The impact of mouth breathing on dentofacial development: A concise review.

Mouth breathing is one of the most common deleterious oral habits in children. It often results from upper airway obstruction, making the air enter completely or partially through oral cavity. In addition to nasal obstruction caused by various kinds of nasal diseases, the pathological hypertrophy of adenoids and/or tonsils is often the main etiologic factor of mouth breathing in children. Uncorrected mouth breathing can result in abnormal dental and maxillofacial development and affect the health of dentofacial system. Mouth breathers may present various types of growth patterns and malocclusion, depending on the exact etiology of mouth breathing. Furthermore, breathing through the oral cavity can negatively affect oral health, increasing the risk of caries and periodontal diseases. This review aims to provide a summary of recent publications with regard to the impact of mouth breathing on dentofacial development, describe their consistencies and differences, and briefly discuss potential reasons behind inconsistent findings.

Nasal breathing and the vertical dimension: A cephalometric study.

INTRODUCTION: The aim of this work was to perform a cephalometric analysis of the craniofacial parameters and natural head posture of mouth-breathers compared with control subjects, and to study the relationship between nose-breathing and the vertical dimension. MATERIAL AND METHODS: The headfilms taken at start of treatment of 53 cases (28 girls, 25 boys) aged 9 to 30 who consulted the dento-facial orthopedic department of the Ibn Rochd Casablanca dental consultation and treatment center were studied. RESULTS: Among the mouth-breathers, we noted mandibular retrusion (SNB) in association with posterior rotation and more pronounced tilt of the mandibular plane (PP-MP) compared with the controls (P<0.05), a disproportionate increase in anterior face height and a lessening of posterior face height (hyperdivergence). These increases in anterior face height are often associated with retrognathism (and open bite). DISCUSSION AND CONCLUSION: Our study has shown that there are cephalometric differences between mouth-breathers and nose-breathers. There are several studies in the literature with results that support ours. Collaboration between the pediatric dentist, the orthodontist and the ENT specialist is important so as to establish an early diagnosis of mouth-breathing in children and initiate appropriate treatment to recreate the best conditions for harmonious development.

Teste de caminhada de seis minutos em crianças com doença respiratória crônica / Six-minute walk test in children with chronic respiratory disease

Introdução: o teste de caminhada de seis minutos (TC6) é amplamente utilizado para avaliar a capacidade funcional em pediatria por ser de fácil administração e baixo custo. Objetivo: avaliar e comparar o desempenho de crianças saudáveis (GC), com fibrose cística (GFC) e síndrome da respiração oral (GRO) no TC6. Método: estudo transversal comparativo controlado. Realizaram-se dois TC6 (TC61 e TC62) segundo recomendação da American Thoracic Society. Aplicou-se o teste de normalidade de Shapiro-Wilk e, para comparação dos dois TC6 em cada grupo, realizou-se o teste-t pareado e posteriormente Anova post-hoc de Bonferroni para as distâncias percorridas (DPTC6). Resultados: participaram 51 crianças (oito a 12 anos), sendo 17 por grupo. Na comparação das DPTC6, apenas o GFC obteve desempenho inferior ao GC nos dois TC6 (p=0,001). Conclusão: o menor desempenho pelo GFC reforça o TC6 como instrumento sensível na avaliação da capacidade de exercício de crianças com doença pulmonar crônica.

Introduction: the six-minute walk test (6MWT) is widely used to assess functional capacity in children because of its easy administration and low cost. Objective: to evaluate and compare the performance of healthy children (CG), cystic fibrosis (CFG) and syndrome of mouth breathing (MBG) the 6MWT. Method: controlled comparative cross-sectional study. There were two 6MWT (6MWT1 and 6MWT2) as recommended by the American Thoracic Society. The Shapiro-Wilk normality test was used and for comparison of the two 6MWT in each group, there was the paired t-test and ANOVA later post-hoc Bonferroni for the distances (D6MWT). Results: 51 children participated (8 to 12 years), 17 per group. In comparing the D6MWT, only the CFG got underperformed the CG in both 6MWT (p = 0.001). Conclusion: the lowest performance by CFG strengthens the 6MWT as a sensitive instrument for assessing exercise capacity of children with chronic lung disease.

