Rapid Maxillary Expansion Appliance Research Articles

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

BackgroundTo evaluate how the amount of expansion of the primary second molars, the patient’s age, and the skeletal maturation stage influence the amount of expansion at the level of the permanent first molars.Material and MethodsFifty-five patients aged between 6 and 11 years with a cervical vertebral maturation stage of CS1 or CS2 were retrospectively selected. The intermolar width was measured before and after expansion to evaluate the amount of expansion achieved at the level of the primary second molars and the permanent first molars. Stepwise multiple linear regression was used to evaluate how the amount of primary molars expansion, the patient’s age, and the cervical vertebral maturation stage predict the amount of permanent molar expansion.ResultsA significant regression equation was found, and for every 1 mm of primary molar expansion, 0.91 mm of permanent molar expansion can be expected. An age between 6 and 11 years and the CS1 or CS2 skeletal maturation stage were not significant predictors of permanent molar expansion.ConclusionsA rapid maxillary expansion appliance anchored on primary second molars is effective in expanding the permanent molars to correct a transverse maxillary deficiency in prepubertal patients, transferring the risks associated with the large forces used to the primary teeth. Key words:Maxillary expansion, transversal deficiency, primary molars.

A novel method for treatment of Class III malocclusion in growing patients

BackgroundManagement of Class III malocclusion is one of the most challenging treatments in orthodontics, and several methods have been advocated for treatment of this condition. A new treatment protocol involves the use of an alternating rapid maxillary expansion and constriction (Alt-RAMEC) protocol, in conjunction with full-time Class III elastic wear and coupled with the use of temporary anchorage devices (TADs). The aim of this study was to evaluate the dento-skeletal and profile soft tissue effects of this novel protocol in growing participants with retrognathic maxilla.MethodsFourteen growing participants (7 males and 7 females; 12.05 ± 1.09 years), who displayed Class III malocclusions with retrognathic maxilla, were recruited. Pre-treatment records were taken before commencing treatment (T1). All participants had a hybrid mini-implant-supported rapid maxillary expansion (MARME) appliance that was activated by the Alt-RAMEC protocol for 9 weeks. Full-time bone-anchored Class III elastics, delivering 400 g/side, were then used for maxillary protraction. When positive overjet was achieved, protraction was ceased and post-treatment records were taken (T2). Linear and angular cephalometric variables were blindly measured by one investigator and repeated after 1 month. An error measurement (Dahlberg’s formula) study was performed to evaluate the intra-examiner reliability. A paired-sample t test (p < 0.05) was used to compare each variable from T1 to T2.ResultsTreatment objectives were achieved in all participants within 8.5 weeks of protraction. The maxilla significantly protracted (SNA 1.87°± 1.06°; Vert.T-A 3.29± 1.54 mm p < 0.001), while the mandibular base significantly redirected posteriorly (SNB −2.03° ± 0.85°, Vert.T-B − 3.43± 4.47 mm, p < 0.001 and p < 0.05 respectively), resulting in a significant improvement in the jaw relationship (ANB 3.95°± 0.57°, p < 0.001; Wits 5.15± 1.51 mm, p < 0.001). The Y-axis angle increased significantly (1.95° ± 1.11°, p < 0.001). The upper incisors were significantly proclined (+ 2.98°± 2.71°, p < 0.01), coupled with a significant retroclination of the lower incisors (− 3.2°± 3.4°, p < 0.05). The combined skeletal and dental effects significantly improved the overjet (5.62± 1.36 mm, p < 0.001) and the soft tissue Harmony angle (2.75° ± 1.8°, p < 0.001).ConclusionsClass III elastics, combined with the Alt-RAMEC activation protocol of the MARPE appliance, is an efficient treatment method for mild/moderate Class III malocclusions. The long-term stability of these changes needs further evaluation.

Effects on nasal airflow and resistance using two different RME appliances: a randomized controlled trial.

