Breathing changes following mini-implant-supported maxillary skeletal expander treatment in late adolescent or adult patients : Assessment of objective and subjective functional breathing changes.

PURPOSE: The aim of this study was to assess objective and subjective breathing changes in adult patients who underwent maxillary skeletal expansion with the mini-implant-supported maxillary skeletal expander (MSE). METHODS: Twenty-nine patients (mean age 18.1 ± 4.3 years) who underwent expansion using the MSE were compared pre- and posttreatment and with a control group (mean age 19.9 ± 2.6 years) to assess objective and subjective functional breathing changes. Objective measurements of the airway including peak nasal inspiratory flow (PNIF) and peak oral inspiratory flow (POIF) were measured utilizing the In-Check medical device (Clement Clarke, Harlow, United Kingdom). Patients reported subjective breathing assessment utilizing the visual analog scale (VAS). Intragroup comparisons were performed with Wilcoxon tests and intergroup comparison with Mann-Whitney U tests. Spearman correlation coefficients were calculated among the studied variables (P < 0.05). RESULTS: Following MSE treatment, there were significantly higher values for PNIF total (P < 0.0001), PNIF right (P < 0.0001), PNIF left (P < 0.0001), and POIF (P < 0.01) compared to pretreatment and control group results. Also, patients reported a significant decrease in troubled breathing as measured by the VAS for breathing through the right nostril (P < 0.01), left nostril (P < 0.001), and both nostrils (P < 0.01). Comparing the objective and subjective variables for both the pre-MSE or post-MSE groups, the results indicated no significant correlation between total PNIF and total VAS. However, the values had significant correlations between PNIF and VAS on each side when the patients were asked to block one nostril. CONCLUSIONS: Objective functional breathing measurements were increased immediately after treatment with MSE. Subjective functional breathing measurements changes were significantly higher after MSE treatment and compared with the control group. MSE presents a nonsurgical alternative to achieving orthopedic expansion in adult patients which may provide a benefit for patients with nasal airway obstruction.

Long-term effects of maxillary skeletal expander treatment on functional breathing.

Objective: : To investigate the long-term effects of maxillary skeletal expander (MSE) treatment on functional breathing. Objective: measures of breathing, the peak nasal inspiratory flow (PNIF), and peak oral inspiratory flow (POIF), and subjective measures of breathing, the visual analog scale (VAS) and nasal obstruction symptom evaluation (NOSE) survey, were used to investigate the long-term effects of MSE in functional breathing. Seventeen patients, mean age 19.4 ± 3.9 years treated at the UCLA Orthodontics Clinic were assessed on their functional breathing at 3 timepoints: pre-expansion (T0), post-expansion (T1), and post-orthodontic treatment (T2). Results: : Immediately after expansion (T1), all the objective functional breathing values were significantly increased in comparison to T0 (P < 0.05). The VAS total, VAS right and VAS left were significantly lower at T1 in comparison to T0 (P < 0.05). At 26.8 ± 3.9 months after MSE expansion (T2), PNIF total, PNIF right, PNIF left, and POIF were significantly higher when compared to T0 (P < 0.05). Also, VAS total, VAS right and VAS left were significantly lower at T2 when compared to T0 (P < 0.05). Additionally, there was a positive correlation between PNIF and the magnitude of expansion at anterior nasal spine and zygomaticomaxillary point (ZMA). There was a positive correlation between total VAS and the magnitude of expansion at the ZMA. There were no significant changes for the NOSE subjective breathing measurement at all time comparisons. Conclusions: : Overall, MSE treatment produces an increased objective and subjective airway improvement that continues to remain stable in the long-term post expansion.

An assessment of the magnitude, parallelism, and asymmetry of micro-implant-assisted rapid maxillary expansion in non-growing patients.