Cephalometric Evaluation of Children with Allergic Rhinitis and Mouth Breathing.

INTRODUCTION: Orthodontists frequently treat children with mouth breathing. The purpose of the present study was to examine dental positions, skeletal effects and the pharyngeal airway space of children with chronic allergic rhinitis, when compared with a control group exhibiting a normal breathing pattern. MATERIAL AND METHODS: Seventy Caucasian children from Santa Maria University Hospital - North Lisbon Hospital Center were evaluated, between September 2009 and February 2013. The study group comprised of 35 children with chronic allergic rhinitis, both genders, aged 5 - 14, with positive reaction to allergens, mouth breathing and malocclusion. The control group was composed of 35 children, both genders, displaying normal nasal breathing and malocclusion, who resorted to the orthodontic department. Measures of Ricketts, Steiner and McNamara's analysis were used and the t- Student test was applied to the data obtained. RESULTS: Statistically significant differences were observed between the oral and nasal breathers, respectively: lower facial height (49.1/45.9 mm), Frankfurt â mandibular plane angle (30.1/26.9º) and Sela-Nasion - oclusal plane angle (17.3/15º), maxillary length (78.4/82.4 mm), mandibular length (102.4/107 mm), overbite (0.8/3.1mm) and overjet (4/4.7 mm). DISCUSSION: Comparison between the allergic rhinitis and control group showed that there is an increased lower facial height, larger Frankfurt â mandibular plane angle and Sela-Nasion oclusal plane angle in children with chronic allergic rhinitis. This group also had a shorter maxillary and mandibular length, less overbite and decreased upper airway space. CONCLUSIONS: Children with allergic rhinitis and mouth breathing have longer faces, shorter maxillas and mandibles and a narrowed pharyngeal airway space. No statistical differences between the groups in sagital relationships or in dental inclinations were found.

Introdução: Os ortodontistas tratam frequentemente crianças com respiração oral. O objectivo deste estudo foi avaliar as posições dentárias, efeitos esqueléticos e espaço aéreo da faringe, causados pela respiração bucal em crianças com rinite alérgica crónica, comparando com grupo de controlo de padrão respiratório normal.Material e Métodos: Foram avaliadas setenta crianças caucasianas do Hospital Universitário de Santa Maria (Lisboa), entre Setembro/ 2009 e Fevereiro/2013. O grupo de estudo compreendia 35 crianças com rinite alérgica crónica de ambos os géneros, idades entre 5 e 14 anos, reação positiva a aeroalergénios, respiração bucal e má-oclusão dentária. O grupo controlo incluiu 35 crianças, da mesma idade, ambos os géneros, com respiração nasal e má-oclusão dentária, que recorreram ao departamento de ortodontia. Utilizaram-semedidas de Ricketts, Steiner e análise de McNamara. Foi aplicado teste estatístico t de Student.Resultados: Verificaram-se diferenças estatísticas significativas entre respiradores orais e nasais, respectivamente quanto à altura facial inferior (49,1/45,9 mm), ângulo entre o plano de Frankfurt e o plano mandibular (30,1/26,9º), ângulo entre a linha Sela-Nasion e o plano oclusal (17,3/15º), comprimento maxilar (78,4/82,4 mm) e mandibular (102,4/107 mm), overbite (0,8/3,1mm) e overjet (4/4,7 mm).Discussão: A comparação entre os grupos demonstrou que as crianças com rinite alérgica e respiração oral apresentam maior altura facial inferior, maior ângulo entre o plano de Frankfurt e o plano mandibular e maior ângulo entre a linha Sela-Nasion e o plano oclusal. Este grupo apresentou também menor comprimento da maxila e da mandíbula, menor overbite e diminuição do espaço aéreo respiratório superior.Conclusões: As crianças com rinite alérgica e respiração oral têm faces mais longas, maxilas e mandíbulas mais curtas e espaço aéreo faríngeo menor. Não existem diferenças estatísticas significativas entre grupos nas bases ósseas (plano sagital) ou inclinações dentárias.

[The influence of breathing mode on the oral cavity]. / Wplyw toru oddechowego na jame ustna.

