Nose Breathing Research Articles

The effect of mouth breathing on dentofacial morphology of growing child

The oral mode of respiration cause postural adaptations of structures in the head and neck region producing the effect on the positional relationship of the jaws. The aim of this study is to verify the skeletal relationship of mouth and nose breathing child. A cross sectional study was performed to assess the association of changed mode of respiration with dentofacial growth. One hundred children among which 54 were mouth breathers and 46 were nasal breathers of 6-12 years of age were submitted to clinical examination and cephalometric radiographical analysis. Statistical analysis : Chi-square test for proportions and independent sample's "t" test for parametric data is used. The mean values of N-Me (P<0.001) ANS-Me (P<0.001) and SN-GoGn (P<0.001) for mouth breathers is significantly higher. ArGo-GoMe (P=0.003) and (P<0.011) for 6-9 and 9-12 years age group, respectively, were significantly low in nasal breathers group. Changed mode of respiration was associated with increased facial height, mandibular plane angle and gonial angle.

It Takes a Mouth to Eat and a Nose to Breathe: Abnormal Oral Respiration Affects Neonates' Oral Competence and Systemic Adaptation

Mammalian, including human, neonates are considered to be obligate nose breathers. When constrained to breathe through their mouth in response to obstructed or closed nasal passages, the effects are pervasive and profound, and sometimes last into adulthood. The present paper briefly surveys neonates' and infants' responses to this atypical mobilisation of the mouth for breathing and focuses on comparisons between human newborns and infants and the neonatal rat model. We present the effects of forced oral breathing on neonatal rats induced by experimental nasal obstruction. We assessed the multilevel consequences on physiological, structural, and behavioural variables, both during and after the obstruction episode. The effects of the compensatory mobilisation of oral resources for breathing are discussed in the light of the adaptive development of oromotor functions.

Assessment of Obstructive Sleep Apnea and its Severity during Wakefulness

In this article, a novel technique for assessment of obstructive sleep apnea (OSA) during wakefulness is proposed; the technique is based on tracheal breath sound analysis of normal breathing in upright sitting and supine body positions. We recorded tracheal breath sounds of 17 non-apneic individuals and 35 people with various degrees of severity of OSA in supine and upright sitting positions during both nose and mouth breathing at medium flow rate. We calculated the power spectrum, Kurtosis, and Katz fractal dimensions of the recorded signals and used the one-way analysis of variance to select the features, which were statistically significant between the groups. Then, the maximum relevancy minimum redundancy method was used to reduce the number of characteristic features to two. Using the best two selected features, we classified the participant into severe OSA and non-OSA groups as well as non-OSA or mild vs. moderate and severe OSA groups; the results showed more than 91 and 83% accuracy; 85 and 81% specificity; 92 and 95% sensitivity, for the two types of classification, respectively. The results are encouraging for identifying people with OSA and also prediction of OSA severity. Once verified on a larger population, the proposed method offers a simple and non-invasive screening tool for prediction of OSA during wakefulness.

Evaluation of a Humidified Nasal High-Flow Oxygen System, Using Oxygraphy, Capnography and Measurement of Upper Airway Pressures

In this study, we evaluated the performance of a humidified nasal high-flow system (Optiflow, Fisher and Paykel Healthcare) by measuring delivered FiO, and airway pressures. Oxygraphy, capnography and measurement of airway pressures were performed through a hypopharyngeal catheter in healthy volunteers receiving Optiflow humidified nasal high flow therapy at rest and with exercise. The study was conducted in a non-clinical experimental setting. Ten healthy volunteers completed the study after giving informed written consent. Participants received a delivered oxygen fraction of 0.60 with gas flow rates of 10, 20, 30, 40 and 50 l/minute in random order FiO2, F(E)O2, F(E)CO2 and airway pressures were measured. Calculation of FiO2 from F(E)O2 and F(E)CO2 was later performed. Calculated FiO2 approached 0.60 as gas flow rates increased above 30 l/minute during nose breathing at rest. High peak inspiratory flow rates with exercise were associated with increased air entrainment. Hypopharyngeal pressure increased with increasing delivered gas flow rate. At 50 l/minute the system delivered a mean airway pressure of up to 7.1 cm H20. We believe that the high gas flow rates delivered by this system enable an accurate inspired oxygen fraction to be delivered. The positive mean airway pressure created by the high flow increases the efficacy of this system and may serve as a bridge to formal positive pressure systems.

