Abstract This study aimed to evaluate the effects of chronic use of fluoxetine on the amount of orthodontic tooth movement and tissue changes in rats. A total of 192 Wistar rats were divided into 4 groups: S, 0.9% saline solution; F, 20 mg/kg of fluoxetine; SM, 0.9% saline solution with orthodontic movement; and FM, 20 mg/kg of fluoxetine with orthodontic movement. After 30 days of daily saline or fluoxetine administration, an orthodontic device (25cN) was used to mesially displace the first molar in animals of the groups SM and FM. The animals were euthanized 2, 7, 14, and 28 days after placement of the orthodontic appliances and animals of groups S and F were euthanized at the same time. The assessment of tooth movement was made in gypsum castings, the collagen neoformation was assessed by polarization microscopy, the number of osteoclasts and root resorption were evaluated using tartrate-resistant acid phosphatase, and presence of hyalinized areas was assessed by hematoxylin-eosin staining. Fluoxetine did not affect the amount of tooth displacement, percentage of collagen, number of osteoclasts, and presence of hyalinized areas (P>0.05). There was a higher frequency of root resorption areas in the FM group than in the SM group only on the second day (P<0.05). The findings of this study show that chronic use of 20 mg/kg fluoxetine does not affect the amount of tooth movement, collagen neoformation, number of osteoclasts, or hyalinized areas and does not affect root resorption until the last day of orthodontic movement.

ABSTRACT Purpose: to map, through a literature survey, which instruments are used to assess swallowing in patients after orotracheal extubation. Methods: available evidence was mapped through six electronic databases and gray literature. There were no restrictions regarding gender, ethnicity of the individuals, language of the studies, time of publication, and diagnosis. Results: the most mentioned protocol in the studies was the Dysphagia Risk Evaluation Protocol and the most cited objective assessment exam was the flexible endoscopic evaluation of swallowing. Conclusion: there is a need for a specific protocol to evaluate this profile of patients, in addition to comparative studies of subjective clinical evaluation and instrumental imaging.

ABSTRACT Objective: This systematic review aims to answer the following focus question: “Is there an association between atypical swallowing and malocclusions?”. Methods: Appropriate word combinations were chosen and tailored specifically for each of the following electronic databases: EMBASE, Latin American and Caribbean Literature in Health Sciences (LILACS), LIVIVO, PubMed/Medline, Scopus, Web of Science, and gray literature, without any restrictions, up to February 2021. According to the selection criteria, only cross-sectional studies were included. The following inclusion criteria were considered: a sample composed of children, adolescents, and adults; patients clinically diagnosed with atypical swallowing; patients with normal swallowing; and outcome of interest of atypical swallowing in patients with malocclusion. The data consisted of study characteristics, sample characteristics, results, and conclusion of each study. The risk of bias was assessed using the JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies, and the certainty of evidence was assessed using the GRADE tool. Results: 4,750 articles were identified. After a two-step selection, four studies were included. A higher frequency of distal occlusion, extreme maxillary overhang, and open bite was related to swallowing disorders; most studies pointed to posterior crossbite as a malocclusion more associated with atypical swallowing. All studies had a moderate to high risk of bias, and the certainty of evidence was very low. Conclusion: The results indicate that atypical swallowing is associated with malocclusions and that posterior crossbite is the main malocclusion found, but only in the young population (3-11 years). Registration: PROSPERO (42020215203).

