Breathing mode assessment with thermography: a pilot study. / Avaliação do modo respiratório por meio da termografia: um estudo piloto.

PURPOSE: To present a method for analyzing breathing modes with infrared thermography. METHODS: This exploratory cross-sectional study used 38 thermal images of inspiration and expiration with nasal breathing and simulated mouth breathing in four nasal breathers without respiratory complaints. Three different data selection forms (line, rectangle, and ellipse) were used to extract the minimum, mean, and maximum temperatures of the regions of interest (nose and mouth) using the FLIR Tools® software. RESULTS: Among the three selection forms, there was greater temperature variability obtained with the line, revealing limitations in this measurement. There were no differences between the rectangle and ellipse values, showing that both selection forms present similar temperature extraction results. The comparison results between nose and mouth temperatures during inspiration and expiration indicated a statistically significant difference between all measurements, except for mean inspiration temperatures with the rectangle and ellipse. The breathing mode can be distinguished in both inspiration and expiration when using mean mouth temperatures with the rectangle and ellipse. CONCLUSION: Breathing modes should be assessed based on mean mouth temperatures during inspiration, using the ellipse.

OBJETIVO: Apresentar um método de análise do modo respiratório por meio da termografia infravermelha. MÉTODO: Estudo transversal exploratório de 38 imagens térmicas que representavam o momento da inspiração e da expiração durante a respiração nasal e durante a simulação da respiração oral de quatro voluntárias respiradoras nasais sem queixas respiratórias. Para a extração da temperatura das regiões de interesse (nariz e boca) foram utilizadas três formas de seleção distintas de dados (linha, retângulo e elipse) e três medidas de temperatura (mínima, média e máxima) por meio do software FLIR Tools®. RESULTADOS: Dentre as três formas de seleção houve maior variabilidade nas medidas obtidas pela linha, revelando limitações nessa medida. Não houve diferenças entre as medidas do retângulo e elipse, mostrando que ambas as formas de seleção apresentam resultados semelhantes para a extração das temperaturas. Na comparação entre as temperaturas do nariz e da boca na inspiração e expiração, os resultados indicaram que houve diferença com relevância estatística em todas as medidas realizadas, exceto para as medidas de temperatura média da inspiração, usando o retângulo e a elipse. Percebe-se diferenciação do modo respiratório tanto na inspiração quanto na expiração quando utilizada a temperatura média da boca com o retângulo e a elipse. CONCLUSÃO: Sugere-se para avaliação do modo respiratório a avaliação da boca, por meio da elipse, com análise da temperatura média durante a inspiração.

Mouth breathing reduces oral function in adolescence.

Although humans breathe naturally through the nostrils, mouth breathing in children has recently gathered attention. In this study, we hypothesized that tongue function and its related maxillofacial morphology would affect breathing in adolescence. To verify this hypothesis, we examined the association between breathing patterns, including mouth and nasal breathing; oral functions, including tongue motor function; and craniofacial morphology during adolescence, which has not been investigated till date. C3-H, which indicates the anteroposterior position of the hyoid bone in relation to the third cervical vertebra, was significantly smaller in mouth-breathers than in nasal-breathers. Lip-closing force, tongue pressure, and masticatory efficiency were lower in the order of nasal-breathers, oronasal-breathers, and mouth-breathers, and the values for mouth-breathers were significantly lower than those for nasal-breathers. Tongue pressure alone was identified as a significant independent variable, with an odds ratio of 1.063 (95% confidence interval, 1.006-1.123; p < 0.05). Our results indicate a relationship between mouth breathing and the lip-closing force, tongue pressure, and masticatory efficiency, as well as the significance of tongue pressure on mouth breathing in adolescents. The findings highlight the importance of clarifying the pathophysiology of mouth breathing and its underlying causes.

The effects of adenoid hypertrophy and oral breathing on maxillofacial development: a review of the literature.

