Three-dimensional assessment of the posterior airway space in subjects with cleft lip/palate and maxillomandibular discrepancy: preliminary results

Purpose: Patients with repaired cleft lip and palate usually develop a characteristic concave profile due to retroposition of the atresic maxilla resulting from maxillary growth restriction caused by primary plastic surgeries. These anatomical changes frequently reduce internal nasal dimension, increase nasal patency and may result in oral breathing in a significant number of patients. Reduced posterior airway space (PAS) and reduced nasal dimensions are characteristics also observed in patients with maxillomandibular discrepancy, even without cleft. Therefore, respiratory complaints are frequently observed and, in severe cases, the obstructive sleep apnea syndrome can be present as a result of reduced PAS. As part of a larger project, this study aimed at assessing the PAS of subjects with Angle class III malocclusion + cleft lip/palate, as compared to subjects with Angle class III malocclusion and without cleft lip/palate. Methods: Cone beam computed tomography images of 4 subjects with class III malocclusion, divided into 2 groups, were retrospectively evaluated: G1-cleft lip/palate, and G2-without cleft. PAS volume (mm3) and minimum cross-sectional area (mm2) and were assessed in tomographic images by means of Dolphin Imaging 11.0 software. Results: The mean volume and minimum cross-sectional area of G1 corresponded to 12970mm3 and 96mm2, respectively. In G2, these values were slightly higher and corresponded to 13642mm3 and 107mm2. Conclusions: These data point out to a possible reduction of PAS in subjects with cleft lip and palate. However, these results are preliminary and a larger study is being conducted at the Laboratory of Physiology/HRAC-USP, in order to assess a more representative sample.CAPESPRODO

Sleep-disordered breathing in middle-aged adults who underwent pharyngeal flap surgery for velopharyngeal insufficiency treatment: polysomnographic analysis

Objetivos: Investigar a ocorrência de apneia obstrutiva do sono (AOS), sua gravidade e sintomas relacionados, em adultos de meia-idade com fissura de palato operada (FPO) e retalho faríngeo, comparativamente a indivíduos com FPO sem retalho e a dados normativos. Adicionalmente, verificar a relação entre a gravidade da AOS e a área seccional mínima da via aérea faríngea (ASF). Método: Estudo prospectivo em 42 indivíduos com FPO, não sindrômicos (22 com retalho- CR, 20 sem retalho-SR), 40-58 anos de idade. A prevalência de AOS foi estimada com base no índice de apneia e hipopneia (IAH) avaliado por polissonografia (sistema EMBLA-N7000). Os sintomas foram investigados pelos questionários de Pittsburgh, Epworth, e Berlin e pela Escala de Trindade. A ASF foi avaliada por rinomanometria anterior modificada em um subgrupo de pacientes dos grupos CR (n=14) e SR (n=10). Local de execução: Unidade de Estudos do Sono-Laboratório de Fisiologia-HRAC/USP. Resultados: No grupo CR, a prevalência de AOS correspondeu a 77%. Quando considerados os sintomas relacionados (SAHOS) foi de 64%. No grupo SR, os percentuais foram menores (60% e 45%, respectivamente), mas as diferenças não foram estatisticamente significantes. A prevalência de SAHOS do grupo CR foi comparativamente maior do que na população em geral. Os indicadores aferidos pelos questionários não diferiram entre os grupos. Não houve correlação entre IAH e ASF. Conclusão: Adultos de meia-idade com fissura palatina apresentam desordens respiratórias do sono em proporção clinicamente significativa, possivelmente relacionadas a alterações anatomo-funcionais das vias aéreas superiores, congênitas ou secundárias às palatoplastias, sendo o retalho um fator obstrutivo agravante.Objectives: To investigate the occurrence and severity of obstructive sleep apnea (OSA) and related symptoms in middle-aged adults with repaired cleft palate and pharyngeal flap, as compared to individuals with repaired cleft palate without flap and to normative data. In addition, to verify the relationship between OSA severity and minimal pharyngeal cross-sectional airway area (PCSA). Methods: Prospective study in 42 nonsyndromic individuals with repaired cleft palate (22 with flap- F group, 20 without flap- NF group), aged 40-58 years. Prevalence of OSA was estimated according to apnea-hipopnea index (AHI), measured by nocturnal polysomnography (EMBLA-N7000 system). Symptoms were investigated by the Pittsburgh, Epworth, and Berlin questionnaires and by the Trindade Scale. PCSA was evaluated by modified anterior rhinomanometry in a subgroup of patients from the F group (n=14) and the NF group (n=10). Setting: Sleep Studies Unit-Laboratory of Physiology, Hospital for Rehabilitation of Craniofacial Anomalies, Brazil. Results: In the F group, the prevalence of OSA corresponded to 77% and when considering related symptoms (OSAHS), 64%. In the NF group, the percentages were lower (60% and 45%, respectively), but differences were not statistically significant. The prevalence of OSAHS in the F group was higher than in the general population. Questionnaire outcomes did not differ between groups. There was no correlation between AHI and PCSA. Conclusion: Middle-aged adults with cleft palate have clinically significant sleep-disordered breathing, possibly related to congenital anatomic or functional abnormalities of the upper airway, or to primary and secondary palatal surgeries, the flap being an aggravating obstructive factor