RESUMO Objetivo: A presente revisão sistemática tem como objetivo responder à seguinte questão focal: “Existe associação entre deglutição atípica e más oclusões?”. Métodos: Combinações de palavras e truncamentos apropriados foram adaptados para as bases de dados eletrônicas: EMBASE, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), LIVIVO, PubMed/Medline, Scopus e Web of Science e a literatura cinzenta, sem qualquer restrição, até fevereiro de 2021. Os critérios de inclusão foram: estudos transversais; amostra composta por crianças, adolescentes e adultos; pacientes com diagnóstico clínico de deglutição atípica; pacientes com deglutição normal, e o desfecho de interesse foi deglutição atípica em pacientes com má oclusão. Os dados extraídos de cada estudo foram características do estudo, da amostra e a conclusão. O risco de viés foi avaliado usando a Lista de verificação de avaliação crítica da JBI para estudos transversais analíticos, e a certeza das evidências foi avaliada usando a ferramenta GRADE. Resultados: Foram identificados 4.750 artigos. Após uma seleção em duas fases, quatro estudos foram incluídos. Maior frequência de disto-oclusão, protuberância maxilar extrema e mordida aberta foram relacionadas a distúrbios da deglutição, com a maioria dos estudos apontando para mordida cruzada posterior como a má oclusão mais associada à deglutição atípica. Todos os estudos tiveram um risco de viés moderado a alto, e a certeza das evidências foi considerada muito baixa. Conclusão: Os resultados indicam que a deglutição atípica está associada à mordida cruzada posterior apenas na população jovem de 3 a 11 anos.

Resumo Introdução Alguns fatores, como a presença de saliva, são capazes de influenciar a adesão do braquete ao dente durante o procedimento de colagem e podem causar falha da resistência adesiva. Objetivo O objetivo deste estudo foi avaliar a resistência ao cisalhamento de braquetes cerâmicos ortodônticos colados com Transbond XT e Transbond Plus Color Change em esmalte de dentes bovinos, contaminado e não contaminado por saliva, além de analisar o local da falha adesiva. Material e método Sessenta incisivos bovinos foram divididos aleatoriamente em quatro grupos (n=15), de acordo com o material de colagem e a presença de contaminação: Grupo 1 (G1): colagem com Transbond XT na ausência de contaminação; Grupo 2 (G2): colagem com Self Etching Pimer e Transbond Color Change na ausência de contaminação; Grupo 3 (G3): colagem com Transbond XT na presença de contaminação, e Grupo 4 (G4): colagem com Self Etching Primer e Transbond Color Change na presença de contaminação. Resultado O teste não paramétrico de Kruskal-Wallis mostrou que G1 diferiu estatisticamente (p<0,05) de G2 e G3. Não houve diferença estatística significativa entre os demais grupos. O índice de adesivo remanescente (IAR) variou entre 2 e 3 no G1 e entre 0 e 1 nos outros grupos. Conclusão A contaminação por saliva diminui a resistência adesiva ao cisalhamento de braquetes cerâmicos colados com a resina hidrofóbica Transbond XT convencional. Por outro lado, a utilização da resina hidrofílica Transbond Plus Color Change associada ao Self Etching Primer, em ambiente contaminado por saliva, confere resistência adesiva adequada para o seu uso clínico.

Abstract Introduction Some fator, such as the presence of saliva, are able to influence the adhesion of the bracket to the tooth enamel during the orthodontic bonding procedure and may cause the adhesive failure. Objective The aim of this study was to evaluate the shear strength of orthodontic ceramic brackets bonded with Transbond XT and Transbond Plus Color Change to bovine teeth, under saliva contamination and the adhesive failure mode. Material and method Sixty bovine permanent incisors were randomly divided into 4 groups (n=15) according to bonding material and saliva contamination: Group 1 (G1) bonded with Transbond XT with no saliva contamination; Group 2 (G2) bonded with Self Etching Primer and Transbond Plus Color Change with no saliva contamination; Group 3 (G3) bonded with Transbond XT with saliva contamination and Group 4 (G4) bonded with Transbond Plus Color Change with saliva contamination. Result The Kruskal-Wallis non-parametric test (p<0,05) was used and showed that G1 differed statistically from G2 and G3. There was no statistical difference between the other groups. The adhesive remnant index (ARI) ranged between 2 and 3 in G1 and between 0 and 1 score in the other groups. Conclusion Saliva contamination decreases the shear bond strength of ceramic brackets bonded with conventional Transbond XT hydrophobic resin. On the other hand, the Transbond Plus Color Change hydrophilic resin associated with a Self Etching Primer, under saliva contamination, provide a sufficient shear bond strength, suitable for their clinical use.