According to modern epidemiological surveys, the prevalence of adenoid hypertrophy in children and adolescents ranges from 42% to 70%. Adenoid hypertrophy can lead to airway obstruction; thus forces a child to breathe through their mouth, thus affecting the normal development of the dental and maxillofacial area, and can lead to malocclusion. Long-term mouth breathing can cause sagittal, vertical and lateral changes in the maxillofacial area. In this article, we review the current research status relating to the association between adenoid hypertrophy, oral breathing and maxillofacial growth and development in children and adolescents. We also discuss the personalized formulation of treatment plans.

Comparison of the prevalence of malocclusion and oral habits between children with cerebral palsy and healthy children.

BACKGROUND: Cerebral palsy (CP) represents for children an important problem of health and affects roughly 2 per 1000 live births and is the most common pediatric developmental motor disability. Therefore, the purpose of this study was to determine the prevalence, type and severity of malocclusion and oral habits in children with Cerebral Palsy (CP) and to compare them with a control group of healthy children in Sana'a city. MATERIALS AND METHODS: A prospective, case-control study was made of two groups, a cerebral palsy and a control group. The study population consisted of 60 children who had CP, and a control group of 60 matched children with no physical or mental disabilities. Data were collected using a questionnaire and assessment for malocclusion was done clinically. The patients were compared with equal number of age-matched controls. The inclusion criteria were individuals aged over 6 years; absence of previous orthodontic treatment; no missing permanent first molars. RESULTS: Results showed an increased prevalence of malocclusion in children with cerebral palsy. Molar class II relationship was statistically higher in cerebral palsy children than healthy control (P = 0.001). Cerebral palsied children are likely to have a significantly increased protrusion of the anterior teeth (P < 0.001) when compared with normal children. Mouth breathing and Tongue thrust. Habits were significantly higher in the CP group (p = 0.0001) when compared with normal children. CONCLUSION: The prevalence of malocclusion was higher in children with Cerebral palsy than in normal children, and the present study concludes that in children with Cerebral Palsy, more oral Habits problems due to oral motor dysfunctions are common and problems of mouth breathing and Tongue thrust produce different malocclusion and poor oral hygiene complications in these children.

Predictors associated with malocclusion in children with and without sleep disorders: a cross-sectional study.

The aim of the present study was to investigate predictors of malocclusion in Brazilian schoolchildren eight to ten years of age based on a causal directed acyclic graph model. A cross-sectional study was conducted with 739 schoolchildren eight to ten years of age. Parents/guardians provided information on sleep disorders of the child (Sleep Disturbance Scale for Children) and family characteristics (Family Adaptability and Cohesion Evaluation Scale). The diagnosis of malocclusion was performed by four trained examiners using the Dental Aesthetic Index. Control variables were selected using a directed acyclic graph. Descriptive analysis was performed, followed by robust logistic regression analysis for complex samples (α = 5%). The following variables were associated with malocclusion in the final model: sleep disorders (OR = 2.61; 95%CI: 2.43-2.86), mouth breathing (OR = 1.04; 95%CI: 1.02-1.99), non-nutritive sucking habits (OR = 2.45; 95%CI: 2.37-4.85), and obesity (OR = 1.54; 95%CI: 1.02-2.33). Sociodemographic characteristics, family functioning, and premature tooth loss did not remain associated with malocclusion. Sleep disorders, mouth breathing, sucking habits, and obesity are predictors of malocclusion in schoolchildren eight to ten years of age.

Oral findings in pediatric patients with allergic rhinitis and asthma: a cohort study of an Italian setting.