To evaluate and compare the effects of tooth-borne (TB) and tooth-bone-borne (TBB) rapid maxillary expansion (RME) on nasal airflow and resistance. Fifty-four consecutive patients who met the eligibility criteria were recruited from September 2010 to December 2015. Of these 54 subjects, 40 agreed to participate in the part of the study involving evaluation of nasal flow and resistance. The 40 subjects were allocated to either the TB group, mean age 9.7 years (SD 1.5), or the TBB group, mean age 10.2 years (SD 1.4). All subjects performed rhinomanometric registration at baseline (T0), but only 30 attended the post-expansion registration (T1), of whom 16 had been randomized to the TB group and 14 to the TBB group. The study outcomes, nasal airflow and nasal airway resistance, were evaluated with linear regression adjusted for baseline variable of the outcome to compare the study groups with complete cases strategy as well as after multiple imputation (MI). Participants were randomly allocated in blocks of different sizes, using the concealed allocation principle in a 1:1 ratio. The randomization list was computer generated to ensure homogeneity between groups. Blinding was done only for outcome assessor due to clinical limitations. The care providers at the ENT unit who conducted all the rhinomanometry examinations were blinded to which group the patients were allocated to. Complete case analysis showed significantly higher post-expansion nasal airflow values for the TBB group compared with the TB group, mean difference 51.0 cm3/s (P = 0.018). The evaluation after MI showed a similar significant mean difference, 52.7 cm3/s (P = 0.020) in favour of the TBB group when taking into account the missing values from the T1 examination. Even reduction in nasal airway resistance showed similar pattern in favour of the TBB group. Our results represent the short-term effects. A longer follow-up period would have been preferable. The TBB RME induced significantly higher nasal airway flow and lower nasal resistance values than TB RME. It might be wiser to use TBB RME in cases with constricted maxilla and upper airway obstruction. This trial was not registered in any external sites. The protocol was not published before trial commencement.

Letters From Our Readers.

To: Editor, The Angle OrthodontistRe: Response to: Dentoskeletal effects of a temporary skeletal anchorage device-supported rapid maxillary expansion appliance (TSADRME): A pilot study. Vassar JW, Karydis A, Trojan T, Fisher J. The Angle Orthodontist. 2016;86:241–249.Thank you for the opportunity to respond to Dr Thakkar's questions regarding our recently published study in your journal. Dr Thakkar is posing some very interesting questions that we want to address.Dr Thakkar suggests that the midpalatal suture could have been used as a marker for skeletal maturity of the stomatognathic system. In our study we were able to identify the midpalatal suture region only in some of our patients. We concluded that the midpalatal suture could not offer an accurate estimate either for the maturation or for the expansion, most likely due to the lower radiation and resolution (0.4 mm) used in our study for patient safety purposes (previous reports used higher radiation CBCTs and higher resolution: 0.25-0.3 mm).1 We addressed this limitation of our sample by dividing our population in two age groups: age group 8-16 years old that corresponds with palatal maturation stage A-C1 (non-fused palatal suture) and skeletal maturation stages CS1-CS4 (Cervical Vertebral Method CVM),2 and age > 16-18 years old that corresponds to more advanced maturation stages.We were able to evaluate the midpalatal suture distance and expansion in some of our patients. Since the mean time between the 1st and the 2nd CBCT in our sample was 7.83±2.49 months, we were able to evaluate the midpalatal suture expansion mainly in those patients where the time between CBCTs was at the lower end of our time range. In patients where the time between CBCTs was at the higher end of our time range, even when the midpalatal suture was identifiable, the bone was already mineralized rendering our measurements less useful.Dr Thakkar raises the most interesting question regarding the effect of RME procedures on circum-maxillary sutures and the anterior face height in hyperdivergent patients. His suggested hypothesis is that the reduction in dental tipping and extrusion resulting from TSAD support would lessen the molar extrusive effect of RME treatment. However, the magnitude of vertical displacement at the circum-maxillary sutures may be a significant contributor to increased anterior face height, especially in the hyperdivergent population. These are very interesting questions, but they were beyond the scope of our study that focused on the assessment of maxillary skeletal expansion and dental tipping using CBCT images and proposed a novel way to quantify the dental tipping effects of temporary skeletal anchorage device–supported RME appliances.Thank you again for the opportunity to discuss very important questions that affect our clinical decisions in selecting the ideal treatment options for our patients. We sincerely hope that the continuous interest in the topic will lead more researchers in studying the above topics.

