Maxillary Transverse Dimensions Research Articles

Evaluation of maxillary transverse dimensions in individuals with a unilaterally impacted canine.

The aim of this study was to investigate the maxillary width within individuals with a unilaterally impacted maxillary canine and to determine any association between the impacted canine location and some canine-related variables. A cross-sectional analytical study using a split-mouth design included 22 CBCTs of individuals with unilaterally impacted maxillary canines (a total of 44 sides). The maxillary width was measured and compared in both impacted and non-impacted sides at various levels: basal, alveolar, and dental. The following canine-related variables were analyzed and compared with impaction location: impacted canine angulation, cusp tip distance from the occlusal plane, type of impaction (vertical or horizontal), presence of root resorption, deciduous teeth, or adjacent teeth transposition. Significance was considered at P < 0.05. There was a significant reduction in maxillary width on the impacted side at the following levels: maxillary first premolar alveolar crest in both coronal and axial sections, dental width measured from the central fossa of maxillary first molar to the midline, and width measured from the canine cusp tip to the midline. Moreover, the distance from the palatally impacted canine cusp tip to the occlusal plane was statistically significantly lower (7.6 ± 1.5 mm) compared to buccal (10.8 ± 3.3 mm) and mid-alveolus (12.0 ± 3.9 mm) impaction, (P values = 0.02). There was a significant association between canine impaction and reduction in the maxillary width at least on the dental level. The palatally impacted canine cusp tip was significantly closer to the occlusal plane compared to the buccal and mid-alveolar impaction.

Comparison of maxillary transversal changes between auxiliary beta-titanium expansion arch and miniscrew-assisted rapid palatal expansion.

This study compared buccal bone thickness, dental inclinations and maxillary transverse width dimensions changes between auxiliary beta-titanium expansion arch (AEA) and miniscrew-assisted rapid palatal expansion (MARPE). The sample consisted of 29 patients, aged between 18 and 40 years, with transverse maxillary deficiency and treated without extractions, divided into two groups: group AEA: comprised 13 individuals (initial mean age: 29.23 ± 9.13 years) treated using auxiliary beta-titanium expansion arch; group MARPE: comprised 16 patients (initial mean age: 24.92 ± 7.60 years) treated with miniscrew-assisted rapid palatal expansion. Buccal bone thickness, dental inclinations and transverse width dimensions (dental, nasal base and jugular) were measured in cone-bean computed tomographies at pre- and post-treatment stages. The variables were compared using the independent t-test. The buccal bone thickness was similar for both groups at the post-treatment stage. The second premolars were significantly more buccal inclined in the AEA group and the right maxillary first molars in the MARPE group. The intercanine and intermolar distances were statistically significantly greater in the MARPE group. Changes in dental arch transverse dimensions were significantly greater for the MARPE group. Both treatment protocols corrected the maxillary transverse discrepancy; however, MARPE provided greater correction.

Evaluation of Maxillary Transverse Arch Dimensions Following Leveling and Alignment with Different Archwire-Bracket Combinations During Fixed Appliance Treatment - A Retrospective Study

Background- Arch expansion is one of the non- extraction methods of gaining space. This study aims to assess and compare the arch expansion achieved during initial leveling and alignment with three different bracket-archwire combinations.&#x0D; Material and Methods- This was a retrospective study done in a university setup. From the available patient information archives, records of 30 subjects based on their advocated bracket system were identified and categorized into three groups. Their pre-treatment (T0) and post aligning (T2) 3D model maxillary scans were superimposed according to the reference points marked on the third palatal rugae using an OrthoAnalyzer software(3 shape version 19.0) to assess the changes in Intercanine width (ICW), Inter-premolar width (IPW) and Intermolar width (IMW) and arch length. For the recorded data, descriptive statistics, One-way ANOVA and Tukey HSD post hoc were analyzed using SPSS software. &#x0D; Results- Except for the Damon group that showed considerable increase in the intermolar and premolar dimensions, other groups had no statistically significant differences in terms of Intercanine width, Interpremolar width, and Intermolar width and Arch length.&#x0D; Conclusion- Changes in the transverse dimension were noticed among all the three groups with maximum in the Damon bracket and Damon archwire combination. Although the difference in expansion between groups showed no statistically significant difference, it was appreciated clinically in relieving dental crowding.