Allergic rhinitis and asthma are two frequent respiratory clinical entities commonly encountered in pediatric clinical settings. Previous studies have evaluated the influence of these two conditions on oral health, but conflicting results have been obtained. The present cohort study aimed to record oral findings (i.e., caries, plaque, gingival inflammation and mouth breathing) in 50 pediatric patients diagnosed with allergic rhinitis and/or asthma in an Italian pediatric setting and to compare them to a control group of 50 healthy children. The following oral indexes were calculated: Periodontal Screening and Recording (PSR), Plaque Control Record (PCR), and Decayed Missing Filled Teeth (DMFT) Index. The absence or presence of mouth breathing was also recorded. Descriptive and inferential statistics were conducted. Statistically significant differences were found between cases and controls for PSR (p = 0.0051) and PCR scores (p < 0.0001), whereas no significant differences were detected for DMFT. Mouth breathing was found among 20 (40.00%) patients of the Case Group, while in the Control group only in 11 (22.00%) patients, and no significant differences were found between allergic rhinitis and asthma gradings for mouth breathers (p > 0.05). Finally, linear regressions showed a significant influence of PSR (p = 0.0051) and PCR (p < 0.0001) on the Case group. Mouth breathing also significantly influenced PCR scores of the Case group (p = 0.0206). Accordingly, allergic rhinitis and asthma can promote mouth breathing, plaque accumulation, and periodontal inflammation. Based on these considerations, pediatric dentists and physicians are expected to know the influence of respiratory conditions on oral health and consider this aspect when taking care of children.

Effect of preoperative patient education and simulated mouth breathing training on opioid requirements in the post-anesthesia care unit after nasal surgery: a randomized controlled study.

BACKGROUND: A simulated education, prior to surgery about postoperative nasal stuffiness and ease of breathing through the mouth may help patients tolerate discomfort after nasal surgery. This study aimed to investigate the effect of preoperative simulated education on immediate postoperative opioid requirements in patients undergoing elective nasal surgery. METHODS: This randomized controlled trial of 110 patients undergoing nasal surgery randomly allocated patients into either a control (group C) or an education group (group E). One day before surgery, patients in group E were intensively trained to breathe through the mouth by using a nasal clip, with informative explanations about inevitable nasal obstruction and discomfort following surgery. Patients in group C were provided with routine preoperative information. Total intravenous anesthesia (TIVA) with propofol and remifentanil was used for anesthesia. No further opioid was used for analgesia intraoperatively. The primary outcome was index opioid (fentanyl) requirements at the post-anesthesia recovery unit (PACU). Secondary outcomes were emergence agitation, pain scores at the PACU, and postoperative recovery using the Quality of Recovery-15 (QoR15-K). RESULTS: The rate of opioid use in the PACU was 51.0% in the group E and 39.6% in the group C (p = 0.242). Additional request for analgesics other than index opioid was not different between the groups. Emergence agitation, postoperative pain severity, and QoR15-K scores were comparable between the groups. CONCLUSION: Preoperative education with simulated mouth breathing in patients undergoing nasal surgery did not reduce opioid requirements. TRIAL REGISTRATION: KCT0006264; 16/09/2021; Clinical Research Information Services ( https://cris.nih.go.kr ).

Effect of breathing patterns on mandibular cortical bone quality in children and establishment of a preliminary screening model.

OBJECTIVE: This retrospective study analyzed breathing patterns and age subgroups effect on cortical bone quality of the mandible in growing subjects, aiming to explore the application value of facial skeletal pattern combined with cortical bone density detection in early screening diagnosis of mouth breathing. METHODS: One hundred twenty-six participants were divided into four groups: mouth breathing group (7-9, 10-12 years old) and nasal breathing group (7-9, 10-12 years old). The mandibular anterior, middle, and posterior cortical bone mineral density (CBMD), cortical bone width (MCW), ANB, and FMA values were measured. Independent T-test and Mann-Whitney U test were used to compare the measured values. Binary logistic regression was employed to analyze the correlation between measured variables and the children's breathing patterns. ROC analysis was used to determine the ability of the cortical bone density measurements in early screening diagnosis of MB. RESULTS: Mouth breathing had a negative impact on CBMD and MCW of the pre-mandibular (Pog) in subjects aged 7-9 years and also impacted the development of (Pog) and submandibular (Me) sites in subjects aged 10-12 years. Older children in the nasal breathing group have higher CBMD, MCW, and SNB values and lower FMA values. Single-factor and multiple-factor logistic binary regression analysis showed that FMA, MSPogCBMD, MSPogMCW, and ANB are correlated factors for children at risk of mouth breathing. CONCLUSION: Mouth breathing pattern is closely associated with decreased mandibular CBMD and MCW values in children aged 7-12, where the anterior (Pog) and inferior (Me) sites of anterior mandible are more significantly affected. Furthermore, in combination with facial skeletal pattern, it provides a basis for the early warning diagnosis of mouth breathing.

