Palatal Expansion Research Articles

Management of impinging “Nickel titanium palatal expander” in cleft palate cases by “Soft flow” (temporary mucosal protector)

The temperature-activated Arndt nickel titanium palatal expander has been a good choice for cleft palate applications because it creates transverse maxillary expansion, uprights and rotates the maxillary molars, and allows a smooth transition to fixed retention with no requirement for patient compliance and little manipulation by the clinician. But the clinical problem sometimes encountered is the impinging of “Nickel-Titanium” metal component of the Nickel titanium palatal expander on the soft palate. “Soft Flow” is a Temporary Mucosal Protector introduced recently in the orthodontic market which prevents the impinging of micro- implants or hooks of the molar buccal tubes. The following article highlights the clinical problem encountered after placement of Nickel Titanium Palatal Expander and how “Soft Flow” helps to overcome it.

Something to consider: rapid palatal expansion for treatment of obstructive sleep apnea in pediatric patients.

This review examines the potential of rapid palatal expansion (RPE) as a treatment for pediatric obstructive sleep apnea (OSA). The focus is on recent findings related to its efficacy, safety, patient selection, timing, appliance options, cost considerations, and long-term outcomes. Recent studies indicate that RPE can lead to significant improvements in pediatric OSA, with a 70% reduction in the Apnea Hypopnea Index (AHI) and increased oxygen saturation levels. It has been particularly effective in children with small or absent tonsils and has been found to reduce adenoid and tonsil size. Long-term follow-up studies suggest the need for ongoing monitoring, as some patients may experience relapse over time. RPE shows promise as an additional treatment for pediatric obstructive sleep apnea. It offers improvements in respiratory function and reduced symptoms in certain patients. However, long-term efficacy and safety require further investigation. Comparative studies and patient-reported outcomes are necessary to optimize treatment approaches. Collaboration between orthodontists, sleep specialists, and ear-nose-throat (ENT) specialists may be essential for optimal outcomes in pediatric OSA patients treated with RPE.

COMPARING ARCH WIDTH, ALVEOLAR WIDTH ANDBUCCOLINGUAL INCLINATION OF POSTERIOR TEETH IN SUBJECTS WITH CLASS IANDCLASS II MALOCCLUSION

Aim: The aim of this study was to compare the arch width, alveolar width and buccolingual inclination of posterior teeth between Class I and Class II Div 1 malocclusion subjects. Materials and method: A sample of120 subjects (60 males and 60 females) in the age group of 16-19 years with Class I and Class II Div 1 malocclusion were chosen and arch width, alveolar width and buccolingual inclination of posterior teeth were measured and compared between the groups. Result: The maxillary posterior teeth showed more palatal inclination in Class II Div 1 malocclusion when compared with Class I group. Conclusion:Transverse discrepancy in Class II Div 1 might be due to more palatal inclination of maxillary posterior teeth rather than arch width and alveolar width. Hence slow maxillary expansion should be preferred for correcting the palatal inclination rather than rapid palatal expansion.

Thermographic analysis during rapid maxillary expansion

The aim of this study was to evaluate the temperature of the palate during rapid maxillary expansion through thermal imaging. Material and methods: Modified Hyrax palatal expander was installed in 11 patients. Thermal images of the palate were obtained using the FLIR A325 infrared camera. The evaluation was carried out 6 times: T0 – without activation; T1 – 4; T2 – 8; T3 – 12; T4 – 16; T5 – 30 screw activations. The thermographic images were analyzed qualitatively by visualizing the colors and quantitatively, by measuring the temperature of the palate at points Sp1, Sp2, Sp3 and Line 1 (Li1), in the midpalatal suture and Sp4 and Line 2 (Li2) in the lateral region of the hard palate. ANOVA and Games-Howell statistical tests were used. Results: When evaluating each region over time, in Sp4 and Li2, it was observed a lower temperature in T5 than in T1 and in Li1 a lower temperature in T5 than in T4 (p<0.05). Conclusion: Similar temperatures were observed in the central and lateral regions of the palate. Higher temperatures were recorded at the time of the first activations and lower temperatures were recorded on the 14th day. > <0.05). Conclusion: Similar temperatures were observed in the central and lateral regions of the palate. Higher temperatures were recorded at the time of the first activations and lower temperatures were recorded on the 14th day.