0808 Comparison of Maxillary Transverse Dimension with Pediatric Obstructive Sleep Apnea Presence and Severity

Abstract Introduction Obstructive Sleep Apnea (OSA) in children and adolescents is commonly discussed amongst dental specialists. Physical attributes such as a high and narrow palate, dolichofacial appearance, and retrognathic mandible are reported to increase pediatric risk for OSA. Previous research states rapid maxillary expansion decreases AHI in children with OSA and may be an effective treatment option. Current literature does not report a consistent method of measuring a maxillary transverse deficiency nor does it report a numerical maxillary threshold deficiency that requires expansion in pediatric patients with OSA. Our aims are to compare two different orthodontic diagnostic methods for measuring the maxillary transverse dimension and to assess whether patients diagnosed with mild, moderate, or severe OSA have a numerical threshold for maxillary deficiency. Methods Participants were ages 7-17 years old (average 11.7 years) with no history of orthodontic treatment, craniofacial syndromes, craniosynostosis forms, or nasal abnormalities. Those with and without adenoids and tonsils were included. Participants presented to the Mayo Clinic Sleep Center for their polysomnogram. Their dentition was scanned, and a digital model was rendered. The maxillary transverse dimension was measured via two different methods: McNamara’s Analysis and Andrew’s Six Elements of Orofacial Harmony. Results There were 65 participants: 31 diagnosed with OSA (13 Mild, 4 Moderate, 5 Severe, and 9 Other) and 34 without (controls). Patients in the Other category were diagnosed based on clinical findings. No statistical difference was found between the maxillary transverse measurements of patients with versus without OSA or between the OSA categories. Patients with OSA were more likely to have permanent teeth (61.3% vs 32.4%, p=0.019), tonsils removed (54.8% vs 26.5%, p=0.020), and to have snored during the PSG (83.9% vs 55.9%, p=0.048). Conclusion Conclusions based on this pilot study should be interpreted carefully due to limited sample sizes. No statistically significant differences of the maxillary transverse dimension were found between those with and without OSA using either diagnostic method. No numerical maxillary deficiency threshold was found. Maxillary expansion should not be recommended based on OSA diagnosis alone. Referral to a dental specialist is recommended based on dental needs. Support (if any) Support was provided by Mayo Clinic CTSA grant UL1TR002377.

Maxillary Transverse Dimensions in Subjects with Impacted Canine Compared with Normal Subjects using Cone Beam Computed Tomography

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Three-Dimensional Evaluation of Dental Arches in Individuals with Syndromic Craniosynostosis.

Individuals with syndromic craniosynostosis present alterations in the dental arches due to anomalies caused by the early fusion of the craniomaxillary sutures. This study aimed to compare intradental and interdental dimensions between individuals with Apert and Crouzon syndromes and nonsyndromic controls. Digital models were obtained from the archive of a public tertiary care hospital. The sample consisted of 34 patients (Apert n = 18, Crouzon n = 16) and 34 nonsyndromic controls matched for gender and age. Measurements of perimeter, length, intercanine and intermolar distances (upper and lower), overjet, and molar ratio were performed. Statistical comparisons were performed using ANOVA and Tukey tests (p < 0.05). Patients with Apert and Crouzon syndromes have severely reduced maxillary transverse dimensions, perimeter, and length of the upper arch compared to the control group (p < 0.001). The lower arch is less impacted. Patients with Apert syndrome had an anterior crossbite (p < 0.001), while patients with Crouzon syndrome had an edge-to-edge bite (p < 0.011). Patients with Apert and Crouzon syndromes do not have serious transverse proportion problems when comparing the upper and lower arches. In this sample, both the Apert and Crouzon groups have severely compromised upper arches compared to the control group. Mild dentoalveolar expansion in the maxilla should be sufficient for the transverse adaptation of the dental arches before frontofacial advancement.

Assessment of Growth Changes in the Width of Dental Arches Caused by Removable Appliances over a Period of 10 Months in Children with Malocclusion.