RESUMO Introdução: o tratamento de danos bucomaxilofaciais é complexo e requer diagnóstico abrangente e preciso, além de um correto plano de tratamento. Objetivo: o objetivo deste relato de caso foi descrever o retratamento de uma paciente do sexo feminino, 27 anos de idade, envolvida em acidente automobilístico grave, que resultou na perda de cinco dentes, além de perda óssea alveolar na região anterior. Relato de caso: a paciente apresentava histórico de insucesso de tratamento ortodôntico e cirúrgico. No caso apresentado, o espaço referente aos molares inferiores ausentes foi reaberto, para possibilitar a reabilitação. Houve melhora no posicionamento dos incisivos inferiores. O canino inferior direito foi deslocado para mesial, possibilitando a correção da relação de Classe II intercaninos do mesmo lado. Implantes foram inseridos a fim de substituir os dentes superiores da região anterior. Conclusão: a reabilitação estética e funcional da região anterior, realizada por meio de uma abordagem multidisciplinar, foi fundamental para valorizar a estética facial da paciente, melhorar a função e promover estabilidade oclusal após dois anos de acompanhamento.

ABSTRACT Introduction: Treatment of maxillofacial injuries is complex and requires the establishment of a comprehensive and accurate diagnosis and correct treatment planning. Objective: The objective of this case report was to describe the re-treatment of a 27-year-old woman who was involved in a severe car accident that resulted in the loss of five anterior teeth and alveolar bone, and whose previous orthodontic and surgical treatments had been unsuccessful. Case report: In this case, the space for the missing mandibular molar was reopened to allow for rehabilitation. The positions of the mandibular incisors were improved. The right mandibular canine was moved to the mesial, allowing for correction of the Class II canine relationship on that side, and implants were placed to replace the maxillary anterior teeth. Conclusion: Anterior aesthetic and functional rehabilitation using a multidisciplinary approach was essential to improve the patient’s facial aesthetics, to obtain great improvement in function and to achieve occlusal stability after 2 years of follow-up.

Abstract The aim of this study was to evaluate the effect of acute administration of nicotine and ethanol on tooth movement in rats. Two hundred rats were divided into eight groups: S: saline; N: nicotine; E: ethanol; NE: nicotine and ethanol; SM: saline with tooth movement; NM: nicotine with tooth movement; EM: ethanol with tooth movement; and NEM: nicotine and ethanol with tooth movement. All the solutions were applied for 32, 44, or 58 days, according to the subgroup. Orthodontic movement (25 cN) was initiated 30 days after solution administration in the groups with tooth movement. The rats were euthanized 2, 14, or 28 days after initiation of tooth movement. Tooth sections were stained using picrosirius and tartrate-resistant acid phosphatase (TRAP). The data were compared by ANOVA using Tukey’s HSD and Games-Howell. On day 28 of tooth movement, the NEM group had a lower percentage of type I collagen compared to the SM group (p = 0.0448), and the S group had a higher number of osteoclasts/μm2 compared to the N group (p = 0.0405). Nicotine and ethanol did not affect the tooth movement rate, regardless of induction of orthodontic movement. Nicotine influenced the number of osteoclasts by decreasing their quantity when dental movement was not induced. When nicotine was associated with ethanol, it interfered in the maturation of collagen fibers during orthodontic movement.

Resumo Este estudo avaliou a interação do movimento dentário entre dois esteróides anabólicos androgênicos (EAA), Deposteron® and Nebido®. Cem ratos Wistar foram divididos em 3 grupos: controle (C) n=30, Nebido experimental (N) n=35 e Deposteron experimental (D) n=35. O grupo controle foi subdivido em 6 subgrupos: 1, 2, 3, 5, 7 e 14. Os grupos experimentais foram subdivididos em 7 subgrupos: 0, 1, 2, 3, 5, 7 e 14, correspondendo ao dia da eutanásia do animal após aplicada a força ortodôntica. Um dispositivo ortodôntico foi utilizado para induzir a movimentação dentária com força recíproca de 50 cN entre o primeiro molar superior direito e os incisivos superiores. Após a eutanásia, o tecido foi processado e corado com hematoxilina e eosina (HE) e fosfatase ácida tartarato-resistente (TRAP). Osteoclastos, lacunas de Howship e vasos sanguíneos foram quantificados. Os grupos N e D demonstraram aceleração na reorganização do ligamento periodontal comparado ao grupo C. O pico dos eventos histológicos ocorreu no grupo C no dia 5 e nos grupos N e D no dia 3, após a instalação do dispositivo ortodôntico. Houve diferença estatisticamente significante no número de osteoclastos (p<0,05) entre os grupos N3 e C3 e entre os grupos N3 e D3. Doses supra-fisiológicas de EAA Nebido® and Deposteron® alteraram o número de osteoclastos, lacunas de Howship e vasos sanguíneos, acelerando a reorganização do ligamento periodontal, resultando na aceleração dos efeitos biológicos na movimentação dentária em ratos.