Skeletal and dentoalveolar modifications in adults with different sagittal facial patterns after personalized miniscrew-assisted rapid palatal expansion: A prospective cone-beam computed tomography study

This study aimed to compare the skeletal and dental modifications in adults with different sagittal facial patterns by a personalized miniscrew-assisted rapid palatal expander (pMARPE). Forty subjects (aged 18-28 years; 15 females and 25 males) with maxillary transverse deficiency were assigned to 1 of 3 groups (Class I, II, and III relationship) on the basis of their sagittal facial patterns. Each patient was treated with an individually customized expander. A similar expansion protocol was used for all patients. Cone-beam computed tomography scans were obtained before and after expansion. One-way analysis of variance was used to analyze differences among 3 groups in skeletal, dentoalveolar, and periodontal changes (P<0.05). The success rates of expansion were higher in patients with a Class I or II relationship than those with a Class III relationship. Patients with a Class I or II relationship had greater changes in the anterior nasal spine and maxillary basal bone widths. A more parallel sutural opening in the anteroposterior direction was seen in those with a Class II relationship. The tipping of the maxillary first molar increased, and the buccal alveolar bone thickness decreased in all groups after expansion, especially in patients with a Class III relationship. The pMARPE effectively split the midpalatal suture among adults. However, midpalatal suture expansion was more difficult, and there were more dentoalveolar side effects and fewer orthopedic effects in patients with a Class III relationship than in those with Class I or II relationships.

Influence of miniscrew-assisted rapid palatal expansion (MARPE) on the interdental papilla height of maxillary central incisors

ObjectivesTo evaluate the influence of miniscrew-assisted rapid palatal expansion (MARPE) on the interdental papilla height of maxillary central incisors.Materials and methodsPatients who completed MARPE treatment at the Radboud University Medical Center between 2018 and 2021 were included in this retrospective study. The papilla height between the maxillary central incisors was evaluated on frontal intraoral photographs taken before expansion (T0) and 1.5 years after MARPE treatment (T1) using the Jemt classification. The difference in Jemt score at T0 and T1 was the primary outcome variable. In addition, gender, age, Angle classification, MARPE duration, midpalatal suture maturation stage, maximal central diastema (MCD) immediately after expansion, crown width to length ratio (W/L), pretreatment overlap of maxillary central incisors, and the distance between the approximal contact point of the central incisors and the bone crest (CP-B) were also record.ResultsTwenty-two patients were included (2 men, 20 women, mean age 27.3 ± 8.8 years) and 4 patients (18%) showed a significant reduction in the Jemt score following MARPE (p = 0.04), indicating papilla recession. Interdental papilla recession was significantly associated with the increase of CP-B (p = 0.02), smaller W/L (p < 0.01), overlapping of maxillary central incisors (p < 0.01), and smaller MCD immediately after expansion (p = 0.02).ConclusionsOne and a half years after MARPE, 18% of patients exhibited mild recession of papilla height of the maxillary central incisors. Overlapping and smaller W/L of maxillary central incisors were prognostic factors for interdental papilla recession.Clinical relevanceClinicians have to be aware of and inform the patients about the occurrence of papilla recession following MARPE.

Monitoring the Opening of Rapid Palatal Expansion (RPE) in a 3D-Printed Skull Model Using Fiber Optic F-P Sensors.

We present a novel method for the online measurement of multi-point opening distances of midpalatal sutures during a rapid palatal expansion (RPE) using fiber optic Fabry-Perot (F-P) sensors. The sensor consists of an optical fiber with a cut flat end face and an optical reflector, which are implanted into the palatal base structure of an expander and is capable of measuring the precise distance between two optical reflective surfaces. As a demonstration, a 3D-printed skull model containing the maxilla and zygomaticomaxillary complex (ZMC) was produced and a miniscrew-assisted rapid palatal expander (MARPE) with two guide rods was used to generate the midpalatal suture expansion. The reflected spectrums of the sensors were used to dynamically extract cavity length information for full process monitoring of expansion. The dynamic opening of the midpalatal suture during the gradual activation of the expander was measured, and a displacement resolution of 2.5 μm was demonstrated. The angle of expansion was derived and the results suggested that the midpalatal suture was opened with a slight V-type expansion of 0.03 rad at the first loading and subsequently expanded in parallel. This finding might be useful for understanding the mechanical mechanisms that lead to different types of expansion. The use of a fiber optic sensor for mounting the rapid palatal expander facilitates biomechanical studies and experimental and clinical evaluation of the effects of RPE.

Can Velopharyngeal MRI be Used in Individuals with Orthodontic Devices?