Do different maxillary expansion appliances influence the outcomes of the treatment?

There is no consensus in the literature regarding which rapid maxillary expansion (RME) design or activation rate benefits the patients the most. Therefore, the primary aim of this systematic review was to see whether there is a difference in the skeletal and dentoalveolar effects of different RME appliances in children and growing adolescents. The secondary aim was to see whether these effects are different when using different activation protocols for these appliances. The search was done in three databases (PubMed, Cochrane Library, and Web of Science). The following inclusion criteria were used: randomized controlled trial, prospective controlled studies, 15 or more patients in each study, human subjects up to 18 years of age, and RME effects had to be assessed by computed tomography/cone beam computed tomography. Quality of the methodology was classified according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines as high, moderate, or low. The search resulted in 145 titles and abstracts; 109 of them were excluded based on pre-established criteria. Thirty-six full-text articles were assessed for eligibility and 18 of which satisfied the inclusion criteria. Finally, seven articles were deemed eligible for full inclusion and revealed that all appliances and protocols showed significant expansion in the mid-palatal suture. No evidence was found for the cause of dental tipping. In this systematic review, having different age groups in each study and using different anatomical landmarks and outcome measures for assessing the skeletal and dental effects made it difficult to conduct a meta-analysis. There is moderate evidence that all designs produce significant expansion at the mid-palatal suture. However, lack of studies comparing appliances and protocols has been found. Finally, no evidence-based conclusions could be drawn about the appliance effect on teeth tipping. No appliance appears to be superior when it comes to expansion in the mid-palatal suture. Therefore, the tooth-borne appliance might be preferable until further high-quality studies conclude otherwise. The project was funded through the Department of Orthodontics, Postgraduate Dental Education Center, Region Örebro County, Örebro, Sweden. This systematic review was not registered in any external databases.

Determination of forces on a split palatal screw after rapid maxillary expansion.

Aim of this study was to develop a finite element model of the forces that patients with rapid maxillary expansion bear and to validate it by a mechanical test. Computer-aided design models of the metallic screw and polymeric splint were modelled and discretized. Two forces were generated and considered independently: F1 at the temporary molar (2.5N) and F2 at the permanent molar (2.5N). The results of the finite element analysis were used to define the strain values which the anterior and posterior arms of the rapid maxillary expansion appliance bore as a linear function of F1-F2 by calculating the strain-force coefficient δ ij . Two strain gauge rosettes were attached to an appliance which was placed in an XY motorized stage to reproduce the same forces used in the finite element analysis. Once the system was validated, the matrix was inverted to determine forces F1 and F2 that a group of 40 patients underwent (median age 8.33years, standard deviation 1.86years) for 75days, using their strain values. The parents of the patients activated a quarter turn (0.20mm) twice a day until 50% transversal overcorrection was achieved. Finite element analysis showed that the effects of the forces on stress at the location of the arms were notably different. There was a satisfactory correlation between finite element analysis predictions and in vitro values. Dissipation of F1 and F2 in patients was predicted to be 62.5 and 80%, respectively, after 75days of retention. These results back the finite element analysis model for force prediction.

Various Contemporary Intraoral Anchorage Mechanics Supported with Temporary Anchorage Devices.