The effects of mouthpiece use on gas exchange parameters during steady-state exercise in college-aged men and women

The authors conducted a study to assess the effects of custom-fitted mouthpieces on gas exchange parameters, including volume of oxygen consumption over time [corrected] (VO(2)), volume of oxygen consumption over time per kilogram of body weight [corrected] (VO(2) /kg) and volume of carbon dioxide production over time [corrected] (VO(2)). Sixteen physically fit college students aged 18 through 21 years performed two 10-minute treadmill runs (6.5 miles per hour, 0 percent grade) for each of three treatment conditions (mouthpiece, no mouthpiece and nose breathing). The authors assigned the conditions randomly for each participant and for each session. They assessed gas exchange parameters by using a metabolic measurement system. The authors used analysis of variance to compare all variables. They set the significance level at α = .05 and used a Tukey post hoc analysis of treatment means to identify differences between groups. The results showed significant improvements (P < .05) in VO(2,) VO(2) /kg and VCO(2) in the mouthpiece condition. The study findings show that use of a custom-fitted mouthpiece resulted in improved specific gas exchange parameters. The authors are pursuing further studies to explain the mechanisms involved in the improved endurance performance exhibited with mouthpiece use. Dental care professionals have an obligation to understand the increasing research evidence in support of mouthpiece use during exercise and athletic activity and to educate their patients.

Changes in lung volume and upper airway using MRI during application of nasal expiratory positive airway pressure in patients with sleep-disordered breathing

Nasal expiratory positive airway pressure (nEPAP) delivered with a disposable device (Provent, Ventus Medical) has been shown to improve sleep-disordered breathing (SDB) in some subjects. Possible mechanisms of action are 1) increased functional residual capacity (FRC), producing tracheal traction and reducing upper airway (UA) collapsibility, and 2) passive dilatation of the airway by the expiratory pressure, carrying over into inspiration. Using MRI, we estimated change in FRC and ventilation, as well as UA cross-sectional area (CSA), in awake patients breathing on and off the nEPAP device. Ten patients with SDB underwent nocturnal polysomnography and MRI with and without nEPAP. Simultaneous images of the lung and UA were obtained at 6 images/s. Image sequences were obtained during mouth and nose breathing with and without the nEPAP device. The nEPAP device produced an end-expiratory pressure of 4-17 cmH(2)O. End-tidal Pco(2) rose from 39.7 ± 5.3 to 47.1 ± 6.0 Torr (P < 0.01). Lung volume changes were estimated from sagittal MRI of the right lung. Changes in UA CSA were calculated from transverse MRI at the level of the pharynx above the epiglottis. FRC determined by MRI was well correlated to FRC determined by N(2) washout (r = 0.76, P = 0.03). nEPAP resulted in a consistent increase in FRC (46 ± 29%, P < 0.001) and decrease in ventilation (50 ± 15%, P < 0.001), with no change in respiratory frequency. UA CSA at end expiration showed a trend to increase. During wakefulness, nEPAP caused significant hyperinflation, consistent with an increase in tracheal traction and a decrease in UA collapsibility. Direct imaging effects on the UA were less consistent, but there was a trend to dilatation. Finally, we showed significant hypoventilation and rise in Pco(2) during use of the nEPAP device during wakefulness and sleep. Thus, at least three mechanisms of action have the potential to contribute to the therapeutic effect of nEPAP on SDB.

Assessment of the body posture of mouth-breathing children and adolescents

To investigate associations between mouth breathing (MBr), nose breathing (NBr) and body posture classification and clinical variables in children and adolescents, by comparing patients with mouth breathing syndrome with a control group of similar age. This was an observational, analytical, controlled, cross-sectional study conducted at a university hospital. Children aged 5 years or more were recruited to one of two groups: healthy controls (NBr) or an MBr group. The MBr group comprised patients with a diagnosis of mouth breathing syndrome confirmed by clinical examination by a physician plus nasal endoscopy. The control group comprised healthy volunteers of the same age, with NBr confirmed by medical examination. All participants underwent postural assessment. Data were analyzed using the Mann-Whitney nonparametric test, the chi-square test and Fisher's exact test, to a significance level of 0.05%. A total of 306 MBr and 124 NBr were enrolled. Mouth breathers were more likely to be male (p = 0.0002), have more frequent and more severe nasal obstruction and larger tonsils (p = 0.0001) than NBr. Mouth breathers also exhibited higher incidence rates of allergic rhinitis (p = 0.0001), of thoracic respiratory pattern (p = 0.0001), high-arched palate (p = 0.0001) and unfavorable postural classifications (p = 0.0001) with relation to the control group. Postural classification scores were directly proportional to nasal obstruction (p = 0.0001) and male sex (p = 0.0008). Postural problems were significantly more common among children in the group with mouth breathing syndrome, highlighting the need for early interdisciplinary treatment of this syndrome.