To evaluate the influence of common pediatric orthodontic appliances on velopharyngeal (VP) MRI and to compare MR image sequences to determine if sequence parameters impact the visibility of key VP structures commonly assessed in clinical VP MRI. Participants undergoing orthodontic treatment completed a VP MRI study. Level of distortion caused by orthodontic devices on 8 anatomical sites of interest and using variable MRI sequences was evaluated. Single institution. Nineteen participants undergoing orthodontic treatment. Level of distortion caused by metal artifacts and MR sequence used. The results of this study demonstrate that appliances such as hyrax palatal expanders and braces with stainless steel brackets are acceptable for a VP MRI, while class II corrector springs are not recommended. The HASTE MRI sequence with 2D imaging techniques should be utilized if the child has orthodontic devices, while FSE and 3D imaging techniques are not recommended. The presence of wire spring coils and molar bands are likely to not to interfere with the MRI evaluation. Findings from this study suggest that the presence of orthodontic appliances does not hinder visualization of all velopharyngeal structures during an MRI. Therefore, careful consideration must be made prior to disqualifying or recommending patients for VP MRI.

Maxillary expansion in nongrowing patients. Conventional, surgical, or miniscrew-assisted, an update.

Maxillary transverse deficiency can occur in various clinical dentoskeletal deformities and include unilateral or bilateral posterior crossbite, narrow, tapering, or high palatal arch. The development of temporary anchorage devices led to a new generation of tooth-bone-borne expansion appliance using two or four screws to apply the mechanical forces to the bone and reduce the stress to the anchored teeth. The aim of these new devices is to reduce the adverse dentoalveolar effect and achieve more skeletal expansion than conventional tooth-borne rapid palatal expansion. This article reviews the age limitation and complication and soft tissue change of nonsurgical maxillary expansion. We discuss the approach of surgical maxillary expansion with maxillary skeletal expander device. The clinical case will show the benefit of nonsurgical and surgical tooth-bone-borne rapid palatal expansion.

The effects of miniscrew-assisted rapid palatal expansion on the upper airway of adults with midpalatal suture in the last two degrees of ossification.

Transverse deficiencies of the maxillary basal bone have been treated in adult patients using miniscrew-assisted rapid palatal expansion (MARPE) therapy. However, the midpalatal suture's degree of ossification may affect the upper airway dimensions. This study compared the volumetric changes of the total upper, retropalatal, retroglossal airways, and the minimal transverse airway constriction after MARPE therapy in patients with midpalatal suture in the last stages of ossification. This controlled clinical trial included a total of 20 adult patients (mean age 24.5 ± 6.2 years) with maxillary atresia treated with MARPE. Preoperative (T0) cone-beam computed tomography scans were used to determine the degree of midpalatal suture ossification. Two groups were formed considering the last two stages of sutural ossification "D" or "E" (n=10 per group). After 120 days of the therapy (T1), cone-beam computed tomography assessments were performed to compare the pre and post-treatment outcomes. The total upper, retropalatal, and retroglossal airways and the minimal transverse airway constriction were evaluated. The three-dimensional reconstruction was performed with OsiriX MD software. The comparisons were carried out using mixed models for repeated measures at fixed time points (α=0.05). Groups D and E showed no significant difference for any of the analyzed parameters (P > 0.05). Both groups showed a statistically significant increasefor all airway segments after the treatment with MARPE (P < 0.05). The total upper airway increased (11.6% and 16.1%) for groups D and E, respectively (P=0.3356). MARPE therapy resulted in dimensional gains of the upper airway for adult patients, irrespective of the intermaxillary sutural degree of ossification.

Impact of orthodontic treatment on speech and phonetics: a review

Orthodontic devices, including both fixed and removable devices, have the potential to impact dental anatomy, the space within the oral cavity, the displacement of the tongue, and the production of speech. The usage of fixed labial appliances may cause transient or persistent speech and phonetics changes, particularly affecting sibilant and stopped sounds. Lingual fixed appliances, while providing aesthetic advantages, can lead to difficulties in maintaining oral hygiene, pain in the tongue, and speech disturbances. Orthodontic retainers, used post-treatment, can also affect speech and phonetics by altering the oral cavity space and tongue position. Other appliances like removable appliances, palatal expanders, and prosthetic dental appliances may also disrupt speech production. Objective, semi-objective, and subjective assessments are utilized to evaluate speech disruptions induced by orthodontic devices. Patients considering orthodontic aligners should be informed about potential temporary limitations in speech production, which can be managed by removing the device when necessary. The adaptation to orthodontic treatment may vary based on individual characteristics. Orthodontists should consider these effects and communicate them to patients. This review article explores the effect of orthodontic treatment on speech and phonetics.

