Effects of the long-term use of maxillary protraction facemasks with skeletal anchorage on pharyngeal airway dimensions in growing patients with cleft lip and palate

Preliminary study on change in the upper airway dimension in growing patients with Pierre-Robin sequence

Objective

This study aimed to evaluate the changes in upper airway (UA) dimensions in growing patients with Pierre-Robin sequence (PRS).

Methods

The subjects were 23 PRS patients who had not undergone growth modification therapy or surgical intervention. Their lateral cephalograms were obtained longitudinally at mean ages of 8.81 (T0) and 14.05 (T1). Patients were categorized based on their SNB value at T0 (Criteria: -2 SD): Group-1 (very retrusive mandible, n = 13) and Group-2 (moderately retrusive mandible, n = 10). Skeletal and UA variables at T0 and T1, as well as ΔT0-T1, were statistically analyzed.

Results

At T0, Group-1 exhibited more retrusive maxilla and mandible (SNA, P < 0.01; SNB, P < 0.001), a more hyperdivergent pattern (facial height ratio, P < 0.05), and a more posteriorly positioned hyoid bone (H-PTV, P < 0.05), while Group-1 showed larger UA spaces (superior pharyngeal airway space [SPAS] and inferior pharyngeal airway space, all P < 0.05) than Group 2, which might indicate the existence of a compensatory response to maintain the UA patency. At T1, Group-1 maintained significantly retrusive maxilla and mandible (SNA and SNB, all P < 0.01), exhibited a less anteriorly positioned tongue (TT-PTV, P < 0.05), and displayed a more obtuse soft palate angle (SPA, P < 0.05) than Group-2. Between T0 and T1, Group-1 demonstrated significant increases in the hyoid symphysis distance (ΔH-RGN, P < 0.001), tongue length (ΔTGL, P < 0.01), and pharyngeal UA spaces (ΔSPAS and ΔPNS-ad2, all P < 0.001).

Conclusions

Even in growing PRS patients with severe mandibular retrusion, the UA dimensions increased due to forward growth of the mandible, repositioning of tongue and hyoid bone, and existence of compensatory mechanism.

The hyoid bone position and upper airway morphology among children with and without adenotonsillar hypertrophy: a cross-sectional study

BACKGROUND

Adenotonsillar hypertrophy (ATH) is a major cause of pediatric obstructive sleep apnea (OSA), potentially impacting craniofacial growth and development. Currently, whether children with ATH exhibit distinctive hyoid bone position and upper airway morphology remains uncertain. This research aimed to compare the hyoid bone position and upper airway morphology of children with and without ATH.

METHODS

A total of 199 children aged 6-8 years were recruited for the study, and their pre-treatment lateral cephalograms were obtained. The size of the adenoids and tonsils on the lateral cephalogram was assessed based on Fujioka's and Baroni's methods for classification into groups: adenoid hypertrophy only (AHO) group, tonsillar hypertrophy only (THO) group, adenoid and tonsillar hypertrophy (AH + TH) group, and control group (CG). The position of the hyoid bone and upper airway morphology was analyzed using Dolphin Image Software.

RESULTS

The distance between the hyoid bone and mentum was greater in the THO group compared to the AHO group (P = 0.005). Children in the AHO group exhibited a longer soft palate (SPL) compared to the THO group (P = 0.014), whereas the THO group displayed a reduced SPL in comparison to healthy controls (P = 0.008). The THO group showed a more inferior tongue position compared to children in the AHO group (P = 0.004). Subjects in the THO group exhibited significantly wider inferior airway space compared to healthy children (P < 0.001).

CONCLUSIONS

Adenotonsillar hypertrophy may be associated with hyoid bone position and upper airway morphology in children seeking for orthodontic treatment. In children with enlarged tonsils, the hyoid bone was positioned farther from the mentum than in those with enlarged adenoids. Conversely, children with enlarged adenoids had a longer soft palate compared to those with enlarged tonsils.

The effect of different functional appliances on the sagittal pharyngeal airway dimension in skeletal class II: a retrospective study

The aim of this study was to compare the changes in the sagittal pharyngeal airway dimension (SPAD) in adolescents with Class II mandibular retrusion treated with Invisalign Mandibular Advancement (IMA), prefabricated Myobrace (MB), and Twin block (TB). For this retrospective study, the pre-treatment and post-treatment lateral cephalograms of 60 patients who underwent myofunctional treatment, using either one of the tested appliances were gathered from the files of treated patients. Changes in the SPAD were measured in each group, and comparisons were carried out between the three study groups. Additionally, sagittal skeletal measurements were carried out. Comparisons of the study variables at T0 and T1 between the three groups were performed using one-way ANOVA, while comparisons of the difference (T1-T0) were performed using Kruskal Wallis test. A significant SPAD increase has been reported using the three tested appliances (p < 0.05), with the least change documented with MB use (p < 0.05). Significant antero-posterior improvements have been found with IMA, MB, and TB with an increase in the SNB°, and a decrease in ANB° and Wits appraisal (p < 0.05). Non-significant FMA° changes have been observed post-treatment in the three test groups (p > 0.05). The IMA, MB, and TB generated significant SPAD and sagittal changes, with both IMA and TB surpassing MB in the airway area improvement post-treatment. Moreover, the three tested Class II functional appliances did not affect the vertical dimension.

Maxillary Protraction: A Bibliometric Analysis

OBJECTIVES

The aim of this analysis was to investigate the historical development, current status, and research hot spots related to maxillary protraction in the treatment of maxillary hypoplasia.