Nasal splinting and mouth breathing training reduce emergence delirium after endoscopic sinus surgery: a randomized controlled trial.

BACKGROUND: Emergence delirium (ED) is generally occurred after anesthesia associated with increased risks of long-term adverse outcomes. Therefore, this study aimed to evaluate the efficacy of preconditioning with nasal splint and mouth-breathing training on prevention of ED after general anesthesia. METHODS: This randomized controlled trial enrolled 200 adult patients undergoing ESS. Patients were randomized to receive either nasal splinting and mouth breathing training (n = 100) or standard care (n = 100) before surgery. The primary outcome was the occurrence of ED within 30 min of extubation, assessed using the Riker Sedation-Agitation Scale. Logistic regression identified risk factors for ED. RESULTS: Totally 200 patients were randomized and 182 aged from 18 to 82 years with 59.9% of males were included in the final analysis (90 in C-group and 92 in P-group). ED occurred in 16.3% of the intervention group vs. 35.6% of controls (P = 0.004). Male sex, smoking and function endoscopic sinus surgery (FESS) were independent risk factors for ED. CONCLUSIONS: Preoperative nasal splinting and mouth breathing training significantly reduced the incidence of emergence delirium in patients undergoing endoscopic sinus surgery. TRIAL REGISTRATION: ChiCTR1900024925 ( https://www.chictr.org.cn/index.aspx ) registered on 3/8/2019.

Assessment of changes in Streptococcus pyogenes levels using N-acetylgalactosamine-6-sulfatase marker and pharyngeal airway space with appliance therapy in mouth breathers - An ELISA-based study.

Background: The frequency of adenotonsillar hypertrophy in mouth-breathing children when compared to the average found in the general population is considered to be higher. Mouth breathing is considered as one of the causative factors for tonsillitis in children. Through continuous irritation on tonsillar wall, tonsils swell up and inflammation develops. Purpose: The purpose of the study is to evaluate Streptococcus pyogenes count using colony-forming units (CFUs) and N-acetylgalactosamine-6-sulfatase side chain marker on ELISA (enzyme linked immunosorbent assay) in mouth breathers and to establish its correlation with pharyngeal airway space pre- and post-oral screen appliance therapy. Materials and Methods: A total number of 24 (n) mouth breathers aged between 5 and 12 years were included in the study and given oral screen appliance therapy. The subjects were evaluated for the various parameters before the delivery of a habit-breaking appliance and then reevaluated for the same parameters (presence of S. pyogenes and its counts, size of tonsils, and pharyngeal airway space dimensions) after 6 months of appliance usage. Results: A statistically significant difference was seen in levels of S. pyogenes using ELISA and CFUs. Furthermore, statistically significant difference was observed in Friedman tonsil scoring and pharyngeal airway space and pre- and post-oral screen appliance therapy. Conclusion: Oral screen appliance therapy reduced the frequency of occurrence of tonsillitis in mouth breathers by decreasing the counts of S. pyogenes bacteria. Upper and lower pharyngeal airway space dimensions were increased after 6 months of appliance therapy in mouth breathers.

[Effect of mouth breathing on upper airway structure in patients with obstructive sleep apnea].