(1) Background: A large number of patients of orthodontic clinics are diagnosed with improper jaw relationships. Intraoral scanners have become an important part of orthodontic practice and provide an opportunity to measure the changes in the width of dental arches. The purpose of the study was to evaluate the impact of removable appliances used over a 10-month period on growth changes in children with narrowed jaw dimensions. (2) Methods: Twenty four patients were included in the study (a study group—patients, treated with removable appliances in the upper dental arch for a minimum of 10 months; a control group—patients with no craniofacial abnormalities and who did not require orthodontic treatment). A panoramic radiograph and digital intraoral scan were taken, followed by palatal width measurements in Ortho-CAD before treatment, and after a period of 10 months of treatment with removable appliances. (3) Results: After a period of 10 months of the treatment, the study group had a statistically significantly greater mean change in the anterior width of the upper dental arch than the control group. (4) Conclusions: The use of removable appliances in children with narrowed maxillary transverse dimension contributes to offsetting growth changes in comparison to children with normal occlusion.

Comparison between Digital Casts and Cone Beam Computed Tomography for Measuring Maxillary Transverse Dimensions in Patients with Impacted Canines.

Cone beam computed tomography (CBTCT) scans (n = 45) and digital dental casts (n = 45) were both used to measure the maxillary transverse dimensions in patients with impacted maxillary canines. The objectives were to explore the associations of these dimensions with the impaction and patient characteristics, and to compare the measurements between these techniques. The maxillary width was measured on scans and casts at the Walaridge, and the intermolar width and interpremolar width levels were measured at the first and second premolars (measured from the buccal grooves and the palatal cuspids, and the palatal and lingual amelocemental junctions). Two examiners independently compared the measurements between the control quadrants (without impaction) and the case quadrants (with impaction) in patients with unilateral impactions, and between the unilateral and bilateral impaction groups. The interclass correlation coefficient (ICC) was calculated to assess the interexaminer reliability and paired or independent Student’s t-tests and ANOVAs were used for comparisons. The ICCs were 0.887 and 0.919, globally, for the measurements on the CBCT scans and casts, respectively, which indicates the excellent interexaminer reliability. On the CBCT scans, statistically significant differences were found between the case and control quadrants in the transverse measurements at the lingual level on the upper first molars, and at the WALA ridge level on the upper second premolars (p < 0.05) in the unilateral impaction group. Significant differences were found between the case quadrants in the unilateral versus the bilateral groups at the WALA ridge on the second premolars in casts (p < 0.05), and at the lingual point on the first molars on the CBCT scans (p < 0.05). No statistically significant differences in the transverse measurements were observed between the impacted buccal and palatal canines on either the casts or CBCT scans. To the best of our knowledge, this is the first study to compare the transverse measurements between digital models and CBCT scans.

UTILIZATION OF CEPHALOMETRIC 2D AND 3D ANALYSIS DURING DIAGNOSIS, TREATMENT PLAN AND CASE MONITORING OF IMPACTED TEETH-CASE REPORT

&nbsp;RTG projections are essential for diagnosis, treatment plan, follow up and treatment outcomes. Three-dimensional(3D) cephalometry, which is done using a cone beam computerized tomography (CBCT) exam, allows more detailed evaluation of the craniofacial hard and soft tissue structure than 2D radiograph. The justification for using 3D analyses in diagnostic and treatment planning in orthodontics are more than necessary in cases with impacted teeth, cleft lip, skeletal discrepancies requiring surgical interventions. CBCT has come into wider usage in other situations as root resorption, temporomandibular joint (TMJ) morphology and pathology, supernumerary teeth, alveolar boundary conditions and asymmetries; maxillary transverse dimensions and maxillary expansion; vertical malocclusion and obstructive sleep apnoea. The present descriptive study aims to explore possible applications of 3D technologies during the diagnosis, treatment plan, case monitoring and result assessment in orthodontics including their advantages and disadvantages. Utilisation of 3D technique was more than necessary in diagnostic and treatment planning in this case because of presence of more than one impacted tooth. The fixed appliances, the surgical exposure, cortectomy and orthodontic traction were done.&nbsp; The tooth movement and positioning to the dental arch started six months ago. The impacted tooth is already seen and the treatment continues. The severity of this case is indication for utilization of control 2D and 3D radiographs in manner following the positioning of the central incisor on the appropriate place. 3D technique is less prone to error and can improve the clinicians’ workflow. Keywords: Diagnosis, Treatment plan, 2D radiograph, CBCT, Cortectomy.