BACKGROUND AND OBJECTIVES: Micro-implant-assisted expanders have shown significant effects on the mid-face, including a degree of asymmetry. The aim of this study is to quantify the magnitude, parallelism, and asymmetry of this type of expansion in non-growing patients. METHODS: A retrospective study on a sample of 31 non-growing patients with an average age of 20.4 years old, with cone beam computed tomography images taken before and right after expansion using maxillary skeletal expander (MSE) were assessed for skeletal expansion at three landmarks bilaterally. RESULTS: Average magnitude of total expansion was 4.98 mm at the anterior nasal spine (ANS) and 4.77 mm at the posterior nasal spine (PNS) which showed statistical significance using a paired t test with p < 0.01. Average expansion at the PNS was 95% of that at the ANS. The sample was divided into symmetric (n = 15) and asymmetric (n = 16) based on the difference in expansion at the ANS, with 16 out of 31 patients exhibiting statistically significant asymmetry. CONCLUSIONS: MSE achieves distinctly parallel expansion in the sagittal plane but can exhibit asymmetrical expansion in the transverse plane.

Tomographic assessment of palatal suture opening pattern and pterygopalatine suture disarticulation in the axial plane after midfacial skeletal expansion.

OBJECTIVE: The purpose of this study was to assess the palatal suture opening and the pterygopalatine suture disarticulation pattern in the tomographic axial plane after treatment with midfacial skeletal expander (MSE). MATERIALS AND METHODS: Pre- and post-expansion CBCT records of 50 subjects (20 males, 30 females, mean age 18 ± 3 years) who were treated with MSE (Biomaterials Korea, Seoul, Korea) appliance were superimposed and compared using OnDemand software. Reference planes were identified and the angulation of the midpalatal suture opening after expansion was calculated as well as the frequency of the pterygopalatine suture split. RESULTS: After MSE treatment, the mean palatal suture opening angle (SOA) was 0.57°. (- 0.8° to 1.3°). There was no significant difference between males and females in terms of the palatal suture opening pattern (P > 0.05). Only 3 out of 50 (6%) subjects presented SOA above 1 degree. Also, 3 out of 50 (6%) patients presented a negative SOA value. With regard to the pterygopalatine suture split, 84 sutures out of 100 (84%) presented openings between the medial and lateral pterygoid plates on both right and left sides. Partial split was detected with 8 patients (5 females, 3 males). Five patients had split only in the medial pterygoid plates of both pterygomaxillary sutures, and 3 patients exhibited disarticulation on the right side only. No significant differences were found in the frequency of suture opening between males and females (P = 1.000). CONCLUSIONS: MSE appliance performed almost parallel expansion in the axial view. Remarkably, this study shows that pterygopalatine suture can be split by MSE appliance without the surgical intervention; the disarticulation of pterygopalatine suture was visible in most of the patients.

Differential assessment of skeletal, alveolar, and dental components induced by microimplant-supported midfacial skeletal expander (MSE), utilizing novel angular measurements from the fulcrum.

BACKGROUND: In order to assess skeletal expansion, alveolar bone bending, and dental tipping after maxillary expansion, linear and angular measurements have been performed utilizing different craniofacial references. Since the expansion with midfacial skeletal expander (MSE) is archial in nature, the aim of this paper is to quantify the differential components of MSE expansion by calculating the fulcrum locations and applying a novel angular measurement system. METHODS: Thirty-nine subjects with a mean age of 18.2 ± 4.2 years were treated with MSE. Pre- and post-expansion CBCT records were superimposed and compared. The rotational fulcrum of the zygomaticomaxillary complex was identified by localizing the interfrontal distance and modified interfrontal distance. Based on the fulcrum, a novel angular measurement method is presented and compared with a conventional linear method to assess changes of the zygomaticomaxillary complex, dentoalveolar bone, and maxillary first molars. RESULTS: From 39 patients, 20 subjects have the rotational fulcrum of the zygomaticomaxillary complex at the most distant points of the interfrontal distance (101.6 ± 4.7 mm) and 19 subjects at the most distant points of the modified interfrontal distance (98.9 ± 5.7 mm). Linear measurements accounted for 60.16% and 56.83% of skeletal expansion, 16.15% and 16.55% of alveolar bone bending, and 23.69% and 26.62% of dental tipping for right and left side. Angular measurements showed 96.58% and 95.44% of skeletal expansion, 0.34% and 0.33% alveolar bone bending, and 3.08% and 4.23% of dental tipping for the right and left sides. The frontozygomatic, frontoalveolar, and frontodental angles were not significant different (P > 0.05). CONCLUSIONS: In the coronal plane, the center of rotation for the zygomaticomaxillary complex was located at the most external and inferior point of the zygomatic process of the frontal bone or slightly above and parallel to the interfrontal distance. Due to the rotational displacement of the zygomaticomaxillary complex, angular measurements should be a preferred method for assessing the expansion effects, instead of the traditional linear measurement method.