Abstract This study evaluated the interaction between tooth movement and two anabolic androgenic steroids (AAS), Deposteron® and Nebido®. One hundred Wistar rats were divided into 3 groups: control (C) n=30, Nebido experimental (N) n=35 and Deposteron experimental (D) n=35. The control group was subdivided into 6 subgroups: 1, 2, 3, 5, 7 and 14. The experimental groups were subdivided into 7 subgroups: 0, 1, 2, 3, 5, 7 and 14, which corresponded to the day of animal’s euthanasia after applying orthodontic force. Orthodontic devices were used to induce tooth movement using 50 cN of reciprocal force between the maxillary right first molar and the maxillary incisors. After euthanasia, the tissues were processed and stained with hematoxylin and eosin (HE) and tartrate-resistant acid phosphatase (TRAP). Osteoclasts, Howship’s lacunae and blood vessels were quantified. Groups N and D showed acceleration in the reorganization of the periodontal ligament compared to group C. The peak of the histological events occurred in group C on day 5 and in groups N and D on day 3 after installation of the orthodontic device. There was a statistically significant difference in the number of osteoclasts (p<0.05) between groups N3 and C3, and between groups N3 and D3. Supra-physiological doses of the AAS Nebido® and Deposteron® altered the number of osteoclasts, Howship’s lacunae and blood vessels, accelerating the reorganization of the periodontal ligament, resulting in accelerated biological effects from the induced tooth movement in rats.

Resumo A proposta deste estudo foi avaliar os efeitos da administração do ácido zoledrônico (ZA) durante a movimentação ortodôntica em ratos. Cento e vinte ratos Wistar, machos, foram submetidos a aplicação de uma força de 30 cN através de uma mola fechada de níquel-titânio para mover o primeiro molar superior direito para mesial. No grupo Controle Movimentação (CM), apenas a movimentação dentária foi realizada; o grupo Controle Ácido Zoledrônico (CAZ) recebeu uma única dose (0,1 mg/kg) de ZA; o grupo Experimental Ácido Zoledrônico (EAZ) recebeu uma única dose (0,1 mg/Kg) uma semana antes do início da movimentação dentária; e o grupo Controle Sem Movimentação (CWM) não receberam nenhum tipo de droga e não foi realizado movimentação dentária. Os animais foram eutanásiados após 3, 7 e 14 dias. A movimentação dentária foi mensurada através de um paquímetro, o número de osteoclastos utilizando coloração TRAP, a expressão do colágeno maturo e imaturo através da coloração Picrosírius, e a presença de áreas hialinas e reabsorção radicular utilizando HE. Os dados foram comparados utilizando ANOVA a dois critérios, Tukey HSD, Games-Howell e teste de qui-quadrado, ao nível de significância de 5%. Verificou-se menor número de osteoclastos e maior porcentagem de área hialina no grupo EAZ. Não houve diferença entre grupos quanto à neoformação óssea, reabsorção radicular e movimentação dentária em todos os tempos observados.