The aim of this review was to provide an overview of the various types of contemporary intaroral anchorage mechanics that are being used with temporary anchorage devices (TADs) and to briefly mention the design and clinical use of these appliances. Original articles on "mini-implants in orthodontics, temporary anchorage devices, orthodontic miniscrews, mini-implants, and skeletal anchorage" were searched for on the PubMed database. Articles published between 2004 and May 2015 were used. References of 10 articles were also searched for and used. Beneslider, Miniscrew-supported EZ slider, Implant-supported Distal Jet, Mini-implant-Borne Pendulum B Appliance, Noncompliance-supported Maxillary Molar Distalization Appliance, Temporary Skeletal Anchorage Device-Supported Rapid Maxillary Expansion Appliance (RME), Mini-Implant-Supported Maxillary Expansion, Implant-Supported RME, Hybrid Hyrax, Frog Appliance, Palatally Anchored Mesialslider, Mousetrap Appliance, Lever Arm, and Mini-implant System were evaluated. In contemporary orthodontics, TADs have an important place. They can be combined with different intraoral mechanics and be efficiently used. The future of orthodontic intraoral anchorage may be based on TADs.

Assessment of the dental and skeletal effects of fan-type rapid maxillary expansion screw and Hyrax screw on craniofacial structures.

Aims and Objectives:The purpose of the study was to assess the skeletal and dental effects of fan-type rapid maxillary expansion (RME) appliance and Hyrax RME appliance on the craniofacial structures.Materials and Methods:The sample of the study included 12 patients with constricted maxillary arches. Acrylic bonded type of attachment was used for both groups. Changes in sagittal, vertical, and transverse relationship were assessed with lateral and frontal cephalograms, respectively. Intercanine and intermolar widths were measured with stone models. Pre- and immediate post-treatment records were statistically analyzed with Wilcoxon signed-rank test. The differences between the groups were evaluated using Mann–Whitney U-test. Since the data pertaining to intercanine width and intermolar width were normally distributed, parametric test of significance (unpaired t-test) was used to compare them.Results:Results showed that Hyrax presented with significantly greater increments for both nasal cavity width and maxillary width when compared to fan-type RME. Both groups had retroclination of incisors. The increase in the intercanine width was almost similar in both groups.Conclusion:Fan-type RME caused only minimal expansion of the intermolar width when compared to the Hyrax. The ratio between the intercanine and intermolar width expansion was nearly 4:1 in the fan-type RME and 0.75:1 in Hyrax.

Pain and discomfort during the first week of rapid maxillary expansion (RME) using two different RME appliances: A randomized controlled trial.

To evaluate and compare perceived pain intensity, discomfort, and jaw function impairment during the first week with tooth-borne or tooth-bone-borne rapid maxillary expansion (RME) appliances. Fifty-four patients (28 girls and 26 boys) with a mean age of 9.8 years (SD 1.28 years) were randomized into two groups. Group A received a conventional hyrax appliance and group B a hybrid hyrax appliance anchored on mini-implants in the anterior palate. Questionnaires were used to assess pain intensity, discomfort, analgesic consumption, and jaw function impairment on the first and fourth days after RME appliance insertion. Fifty patients answered both questionnaires. Overall median pain on the first day in treatment was 13.0 (range 0-82) and 3.5 (0-78) for groups A and B, respectively, with no significant differences in pain, discomfort, analgesic consumption, or functional jaw impairment between groups. Overall median pain on the fourth day was 9.0 (0-90) and 2.0 (0-71) for groups A and B, respectively, with no significant differences between groups. There were also no significant differences in pain levels within group A, while group B scored significantly lower concerning pain from molars and incisors and tensions from the jaw on day 4 than on the first day in treatment. There was a significant positive correlation between age and pain and discomfort on the fourth day in treatment. No correlations were found between sex and pain and discomfort, analgesic consumption, and jaw function impairment. Both tooth-borne and tooth-bone-borne RME were generally well tolerated by the patients during the first week of treatment.