Assessment of respiratory muscle strength and airflow before and after microimplant-assisted rapid palatal expansion.

OBJECTIVES: To assess alterations in respiratory muscle strength and inspiratory and expiratory peak flow, as well as skeletal and dental changes in patients diagnosed with transverse maxillary deficiency before and after microimplant-assisted rapid maxillary expansion (MARPE). MATERIALS AND METHODS: Twenty patients (13 female and 7 male) were assessed by respiratory tests in three different periods: T0 initial, T1 immediately after expansion, and T2 after 5 months. Tests included: maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), oral expiratory peak flow, and inspiratory nasal flow. Cone-beam computed tomography measurements were performed in the maxillary arch, nasal cavity, and airway before and immediately after expansion. RESULTS: There was a significant increase in MIP between T0 and T2 and MEP between T0 and T1 (P<.05). Oral and nasal peak flow increased immediately after and 5 months later, especially in patients with initial signs of airway obstruction (P<.05). In addition, after expansion there was a significant enlargement of the nasal cavity, alveolar bone, and interdental widths at the premolar and molar region. Molars tipped buccally (P<.05) but no difference was found in premolar inclination. MARPE increased airway volume significantly. CONCLUSIONS: Skeletal changes promoted by MARPE directly affected airway volume, resulting in a significant improvement in muscle strength and nasal and oral peak flow.

Effects of maxillary skeletal expansion on respiratory function and sport performance in a para-athlete - A case report.

The aim of this case report was to demonstrate the effects of the Maxillary Skeletal Expander (MSE) used to orthopedically correct a maxillary constriction, on the respiratory functions and swimming performance of a Para-athlete. Cone-beam computed tomography (CBCT) images taken before and after MSE activation were used to demonstrate the disarticulation of midpalatal suture, and the changes involved in dental and nasomaxillary structures, nasal cavity and pharyngeal airway. Respiratory tests included: maximum inspiratory and expiratory pressure, oral peak expiratory flow and inspiratory nasal flow. The 6-min-walk and heart rate recovery tests were also performed. Patient's swimming performances during national swimming competitions were compared. CBCT images showed that palatal expansion was 5.91  mm at the suture, and that nasal and pharyngeal airways increased in volume by 31%. All respiratory indices improved after MSE activation. The 6-min walk test and heart rate recovery test performance also improved after the maxillary expansion. Patient's swimming performance in all category were anemic prior to the treatment, but performance improved considerably after the expansion, particularly the 100 m-Backstroke modality. MSE treatment had a significant positive impact in respiratory functions and sport performance.

Three-dimensional soft tissue analysis of the face following micro-implant-supported maxillary skeletal expansion.

BACKGROUND: Skeletal maxillary expander (MSE) is one of the more recent expander designs being utilized for skeletal expansion by splitting the midpalatal sutures applying forces through palatal micro-implants. Its effects on the soft tissue remain a question asked by both patients and clinicians. The aim of this study was to analyze and quantify soft tissue facial changes induced by MSE. METHODS: 3D facial images (3dMD) were used to capture face scans of 25 patients generating 3D soft tissue meshes before expansion (T0), right after expansion (T1), and 1 year in retention (T2). MATLAB was then used, utilizing non-rigid iterative closest point algorithm, to align all samples in vertex correspondence and generate averages. Surface mapping of each average, along with its variance, allows for quantification of changes between the three pools of samples in 3D space. RESULTS: The generated 3D p-maps between T0 and T1 demonstrate that statistically significant changes (p < 0.05 and p < 0.01) are localized in the circummaxillary area (paranasal, lips, and both cheeks). Vector map shows a mean displacement of 1.5 mm in the paranasal area. The right cheek showing a mean displacement magnitude of 2.5 mm while the left cheek has a mean of 2.9 mm. Direction of vectors are latero-anterior with more dominant anterior direction. CONCLUSIONS: There are significant changes in paranasal, upper lip, and at both cheeks following expansion using MSE with greater magnitude at the cheeks area. Those changes do not relapse after 1 year (p < 0.05).