Upper airways and sleep-disordered breathing in individuals with cleft lip and palate and maxillomandibular discrepancy: polysomnography, cone-beam computed tomography and computational fluid dynamics assessment

Objetivos: Investigar a ocorrência de apneia obstrutiva do sono (AOS) e sua gravidade em adultos jovens com fissura labiopalatina e discrepância maxilomandibular (DMM), e correlacionar os achados polissonográficos com as características anatômicas e funcionais das vias aéreas superiores, aferidas por tomografia computadorizada de feixe cônico (TCFC) e por fluidodinâmica computacional (CFD). Método: Um estudo prospectivo foi realizado em 27 indivíduos com fissura de lábio e palato operada e DMM tipo classe III, não sindrômicos, com idade entre 20 e 29 anos. Todos os indivíduos realizaram polissonografia noturna e o índice de apneia e hipopneia 5eventos/hora foi considerado como indicativo de AOS. As características da DMM horizontal foram avaliadas pelos ângulos cefalométricos SNA e SNB, e sua gravidade pelo ângulo ANB; o padrão facial vertical foi avaliado pelo ângulo SNMP. As images de TCFC de um subgrupo de indivíduos (n=21) foram avaliadas e o volume da via aérea superior e a área seccional faríngea mínima (ASFm) determinados. A partir dos modelos tridimensionais da via aérea, simulações de fluxo aéreo inspiratório foram realizadas por meio da técnica de CFD, sendo determinadas as pressões inspiratórias médias e máximas geradas na via aérea e a resistência ao fluxo respiratório. Local de execução: Unidade de Estudos do Sono do Laboratório de Fisiologia do HRAC/USP; Centro Craniofacial e Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço da University of North Carolina at Chapel Hill, EUA. Resultados: Os resultados mostraram que 26% dos indivíduos avaliados apresentaram AOS ao exame polissonográfico. O grupo com AOS apresentou volume médio da via aérea superior significantemente menor que o grupo sem AOS, particularmente na região da orofaringe. Não houve correlação entre as características cefalométricas lineares e angulares e a ocorrência de AOS. Também não foram detectadas diferenças entre indivíduos com e sem AOS para as variáveis avaliadas pela técnica de CFD, embora as pressões geradas na via aérea tenham sido mais negativas e as resistências maiores no grupo com AOS. Conclusão: Os resultados sugerem que a discrepância maxilomandibular constitui fator de risco para ocorrência de AOS em adultos jovens com fissura labiopalatina. A redução dos volumes observada pode levar a uma maior colapsabilidade faríngea e predispor à AOSObjectives: To investigate the occurrence and severity of obstructive sleep apnea (OSA) in individuals with cleft lip and palate and maxillomandibular discrepancy (MMD), and correlate polysomnographic findings with upper airway anatomic and functional characteristics, by means of cone-beam computed tomography (CBCT) and computational fluid dynamics (CFD). Methods: A prospective study was performed in 27 non-syndromic adults with repaired cleft lip and palate and class III MMD, aged 20-29 years. All subjects underwent nocturnal polysomnography. OSA was defined as an apnea-hypopnea index 5 events/h. Horizontal MMD characteristics were evaluated using the cephalometric angles SNA and SNB, and its severity using the ANB angle; the vertical facial pattern was evaluated using the SNMP angle. CBCT images of a subgroup of subjects (n=21) were analyzed and the upper airway volume and the minimum pharyngeal cross-sectional area (CSAm) were measured. Inspiratory airflow simulations were done by the CFD technique using three-dimensional airway models, and the mean and maximum inspiratory pressures and the resistance to respiratory flow were determined. Setting: Sleep Studies Unit, Laboratory of Physiology, Hospital for Rehabilitation of Craniofacial Anomalies, Brazil; Craniofacial Center and Department of Otolaryngology/Head and Neck Surgery, University of North Carolina at Chapel Hill, USA. Results: Polysomnographic exams showed that 26% of the subjects had OSA. Subjects with OSA had significantly smaller upper airway volume than subjects without OSA, particularly at the oropharynx. There was no significant correlation between linear or angular cephalometric characteristics and the occurrence of OSA. Variables evaluated by the CFD technique did not differ between subjects with and without OSA; however, a tendency for more negative inspiratory pressures and higher resistance was noted among subjects with OSA. Conclusion: The results have shown that young adults with cleft lip and palate and maxillomandibular discrepancy are at risk for OSA. The reduced airway volumes observed may increase pharyngeal collapsability and predispose to OS