Combination of expansion and orthognathic surgery in a severe hyperdivergent skeletal Class III malocclusion

Class III malocclusions with a severe hyperdivergent growth pattern are very complex to plan and treat. This case report describes the treatment of an adult with a skeletal Class III malocclusion with a midface deficiency, severe bilateral posterior crossbite, and a severe hyperdivergent growth pattern by a combination of a bonded rapid maxillary expansion appliance and surgical procedure of Le Fort I osteotomy for maxillary advancement.

Volumetric upper airway changes after rapid maxillary expansion: a systematic review and meta-analysis.

Although Rapid Maxillary Expansion (RME) has been used for over a century, its effect on upper airways has not yet adequately been assessed in an evidence-based manner. To investigate the volumetric changes in the upper airway spaces following RME in growing subjects by means of acoustic rhinometry, three-dimensional radiography and digital photogrammetry. Literature search of electronic databases and additional manual searches up to February 2016. Randomized clinical trials, prospective or retrospective controlled clinical trials and cohort clinical studies of at least eight patients, where the RME appliance was left in place for retention, and a maximum follow-up of 8 months post-expansion. After duplicate data extraction and assessment of the risk of bias, the mean differences and 95 per cent confidence intervals (CIs) of upper airway volume changes were calculated with random-effects meta-analyses, followed by subgroup analyses, meta-regressions, and sensitivity analyses. Twenty studies were eligible for qualitative synthesis, of which 17 (3 controlled clinical studies and 14 cohort studies) were used in quantitative analysis. As far as total airway volume is concerned patients treated with RME showed a significant increase post-expansion (5 studies; increase from baseline: 1218.3mm3; 95 per cent CI: 702.0 to 1734.6mm3), which did not seem to considerably diminish after the retention period (11 studies; increase from baseline: 1143.9mm3; 95 per cent CI: 696.9 to 1590.9mm3). However, the overall quality of evidence was judged as very low, due to methodological limitations of the included studies, absence of untreated control groups, and inconsistency among studies. RME seems to be associated with an increase in the nasal cavity volume in the short and in the long term. However, additional well-conducted prospective controlled clinical studies are needed to confirm the present findings. None. Australian Society of Orthodontics Foundation for Research and Education Inc.

Rapid maxillary expansion: a review of appliance designs, biomechanics and clinical aspects

Rapid maxillary expansion (RME) is an orthopaedic procedure that utilizes heavy forces to correct transverse maxillary arch discrepancies. There is a substantial body of literature relating to the various designs of RME devices and their clinical indications. CPD/Clinical Relevance: To provide the dental practitioner and orthodontist with evidence-based facts about types, designs and uses of RME appliances and to promote understanding of their biomechanical effects.

Evaluation of the effects of modified bonded rapid maxillary expansion on occlusal force distribution: A pilot study.

Objective:To evaluate the effects of modified bonded rapid maxillary expansion (RME) on occlusal force distribution.Materials and Methods:The sample included 12 patients (7 girls and 5 boys; mean age: 13.1 years) at the permanent dentition stage with bilateral posterior cross-bite. The patients were treated with a modified bonded RME appliance, activated twice a day. The study was terminated when the palatal cusps of the maxillary posterior teeth were occluding with the buccal cusps of the mandibular posterior teeth. The postretention period was 3 months. The T-Scan III device was used to analyze the percentages of occlusal force distribution, and records were taken at the pretreatment (T1), the postreatment (T2), and the postretention (T3) periods. Wilcoxon signed rank test was used for statistical analyses.Results:Incisors were most frequently without contact, followed by canines. The highest forces were seen in the second and first molar regions. A significant decrease was seen in total occlusal force during treatment (T1–T2); however, during retention, the force returned to its initial value, and no significant differences were found (T1–T3). No differences were found between right and left sides and in occlusal forces of the teeth in all time periods.Conclusion:The use of modified bonded RME decreases the total occlusal forces during the treatment period, but it does returns to its initial value after the postretention period.