Nose breathing is one of the key factors in the proper development and functioning of the oral cavity. The air passing through the nasal cavity is warmed and humidified while dust and other particulate matter is removed. It is also important as far as bone formation is concerned. The obstruction or congestions of the upper respiratory tract may negatively affect the correct and most optimal (nasal) respiratory tract. The switch from nasal to mouth breathing may lead to serious clinical consequences. Children with the clinical diagnosis of mouth breathing are usually pale, apathetic and they lack concentration and often get tired. Disorders resulting from hypoxy may also be the reason from sleep disturbances, such as frequent waking-up, nocturia, difficulties falling aslee. The main clinical manifestations of mouth breathing appear in the craniofacial structures. Mouth breathers frequently suffer from dental malocclusions and craniofacial bone abnormalities. Chronic muscle tension around the oral cavity could result in the widening of cranio-vertebral angle, posterior position of mandibula and narrow maxillary arch. Among dental alterations the most common are class II malocclusion (total or partial) with the protrusion of the anterior teeth, cross bite (unilateral or bilateral), anterior open bite and primary crowded teeth. Apart from malocclusion, chronic gingivitis, periodontitis, candida infections and halitosis are frequently present in mouth--breathing patients.

Adenotonsillar hypertrophy as a risk factor of dentofacial abnormality in Korean children.

No studies for the role of adenotonsillar hypertrophy in development of dentofacial abnormalities have been performed in Asian pediatric population. Thus, we aimed to investigate the relationship between adenotonsillar hypertrophy and dentofacial abnormalities in Korean children. The present study included consecutive children who visited a pediatric clinic for sleep-disordered breathing due to habitual mouth breathing, snoring or sleep apnea. Their palatine tonsils and adenoids were graded by oropharyngeal endoscopy and lateral cephalometry. Anterior open bite, posterior crossbite, and Angle's class malocclusions were evaluated for dentofacial abnormality. The receiver-operating characteristic curve analysis was used to identify age cutoffs to predict dentofacial abnormality. A total of 1,083 children were included. The presence of adenotonsillar hypertrophy was significantly correlated with the prevalence of dentofacial abnormality [adjusted odds ratio = 4.587, 95% CI (2.747-7.658)] after adjusting age, sex, body mass index, allergy, and Korean version of obstructive sleep apnea-18 score. The cutoff age associated with dentofacial abnormality was 5.5 years (sensitivity = 75.5%, specificity = 67%) in the children with adenotonsillar hypertrophy and 6.5 years (sensitivity = 70.6%, specificity = 57%) in those without adenotonsillar hypertrophy. In conclusion, adenotonsillar hypertrophy may be a risk factor for dentofacial abnormalities in Korean children and early surgical intervention could be considered with regards to dentofacial abnormality.

Palatal surface and volume in mouth-breathing subjects evaluated with three-dimensional analysis of digital dental casts-a controlled study.

OBJECTIVE: To compare the anatomical characteristics of the maxillary arch, identified as palatal surface area and volume, between mouth-breathing and nose-breathing subjects using a three-dimensional (3D) analysis of digital dental casts. METHODS: Twenty-one Caucasian subjects (14 females and 7 males) with a mean age of 8.5 years [standard deviation (SD) 1.6 years] were selected according to the following criteria: mouth-breathing pattern due to allergic rhinitis, early mixed dentition, skeletal Class I relationship, and pre-pubertal stage of cervical vertebral maturation. This study group (SG) was compared with a control group (CG) of 17 nose-breathing subjects (9 females and 8 males, mean age: 8.5 years; SD: 1.7 years). For each subject, initial dental casts were taken and the upper arch was scanned using a 3D laser scanner. On each digital model, 3D measurements were performed to analyse maxillary arch morphology. Between-group differences were tested with the independent sample Student's t-test (P < 0.05). RESULTS: In mouth-breathing subjects, changes in physiological function of the upper respiratory tract resulted in skeletal adaptations of the maxillary arch. In the SG, both palatal surface area and volume were significantly smaller when compared with values of the CG. In particular, the palatal surface area and palatal volume were, respectively, 13.5 and 27.1 per cent smaller in the SG when compared to the CG. CONCLUSIONS: Subjects with prolonged mouth breathing showed a significant reduction of the palatal surface area and volume leading to a different development of the palatal morphology when compared with subjects with normal breathing pattern.