Legal Briefs

A 2,222-g 34-weeks' gestation male twin was delivered in the winter to a mother whose pregnancy was unremarkable except for diamniotic, dichorionic twins. This twin was delivered via normal spontaneous vaginal delivery. Apgar scores were 8 at 1 and 5 minutes. Both twins were admitted to the newborn intensive care unit because of their gestational age. The male twin exhibited tachypnea at birth and received a 7-day course of antibiotics. Findings on chest radiography were consistent with transient tachypnea, and a blood culture was negative after 1 week. Other than mild apnea of prematurity and a slightly elevated serum bilirubin concentration, his course was unremarkable. The mother missed several days of visitation near the time of discharge because she had an upper respiratory tract infection. The infant was discharged 16 days after birth at 36–1/7 weeks' gestation. He had three siblings at home: his twin sister, who was discharged close to the time he went home; a 3-year-old brother who had an upper respiratory tract infection; and a 7-year-old healthy sister. After being home for 6 days, when he was 22 days old (37 weeks' gestation), his mother called the pediatrician because the infant had developed nasal congestion, refused to nurse, and seemed excessively sleepy. The pediatrician reassured the mother over the telephone. A few hours later, she brought the infant to the hospital because he had vomited three times and she had ongoing concerns about his poor feeding and excessive sleepiness. On physical examination, the infant's respiratory rate was 40 breaths/min, temperature was 37.4°C, heart rate was 140 beats/min, and oxygen saturation was 97% in room air. The emergency department (ED) physician noted clear breath sounds, unlabored breathing, and moist mucous membranes. The ED nurse noted and documented a congested cough for the infant, and the heart rate was …

Diurnal and nocturnal drooling in Parkinson’s disease

Drooling as symptom of Parkinson’s disease (PD) has thus far been poorly defined. This uncertainty is reflected by high variations in published prevalence rates. The aim of this study was to investigate the prevalence of saliva loss versus accumulation of saliva as a possible preliminary stage, and diurnal drooling versus nocturnal drooling. In addition, we evaluated the association between drooling severity and the severity of facial and oral motor disorders. We collected age, disease duration, UPDRS III and Hoehn & Yahr stage from 104 consecutive outpatients with PD. Diurnal and nocturnal drooling was evaluated with a validated questionnaire (ROMP-saliva). A speech pathologist, blinded for drooling severity, rated facial expression, involuntary mouth opening and difficulty with nose breathing and also interviewed patients about sleeping position and nose-breathing during the night. Thirty patients (29%) had no complaints with saliva control (‘non-droolers’), 45 patients (43%) experienced accumulation of saliva or only nocturnal drooling (‘pre-droolers’), and 29 (28%) had diurnal drooling (24 of which also drooled during the night; ‘droolers’). The droolers had longer disease duration (10 vs. 7 years, p = 0.01) and drooling was independently associated with involuntary mouth opening (OR = 2.0; 95% CI 1.02–3.99) and swallowing complaints (OR = 1.2; 95% CI 1.03–1.31). Diurnal drooling—defined as dribbling of saliva while awake—is present in about 28% of PD patients. This is less than usually reported. Diurnal drooling typically appeared later in the disease course. The association with oral motor behavior should encourage the development of behavioral treatment approaches.

