Electromyographic analysis of trapezius and sternocleidomastoideus muscles during nasal and oral inspiration in nasal- and mouth-breathing children

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.

Surface electromyography in orofacial and cervical musculature in mouth breathing children: an integrative literature review

ABSTRACT Purpose: to review, in an integrative manner, studies using surface electromyography in the orofacial and cervical musculature in mouth breathing children aged from three to 11 years and 11 months old. Methods: the survey was conducted in national and international databases, from 1998 to 2018, in Portuguese, English and Spanish. Review articles, dissertations, book chapters, case studies and editorials were excluded. Results: 86 articles were found, 14 of which met the inclusion criteria. Most of these studies used surface electromyography to assess and describe the muscle condition of the mouth breathing population. Only one study addressed the influence of myofunctional speech therapy and two studies included physical therapy treatment, using electromyographic evaluation before and after the intervention. Given the main categories of analysis, the discussion was based on the year, state of publication and journal, sample size, scientific methodology, muscles assessed, assessment protocols used and the results of the publications. Conclusions: surface electromyography has been used mainly in the initial assessment of orofacial and postural myofunctional changes caused by mouth breathing and not as a therapeutic biofeedback, thus, it is important to conduct longitudinal studies using this instrument in mouth breathers.

Impact of moderate-severe persistent allergic rhinitis on thoraco-abdominal kinematics and respiratory muscle function

Objective: To assess thoraco-abdominal kinematics, respiratory muscle strength and electromyographic activity of the diaphragm (EAdi) in moderate-severe allergic rhinitis (AR) patients. Methods: A cross-sectional study involving 40 individuals (20 in the AR group) and 20 in the control group [CG]) was conducted. Ventilatory pattern and chest wall volume distribution (optoelectronic plethysmography), respiratory muscle strength (manovacuometry and sniff nasal inspiratory pressure [SNIP]), and EAdi were assessed in both groups. Results: The AR patients had impaired thoraco-abdominal kinematics (reduced total chest wall volume) (p = 0.004), lower values of total respiratory cycle time (p = 0.014) and expiratory time (p = 0.006). They also presented an increase of percentage contribution of the abdominal rib cage (p = 0.475) and respiratory rate (p = 0.019). A positive correlation among pulmonary rib cage tidal volume and MIP (r = 0.544; p < 0.001), SNIP (r = 0.615; p < 0.001), and MEP (r = 0.604; p < 0.001) was observed. After adjusting for age, BMI and gender through multivariate analysis, the individuals with AR presented lower values ​​of MIP (β = -24.341; p < 0.001), MEP (β = -0.277; p < 0.001), SNIP (β = -34.687; p < 0.001) and RMS (β = -0.041; p = 0.017). Conclusions: The individuals with moderate-severe persistent AR had worse respiratory muscle strength, diaphragm activation and chest wall volume distribution with a higher abdominal contribution to tidal volume than the control group. These findings reinforce the notion that the upper and lower airways work in an integrated and synergistic manner.

Correlation between forward head posture, respiratory functions, and respiratory accessory muscles in young adults

BACKGROUND

Forward head posture (FHP) causes changes in the strengths and rigidities of cervical muscles.

OBJECTIVE

The aim of this study was to investigate correlations between FHP and respiratory functions and the muscle activities of respiratory accessory muscles in young adults in their 20s.

METHODS

A volunteer sample of 33 healthy young adults participated in this study. Craniovertebral angle (CVA), cranial rotational angle (CRA), vital capacity (VC), forced vital capacity (FVC), forced expiratory volume at 1 second (FEV1), peak expiratory flow (PEF), maximal voluntary ventilation (MVV), and sternocleidomastoid (SCM) and upper trapezius activity ratios were measured.

RESULTS

Significant positive correlations were found between CVA and VC, FVC, FEV1, PEF, and MVV, and a significant negative correlation was found between CVA and SCM activity ratio. Significant negative correlations existed between CRA and VC and FVC, and significant positive correlations between CRA and SCM and upper trapezius activity ratios.

CONCLUSION

FHP may act to lower respiratory functions, and thus, the maintenance of correct head posture is required to prevent such functional reductions.