What are the intra-arch risk factors for palatally displaced maxillary canine? - Results of a case-control study.

This study aimed to identify the intra-arch risk factors for palatally displaced canine by comparing the maxillary transverse dimensions, palatal depth (PD), and arch length (AL) of the subjects with and without impacted canine using cone-beam computed tomography (CBCT). In this prospective case-control study, 79 CBCT images of gender- and skeletal feature-matched subjects (25 cases and 54 controls) were compared. Based on the CBCT images, maxillary transverse widths at four levels (molar basal, molar alveolar, premolar basal, and premolar alveolar), maxillary PD, and maxillary AL were measured. Group comparisons were assessed using analysis of variance (ANOVA), followed by post-hoc Scheffe's test, and risk factors were identified using univariate and multivariate logistic regression. The impacted canine group showed significantly smaller molar alveolar width, premolar alveolar width, PD, and greater AL compared to the control group (P = 0.046, P < 0.001, P = 0.003, and P = 0.001, respectively). No significant difference was observed in the molar and premolar basal width measurements between the two groups. Multivariate analysis showed that impacted maxillary canine was influenced by premolar alveolar width (odds ratio (OR): 0.669), PD (OR: 0.532), and AL (OR: 1.739). Intra-arch risk factors, such as reduced maxillary premolar transverse alveolar width, PD, and greater AL, are associated with palatally displaced canine.

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

BackgroundThe 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).MethodsAOB 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.ResultsAt 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.ConclusionsRME/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.

CONE-BEAM COMPUTED TOMOGRAPHY EVALUATION OF THE RELATIONSHIP BETWEEN MAXILLARY TRANSVERSE DIMENSIONS AND IMPACTED MAXILLARY CANINES

Aim: Evaluate the relationship between maxillary transverse dimensions and impacted maxillary canines using cone beam computed tomography (CBCT). Materials and Methods: This retrospective radiographic study reviewed 45 CBCT records of 45 subjects their ages above 12 years. The records were divided into 3 groups, Group I: normally erupted maxillary canine group (control group), group II: labial impacted maxillary canine group, group III: palatal impacted maxillary canine group. Maxillary width was measured at 4 levels: basal first molar width, alveolar first molar width, basal first premolar width, and alveolar first premolar width. The depth of the palatal vault was measured to evaluate the shape of the palate in all groups. Results: labial and palatal impacted groups showed significantly smaller basal first molar widths, alveolar first molar and first premolar widths, compared with the control group (P < 0.05). Basal first premolar widths and palatal vault depths were not significantly different between the groups. Conclusions: Maxillary width was smaller in subjects with labial or palatal maxillary canine impaction than subjects without impaction.

Correlation between the transverse dimension of the maxilla, upper airway obstructive site, and OSA severity.