Abstract The purpose of this study was to assess the effects of the administration of zoledronic acid (ZA) during orthodontic movement in rats. A hundred and twenty male Wistar rats were applied force of 30 cN with spring closed nickel-titanium to move the upper right first molar to mesial. In the Control Movement group (CM), only tooth movement was performed; the Control Acid Zoledronic group (CAZ) received a single dose (0.1 mg/kg) of ZA; the Experimental Acid Zoledronic group (EAZ) received a single dose (0.1 mg/kg) one week prior to the start of tooth movement; and the Control Without movement group (CWM) that received no drug and without application of tooth movement. The animals were euthanized after 3, 7 and 14 days. Tooth movement was measured using a caliper, the number of osteoclasts using TRAP staining, the expression of mature and immature collagen using picrosirius staining, and the presence of hyaline areas and root resorption using HE. The data were compared using two-way ANOVA, Tukey HSD, Games-Howell and chi-squared test, at the 5% significance level. It was observed a smaller number of osteoclasts and greater percentage of hyaline area in the EAZ group. There was no difference among the groups regarding bone remodeling, root resorption and tooth movement for all observed times.

Objective: The aim of this study was to evaluate in vitro the effects of frequently ingested beverages on force degradation of intermaxillary elastics. Material and Methods: One hundred and eighty 1/4-inch intermaxillary elastics (TP Orthodontics) were immersed into six different beverages: (1) Coca-Cola®; (2) Beer; (3) Orange juice; (4) Red wine; (5) Coffee and (6) artificial saliva (control). The period of immersion was 15 min for the first and second cycles and 30 min for the third to fifth cycles. Tensile forces were read in a tensile testing machine before and after the five immersion cycles. One-way repeated measures ANOVA was used to identify significant differences. Results: Force degradation was seen in all evaluated groups and at all observation periods (p<0.05). A greater degree of degradation was present at the initial periods, decreasing gradually over time. However, no statistically significant differences were seen among groups at the same periods, showing that different groups behaved similarly. Conclusions: The chemical nature of the evaluated beverages was not able to influence the degree of force degradation at all observation periods.

OBJECTIVE: This work aimed at assessing the bond strength (AS), the site of the flaw and the relation between them and Ortho Primer Morelli® (OPM) adhesion optimizer. METHODS: Sixty test specimens, made out of bovine permanent lower incisors, were divided into three groups: TXT Primer (control), in which a conventional adhesive system was applied (primer and paste); OPM, in which TXT primer was replaced by OPM; and TXT without Primer, in which only TXT paste was used. A shear force was applied at a speed of 0,5 mm/min. Failure site was assessed by the Remaining Adhesion Index (RAI). RESULTS: Kruskal-Wallis demonstrated that OPM (8.54 ± 1.86 MPa) presented a statistically higher AS (p < 0.05) IF compared to TXT Primer (6.83 ± 2.05 MPa). There was no statistically significant difference (p > 0.05) between TXT with or without Primer (6.42 ± 2.12 MPa). Regarding the RAI, the K test demonstrated that TXT Primer and OPM (prevailing scores 2 and 3) showed higher values (p < 0.05) IF compared to TXT without Primer (prevailing scores 0 and 1). Spearman demonstrated that there was no correlation between AS and RAI (p > 0.05). CONCLUSION: OPM increases AS and presents the same bond failure location if compared to a conventional adhesive system; the use of the TXT adhesive system paste only was shown to have the same AS if compared to conventional systems, except it does not allow to predict the adhesive failure site; there is no correlation between AS and bond failure location, regardless of the use of any adhesion optimizer.

OBJECTIVE: The aim of this study was to assess the impact of blood contamination on shear bond strength (SBS) and bond failure pattern of metallic brackets bonded using a new hydrophilic resin. MATERIAL AND METHODS: Eighty human premolars were randomly allocated into 4 groups (n=20) according to the bonding material and contamination pattern. GI: brackets bonded with the Transbond XT conventional system without contamination; GII: brackets bonded with the Transbond XT conventional system with blood contamination; GIII: brackets bonded with the Transbond Self Etching Primer and Transbond Plus Color without contamination; GIV: brackets bonded with the Transbond Self Etching Primer and Transbond Plus Color with blood contamination. The specimens were stored in distilled water at 37°C for 24 h and then submitted to SBS test at a crosshead speed of 0.5 mm/min. After bond failure, the enamel surfaces were observed under an optical microscope at 40x magnification. RESULTS: Blood contamination decreased (P<0.05) shear bond strength when both the hydrophobic (GII) and the hydrophilic resin (GIV) were used. However, the bond strength of Transbond Color Change group was significantly higher (P<0.05) than that of the Transbond XT conventional system group under blood contamination condition. Under dry conditions no difference was observed between the hydrophobic and hydrophilic resin groups. Regarding the bond failure pattern, when blood contaminated the enamel, the adhesive remnant index (ARI) showed predominance of scores 0 and 1, which indicates low adhesion to enamel. CONCLUSIONS: Although there was a significant decrease in the shear bond strength for both adhesive systems under blood contamination, the hydrophilic system showed significantly higher bond strength than the hydrophobic resin adhesive. Therefore, it is advisable to use the hydrophilic resin under risk of blood contamination.

