Abstract
Purpose: The aim of the current study was to evaluate nasal patency by acoustic rhinometry in children aged 4–8 years with repaired complete unilateral cleft lip and palate (UCLP) compared with an age-matched control group without cleft lip and palate (CLP). Methods: This comparative cross-sectional study was conducted at a tertiary care teaching hospital and a private ENT clinic in Porto Alegre, southern Brazil. The case group consisted of 38 children who had undergone surgery for complete UCLP (mean age, 6.44 years), and the control group of 21 children without CLP (mean age, 6.21 years) recruited among patients seeking medical care for ear diseases at the private clinic. Acoustic rhinometry was performed in all children after administration of oxymetazoline hydrochloride (2 × 0.25 mg/mL) for nasal vasoconstriction. Results: The minimal cross-sectional area and nasal volume of the cleft side were smaller than those of the non-cleft side in the case group (p = 0.001). When the two groups were compared, the non-cleft side in the case group did not differ from the control group (p = 0.175), but the minimal cross-sectional area and volume of the cleft nasal cavity were smaller than the mean values of the two nostrils of controls (p = 0.001). Conclusion: In conclusion, our findings show that nasal patency on the cleft side is impaired in children surgically treated for complete UCLP.
Introduction
Cleft lip and palate (CLP) is a congenital malformation of the central portion of the mid-face, which can lead to facial deformities and dysfunction even after timely, well-performed surgical correction. Structural abnormalities of the nasal cavity in patients with CLP can affect ciliary mucus function, increasing the risk of viral and bacterial infections [Citation1]. They can also affect the patient’s capacity for normal olfaction, normal facial growth and speech development [Citation1,2].
Treatment to correct deformities of the nasal cavity is, therefore, essential to normal facial growth and nasal airway development in children with CLP. However, although facial growth and nasal patency after CLP repair have been widely discussed, the extent and quality of restoration of nasal anatomy, as well as its influence on nasal function, have yet to be established. It also remains unknown to what extent the mid-facial hypoplasia found in CLP is caused by nasal obstruction.
Measurement of the degree and location of airway obstruction has direct therapeutic impact on CLP rehabilitation, because these data may serve as a basis to select therapy for individual patients in order to prevent residual airway problems postoperatively [Citation3]. Among several methods and instruments that have been developed for objective evaluation of airway patency in patients with respiratory compromise, acoustic rhinometry has become a valuable tool for assessment of nasal obstruction [Citation4].
Acoustic rhinometry is a non-invasive, easy to perform assessment technique [Citation2] that provides reproducible metric data concerning the severity and location of airway obstruction. Unlike rhinomanometry, it does not require nasal airflow. It measures nasal patency by quantifying the cross-sectional area and volume of the nasal cavities [Citation5], measured from the opening of the nostril to the nasopharynx, and analyses the sound waves reflected from the nasal cavities with the aid of a computer. Because the technique is rapid, painless and requires minimal cooperation from the patient, it is of particular help in evaluating nasal obstruction in children and reference values have already been established for the method in the paediatric population [Citation6].
The aim of the current study was to evaluate nasal airway patency by acoustic rhinometry in children with repaired complete unilateral CLP (UCLP) compared with children without CLP.
Materials and methods
This comparative cross-sectional study was conducted at the Cranio-Maxillofacial Surgery Unit of the Department of Plastic Surgery at Hospital de Clínicas de Porto Alegre (a tertiary care teaching hospital affiliated with the Universidade Federal do Rio Grande do Sul School of Medicine) and at Clínica Otorrinos Porto Alegre (a private ENT clinic). Both institutions are located in Porto Alegre, city and capital of the state of Rio Grande do Sul, Southern Brazil. The study was approved by the Research Ethics Committee of the Universidade Federal do Rio Grande do Sul School of Medicine (registration number 08059/2008) and conducted in accordance with the provisions of the Declaration of Helsinki.