Acquiring a better comprehension of obstructive sleep apnea physiopathology can contribute to improving patient selection for surgical treatments. We hypothesize that maxillary transverse deficiency restricts the space available for the tongue, leading to upper airway obstruction during sleep. Our primary hypothesis was that maxillary transverse deficiency increases the prevalence of tongue collapse during drug-induced sleep endoscopy (DISE). The secondary hypothesis was that maxillary transverse deficiency will also increase the prevalence of circumferential collapse at the velopharynx. The exploratory hypothesis was that maxillary transverse deficiency is associated with increased obstructive sleep apnea severity. The objectives of this study were to correlate maxillary morphometric measurements with (1) the anatomic level of obstruction during DISE and (2) the apnea-hypopnea index on polysomnography. We made a cross-sectional analysis of patients with obstructive sleep apnea undergoing DISE in search of positive airway pressure alternative treatment. Maxillary measurements were collected from a computed tomography scan (interpremolar distance, intermolar distance [IMD] and sella-nasion A point angle), findings from DISE, and sleep study variables from polysomnography. Correlation between computed tomography, DISE, and polysomnography data was assessed using Pearson's correlation, and receiver operating characteristic curves were determined for each facial measurement. Sixty-nine patients were included in the study. The group with velopharyngeal circumferential collapse had mean IMD = 26.30 mm (25.5-31.45), and the group with anteroposterior collapse had mean IMD = 29.20 mm (26.8-33.10; P = .040). The group with complete tongue-base obstruction had mean interpremolar distance = 26.40 mm (25.1-28) and IMD = 26.30 mm (25.6-28.4), and the group without obstruction had mean interpremolar distance = 28.7 mm (27.2-30; P = .003) and IMD = 34.06 mm (32.1-37; P < .001). The receiver operating characteristic curve determined an IMD cutoff of 29.8 mm for predicting tongue-base obstruction. The maxillary transverse deficiency, identified by reduction in interpremolar distance and IMD, predicted the occurrence of complete tongue-base obstruction, complete concentric collapse at the velopharynx, and multilevel obstruction during DISE. We did not find an association between the maxillary measurements and obstructive sleep apnea severity. These associations hold some promise in ultimately supplanting insights previously available only through DISE.

Modified Arnold expander: an alternative for mandibular arch expansion.

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

Maxillary transverse dimensions in subjects with and without impacted canines in South Indian population: a comparative cone-beam computed tomography study

ABSTRACT Aim: Aim of this study was to assess transverse maxillary dimension in subjects with unilateral and bilateral canine impaction, compare with a similar control group and to establish correlation, if any. Materials and Methods: This study included 135 subjects who were split into three groups: (i) unilateral canine impaction group, (ii) bilateral canine impaction and (iii) control group each having 45 subjects. For each subject 4 maxillary transverse dimensions were evaluated on the following 4 levels: first molar basal width (MBW), first molar alveolar width (MAW) (Figure 2), first premolar basal width (PMBW), and first premolar alveolar width (PMAW) using CBCT. Results: MBW, MAW, PMBW and PMAW were significantly reduced in groups with bilateral and unilateral canine impaction (p-value<0.001). Conclusion: It can be concluded that subjects with bilateral and unilateral canine impactions have narrower maxillary transverse dimensions than those without impaction. Orthodontists must be aware and should consider the relationship between transverse maxillary width and canine impaction during pedantic treatment planning.

A Decision Tree for Orthodontic and Surgical Management of the Maxillary Transverse Dimension in Orthognathic Surgery

Correction of the transverse dimension of the maxilla is unique in orthognathic surgery as it has the potential to maintain or create the dental arch perimeter based on the choice of procedure. This orthognathic transverse decision tree (Fig 1) presents a systematic process for evaluation of the maxillary skeletal dimension and dental arch perimeter when surgical correction is indicated for dentofacial dysplasia. The goal of the method is to formalize evaluation, quantify the severity of deficiencies, and identify appropriate treatment solutions.

Selected Orthodontic Principles for Management of Cranio-Maxillofacial Deformities.

An understanding of fundamental orthodontic principles involving diagnosis, treatment planning, and clinical strategies is essential for achieving successful outcomes in the treatment of craniofacial patients, particularly cleft lip/palate. This article focuses on: customizing a mandibular dental arch form using the WALA ridge; accurately diagnosing the maxillary skeletal transverse dimension (cusp to cusp/fossa to fossa); coordinating the upper dental arch with the lower; using a smiling profile and glabella vertical to assess anteroposterior jaw position; and leveling the mandibular curve of Spee while considering the lower one-third of the face. These concepts influence treatment outcomes to the extent they are used.

Tomographic evaluation of dentoskeletal effects of rapid maxillary expansion using Haas and Hyrax palatal expanders in children: A randomized clinical trial.

