review of the current evidence from systematic reviews and meta‐analyses

The aim was to assess the quality and to summarise the findings of the Systematic Reviews (SRs) and Meta‐Analyses (MAs) on the dental and skeletal effects of maxillary expansion. Electronic and manual searches have been independently conducted by two investigators, up to February 2015. SRs and MAs on the dentoalveolar and skeletal effects of fixed expanders were included. The methodological quality was assessed using the AMSTAR (A Measurement Tool to Assess Systematic Reviews). The design of the primary studies included in each SR/MA was assessed with the LRD (Level of Research Design scoring). The evidence for each outcome was rated applying a pre‐determined scale. Twelve SRs/MAs were included. The AMSTAR scores ranged from 4 to 10. Two SRs/MAs included only RCTs. The current findings from SRs/MAs support with high evidence a significant increase in the short‐term of maxillary dentoalveolar transversal dimensions after Rapid Maxillary Expansion (RME). The same effect is reported with moderate evidence after Slow Maxillary Expansion (SME). However, there is moderate evidence of a non‐significant difference between the two expansion modalities concerning the short‐term dentoalveolar effects. With both RME and SME, significant increase of skeletal transversal dimension in the short‐term is reported, and the skeletal expansion is always smaller than the dentoalveolar. Even though dental relapse to some extent is present, long‐term results of the dentoalveolar effects show an increase of the transversal dimension, supported by moderate evidence for RME and low evidence for SME. Skeletal long‐term effects are reported only with RME, supported by very low evidence.