There is controversy in the literature about possible interaction of the respiratory mode with the facial and dental structures. OBJECTIVES: The 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 METHODS: Pogonium 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). RESULTS: The 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. CONCLUSIONS: There were alterations in the facial measurements, without interference of the breathing pattern. However, the breathing pattern infuenced dental alterations.

This study evaluated the mechanical performance of teardrop-shaped loops and teardrop-shaped loops with helix used in orthodontic space closure. Sixty retraction loops made with 0.019" x 0.025" stainless steel (SS) and beta-titanium (BT) wires were used. They were attached to a testing machine to measure the magnitudes of the sagittal force and the load-deflection ratio necessary for 1 mm, 2 mm and 3 mm activation. The results demonstrated that the BT alloy presented significantly smaller mean values (p < 0.01) of sagittal force and load-deflection than the SS alloy. The loop with the highest mean value of sagittal force and load-deflection was the teardrop-shaped loop (p < 0.01). Differences were observed in the mean values of sagittal force and load-deflection among activations, and the highest mean value was found in the activation of 3 mm, while the smallest mean value was evident in the activation of 1 mm (p < 0.01). It could be concluded that the metallic alloy used and the presence of a helix in configuration of the loops may have a strong influence on the sagittal force produced and on the load-deflection ratio; the teardrop-shaped loops and teardrop-shaped loops with helix in BT presented the release of lighter forces; the teardrop-shaped loop in SS generated a high load-deflection ratio, providing high magnitudes of horizontal force during its deactivation.

A finalidade deste artigo é avaliar o efeito da expansão rápida da maxila (ERM) na via aérea superior. Por intermédio de um caso clínico, será relatado como indivíduos com atresia da maxila e com comprometimento da função naso-respiratória podem beneficiar-se com a ERM. Para entender melhor as alterações morfológicas decorrentes do paciente com problemas respiratórios, deve-se conhecer a anatomia e a fisiologia do sistema respiratório. Entretanto, não se pode esquecer que o tratamento deste paciente é multidisciplinar, envolvendo o ortodontista, otorrinolaringologista e a fonoaudióloga.

The aim of the present investigation is to evaluate the effect of rapid maxillary expansion (RME) on the upper airway. A clinical case is presented to describe how patients with atresic maxilla and reduced naso-respiratory function can have benefits from rapid maxillary expansion. In order to better understand the morphological alterations present in patients with respiratory disorders, it is necessary to understand the respiratory system's anatomy and physiology. However, it is relevant to mention that this patient undergoes a multidisciplinary treatment, involving the orthodontist, the otorhinolaryngologist and the phonoaudiologist.

A finalidade deste artigo é avaliar o efeito da expansão rápida da maxila (ERM) no padrão respiratório. Por intermédio de um caso clínico, será relatado como indivíduos com atresia da maxila e problemas respiratórios podem se beneficiar com a expansão rápida da maxila. Outro aspecto que deve-se salientar é como profissionais da área da saúde, principalmente ortodontistas e otorrinolaringologistas, têm à sua disposição exames complementares para o diagnóstico do paciente com "Respiração Bucal"

The aim of the present investigation is to evaluate the effect of rapid maxillary expansion (RME) on the respiratory pattern. A clinical case is presented to describe how patients with atresic maxilla and respiratory problems can benefit from rapid maxillary expansion. The article highlights that the health professional, mainly the Orthodontist and the Otorhinolaryngologist, may use complementary exams to diagnose a mouth breather patient