Dental arch dimensional changes after adenotonsillectomy in prepubertal children.

INTRODUCTION: The purposes of this study were to investigate the dental arch changes after adenotonsillectomies in prepubertal children and to compare the dental arch dimensions of mouth-breathing and nasal-breathing children. METHODS: The sample included 49 prepubertal severely obstructed mouth-breathing children and 46 prepubertal nasal-breathing children. Twenty-four of the 49 mouth-breathing children had an adenotonsillectomy and composed the adenotonsillectomy subgroup. The 25 children in whom the mouth-breathing pattern was unchanged during the 1-year study period composed the control subgroup. RESULTS: The mouth-breathing children showed a deeper palatal vault, a larger mandibular width, and a larger mandibular arch length in comparison with the nasal-breathing children. After airway clearance, the adenotonsillectomy group showed a significant maxillary transverse width gain compared with the control subgroup. The control subgroup showed a significant deepening of the palatal height when compared with the adenotonsillectomy subgroup after 1 year. CONCLUSIONS: The adenotonsillectomy subgroup had a significantly different pattern of arch development compared with the untreated controls. After adenotonsillectomy, the mouth-breathing children showed greater maxillary transverse development than did the controls. The palatal vault deepened in the untreated children. The mouth-breathing children showed a deeper palatal vault, a larger mandibular width, and a larger mandibular arch length in comparison with the nasal-breathing children.

Comparision of orofacial airway dimensions in subject with different breathing pattern.

OBJECTIVE: To test the null hypothesis that there is no significant difference in the craniofacial morphology and orofacial airway dimensions between mouth breathing (MB) and nasal breathing (NB) subjects. MATERIALS AND METHODS: Lateral cephalometric radiographs of 34 MB subjects (mean age: 12.8±1.5 years; range: 12.0-15.2 years) and 33 NB subjects (mean 13.9±1.3 years; age range: 12.2-15.8 years) with Class I occlusion were examined. Totally, 34 measurements (27 craniofacial and 7 orofacial airway) were evaluated. Group differences were statistically evaluated by independent samples t-test at p<0.05 levels. RESULTS: Statistical comparisons showed that SNA (p<0.01), ANB (p<0.01), A to N perp (p<0.05), convexity (p<0.05), IMPA (p<0.05) and overbite (p<0.05) measurements were significantly lower in MB group when compared to NB group. However, SN-MP (p<0.01) and PP-GoGn (p<0.01) from angular measurements and S-N (p<0.05) and anterior facial height (p<0.05) from linear measurements were significantly higher in MB subjects. Among orofacial airway measurements, only upper posterior airway space was found significantly higher(p<0.001) in MB than NB subjects. CONCLUSIONS: The null hypothesis was rejected. Mouth breathing affects craniofacial morphology and orofacial airway dimensions.

Influence of adenotonsillectomy on hard palate dimensions.

OBJECTIVE: To evaluate hard palate width and height in mouth-breathing children pre- and post-adenotonsillectomy. METHODS: We evaluated 44 children in the 3-6 year age bracket, using dental study casts in order to determine palatal height, intercanine width, and intermolar width. The children were divided into two groups: nasal breathing (n=15) and mouth breathing (n=29). The children in the latter group underwent adenotonsillectomy. The study casts were obtained prior to adenotonsillectomy, designated time point 1 (T1), at 13 months after adenotonsillectomy (T2), and at 28 months after adenotonsillectomy (T3). Similar periods of observation were obtained for nasal breathing children. RESULTS: At T1, there was a significantly lower intercanine width in mouth breathing children; intermolar width and palate height were similar between groups. After surgery, there was a significant increase in all the analyzed parameters in both groups, probably due to facial growth. Instead, the increase in intercanine width was substantially more prominent in mouth breathing children than in nasal breathing children, and the former difference failed in significance after the procedure. CONCLUSIONS: There were no significant differences between the nasal-breathing and mouth-breathing children in terms of intermolar width and palatal height prior to or after tonsillectomy. Although intercanine width was initially narrower in the mouth-breathing children, it showed normalization after the surgical procedure. These results confirm that the restoration of nasal breathing is central to proper occlusal development.