METHODS

The term "TS = maxillary protraction" was used to search for articles in the Web of Science Core Collection at the library of Capital Medical University. The results were analysed using CiteSpace6.2.R1 software, including the examination of annual publication trends and analysis of author, country, institution, and keywords.

RESULTS

A total of 483 papers were included in this study. The annual publications showed an overall increasing trend. The top 5 authors with the most published papers were Lorenzo Franchi, Tiziano Baccetti, Seung-Hak Baek, Paola Cozza, and U Hagg. The top 5 countries with the highest publication counts were the US, Turkey, South Korea, Italy, and China. The top 5 institutions in terms of the number of published papers were the University of Florence, the University of Michigan, Kyung Hee University, Seoul National University, and Gazi University. The top 3 journals with the most citations were the American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, and the European Journal of Orthodontics. Furthermore, "Maxillary protraction," "Class III malocclusion," and "Maxillary expansion" were the most common keywords.

CONCLUSIONS

The effective age range for maxillary protraction has been expanded with the introduction of skeletal anchorage and the combination of maxillary expansion and protraction. Skeletal anchorage offers significant advantages over dental anchorage, but there is a need for further research to further substantiate its stability and safety. In recent years, the positive effects of maxillary protraction on the nasopharyngeal area have been well established, but its impact on the oropharyngeal area remains a topic of debate. Therefore, it is crucial to conduct further investigations into the effects of maxillary protraction on the oropharyngeal area and explore the factors that influence different outcomes.

A 3-Dimensional Measurements of Bone and Airway Variables After Le Fort I Distraction Osteogenesis in Patients With Cleft Lip and/or Palate-Induced Midface Hypoplasia: A Retrospective Study

The authors retrospectively analyzed the effects of Le Fort I advancement with distraction osteogenesis on skeletal and airway variables in patients with midfacial hypoplasia induced by cleft lip and/or palate using 3-dimensional computed tomography reconstructions. The authors enrolled 23 subjects with moderate-to-severe midface hypoplasia induced by cleft lip and palate who were treated with Le Fort I distraction osteogenesis (mean age, 19.22±3.48 y; male/female ratio, 20/3); computed tomography images (1 before distraction and another at completion of distraction) were acquired. A 3-dimensional craniometric findings and airway volumes for the nasal cavity, nasopharynx, velopharynx, and upper and lower oropharynx were compared before and after distraction. The relationships between craniofacial morphology and changes in airway volume were also assessed ( P <0.05 was considered significant). Significant increases were observed in airway volumes for the nasal cavity (13.85%), nasopharynx (50.82%), velopharynx (29.57%), and upper oropharynx (36.92%) ( P =0.007, P <0.001, P =0.023, and P <0.001, respectively), whereas no significant changes were observed for the lower oropharynx ( P =0.117). Maxillary horizontal advancement was positively correlated with the airway volumes of the nasopharynx and upper oropharynx after distraction osteogenesis ( rs =+0.451, P =0.031; rs =+0.548, P =0.007); however, no significant correlations were observed for the nasal cavity and velopharynx. The authors' finding indicate that despite rotation of the mandible along with the maxilla, this change does not impact airway volume at the mandibular level. Le Fort I distraction osteogenesis can be feasible for patients with cleft lip and palate-induced midface hypoplasia, with satisfactory appearance and occlusion. Long-term detailed follow-up of the patients postdistraction osteogenesis is warranted.

Rationale and design for efficacy and safety evaluation of Bone-Anchored Maxillary Protraction (BAMP) for patients with unilateral cleft lip and palate with skeletal anterior crossbite: a single-arm, open-label, non-randomised prospective study protocol

INTRODUCTION

Bone-anchored maxillary protraction (BAMP) was devised recently as a method of direct maxillary protraction using anchor plates implanted in the maxilla and mandible without involving the teeth. Although several reports have described orthognathic effects of BAMP on patients with cleft lip and palate (CLP) with skeletal crossbite, none has described a study of Japanese patients with CLP or of BAMP treatment effects on speech in patients with CLP. This study, by performing BAMP treatment, and by evaluating speech function and skeletal and soft tissues, is intended to clarify BAMP efficacy and safety for patients with unilateral CLP (UCLP) who have skeletal crossbite.

METHODS AND ANALYSIS

This single-arm, open-label, non-randomised prospective study examines 20 patients with UCLP with skeletal crossbite (Wits appraisal ≤-5.0 mm). These 10-15 year-old participants had already undergone cheiloplasty, palatoplasty and bone grafting. The anchor plates are implanted in the zygomatic process in the maxilla and in the anterior part of the mandible. Two weeks after anchor plate implantation, maxillary protraction is started using elastics. Protraction is performed at 150 g per side at the start of protraction, 200 g per side from 1 month after the start of protraction and 250 g per side from 3 months after the start of protraction. The treatment period will be approximately 1½ years. Pretreatment and post-treatment, cephalometric analysis, speech evaluation, nasopharyngeal closure function evaluation and facial soft tissue evaluation will be performed to ascertain the effects of BAMP on patients with UCLP.

ETHICS AND DISSEMINATION

Ethical approval for this study has been received from Tohoku Certificated Review Board of Tohoku University, Japan, CRB2200003. The approval number is 2021-34-2. The results of this research shall be presented at domestic and international academic conferences, and be published to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

jRCTs022210007.