What is the impact of miniscrew-assisted rapid palatal expansion on the midfacial soft tissues? A prospective three-dimensional stereophotogrammetry study

ObjectivesTo evaluate the midfacial soft tissue changes of the face in patients treated with miniscrew-assisted rapid palatal expansion (MARPE).Materials and methods3D facial images and intra-oral scans (IOS) were obtained before expansion (T0), immediately after completion of expansion (T1), and 1 year after expansion (T2). The 3D images were superimposed and two 3D distance maps were generated to measure the midfacial soft tissue changes: immediate effects between timepoints T0 and T1 and overall effects between T0 and T2. Changes of the alar width were also measured and dental expansion was measured as the interpremolar width (IPW) on IOS.ResultsTwenty-nine patients (22 women, 7 men, mean age 25.9 years) were enrolled. The soft tissue in the regions of the nose, left of philtrum, right of philtrum, and upper lip tubercle demonstrated a statistically significant anterior movement of 0.30 mm, 0.93 mm, 0.74 mm, and 0.81 mm, respectively (p < 0.01) immediately after expansion (T0–T1). These changes persisted as an overall effect (T0–T2). The alar width initially increased by 1.59 mm, and then decreased by 0.08 mm after 1 year, but this effect was not significant. The IPW increased by 4.58 mm and remained stable 1 year later. There was no significant correlation between the increase in IPW and alar width (r = 0.35, p = 0.06).ConclusionsOur findings indicate that MARPE results in significant but small changes of the soft tissue in the peri-oral and nasal regions. However, the clinical importance of these findings is limited.Clinical relevanceMARPE is an effective treatment modality to expand the maxilla, incurring only minimal and clinically insignificant changes to the midfacial soft tissues.

Maxillary Response Induced by Rapid Palatal Expansion vs. Clear Aligners: A Short-Term Retrospective Evaluation of the Dento-Alveolar Effects in Mixed Dentition

Background: to analyze the dento-alveolar effects induced by two treatment appliances (i.e., RME and Clear Aligners) in growing subjects presenting with early mixed dentition and mild maxillary deficiency. Methods: digital casts of 32 children treated with RME (RG: 17 subjects) or with Clear aligners (CAG: 15 subjects) were collected. Linear and angular values were measured in both groups on the upper arch for both pre- (T1) and post-treatment (T2) models. An unpaired t-test was used to test significant differences between groups (p &lt; 0.05). Results: the comparison of T2-T1 changes for linear measurements between groups showed a greater increase in the inter-canine width (+1.5 mm ± 0.5 mm) and in the first inter-deciduous molar width (+1.4 ± 0.4 mm), also at the trans-palatal level in the CAG group. Conversely, in the posterior region of the upper arch, a greater increase in the first inter-molar distal width was found in the RG group (+1.2 ± 0.4 mm) when compared with the CAG group. A significant increase in the crown angulation in the CAG group was found for all the teeth except for the first molars. Conclusions: the rapid palatal expander widened the palate, tipping the first upper molars buccally to a greater extent, whereas the Clear aligners caused a greater increase in the canine width.

Associations Between Medicaid Expansion and Timely Repair of Cleft Lip and Palate.

The expansion of Medicaid under the Affordable Care Act (ACA) increased access to health care for many low-income children. However, the impact of this expansion on the timing of primary cleft lip and palate repair remains unclear. This study aimed to evaluate whether Medicaid expansion improved access to timely cleft lip and palate repair and whether it reduced preexisting ethnoracial disparities. Using a quasi-experimental design, the study analyzed data from 44 pediatric surgical centers across the United States. The results showed that Medicaid expansion was associated with a 9.0 percentage-point increase in delayed cleft lip repairs, resulting in an average delay of 16 days. Non-White patients were disproportionately affected by this delay, experiencing a 14.8 percentage-point increase compared with a 4.9 percentage-point increase for White patients. In contrast, Medicaid expansion had no significant effect on the timing of palate repair or on ethnoracial disparities in palate repair. The study underscores the importance of monitoring unintended consequences of large-scale health system changes, especially those affecting disadvantaged populations. Delayed cleft lip repair can lead to worse outcomes for patients, and the disproportionate impact on non-White patients is concerning. Further research is needed to identify the reasons for this delay and to mitigate its effects. Overall, the study highlights the need for ongoing vigilance to ensure that health care policies and interventions do not inadvertently worsen health disparities.