Maternal breastfeeding, parafunctional oral habits and malocclusion in adolescents: a multivariate analysis.

OBJECTIVE: Malocclusion may result in esthetic impairment and functional disorders such as bad chewing, speech and swallowing, with a negative impact on quality of life. There is uncertainty regarding the effects of breastfeeding on dentofacial malocclusions. The purpose of the study was to evaluate the relationship between maternal breastfeeding and dental malocclusions and facial characteristics in adolescents with permanent dentition. METHODS: Probabilistic sampling of 2060 12- to 15-year-old students in a cross-sectional study was used. Malocclusion, as defined by Angle, and facial characteristics were the dependent variables. The duration of breastfeeding was the main independent variable. Other covariates were tested as effect modifiers or confounders. The associations were estimated using the odds ratio (OR) in multinomial logistic regression analysis (α=5%). RESULTS: There was an association between a short duration of breastfeeding (less than 6 months) and Angle class II (OR=3.14; 95% CI: 1.28-7.66) and class III (OR=2.78; 95% CI: 1.21-6.36) malocclusion only in students with a prolonged history of bruxism. A higher occurrence of severe convex profile (OR=3.4; 95% CI: 0.63-18.26) and a lower occurrence of cancave profile (OR=0.43; 95% CI: 0.21-0.88) were also observed only among adolescents who had been breastfed for a short period and exposed to a long periods of mouth breathing. CONCLUSIONS: These findings support the hypothesis that breastfeeding alone seems not to be directly associated with malocclusions, but it may have a synergetic effect with parafunctional oral habits on the development of occlusofacial problems. It is recommended that deleterious oral habits be avoided, especially by children who were breast-fed for less than 6 months.

Cephalometric evaluation of oropharyngeal airway dimension changes in pre- and postadenoidectomy cases.

AIM: The aim is to compare and evaluate the airway dimension changes, adenoidal nasopharyngeal ratio (ANR), airway area and airway percentage in patients in pre- and postadenoidectomy with normal individuals. MATERIALS AND METHODS: After obtaining informed consent, a sample of 15 patients (eight males and seven females) of 7 to 12 years were selected for adenoidectomy by an otolaryngologist, lateral cephalograms were taken in natural head position before adenoidectomy and after 1 month postadenoidectomy. Statastical analysis was done to evaluate the results using Statastical Package for Social Sciences. Results showed airway (P1, P2, P3, P4), airway percentage, airway area showed significant increase (p < 0.0001), whereas ANR showed significant reduction after 1 month postadenoidectomy. CONCLUSION: One month postadenoidectomy showed increased airway area, airway percentage and reduced ANR. CLINICAL SIGNIFICANCE: Obstructive mouth breathing due to adenoids in growing children can cause alteration in craniofacial morphology leading to adenoid facies, adenoidectomy procedure helps in alleviating the obstruction and facilitates the normal growth of craniofacial complex.

Dimensões do palato duro de respiradores nasais e orais por diferentes etiologias / Hard palate dimensions in nasal and mouth breathers from different etiologies

OBJETIVO: Comparar as dimensões do palato duro de crianças respiradoras nasais, respiradoras orais por etiologia obstrutiva e respiradoras orais por etiologia viciosa. MÉTODOS: A amostra foi composta por 76 crianças, 37 meninos e 39 meninas, com média de idade de 9,32±1,16 anos, distribuídas conforme diagnóstico do modo respiratório e etiologia da respiração oral. Foram obtidos modelos em gesso do arco dental maxilar para a realização de medidas do palato duro com paquímetro digital. Foram obtidas as medidas transversais, verticais e do comprimento anteroposterior do palato duro. A comparação das medidas do palato duro entre os grupos foi realizada por meio de testes estatísticos. RESULTADOS: Na comparação das dimensões do palato duro entre os grupos de respiradores nasais e respiradores orais, verificou-se diferença na distância e profundidade ao nível dos segundos pré-molares e na distância entre os primeiros molares. Também foi verificada diferença entre os grupos de respiradores orais por etiologia obstrutiva e por etiologia viciosa na profundidade do palato duro ao nível dos caninos. CONCLUSÃO: Respiradores orais apresentam palato duro mais estreito ao nível dos segundos pré-molares e primeiros molares, e mais profundo ao nível dos segundos pré-molares quando comparados aos respiradores nasais. Evidencia-se também que os respiradores orais por etiologia viciosa apresentam maior profundidade do palato duro ao nível dos caninos quando comparados aos respiradores orais por etiologia obstrutiva.