Objective:To compare the changes of morphology of pharynx in patients with obstructive sleep apnea hypopnea syndrome （OSAHS） and healthy individuals during oral or nasal breathing, and explore the relevant influencing factors. Methods:Twenty-nine adult patients with OSAHS and 20 non-snoring controls underwent MRI to obtain upper airway structural measurements while the subjects were awake and during mouth breathing with a nasal clip.The following were analyzed. ①The changes of upper airway structure of oral and nasal respiration in non-snoring control/OSAHS patients were observed; ②The differences and influencing factors of upper airway structure changes between OSAHS patients and controls were compared during breathing. Results:The control group consisted of 15 males and 5 females, with an apnea-hypopnea index （AHI）<5 events/h, while the OSAHS group comprised 26 males and 3 females with an AHI of 40.4±23.1 events/h and the mean lowest arterial oxygen saturation （LSaO2） was 79.5% ±10.0%. In the both groups, the vertical distance between the mandible and the posterior pharyngeal wall decreased （P<0.05）; The long axis of tongue body decreased （P<0.05）, and the contact area between tongue and palate decreased. There was no significant change in the total volume of the retropalatine（RP） and retroglossal（RG） airway in the control group （P>0.05）. However, the minimum cross-sectional area and volume of the RP airway in OSAHS decreased （P<0.001）. The lateral diameters of uvula plane in OSAHS decreased during mouth breathing, which was contrary to the trend in the control group （P=0.017）. The AHI of patients was positively correlated with the reduction of the volume of the RP airway during oral breathing （P=0.001）; The reduction of the distance between the mandible and the posterior pharyngeal wall was positively correlated with the length of the airway （P<0.001）. Conclusion:Mouth breathing leads to the shortening of the long axis of the tongue, the reduction of the contact area between the soft palate and the tongue, vertical distance between the mandible and the posterior pharyngeal wall, and the cross-sectional area of the epiglottis plane. These changes vary between OSAHS patients and controls. During mouth breathing, the diameters, areas and volumes of the RP area decreased, and were more significant in severe cases.

[Effects of mouth opening breathing for different reasons on maxillofacial development in children].

Objective:To explore the effects of mouth opening breathing for different reasons on children's maxillofacial development. Methods:One hundred and fifty-one children were selected as the research objects of this experiment. They were divided into 49 cases of adenoid hypertrophy group（group A）, 52 cases of tonsillar hypertrophy group（group B） and 50 cases of adenoid with tonsillar hypertrophy group（Group C）. Healthy children in the same period were selected as the control group, a total of 45 cases. The reflex nasopharyngeal measurement parameters, facial development indexes and cephalometric parameters of group A, group B, group C and control group were analyzed, and the incidence of Angle ClassⅡand Angle Class Ⅲ in group A, group B and group C were studied. Results:Compared with the control group, the reflex nasopharyngeal measurement parameters in group A, group B and group C was significantly different（P<0.05）, and the cephalometric parameters changed with variation in groups（P<0.05）. The incidence of Angle Class Ⅱ facial pattern in group A and group C was higher, but the incidence of Angle Class Ⅲ facial pattern in group B and group C was higher（P<0.05）. Conclusion:Adenoid hypertrophy leads to mandibular retraction; tonsil hypertrophy leads to anterior mandibular arch; adenoid hypertrophy and tonsil hypertrophy are easy to lead to clockwise rotation of the mandible. In clinical practice, to avoid children's uncoordinated maxillofacial development, we should correct the maxillofacial situation of children as soon as possible.

[Effect of maxillary expansion combined with orofacial myofunctional therapy on the position of the tongue of children with mouth breathing].