The case group was a non-random convenience sample of children aged 4–8 years who underwent surgical repair of complete UCLP at Hospital de Clínicas de Porto Alegre from May 2003 to October 2009. All procedures were performed by the same surgeon using the following technique: modified Millard II for cleft lip, vomer flap for the whole hard palate and modified McComb repair for the nasal deformity as the first stage, followed by Veau-Wardill-Kilner palatoplasty plus extended Braithwaite intravelar veloplasty plus a Collares nasal mucosa Z-plasty for palatal closure at 12 months of age [Citation7]. The control group was age-matched to the case group, and the participants were recruited among children without CLP seeking medical care for ear diseases at Clínica Otorrinos Porto Alegre.
Exclusion criteria for both case and control groups were (a) acute symptoms of nasal congestion, allergic rhinitis or respiratory infections at the time of examination, (b) a history of trauma, tumour, or infections of the nasal bones or soft tissues, (c) septal perforation, (d) fistula, (e) previous adenoidectomy, (f) previous treatment with maxillary orthopaedic appliances and/or alveolar bone graft, and (g) presence of other craniofacial syndromes. Although previous adenoidectomy would not affect acoustic rhinometry measurements, these children were excluded because, at the same consultation, they would also be evaluated by computerised rhinomanometry for another study conducted by our research group; and for rhinomanometry, which measures the rate of airflow in the nasal airway, previous adenoidectomy may affect the results.
The parents of each eligible patient and control were sent a letter inviting the child to participate in the study, and inviting the parents to attend a meeting at Hospital de Clínicas de Porto Alegre for further explanations on the study. On the scheduled date, the parents and children attending the meeting were adequately informed about the project and received detailed explanations about testing procedures. All invited patients and controls who attended the meeting agreed to participate, and written informed consent was obtained from the child’s parents or legally authorised representative for enrolment in the study.
Acoustic rhinometry
All acoustic rhinometry measurements were performed at Clínica Otorrinos Porto Alegre from June–December 2009. The SRE 2000 rhinometer (RhinoMetrics, Lynge, Denmark) with Rhin98 2.0 software was used for evaluation. The device was calibrated before and after each testing session. Standard procedures were followed according to the international consensus for acoustic rhinometry [Citation8].
Rhinometry was always performed in the same room, with the same equipment, and by the same physician in a low-noise, controlled-temperature (22–24°C) environment. All children were examined 15 minutes after administration of oxymetazoline hydrochloride 0.25 mg/mL, two sprays in each nostril, repeated after 5 minutes, for nasal vasoconstriction. The vasoconstrictor was used to eliminate the functional effects of the nasal mucosa and to ensure measurement only of the anatomic area of the nasal cavity.
The cross-sectional area was calculated based on the wave speed in the nostril and the time the echo took to return. These data were processed and plotted as a chart on the computer screen. This chart, known as the echogram, was printed. Three measurements were made on each nostril. The final curve was the average of these three curves, as calculated directly by the software. The software provides a reliability of 95%, and the maximum difference tolerated between the three independent measurements was a standard deviation (SD) of 5%.
During the examination, children sat in a reclining procedure chair at a 45-degree angle with the head resting against the backrest, to ensure stability. The sound wave was captured during breath-holding after exhalation and with the mouth open. Children were instructed to remain still during data capture to avoid interference. Leakage at the nostril was controlled by the acoustic rhinometry equipment. The test apparatus includes a stop mechanism which will prevent a graph from being generated (no curve will be produced) if there is air leakage. In the case of air leakage, the measurements were repeated as many times as necessary to obtain the required curves.
The curves were analyzed and the distance (in cm) from the nostrils to the nasopharynx was measured. The parameters of interest were the minimal cross-sectional area (MCA, in cm2) and nasal volume (in cm3) (). The average length of the nasal cavity is 5 cm in children aged 4–8 years [Citation9]. Therefore, for the purpose of the current evaluation, the nasal cavity was divided into two anatomical segments, as recommended by Millqvist and Bende [Citation9]: segment 1, from the nostril opening (0 cm) to 2.20 cm into the nasal cavity; and segment 2, from 2.21–5.40 cm into the nasal cavity, as the valve and the turbinate are located in this anatomical region. The MCA and nasal volume were measured for segments 1 and 2 separately.