Comparison of Different Types of Palatal Expanders: Scoping Review.

We chose studies that compared effects determined by palatal expansion using a rapid palatal expander, expander on palatal screws, and leaf expander. Reports assessed for eligibility are 26 and the reports excluded were 11. A final number of 15 studies were included in the review for qualitative analysis. Clinically and radiographically, the outcomes are similar to those obtained with RME and SME appliances; Therefore, it might be a useful treatment choice as an alternative to RME/SME equipment in cases of poor patient compliance or specific situations. Finally, all of the devices studied produce meaningful skeletal growth of the palate. The use of skeletally anchored devices does, without a doubt, promote larger and more successful growth in adolescent patients.

Comparing Airway Analysis in Two-Time Points after Rapid Palatal Expansion: A CBCT Study.

The aim of this study is to investigate the upper airway analysis at two-time points after the rapid maxillary expansion was performed, using cone-beam computed tomography. Subjects from the Orthodontic Department at the Aristotle University of Thessaloniki with unilateral or bilateral posterior crossbite were screened according to the selection criteria. A sample size calculation was performed, and a total of 14 subjects were recruited. All subjects received a rapid maxillary expansion with a Hyrax-type device as part of their comprehensive treatment. A CBCT was taken before the treatment (T1), immediately after the expansion was completed (T2), and 6 months after (T3). Their upper airway was measured using the CBCT images. Airway volume (V) and minimal cross-sectional area (MCS) were extracted and compared using SPSS to analyze the means. A statistically significant difference was found between all time points regarding both V and MCS (p < 0.001, p = 0.001). There was a statistically significant increase in both V and MCS measurements immediately after RPE expansion (T1-T2) and six months after expansion (T1-T3). Between the end of expansion and 6 months after (T2-T3), there was a decrease in V and no statistical difference in MCS. RPE can significantly increase the volume and minimal cross-sectional area of the nasal passage airway.

Can surgically assisted rapid palatal expansion (SARPE) be recommended over orthodontic rapid palatal expansion (ORPE) for girls above the age of14? : Acone-beam CT study on midpalatal suture maturation.

For patients with amaxillary transversal deficiency (MTD), various treatment options are available, partly based on the practitioner's experience. This study aimed to determine acut-off age for decision making between surgically assisted rapid palatal expansion (SARPE) over orthodontic rapid palatal expansion (ORPE) based on skeletal maturation in afemale population. A total of 100 cone beam computed tomography (CBCT) images of young females were analyzed on maturation of the pterygomaxillary (PMS), zygomaticomaxillary (ZMS), transpalatal (TPS), and midpalatal (MPS) sutures. Based on the maturation of these four junctions, four independent observers had to determine whether they would prefer ORPE or SARPE to widen the maxilla. For the PMS, the results show aclosure of 83-100% from 13to 17years. As for the TPS, aclosure of 78-85% was observed from 15years of age. For the 15- to 17-year-old females, aclosed ZMS was present in 32-47%. Regarding MPS, closed sutures presented in 61% (stagesD andE) of the 15-year-old females. The cut-off age at which SARPE was recommended was 15.1years for the orthodontist observers and 14.8years for the maxillofacial surgeon observers. Significant maturation of MPS was reached at the age of15 in afemale population. The PMS, TPS, MPS, and ZMS closed sequentially. Acomprehensive diagnostic approach is necessary for choosing the appropriate treatment. When in doubt, age could assist decision making in afemale population, with acut-off age of 15years in favor of SARPE based on this study.

Skeletal and dentoalveolar effects of different types of microimplant-assisted rapid palatal expansion.

To evaluate the following null hypothesis: the skeletal and dentoalveolar expansion patterns in the coronal and axial planes are not different with two different types of microimplant-assisted rapid palatal expansion (MARPE) systems. Pretreatment (T0) and post-MARPE (T1) cone-beam computed tomography (CBCT) images of 32 patients (14 males and 18 females; mean age, 19.37) were analyzed. We compared two different MARPE systems. One MARPE system included the maxillary first premolars, maxillary first molars, and four microimplants as anchors (U46 type, n = 16), while the other included only the maxillary first molars and microimplants as anchors (U6 type, n = 16). In the molar region of the U6 and U46 groups, the transverse expansion at the midnasal, basal, alveolar, and dental levels was 2.64, 3.52, 4.46, and 6.32 mm and 2.17, 2.56, 2.73, and 5.71 mm, respectively. A significant difference was observed in the posterior alveolar-level expansion (p = 0.036) and posterior basal-bone-level expansion (p = 0.043) between the groups, with greater posterior skeletal and alveolar expansion in the U6 group. Compared with the U46 group, the U6 group showed greater posterior expansion at the alveolar and basal-bone levels, with an almost parallel split. Both groups showed a pyramidal expansion pattern in the coronal view.