Zygomaticomaxillary modifications in the horizontal plane induced by micro-implant-supported skeletal expander, analyzed with CBCT images.

BACKGROUND: Miniscrew-assisted rapid palatal expansion (MARPE) has been adopted in recent years to expand the maxilla in late adolescence and adult patients. Maxillary Skeletal Expander (MSE) is a device that exploits the principles of skeletal anchorage to transmit the expansion force directly to the maxillary bony structures and is characterized by the miniscrews' engagement of the palatal and nasal cortical bone layers. In the literature, it has been reported that the zygomatic buttress is a major constraint that hampers the lateral movement of maxilla, since maxilla is located medially to the zygomatic arches. The objective of the present study is to analyze the changes in the zygomatic bone, maxillary bone, and zygomatic arches and to localize the center of rotation for the zygomaticomaxillary complex in the horizontal plane after treatment with MSE, using high-resolution cone-beam computed tomography (CBCT) images. METHODS: Fifteen subjects with a mean age of 17.2 (± 4.2) years were treated with MSE. CBCT records were taken before and after miniscrew-assisted maxillary expansion; three linear and four angular parameters were identified in the axial zygomatic section (AZS) and were compared from pre-treatment to post-treatment using the Wilcoxon signed rank test. RESULTS: Anterior inter-maxillary distance increased by 2.8 mm, posterior inter-zygomatic distance by 2.4 mm, angle of the zygomatic process of the temporal bone by 1.7° and 2.1° (right and left side) (P < 0.01). Changes in posterior inter-temporal distance and zygomaticotemporal angle were negligible (P > 0.05). CONCLUSIONS: In the horizontal plane, the maxillary and zygomatic bones and the whole zygomatic arch were significantly displaced in a lateral direction after treatment with MSE. The center of rotation for the zygomaticomaxillary complex was located near the proximal portion of the zygomatic process of the temporal bone, more posteriorly and more laterally than what has been reported in the literature for tooth-borne expanders. Bone bending takes place in the zygomatic process of the temporal bone during miniscrew-supported maxillary expansion.

Midfacial changes in the coronal plane induced by microimplant-supported skeletal expander, studied with cone-beam computed tomography images.

INTRODUCTION: Our objectives were to evaluate midfacial skeletal changes in the coronal plane and the implications of circummaxillary sutures and to localize the center of rotation for the zygomaticomaxillary complex after therapy with a bone-anchored maxillary expander, using high-resolution cone-beam computed tomography. METHODS: Fifteen subjects with a mean age of 17.2 ± 4.2 years were treated with a bone-anchored maxillary expander. Pretreatment and posttreatment cone-beam computed tomography images were superimposed and examined for comparison. RESULTS: Upper interzygomatic distance increased by 0.5 mm, lower interzygomatic distance increased by 4.6 mm, frontozygomatic angles increased by 2.5° and 2.9° (right and left sides), maxillary inclinations increased by 2.0° and 2.5° (right and left sides), and intermolar distance increased by 8.3 mm (P <0.05). Changes in frontoethmoidal, zygomaticomaxillary, and molar basal bone angles were negligible (P >0.05). CONCLUSIONS: A significant lateral displacement of the zygomaticomaxillary complex occurred in late adolescent patients treated with a bone-anchored maxillary expander. The zygomatic bone tended to rotate outward along with the maxilla with a common center of rotation located near the superior aspect of the frontozygomatic suture. Dental tipping of the molars was negligible during treatment.