Treatment Options for Pediatric Obstructive Sleep Apnea

There are a variety of therapies available for the treatment of pediatric obstructive sleep apnea syndrome (OSAS). In children with enlarged adenoids or tonsils, adenotonsillectomy (AT) is the preferred treatment, but other surgical options include partial tonsillectomy and lingual tonsillectomy. In specific populations, craniofacial or bariatric surgery may be indicated, and tracheostomy should be reserved for cases where there is no other therapeutic option. Positive airway pressure (PAP) is the most effective non-surgical therapy for OSAS as it can be successfully used in even cases of severe OSAS. Nasal steroids and leukotriene receptor antagonists may be used in the treatment of mild or moderate OSAS. Rapid maxillary expansion and dental appliances may be effective in select populations with dental problems. Other non-surgical therapies, such as positional therapy, supplemental oxygen, and weight loss have not been shown to be effective in most pediatric populations.

Effects of different rapid maxillary expansion appliances on facial soft tissues using three-dimensional imaging

To determine three-dimensional (3D) effects of three different rapid maxillary expansion (RME) appliances on facial soft tissues. Forty-two children (18 boys, 24 girls) who required RME treatment were included in this study. Patients were randomly divided into three equal groups: banded RME, acrylic splint RME, and modified acrylic splint RME. For each patient, 3D images were obtained before treatment (T1) and at the end of the 3-month retention (T2) with the 3dMD system. When three RME appliances were compared in terms of the effects on the facial soft tissues, there were no significant differences among them. The mouth and nasal width showed a significant increase in all groups. Although the effect of the acrylic splint RME appliances on total face height was less than that of the banded RME, there was no significant difference between the appliances. The effect of the modified acrylic splint appliance on the upper lip was significant according to the volumetric measurements (P < .01). There were no significant differences among three RME appliances on the facial soft tissues. The modified acrylic splint RME produced a more protrusive effect on the upper lip.

Rapid maxillary expansion in therapy-resistant enuretic children: An orthodontic perspective.

To evaluate whether rapid maxillary expansion (RME) could reduce the frequency of nocturnal enuresis (NE) in children and whether a placebo effect could be ruled out. Thirty-four subjects, 29 boys and five girls with mean age of 10.7 ± 1.8 years suffering from primary NE, were recruited. All subjects were nonresponders to the first-line antienuretic treatment and therefore were classified as "therapy resistant." To rule out a placebo effect of the RME appliance, all children were first treated with a passive appliance for 4 weeks. Rhinomanometry (RM), acoustic rhinometry (AR), polysomnographic registration, and study casts were made at different time points. One child experienced severe discomfort from the RME appliance and immediately withdrew from the study. Following RME, the long-term cure rate after 1 year was 60%. The RM and AR measurements at baseline and directly after RME showed a significant increase in nasal volume and nasal airflow, and there was a statistically significant correlation between reduction in enuresis and increase in nasal volume. Six months postretention, a 100% relapse of the dental overexpansion could be noted. RME has a curative effect in some children with NE, which could be connected to the positive influence of RME on the sleep architecture. Normal transverse occlusion does not seem to be a contraindication for moderate maxillary expansion in attempts to cure NE in children.

Evaluation and comparison of root resorption between tooth-borne and tooth-tissue borne rapid maxillary expansion appliances: A CBCT study.

To compare volumetric root resorption after rapid maxillary expansion (RME) between tooth-borne and tissue-borne appliances using CBCT. Repair in resorption cavities after 6 months of fixed retention was also compared. A sample of 33 subjects were randomly divided into two groups: Hyrax (n = 16) and Haas (n = 17). CBCT scans were taken 6 months before expansion, immediately after expansion, and 6 months after fixed retention. Mimics Innovation V 16.0 software was used for segmentation and volumetric measurement of 198 teeth. Bland-Altman plots, independent samples t test, repeated measures analysis of variance, and the Friedman test were used for statistical analysis. Differences in root resorption after RME and repair after retention were not significant between the hyrax and Haas appliances or between male and female. Significant differences were found between preexpansion and postexpansion root volumes in the first premolars and molars--even in unattached second premolars. When the percentage of root volume loss is considered, no significant difference was found between the first premolar, second premolar, and first molar. Volumetric changes after 6 months of retention were not statistically significant. More resorption was observed in the Hyrax expander group. But it was not statistically significant. Repair was observed after 6 months of retention. Heavy RME forces affected premolars and molar similarly.