PURPOSE: To compare the hard palate dimensions of nasal-breathing children, mouth breathers from obstructive etiology, and habitual mouth breathers. METHODS: The sample comprised 76 children, 37 boys and 39 girls, with mean age of 9.32±1.16 years, distributed according to the diagnosis of breathing mode and to the etiology of mouth breathing. Plaster cast models of the subjects' superior dental arch were obtained in order to measure the hard palate with a digital caliper. Measurements of transverse, vertical and anteroposterior palatal length were taken. The hard palate measures were compared among the groups through statistical analysis. RESULTS: The comparison of hard palate dimensions observed in nasal and mouth breathers showed differences regarding the distance and depth of second premolars, and the distance of first molars. Differences were also found between the groups of mouth breathers regarding the hard palate depth at the level of canines. CONCLUSION: Mouth breathers showed narrower hard palate at the level of second premolars and first molars, and deeper palate in the level of second premolars, when compared to nasal breathers. It is evidenced that habitual mouth breathers presented deeper hard palate at the level of canines, when compared to mouth breathers from obstructive etiology.

Changes in facial morphology after adenotonsillectomy in mouth-breathing children.

BACKGROUND: Morphological and dentofacial alterations have been attributed to impaired respiratory function. OBJECTIVE: To examine the influence of mouth breathing (MB) on children facial morphology before and after adenoidectomy or adenotonsillectomy. METHODS: Thirty-three MB children who restored nasal breathing (NB) after surgery and 22 NB children were evaluated. Both groups were submitted to lateral cephalometry, at time 1 (T1) before and at time 2 (T2) 28 months on average postoperatively. RESULTS: Comparison between the MB and NB groups at T1 showed that mouth breathers had higher inclination of the mandibular plane; more obtuse gonial angle; dolichofacial morphology; and a decrease in the total and inferior posterior facial heights. Twenty-eight months after the MB surgical intervention, they still presented a dolichofacial morphologic pattern. During this period, MB altered the face growth direction and decreased their mandible plane inclination, with reduction in the SN.GoGn, PP.MP, SNGn, and ArGo.GoMe parameters as well as an increase in BaN.PtGn. CONCLUSION: After the MB rehabilitation, children between 3 and 6 years old presented significant normalization in the mandibular growth direction, a decrease in the mandible inclination, and an increase in the posterior facial height. Instead, they still persisted with a dolichofacial pattern when compared with nasal breathers.

Ventilatory disorders and facial growth: benefits of early genioplasty.

AIM: The purpose of this prospective study was to determine whether combined functional genioplasty and orthodontic treatment in patients with vertical mandibular growth can be beneficial not only in achieving an esthetic outcome and orthodontic stability but also for the multi-disciplinary management of oral ventilation. METHODS: Twenty-five non-obese adolescents (mean age: 14.6 ± 1.4 years) with vertical excess of the lower third requiring genioplasty received surgery following orthodontic treatment. All were predominantly mouth-breathers despite ENT treatment and rehabilitation. The functional before-after impact of genioplasty was examined in a clinical setting using polysomnography. RESULTS: Before genioplasty, 52% of the adolescents presented an upper airways resistance syndrome (UARS) with obstructive hypopnea and poor sleep quality. Three to 6 months after genioplasty, the mode of ventilation shifted from oral to nasal (p < 0.001). Lip seal was significantly restored with no contraction of the labio-mental muscles. All nighttime symptoms improved. The proportion of patients suffering from ronchopathy (pathological snoring), dry mouth and disturbed sleep dropped significantly (p = 0.08, p = 0.001, p = 0.0009, respectively). Respiratory events and sleep pattern became normal. Below, we present two clinical reports involving obstructive sleep apnea syndrome (OSAS). CONCLUSIONS: Genioplasty performed during puberty promotes spontaneous lip closure and helps restore nasal ventilation. It improves the obstructive disorder and its manifestations during sleep.

Classification of postural profiles among mouth-breathing children by learning vector quantization.