Figure 1. An example of an acoustic rhinometry trace, with nasal cross-sectional area along the x-axis and distance from the wave tube along the y-axis. MCA = minimal cross-sectional area; VOL = nasal volume.
Sample size
The sample size calculation was based on the assumption that the response within each (case and control) subject group would be normally distributed with 1.0 SD [Citation10]. In order to reject the null hypothesis that the population means of the case and control groups are equal, a minimum sample of 21 participants per group was required to detect a difference ≥ 1.0 SD between children with UCLP (case group) and children without CLP (control group), with 90% power and 5% significance (α = 0.05).
Statistical analysis
Quantitative data from acoustic rhinometry measurements were expressed as mean ± SD. The measurements in the case group were reported individually for the cleft and non-cleft side separately. In the control group, however, because the predominance of left septal deviation in the general population does not apply to patients with CLP, the measurements were reported as a mean for both the left and right side to avoid a selection bias.
Comparative analyses were performed between the (a) mean value of the cleft vs non-cleft nasal cavity in the case group, (b) mean value of the cleft nasal cavity of cases vs mean value of the two nostrils of controls, and (c) mean value of the non-cleft nasal cavity of cases vs mean value of the two nostrils of controls. The Student t-test for paired or independent samples was used as appropriate. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 19.0 (SPSS Inc., Chicago, IL). The level of significance was set at p < 0.05.
Results
The case group consisted of 38 children with repaired complete UCLP, 23 male (60.5%) and 15 female (39.5%), and the control group of 21 children without CLP, 12 male (57.1%) and nine female (42.9%). The mean age of children with UCLP was 6.44 years (range = 4–8 years), and mean age of controls was 6.21 years (range = 4–8 years). There was no difference between groups regarding gender or age (p > 0.05).
The acoustic rhinometry measurements obtained from the cleft side and non-cleft side in children with repaired complete UCLP (case group) are described in . The MCA and volume of the nasal cavity on the cleft side were smaller than those of the non-cleft side (p = 0.001).
Table I. Acoustic rhinometry measurements of the cleft side and non-cleft side in 38 children with repaired complete unilateral CLP.
When the case and control groups were compared, the MCA and volume of the cleft nasal cavity of children in the case group were smaller than the mean values of the two nostrils of control children without CLP (p = 0.001) ().
The measurements of the non-cleft side of children in the case group did not differ from the mean values of the two nostrils obtained from children in the control group (p = 0.175) ().
Table III. Comparison of acoustic rhinometry measurements of the non-cleft side in 38 children with repaired complete unilateral CLP and the mean value of the two nostrils of 21 control children without CLP.
Table II. Comparison of acoustic rhinometry measurements of the cleft side in 38 children with repaired complete unilateral CLP and the mean value of the two nostrils of 21 control children without CLP.
Discussion
The current study evaluated nasal airway patency by acoustic rhinometry in children who were surgically treated for complete UCLP. The results showed decreased nasal patency on the cleft side in comparison with the nostril of the non-cleft side and the mean of the two nostrils of children without CLP.
Primary repair of nasal deformities in patients with CLP is widely accepted [Citation7,11]. Early aesthetic and functional treatment of the nose can benefit these patients in terms of both respiratory function and mid-facial growth, due to aeration of the paranasal sinuses [Citation12]. However, the effect of nasal obstruction on facial growth remains debatable [Citation13] and so does the age to be selected for analysis of nasal patency in children with repaired CLP.
In this study, the initial age of 4 years and the final age of 8 years were selected based on a previous study by Millqvist and Bende [Citation9]. The authors assessed the nasal geometry of 88 healthy children aged 4–16 years over a 2-year period by acoustic rhinometry and, although large individual variations were reported, children aged 4–8 years showed less variation in nasal geometry.