BackgroundRapid maxillary expansion (RME) is a usual procedure for correcting the transversal maxillary deficiency. Among the most used appliances are the Haas type (tooth-tissue-borne) and Hyrax (tooth-borne) whose main difference is the design. This study aimed to evaluate the dentoskeletal effects of RME using two different expanders in children. Material and MethodsThe sample was composed of 42 children of both gender presenting unilateral or bilateral posterior crossbite with mean age 9.49 (SD± 1.35). Patients were randomized into two groups according to the type of expander: Hyrax (n= 21, 9 boys and 12 girls) and Haas (n= 21, 11 boys and 10 girls). Multiplanar coronal and axial slices obtained from cone-beam computed tomography images (i-Cat, Hartsfield, PA, USA) were used at pretreatment (T1) and after 6 months when the expander was removed (T2). Measurements were performed on Dolphin Imaging Systems 11.7 software (Chatsworth, California, USA). The following variables were evaluated: inclinations of the posterior teeth, transverse skeletal widths, length of maxillary dental arch, buccal bone thickness and level of buccal alveolar crest. Statistical analysis performed using chi-squared test to compare the sex ratios between groups and independent t test with the Bonferroni correction for multiple tests. ResultsRME increased all maxillary transverse dimensions, regardless of the type of expanders used. Subjects in the Hyrax group experienced significantly increase in the lingual bone thickness (0.94 mm) compare to Haas group (0.21 mm). ConclusionsThe Hyrax-type expander produced greater increase in the lingual bone thickness than did the Haas-type expander, but this effect might not be clinically significant. Both appliances presented similar transversal gain and tended to produce similar orthopedic and orthodontic effects. Key words:Cone-beam computed tomography, palatal expansion technique, palate.

Skeletal and dental effects of surgically assisted rapid palatal expansion: a systematic review of randomized controlled trials.

Surgically assisted rapid maxillary expansion (SARME) is a surgical technique developed to correct transverse discrepancies in skeletally mature patients. However, there is limited evidence concerning the immediate skeletal and dental changes obtained only due to SARME. The aim of the present systematic review is to investigate the immediate skeletal and dental effects of SARME in adult patients with transverse maxillary hypoplasia. An electronic search of the literature in MEDLINE, The Cochrane Library, Lilacs and Scopus databases was performed. Only randomized controlled trials (RCTs) studies investigating the skeletal and dental effects of SARME procedures in adult patients were included. The included studies received a methodological quality scoring according to the revised Cochrane risk-of-bias tool for randomized trials. The quality of evidence was assessed by means of the Grading Recommendation Assessment, Development and Evaluation (GRADE) system. For each included study and for each analysed parameter, the difference in means and 95 per cent confidence interval was calculated between baseline and immediate post-expansion. A meta-analysis of original outcome data, if possible, was conducted. Nine articles were selected. The methodological quality ratings indicated that one study was at low risk of bias, seven presented some concerns and only one was at high risk of bias. In all the included studies, the SARME procedure resulted in a significant expansion of the maxillary transverse dimension. The meta-analysis compared skeletal and dental inter-molar width before and after treatment: the mean difference was of 3.3 mm (2.8-3.9) and 7.0 mm (6.1-7.8), respectively (P-value less than 0.001). The quality of evidence was low-moderate. SARME is effective in obtaining a significant expansion of the maxillary transverse dimension. However, the immediate SARME effect is mainly a molar expansion rather than a pure bone transverse widening of the maxilla. The review protocol was registered at PROSPERO database with the registration number CRD42018117967.

Transversal Maxillary Distraction in Patients with Cleft Lip and Palate.

The aim of this study is to describe the importance of osteodistraction with transpalatal distractors for treating transversal maxillary hypoplasia in patients with cleft and lip palate. The participants were 17 patients (9 females and 8 males) with cleft lip and palate. Among these, 10 presented unilateral cleft lip and palate, 4 bilateral cleft lip and palate, and 3 cleft palate only. All patients experienced a satisfactory palatal expansion and crossbite correction. The mean lengthening was 12.7 mm. The average increase of intercanine distance, intermolar distance, maxillary transverse dimension (MTD), facial transverse dimension (FTD) was 12.16, 8.45, 1.77, and 1.67 mm, respectively. The clinical follow-up was 29.7 months (range: 6-61 months). Palatal distraction is a safe and successful alternative for treating maxillary transversal alterations in patients with cleft lip and palate. This technique facilitates the establishment of an adequate transverse dimension of maxillary, and consequently a proper dental occlusion.