Objective:This study aimed to investigate the change of the position of the tongue before and after combined treatment of maxillary expansion and orofacial myofunctional therapy in children with mouth-breathing and skeletal class Ⅱmalocclusion. Methods:A total of 30 children with skeletal class Ⅱ malocclusion and unobstructed upper airway were selected. The 30 children were divided into mouth-breathing group（n=15） and nasal-breathing group（n=15） and CBCT was taken. The images were measured by Invivo5 software. The measurement results of the tongue position of the two groups were analyzed by independent samples t-test. 15 mouth-breathing children with skeletal class Ⅱ malocclusion were selected for maxillary expansion and orofacial myofunctional therapy. CBCT was taken before and after treatment, the measurements were analyzed by paired sample t test with SPSS 27.0 software package. Results:The measurement of the tongue position of the mouth-breathing and nasal-breathing groups were compared, the differences were statistically significant（P<0.05）. The measurement of the tongue position showed significant difference after the combined treatment of maxillary expansion and orofacial myofunctional therapy in children with mouth-breathing and skeletal class Ⅱmalocclusion（P<0.05）. Conclusion:Skeletal class Ⅱ malocclusion children with mouth-breathing have low tongue posture. The combined treatment of maxillary expansion and orofacial myofunctional therapy can change the position of the tongue.

Mouth breathing induces condylar remodelling and chondrocyte apoptosis via both the extrinsic and mitochondrial pathways in male adolescent rats.

The prevalence of mouth breathing is high in children and adolescents. It causes various changes to the respiratory tract and, consequently, craniofacial growth deformities. However, the underlying mechanisms contributing to these effects are obscure. Herein, we aimed to study the effects of mouth breathing on chondrocyte proliferation and death in the condylar cartilage and morphological changes in the mandible and condyle. Additionally, we aimed to elucidate the mechanisms underlying chondrocyte apoptosis and investigate any variations in the related pathways. Subchondral bone resorption and decreased condylar cartilage thickness were observed in mouth-breathing rats; further, mRNA expression levels of Collagen II, Aggrecan, and Sox 9 were lower in the mouth breathing group, while those of matrix metalloproteinase 9 increased. TdT-mediated dUTP nick end labelling staining and immunohistochemistry analyses showed that apoptosis occurred in the proliferative and hypertrophic layers of cartilage in the mouth breathing group. TNF, BAX, cytochrome c, and cleaved-caspase-3 were highly expressed in the condylar cartilage of the mouth-breathing rats. These results suggest that mouth breathing leads to subchondral bone resorption, cartilage layer thinning, and cartilage matrix destruction, inducing chondrocyte apoptosis via both the extrinsic and mitochondrial apoptosis pathways.

Rapid maxillary expansion and nasal patency in mouth breathing children with maxillary atresia due to or not due to allergic rhinitis.

AIM: To evaluate the effects of rapid maxillary expansion (RME) on nasal patency in mouth breathing (MB) children with maxillary atresia due to or not due to allergic rhinitis (AR) associated with asthma. METHODS: Fifty-three MB children/adolescents (aged 7-14 years) with mixed or permanent dentition and maxillary atresia participated, with or without unilateral or bilateral crossbite. They formed the groups: RAD (AR + asthma; clinical treatment, RME); RAC (AR + asthma; clinical treatment, no RME); and D (mouth breathers; RME only). RAD and RAC patients received topical nasal corticosteroid and/or systemic H1 antihistamine (continuous use) and environmental exposure control. All were evaluated before RME (T1) and 6 months after (T2) with the CARATkids score, acoustic rhinometry, and nasal cavity computed tomography (CT). Patients RAD and D underwent RME (Hyrax® orthopedic appliance). RESULTS: A significant reduction in the CARATkids score occurred in the RAD (-4.06; p < 0.05), similarly when patient and parent/guardian scores were evaluated (-3.28 and -3.16, respectively). Acoustic rhinometry (V5) showed increased nasal volume in all groups, significantly higher in RAD patients than in RAC and D (0.99 × 0.71 × 0.69 cm3, respectively). CT of the nasal cavity documented increased volume in all three groups, with no significant differences between them. CONCLUSION: In MB patients with AR, asthma, and maxillary atresia, RME increased nasal cavity volume and improved respiratory symptoms. However, it should not be used as the only treatment for managing patients with respiratory allergies.

Respiratory Fluid Mechanics of the Effect of Mouth Breathing on High-Arched Palate: Computational Fluid Dynamics Analyses.