In the context of CLP research, studies have reported on the use of acoustic rhinometry to measure the nasal cavity mainly in adult and adolescent patients [Citation14-16]. The finding of increased nasal obstruction on the cleft side in adults with repaired CLP is similar to the result presented here for children. A study of 34 adult patients with complete UCLP and 15 controls with subjective normal nasal patency revealed that 75% of patients with UCLP experienced nasal valve obstruction on the cleft side, but only 15% of these patients had obstruction on the contralateral side [Citation17]. These results were confirmed 1 year later in a study with a larger sample of adult patients with complete UCLP [Citation18]. To the best of our knowledge, no studies have been published to date reporting on CLP and acoustic rhinometry measurements in children aged 4–8 years.
Acoustic rhinometry is a well-established method for objective evaluation of nasal patency [Citation2,4]. It provides reproducible metric data concerning the degree and location of airway obstruction, which can be transformed into an objective measure for comparison [Citation19]. In patients with CLP, these data allow us to objectively assess the impact of the baseline deformity and of the primary operations performed on the involved structures of the nasal cavity. However, as with all objective methods, acoustic rhinometry has limitations both in methodology and interpretation. In this study, standardisation of measurement procedures was ensured by following the recommendations of the Standardisation Committee on Acoustic Rhinometry of the European Rhinological Society [Citation8]. There are currently no clinical or imaging tests able to provide objective measurements of the cross-sectional area of the nasal cavity in these patients. In this sense, acoustic rhinometry fills that gap and allows reliable non-invasive measurement of the area and volume of the nasal cavity.
Early detection of nasal obstruction is relevant because this condition may lead to other functional disorders, such as mouth breathing and abnormal lung compliance, thus impairing overall health [Citation20]. A previous study using radiographic cephalometric and otolaryngological tests to correlate the degree of nasal obstruction with facial growth patterns in 30 children aged 7–12 years not treated orthodontically demonstrated the influence of mouth breathing on craniofacial growth. The study also stressed the importance of early treatment of chronic nasal obstruction in children [Citation21].
Early septal repair in children with nasal obstruction remains controversial among otolaryngologists. It also remains unanswered whether early septoplasty plays a role in children with CLP. Many authors recommend septoplasty in these children for various reasons, such as sleep apnea, facial growth, sinusitis and otitis [Citation21,22]. In this setting, acoustic rhinometry can be a very useful tool for the longitudinal assessment of the outcomes of surgical procedures performed in these children, as well as to investigate whether early septoplasty may have an influence on the volume and patency of the nasal cavity.
A potential limitation of this study is the cross-sectional design, which introduces the possibility of selection bias. However, selection bias was limited by the high participation rate and by using a mean value for both the left and right nostril in controls. Another limitation is that patients who had undergone treatment with maxillary orthopaedic appliances and/or alveolar bone graft were excluded. It has been shown that these procedures can modify the internal dimensions of the nasal cavity [Citation23]. In the current study, however, we could not assess the influence of these procedures on the shape and size of the nasal cavity.
In summary, this study sought to add to the existing literature by quantifying the degree of nasorespiratory obstruction in children with repaired UCLP and without CLP within a specific age range (4–8 years) and by comparing sides and individuals for relevant differences, thus providing additional data to contribute to the debate of the relationship between nasal obstruction and facial growth in the setting of CLP. Our findings show that nasal patency on the cleft side is impaired in children surgically treated for complete UCLP. Further acoustic rhinometry measurements will be conducted in this population at the end of their growth. Hopefully, this study will allow us to determine the relevance of nasal obstruction and its effect on facial growth. Nevertheless, further studies are warranted in this population to establish the amount of and at what age the onset of nasal obstruction may have a critical effect on facial growth.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References
- Hilberg O, Jackson AC, Swift DL, Pedersen OF. Acoustic rhinometry: evaluation of nasal cavity geometry by acoustic reflection. J Appl Physiol (1985) 1989;66:295–303.
- Hilberg O. Objective measurement of nasal airway dimensions using acoustic rhinometry: methodological and clinical aspects. Allergy 2002;57:5–39.