Dentoskeletal effects of a temporary skeletal anchorage device-supported rapid maxillary expansion appliance (TSADRME): A pilot study.

To quantitatively evaluate maxillary skeletal expansion using cone-beam computed tomography (CBCT) images and propose a novel way to quantify the dental tipping effects of temporary skeletal anchorage device-supported rapid maxillary expansion appliance (TSADRME). Images from 25 patients receiving rapid maxillary expansion with incorporated temporary skeletal anchorage devices (TSADs) before activation (T1) and after removal (T2) were analyzed to detect dentoskeletal changes. A significant increase from T1 to T2 was found for all linear measurements except buccal maxillary width at the canines. The greatest buccal expansion was at the first molar, decreasing anteriorly. However, the greatest palatal expansion was at the first premolar. All younger subjects (8-16 years old) exhibited less dental tipping and greater expansion overall compared with the older subjects. There was great variability in dental tipping of first molars (mean = 4.31°), with some subjects demonstrating mild uprighting of these teeth. The TSADRME appliance is an effective, clinically useful device that results in mild molar tipping and may positively affect expansion in the area of TSAD placement.

Transverse changes in lateral and medial aspects of palatal rugae after mid palatal expansion: A pilot study.

Introduction:Palatal rugae has established role in forensic identification of an individual due to its stability in growth as well as orthodontic treatment. However effect of orthodontic mid-palatal expansion on rugae stability still requires further investigation. Hence, this study was aimed at evaluating the stability of palatal rugae in transverse dimension in adolescent patients of mid-palatal expansion.Materials and Methods:The study sample consists of 14 subjects (10F,4M, age 12.4 ± 2.0 years) with transverse maxillary constriction, treated with bonded and banded rapid maxillary expansion (RME) appliance. 1st to 3rd rugae on pre- and post-expansion casts were recorded synchronously. Inter-medial and inter-lateral rugae distance were measured with digital calipers to record the transverse positional rugae changes.Results:There was a statistically significant (p < 0.05) increase in values after expansion between medial aspects of 2nd (p = 0.002) and 3rd rugae (p = 0.005) and lateral aspects of 1st (p = 0.015), 2nd (p = 0.006) and 3rd (p = 0.001) rugae. The transverse changes were recorded in the order of 3rd rugae >2nd rugae >1st rugae.Conclusion:This pilot study does not support stability of medial and lateral ruga points of 2nd and 3rd primary rugae for forensic identification in individuals treated with mid palatal expansion.

Effect of rapid maxillary expansion on monosymptomatic primary nocturnal enuresis.

To evaluate the effects of rapid maxillary expansion (RME) on nocturnal enuresis (NE) related to the nasal airway, nasal breathing, and plasma osmolality (as an indicator for antidiuretic hormone). Nineteen patients with monosymptomatic primary NE, aged 6-15 years, were treated with RME for 10-15 days. To exclude a placebo effect of the RME appliance, seven patients were first treated with a passive appliance. Computed tomography of nasal cavity, rhinomanometric, and plasma osmolality measurements were made 2-3 days before and 2-3 months after the RME period. RME effects on NE were followed for three more years. Two to three months after the expansion there were significant improvements in the breathing function and a decrease in the plasma osmolality. NE decreased significantly in all patients after the RME period, and all patients showed full dryness after 3 years. This study demonstrates that RME causes complete dryness in all patients, with significant effects on pathophysiological mechanisms related to NE.