A new method that uses cyanoacrylate tissue adhesive to fill scoring incisions in septal cartilage correction

Numerous methods are used in the correction of deviated septal cartilage. One of these methods is to perform partial-thickness incisions (scoring) on the concave side of the deviated cartilage. In this retrospective report, we present a series of patients who were treated by filling the scoring incision gaps with cyanoacrylate-based tissue adhesives to increase the effectiveness of scoring incisions and to maintain stability of the corrected concave cartilage segments. A retrospective clinical study presenting a patient group who was treated using a new surgical method for septal deviation. Twenty-three patients with septum deviation and nasal deformity underwent surgery with the open rhinoplasty approach. Intra- or extracorporeal scoring incisions were performed on the concave side of the deviated septal cartilage, and cyanoacrylate tissue adhesives were applied to the incisions of the corrected cartilage. After polymerization and hardening of the cyanoacrylate tissue adhesive, the operation continued in the normal manner. Preoperative and postoperative clinical results and computed tomography images of the patients were assessed. With a mean 24-month follow-up, all patients with respiratory complaints related to deviated septum reported improvement in nose breathing. Clinical and radiologic observations showed that the corrected septum was stable in its new position. There were no complications arising from the use of cyanoacrylate. Cyanoacrylate is an effective, instant, safe method of treatment in correcting deviated septal cartilage with scoring incisions and filling the gaps of the incisions.

In vitro deposition measurement of inhaled micrometer-sized particles in extrathoracic airways of children and adolescents during nose breathing

An in vitro study was conducted with the goal of developing empirical correlations to predict the deposition of particles with an aerodynamic diameter of 0.5–5.3 μm in nasal airways of children with ages 4–14 years. CT images of nasal airways of thirteen healthy subjects and one with congested nasal airways were used for fabricating the replicas by rapid prototyping. Replicas included nasal airways to the level of the upper trachea as well as the face. Four physiological breathing patterns (sinusoidal waves) of children were simulated by a pulmonary waveform generator. Using an Electrical Low Pressure Impactor (ELPI) we measured deposition of sunflower oil particles generated by a Collison atomizer. Moreover, using the same setup, particle deposition in five adult replicas fabricated using MRI images was measured for direct comparison with the child replicas and in vivo data available for adults. Deposition increased by increasing particle size and flow rate, indicating impaction as the dominant deposition mechanism. Existing correlations for adults were unable to reduce the scatter in the deposition data for children. A correlation was developed for prediction of deposition including the relevant non-dimensional numbers (Stokes and Reynolds numbers) that were calculated considering the dimensions of the airways. The corrected correlations should be useful for exposure estimation of children and for efficient pediatric drug delivery using face masks.

Pathophysiology of diurnal drooling in Parkinson's disease

Drooling is an incapacitating feature of Parkinson's disease. Better pathophysiological insights are needed to improve treatment. In this study, we tested the hypothesis that the cause of drooling is multifactorial. We examined 15 patients with Parkinson's disease with distinct diurnal saliva loss ("droolers") and 15 patients with Parkinson's disease without drooling complaints ("nondroolers"). We evaluated all factors that could potentially contribute to drooling: swallowing capacity (maximum volume), functional swallowing (assessed with the dysphagia subscale of the Therapy Outcome Measures for rehabilitation specialists), unintentional mouth opening due to hypomimia (Unified Parkinson's Disease Rating Scale item), posture (quantified from sagittal photographs), and nose-breathing ability. We also quantified the frequency of spontaneous swallowing during 45 minutes of quiet sitting, using polygraphy. Droolers had more advanced Parkinson's disease than nondroolers (Unified Parkinson's Disease Rating Scale motor score 31 vs 22; P=.014). Droolers also scored significantly worse on all recorded variables except for nose breathing. Swallowing frequency tended to be higher, possibly to compensate for less efficient swallowing. Logistic regression with adjustment for age and disease severity showed that hypomimia correlated best with drooling. Linear regression with hypomimia as the dependent variable identified disease severity, dysphagia, and male sex as significant explanatory factors. Drooling in Parkinson's disease results from multiple risk factors, with hypomimia being the most prominent. When monitored, patients appear to compensate by increasing their swallowing frequency, much like the increased cadence that is used to compensate for stepping akinesia. These findings can provide a rationale for behavioral approaches to treat drooling.