- Kunkel M, Wahlmann U, Wagner W. Nasal airway in cleft-palate patients: acoustic rhinometric data. J Craniomaxillofac Surg 1997;25:270–4.
- Roithmann R. Testes específicos da permeabilidade nasal. Rev Bras Otorrinolaringol 2007;73:2.
- Fonseca MT, Goto EY, Nigro CE, et al. Reprodutibilidade e repetibilidade de rinometria acústica. Arquivos Int Otorrinolaringol 2003;7:213–17.
- Zavras AI, White GE, Rich A, Jackson AC. Acoustic rhinometry in the evaluation of children with nasal or oral respiration. J Clin Pediatr Dent 1994;18:203–10.
- Collares MV. Rinoplastia no tratamento primário do lábio leporino. Avaliação de 256 casos operados pela técnica de McComb. Revista da Sociedade Brasileira de Cirurgia Plástica 1992;7:53–60.
- Hilberg O, Pedersen OF. Acoustic rhinometry: recommendations for technical specifications and standard operating procedures. Rhinol Suppl 2000;16:3–17.
- Millqvist E, Bende M. Two-year follow-up with acoustic rhinometry in children. Am J Rhinol 2006;20:203–4.
- Hulley SB, Cummings SR, Browner WS, et al. editors. Designing clinical research: an epidemiologic approach. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2001.
- Bardach J, Sayler KE, Jackson I. Correction of nasal deformity in cleft lip and palate associated with unilateral cleft lip. In Bardach J, Sayler KE, editors. Surgical techniques in cleft and palate. Chicago, IL: Year Book Medical Publishers; 1987.
- Ferreira JC, Minami E. Introdução ao estudo das fissuras labiopalatais em cirurgia plástica. In Mélega JM, editor. Cirurgia Plástica: Fundamentos e Arte. Rio de Janeiro: Medsi; 2002.
- Vig KW. Nasal obstruction and facial growth: the strength of evidence for clinical assumptions. Am J Orthod Dentofacial Orthop 1998;113:603–11.
- Bertier CE, Trindade IE. Deformidades nasais: avaliação e tratamento cirúrgico. In Trindade IE, Silva-Filho OG, editors. Fissuras labiopalatinos: uma abordagem interdisciplinar. São Paulo: Santos; 2007.
- Bertier CE. Efeitos da rinosseptoplastia sobre as dimensões internas nasais e ressonância da fala em indivíduos com fissura de lábio e palato unilateral reparada: análise por rinometria acústica e nasometria [Doctorate]. Bauru: Universidade de São Paulo; 2006.
- Fukushiro AP, Trindade IE. Nasal airway dimensions of adults with cleft lip and palate: differences among cleft types. Cleft Palate Craniofac J 2005;42:396–402.
- Wahlmam U, Kunkel M, Wagner W. Preoperative assessment of airway patency in the planning of corrective cleft nose surgery. Mund Kiefer Gesichtschir 1998;2:S153–7.
- Kunkel M, Wahlmann U, Wagner W. Acoustic airway profiles in unilateral cleft palate patients. Cleft Palate Craniofac J 1999;36:434–40.
- Zancanella E, Lima WT. Uso da rinometria acústica como método diagnóstico. Rev Bras Otorrinolaringol 2004;70:500–3.
- Warren DW, Drake AF. Cleft nose. Form and function. Clin Plast Surg 1993;20:769–79.
- Mocellin M, Fugmann EA, Gavazzoni FB, et al. Estudo cefalométrico-radiográfico e otorrinolaringológico correlacionando o grau de obstrução nasal e o padrão de crescimento facial em pacientes não tratados ortodonticamente. Rev Bras Otorrinolaringol 2000;66:1–6.
- Crysdale WS. Septoplasty in children--yes, but do the right thing. Arch Otolaryngol Head Neck Surg 1999;125:701.
- Cappellette MJr, Carlini D, Pignatari SS, et al. Rinometria acústica em crianças submetidas à disjunção maxilar. Rev Dent Press Ortodon Ortop Facial 2006;11:84–92.