BACKGROUND: 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. OBJECTIVES: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

Hard palate dimensions in nasal and mouth breathers from different etiologies.

PURPOSE: To compare the hard palate dimensions of nasal-breathing children, mouth breathers from obstructive etiology, and habitual mouth breathers. METHODS: The sample comprised 76 children, 37 boys and 39 girls, with mean age of 9.32±1.16 years, distributed according to the diagnosis of breathing mode and to the etiology of mouth breathing. Plaster cast models of the subjects' superior dental arch were obtained in order to measure the hard palate with a digital caliper. Measurements of transverse, vertical and anteroposterior palatal length were taken. The hard palate measures were compared among the groups through statistical analysis. RESULTS: The comparison of hard palate dimensions observed in nasal and mouth breathers showed differences regarding the distance and depth of second premolars, and the distance of first molars. Differences were also found between the groups of mouth breathers regarding the hard palate depth at the level of canines. CONCLUSION: Mouth breathers showed narrower hard palate at the level of second premolars and first molars, and deeper palate in the level of second premolars, when compared to nasal breathers. It is evidenced that habitual mouth breathers presented deeper hard palate at the level of canines, when compared to mouth breathers from obstructive etiology.

Long-term effects of rapid maxillary expansion on nasal area and nasal airway resistance.

BACKGROUND: Rapid maxillary expansion (RME) may improve the nasal respiratory pattern. This study was performed to evaluate the effect of RME on the nasal cavity by acoustic rhinometry and computed rhinomanometry and to determine nasal and maxillary width by posteroanterior cephalometric radiography, up to 30 months after the orthodontic procedure. METHODS: Twenty-seven children with oral breathing, ranging in age from 7 to 10 years, and with mixed dentition were selected. The children had uni- or bilateral posterior crossbite involving deciduous canines and the first permanent molars. All subjects were submitted to nasofibroscopy, acoustic rhinometry, and computed rhinomanometry and posteroanterior cephalometric radiography at four different times, i.e., before expansion, immediately, 90 days and 30 months after expansion. RESULTS: The mean linear left-to-right nasal cavity lateral prominence and left-to-right jugal points cephalometric measures increased considerably after expansion and this increase was maintained throughout the period of evaluation. There was an immediate significant decrease in nasal resistance, up to 90 days after RME, but the nasal resistance increased 30 months after the procedure. The acoustic rhinometry results did not show any difference in values throughout time. CONCLUSION: RME significantly increased nasal and maxillary width as measured by frontal cephalometry, but the nasal mucosal effects were more subtle. Also, the influence of RME on nasal resistance was not stable, and nasal resistance values returned to close to the initial ones after 30 months.

Non-invasive 3D facial analysis and surface electromyography during functional pre-orthodontic therapy: a preliminary report.

OBJECTIVES: Functional orthodontic devices can modify oral function thus permitting more adequate growth processes. The assessment of their effects should include both facial morphology and muscle function. This preliminary study investigated whether a preformed functional orthodontic device could induce variations in facial morphology and function along with correction of oral dysfunction in a group of orthodontic patients in the mixed and early permanent dentitions. MATERIAL AND METHODS: The three-dimensional coordinates of 50 facial landmarks (forehead, eyes, nose, cheeks, mouth, jaw and ears) were collected in 10 orthodontic male patients aged 8-13 years, and in 89 healthy reference boys of the same age. Soft tissue facial angles, distances, and ratios were computed. Surface electromyography of the masseter and temporalis muscles was performed, and standardized symmetry, muscular torque and activity were calculated. Soft-tissue facial modifications were analyzed non-invasively before and after a 6-month treatment with a functional device. Comparisons were made with z-scores and paired Student's t-tests. RESULTS: The 6-month treatment stimulated mandibular growth in the anterior and inferior directions, with significant variations in three-dimensional facial divergence and facial convexity. The modifications were larger in the patients than in reference children. In several occasions, the discrepancies relative to the norm became not significant after treatment. No significant variations in standardized muscular activity were found. CONCLUSIONS: Preliminary results showed that the continuous and correct use of the functional device induced measurable intraoral (dental arches) and extraoral (face) morphological modifications. The device did not modify the functional equilibrium of the masticatory muscles.