Facial and dental alterations according to the breathing pattern

There is controversy in the literature about possible interaction of the respiratory mode with the facial and dental structures.ObjectivesThe aim of this study was to perform a longitudinal assessment of the changes in facial and dental structures in Angle’s Class II, division 1 malocclusion individuals, divided according to the respiratory pattern (predominantly nasal or mouth), at two distinct moments of craniofacial development.Material and MethodsPogonium and nose measurements were made on the lateral cephalometric tracings (LS’-Pog’, LS’-B’, B’-Pog’, Pog’-PogTeg’, Line NB, Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn, Prn-Sn-LS). Dental measurements were made on the plaster models (distances between the tips of the canine cusps and the tips of mesial cusps of the first molars) of 40 individuals aged 10 to 14 years (moment 1) and 13 to 16 years (moment 2), 23 being nose breathers (NB) and 17 being predominantly mouth breathers (MB).ResultsThe Student’s-t test and two-way ANOVA with repeated measures were applied to indicate differences between the mean values of these variables according to the moments and/or respiratory mode.ConclusionsThere were alterations in the facial measurements, without interference of the breathing pattern. However, the breathing pattern influenced dental alterations.

Heat and moisture exchange capacity of the upper respiratory tract and the effect of tracheotomy breathing on endotracheal climate

The aim of this study was to assess the heat and moisture exchange (HME) capacity of the upper respiratory tract and the effect of tracheotomy breathing on endotracheal climate in patients with head and neck cancer. We plotted the subglottic temperature and humidity measurements in 10 patients with head and neck cancer with a temporary precautionary tracheotomy during successive 10-minute periods of nose, mouth, and tracheotomy breathing in a randomized sequence. End-inspiratory temperatures of nose, mouth, and tracheotomy breathing were 31.1, 31.3, and 28.3°C, respectively. End-inspiratory humidity measurements of nose, mouth, and tracheotomy breathing were 29.3, 28.6, and 21.1 mgH₂O/L, respectively. There was a trend toward lower end-inspiratory humidity in patients with radiotherapy or with large surgery-induced oropharyngeal mucosal defects, whereas temperatures were similar. This study gives objective information about the HME capacity of the upper respiratory tract in patients with head and neck cancer with precautionary tracheotomy, and thus provides target values for HMEs for laryngectomized and tracheotomized patients.

Classification of Postural Profiles among Mouth-breathing Children by Learning Vector Quantization

Mouth breathing is a chronic syndrome that may bring about postural changes. Finding characteristic patterns of changes occurring in the complex musculoskeletal system of mouth-breathing children has been a challenge. Learning vector quantization (LVQ) is an artificial neural network model that can be applied for this purpose. The aim of the present study was to apply LVQ to determine the characteristic postural profiles shown by mouth-breathing children, in order to further understand abnormal posture among mouth breathers. Postural training data on 52 children (30 mouth breathers and 22 nose breathers) and postural validation data on 32 children (22 mouth breathers and 10 nose breathers) were used. The performance of LVQ and other classification models was compared in relation to self-organizing maps, back-propagation applied to multilayer perceptrons, Bayesian networks, naive Bayes, J48 decision trees, k, and k-nearest-neighbor classifiers. Classifier accuracy was assessed by means of leave-one-out cross-validation, area under ROC curve (AUC), and inter-rater agreement (Kappa statistics). By using the LVQ model, five postural profiles for mouth-breathing children could be determined. LVQ showed satisfactory results for mouth-breathing and nose-breathing classification: sensitivity and specificity rates of 0.90 and 0.95, respectively, when using the training dataset, and 0.95 and 0.90, respectively, when using the validation dataset. The five postural profiles for mouth-breathing children suggested by LVQ were incorporated into application software for classifying the severity of mouth breathers' abnormal posture.

Surgical treatment of nasal septal deviation (septoplasty) in children

The aim of this study was to indicate the importance of surgical treatment of nasal septal deviation in children as early correction of functional and cosmetic nose deformities. In this study, we presented 76 children, from age of 7 to 15, who were surgical treated for the reason of nasal septal deviation starting from January 2001. to December 2009. There were 48 (63%) male and 28 (37%) female patients. The lowest number of patients were between 7 and 9 years old--5 (6.5%), between 10 and 12 years--28 (37%) and 43--(56.5%) between 13 and 15 years. Only 7 (9%) patients indicated genetics inheritance, and 11 of them (14%) could not determine the exact cause of deviation origin. References taken from the parents showed that nasal septal deviation developed like consequence of injury in 58 (76%) cases. We used closed technique of septoplasty with hemitransfictional incision and sub mucosal resection. Deviated portion of septum was completely removed. Patients felt improvement in nose breathing in 65 (85%) cases. The most often complication was nasal obstruction in 6 (8%) cases which occurred due to the insufficient removal of deviated portion. We also had a septal perforation in one and abscess of nasal septum in another case. There were no esthetic deformities.Surgical treatment of nasal septal deviation in children must to be conservative and limited on injured part of septum. After the operation nose breathing significantly improved, without consequences on esthetic appearance or the growth of central part of a face.