Effects of novel microimplant-assisted rapid palatal expanders manufactured by 3-dimensional printing technology: A finite element study

The expansion effects of several new microimplant-assisted rapid palatal expanders (MARPEs) manufactured by 3-dimensional printing technology were evaluated by finite element analysis (FEA). The aim was to identify a novel MARPE suitable for treating maxillary transverse deficiency. The finite element model was established using MIMICS software (version 19.0; Materialise, Leuven, Belgium). First, the appropriate microimplant insertion characteristics were identified via FEA, and several MARPEs with the above insertion patterns were manufactured by 3-dimensional printing technology. Then, the stress distribution and displacement prediction of the 4 MARPEs and hyrax expander (model E) were evaluated via FEA: bone-borne (model A), bone-tooth-borne (model B), bone-mucous-borne (model C), bone-tooth-mucous-borne (model D). Monocortical microimplants perpendicular to the cortical bone on the coronal plane resulted in better expansion effects. Compared with a conventional hyrax expander, the orthopedic expansion of each of the 4 MARPEs was far larger, the parallelism was greater, and the posterior teeth tipping rate was lower. Among them, the expansion effects of models C and D were the best; the von Mises peak values on the surfaces of the microimplants were smaller than those of models A and B. This study may demonstrate that the 4 MARPEs obtained more advantageous orthopedic expansion effects than a hyrax expander. Models C and D obtained better biomechanical effects and had better primary stability. Overall, model D is the recommended expander for treating maxillary transverse deficiency because its structure acts like an implant guide and is beneficial for the accurate insertion of the microimplant.

0530 Efficacy of obstructive sleep apnea treatment by a unique oral appliance and effect of concurrent myofunctional and CPAP therapy

Abstract Introduction Current treatment options for obstructive sleep apnea (OSA) include positive airway pressure, oral appliances, and upper airway surgery. The Day and Night Appliance (DNA) is a component of a dentist-guided system (Complete Airway Repositioning and Expansion [CARE], Vivos Therapeutics) that leads to gradual increases in upper airway volume. This study examines the effects of DNA treatment on OSA in patients before and after use of the device; we also examined how DNA treatment was impacted by concurrent myofunctional and CPAP therapy. Methods Data from a prospectively-collected clinical database (Vivos Airway Intelligence Service [AIS]) were reviewed, and 94 adult OSA patients who met DNA use criteria and had pre- and post-treatment sleep studies without the device in place were included. We compared the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) pre- and post-treatment using a paired t-test and fit linear regression models with change in AHI and ODI as dependent variables. Results Mean patient age was 47.8±14.7 years and 44.7% were men. Pre- and post-treatment sleep studies were conducted 15.2±7.0 months apart. 24.5% of patients were treated with DNA and myofunctional therapy (14.1% exclusively myofunctional, 10.4% myofunctional plus another treatment, e.g., tonsillectomy, frenectomy). 17.0% of patients were treated with CPAP (12.8% exclusively CPAP, 4.2% CPAP plus another treatment). For both pre-treatment and post-treatment, mean AHIs were 22.3±19.4 and 12.7±11.2 respectively (p&amp;lt; 0.0001) and mean ODIs were 11.6±13.7 and 7.8±9.1 respectively (p&amp;lt; 0.0001). Excluding patients who had undergone myofunctional therapy and another treatment modality and adjusting for patient age, BMI, and gender, we found myofunctional therapy was associated with a -10.4 change in AHI (p=0.038). However, myofunctional therapy was not associated with a significant change in ODI (p=0.905). Concurrent CPAP use did not have a significant association with change in either AHI (p=0.47) or ODI (p=0.61). Conclusion This study shows that DNA use significantly improved post-treatment OSA severity, and that concurrent myofunctional but not CPAP therapy may result in further OSA improvement. An oral appliance system that provides palatal expansion with consequent improvement in OSA severity but does not require permanent nightly use has advantages over conventional oral appliances; however, further investigation is warranted. Support (if any)