Aeração nasal e força muscular respiratória em crianças respiradoras orais

Resumo: OBJETIVO: observar se existe relação entre força muscular respiratória e área da aeração nasal em crianças respiradoras orais. MÉTODOS: trata-se de um estudo do tipo observacional, transversal comparativo entre dois grupos. Participaram 32 crianças com Respiração Oral secundária à rinite alérgica (21 meninos e 11 meninas) e 30 respiradoras nasais sem rinite alérgica (09 meninos e 21 meninas), 7 a 12 anos, submetidas à avaliação da aeração nasal com o espelho de Altmann e à avaliação da força muscular respiratória com o manovacuômetro digital (MVD(r)30). RESULTADOS: não houve correlação entre aeração nasal e força muscular respiratória em cada subgrupo. Houve diferença comparando-se valores das pressões expiratórias máximas entre meninos e meninas respiradores orais (p=0,0064) e entre meninos e meninas respiradores nasais (p=0,0030). Também houve diferença das pressões inspiratórias máximas entre meninos e meninas respiradores orais (p=0,0324) e entre meninos e meninas respiradores nasais (p=0,0210). CONCLUSÃO: não foi possível confirmar a relação entre a área de aeração nasal e a força muscular respiratória nos respiradores orais.

Association between respiratory and postural adaptations and self-perception of school-aged children with mouth breathing in relation to their quality of life

OBJECTIVE

To investigate the respiratory and postural adaptations associated with mouth and nasal breathing and to evaluate the associations of such adaptations in mouth breathers' self-perceived quality of life.

METHOD

Cross-sectional study with mouth breathers (initial n=116 and final n=48) and nasal breathers (initial n=131 and final n=24) from elementary school, aged between 7 and 14 years. Chest expansion, using cirtometry, the breathing pattern and the use of accessory muscles, by means of clinical evaluations and photogrammetry, and flexibility tests were evaluated in both groups. Subsequently, the mouth breathers were asked to complete the quality of life questionnaire. Statistical tests: Chi-square, odds ratio, Mann-Whitney, and binomial tests were first applied followed by logistic regressions.

RESULTS

Thoracic breathing (p=0.04), using of accessory muscles (p=0.03) and reductions in flexibility (p=0.001) increased the chances of an individual being a mouth breather when compared to nasal breathers. Subsequently, using of accessory muscles decreased the chances of snoring among mouth breathers (p=0.03); the presence of shoulder asymmetry reduced the chances of experiencing quiet sleep (p=0.05) and increased the chances of coughing or being tired when playing or running (p=0.008). Finally, forward head position reduced the chances of waking up at night (p=0.04) and experiencing shortness of breath (p=0.05).

CONCLUSIONS

Respiratory and postural adaptations increased the chances of individuals persisting with mouth breathing. Additionally, these adaptations could be associated with mouth breathers' self-perceived quality of life.

Qualidade de vida em sujeitos respiradores orais e oronasais

OBJETIVO: investigar a qualidade de vida de sujeitos com respiração oral ou oronasal. MÉTODO: compuseram a amostra 49 voluntários, distribuídos em dois grupos: grupo de respiradores orais com 24 sujeitos e grupo de respiradores oronasais com 25 sujeitos, com faixa etária ente 18 e 38 anos de idade, de ambos os sexos. O protocolo utilizado foi o WHOQOL-BREF (versão em português) e o registro e análise dos dados foi realizado pelo sistema Statistical Analysis System. RESULTADOS: os resultados obtidos foram submetidos aos testes de qui-quadrado de Mantel-Haenszele análise de variância. A qualidade de vida dos respiradores mistos se revelou inferior nos domínios ambiental, físico e psicológico em relação aos respiradores orais. CONCLUSÃO: com a detecção das diferenças obtidas, o estudo chama a atenção para a necessidade de aprofundar investigações sobre o perfil dos respiradores oronasais e sua relevância. Para que condutas como desconsiderar o grupo de respiradores oronasais ou agrupá-los como respiradores orais não sejam adotadas de forma inadequada.

Electromyographic muscle EMG activity in mouth and nasal breathing children

Mouth breathing may cause changes in muscle activity, because an upper airway obstruction leads may cause a person to extend his/her head forward, demanding a higher inspiratory effort on the accessory muscles (sternocleidomastoids). This purpose of this study is to compare, using electromyography (EMG), the activity pattern the sternocleidomastoid and upper trapezius muscles in mouth breathing children and nasal breathing children. Forty-six children, ages 8-12 years, 33 male and 13 female were included. The selected children were divided into two groups: Group I consisted of 26 mouth breathing children, and Group II, 20 nasal breathing children. EMG recordings were made using surface electrodes bilaterally in the areas of the sternocleidomastoideus and upper trapezius muscles, while relaxed and during maximal voluntary contraction. The data were analyzed using the Kruskall-Wallis statistical test. The results indicated higher activity during relaxation and lower activity during maximal voluntary contraction in mouth breathers when compared to the nasal breathers. It is suggested that the activity pattern of the sternocleidomastoid and upper trapezius muscles differs between mouth breathing children and nasal breathing children. This may be attributed to changes in body posture which causes muscular imbalance. Because of the limitations of surface EMG, the results need to be confirmed by adding force measurements and repeating the experiments with matched subjects.