The effect of mouth breathing versus nasal breathing on dentofacial and craniofacial development in orthodontic patients

To determine the effect of mouth breathing during childhood on craniofacial and dentofacial development compared to nasal breathing in malocclusion patients treated in the orthodontic clinic. Retrospective study in a tertiary medical center. Clinical variables and cephalometric parameters of 116 pediatric patients who had undergone orthodontic treatment were reviewed. The study group included 55 pediatric patients who suffered from symptoms and signs of nasal obstruction, and the control group included 61 patients who were normal nasal breathers. Mouth breathers demonstrated considerable backward and downward rotation of the mandible, increased overjet, increase in the mandible plane angle, a higher palatal plane, and narrowing of both upper and lower arches at the level of canines and first molars compared to the nasal breathers group. The prevalence of a posterior cross bite was significantly more frequent in the mouth breathers group (49%) than nose breathers (26%), (P = .006). Abnormal lip-to-tongue anterior oral seal was significantly more frequent in the mouth breathers group (56%) than in the nose breathers group (30%) (P = .05). Naso-respiratory obstruction with mouth breathing during critical growth periods in children has a higher tendency for clockwise rotation of the growing mandible, with a disproportionate increase in anterior lower vertical face height and decreased posterior facial height.

Brachyzephalie bei Hund und Katze: eine „menschengemachte” Obstruktion der oberen Atemwege

Selective breeding for exaggerated features caused in many brachycephalic dog and cat breeds virtually a loss of the nose, with serious anatomical and functional consequences. In addition to respiratory and olfactory tasks, in dogs the nose is of vital importance for thermoregulation. As obligatory nose breathers, dogs suffer far more than humans when their nasal ventilation is restricted. An open discussion in the broad public has to motivate authorities and kennel clubs to recognize extreme brachycephalic breeding as seriously affecting animal health and welfare.

Transverse craniofacial dimensions in Angle Class II, Division 1 malocclusion according to breathing mode

The aim of this longitudinal study was to assess the relation between the transverse craniofacial dimensions of subjects with Class II, Division 1 malocclusion and the breathing mode presented by them. Forty Angle Class II, Division 1 malocclusion subjects of both genders participated in the study, 23 of which were predominantly nose breathers and 17 were predominantly mouth breathers. The mean age ranged from 10 years and 9 months to 14 years--Age range 1; and from 13 years and 4 months to 16 years and 6 months--Age range 2. Measurements of six transverse craniofacial dimensions were performed in P-A teleradiographs: Total Sphenoid, Total Zygomatic, Total Nasal Cavity, Total Maxilla, Total Mastoid and Total Antegonion. The transversal craniofacial dimensions were measured and compared in both groups at age ranges 1 and 2. The longitudinal assessment of age ranges 1 and 2 showed that there was no statistically significant influence of the breathing mode on the craniofacial dimensions evaluated, or on the alteration of these dimensions. Breathing mode had no influence on craniofacial development in the sample studied.

Electromyographic evaluation of the upper lip according to the breathing mode: a longitudinal study

The present study aimed at analyzing and comparing longitudinally the EMG (electromyographic activity) of the superior orbicularis oris muscle according to the breathing mode. The sample, 38 adolescents with Angle Class II Division 1 malocclusion with predominantly nose (PNB) or mouth (PMB) breathing, was evaluated at two different periods, with a two-year interval between them. For that purpose, a 16channel electromyography machine was employed, which was properly calibrated in a PC equipped with an analogue-digital converter, with utilization of surface, passive and bipolar electrodes. The RMS data (root mean square) were collected at rest and in 12 movements and normalized according to time and amplitude, by the peak value of EMG, in order to allow comparisons between subjects and between periods. Comparison of the muscle function of PNB and PMB subjects at period 1 (P1), period 2 (P2) and the variation between periods (Delta) did not reveal statistically significant differences between groups (p < 0.05). However, longitudinal evaluation of the muscle function in PNB and PMB subjects demonstrated different evolutions in the percentage of required EMG for accomplishment of the movements investigated. It was possible to conclude that there are differences in the percentage of electric activity of the upper lip with the growth of the subjects according to the breathing mode.