Computational fluid dynamics (CFD) was introduced into the study of palate growth and development to explain the mechanisms by which mouth breathing affects palate descent from an aerodynamic perspective. Cone beam computed tomography (CBCT) data were used to reconstruct a 3-dimensional model during natural mouth breathing of a volunteer. The model was imported into CFX 19.0 for numerical simulation of nasal breathing, mouth-nasal breathing, and mouth breathing. The pressure in the oronasal cavity was analyzed, and the pressure difference between the oral and nasal surfaces of hard palate under different breathing patterns was calculated. CFD can be used to simulate the stress on the oral and nasal surfaces of the palate under different breathing patterns. The pressure differences and resultant force between the oral and nasal surfaces of the hard palate during nasal inspiration, nasal expiration, mouth-nasal inspiration, mouth-nasal expiration, mouth inspiration, and mouth expiration were 0 Pa, 4 Pa (upward), 9 Pa (upward), 3 Pa (downward), 474 Pa (upward), 263 Pa (downward), respectively, and 87.99 N (upward), 88.03 N (upward), 88.01 N (upward), 88.01 N (upward), 88.05 N (upward), 87.94 N (upward), respectively. Therefore, CFD can be used to investigate the growth and development of the palate. When the volunteer opened his mouth, the pressure difference between the oral and nasal surfaces of the hard palate was about 88 N upward regardless of whether there was airflow in the mouth. The reversal of the direction of the force on the hard palate may be one of the factors affecting its descent of it.

Assessment of mouth breathing by Speech-Language Pathologists: an international Delphi consensus.

PURPOSE: mouth breathing (MB) has detrimental effects on children's growth. Diagnosis of MB is possible through a multidisciplinary approach including Speech-Language Pathologist's (SLP) assessment; however, SLPs currently have little to no defined selection criteria to determine the awake and habitual breathing pattern. This study aims at identifying relevant criteria for the assessment of the habitual and awake breathing pattern of preschool children, and developing a grid that would help SLPs diagnose MB in their clinical practice. METHODS: A three-rounded online international Delphi process was conducted to achieve a consensus on the relevant items and their interpretation. Agreement was established through a Content Validity Ratio calculation. Based on the agreed items, we developed a grid through a scoring function. RESULTS: Observing the child at rest (i.e., time spent with an open/closed mouth and position of the tongue/lips) was considered the most important criterion. The experts also considered that observing the breathing pattern while chewing (open/closed mouth) and after swallowing (i.e., air intake and open/ closed mouth just after swallowing) should provide relevant but secondary information in decision-making. We were able to establish a clinical grid based on those criteria. CONCLUSION: The Delphi procedure provided content-valid criteria and conditions of observation for the myofunctional SLP assessment of the awake and habitual breathing pattern in preschoolers. A clinical validation of the developed prototype grid should be conducted in preschool children to explore its effectiveness in the diagnosis of MB.

Evaluation of a prototype local ventilation system to mitigate retail store worker exposure to airborne particles.

The objective of this study is to evaluate a prototype local ventilation system (LVS) intended to reduce retail store workers' exposure to aerosols. The evaluation was carried out in a large aerosol test chamber where relatively uniform concentrations of polydisperse sodium chloride and glass-sphere particles were generated to test the system with nano- and micro-size particles. In addition, a cough simulator was constructed to mimic aerosols released by mouth breathing and coughing. Particle reduction efficiencies of the LVS were determined in four different experimental conditions using direct reading instruments and inhalable samplers. The particle reduction efficiency (%) depended on the position beneath the LVS, but the percentage was consistently high at the LVS center as follows: (1) > 98% particle reduction relative to background aerosols; (2) > 97% in the manikin's breathing zone relative to background aerosols; (3) > 97% during mouth breathing and coughing simulation; and (4) > 97% with a plexiglass barrier installation. Lower particle reduction (<70%) was observed when the LVS airflow was disturbed by background ventilation airflow. The lowest particle reduction (<20%) was observed when the manikin was closest to the simulator during coughing.