Value of Interceptive Orthodontic Treatment for the Management of Sleep Disordered Breathing: A Prospective Longitudinal Study

Research Article

J Dent & Oral Disord. 2021; 7(3): 1164.

Value of Interceptive Orthodontic Treatment for the Management of Sleep Disordered Breathing: A Prospective Longitudinal Study

Ordoñez M¹*, De Pedro C¹, Monllau M¹, Vázquez I¹, Sans O², Moncunill J³, Rivera-Baró A³

1Department of Orthodontics and Dentofacial Malformations, Sant Joan de Déu Hospital, University of Barcelona, Spain

2Sant Joan de Déu Hospital, Institute of AdSalutem. Coordinator of the Sleep Disorder Unit, Spain

3Department of Orthodontics and Paediatric Dentistry, Sant Joan de Déu Hospital, Spain

*Corresponding author: M Ordóñez Vilà, Department of Orthodontics and Dentofacial Malformations, Sant Joan de Déu Hospital, University of Barcelona, 208950, Esplugues de Llobregat, Barcelona, Spain

Received: April 29, 2021; Accepted: May 22, 2021; Published: May 29, 2021


Background: The paediatric population has a high incidence of sleepdisordered breathing (SDB). One notable risk factor for SDB is the presence of craniofacial abnormalities. The aim of this study was to evaluate the prevalence of SDB by means of questionnaires in patients who received interceptive treatment, to determine whether there is a relationship between the nature and duration of treatment and the prevalence of SDB, and to correlate cephalometric changes with the type of orthopaedic treatment received and questionnaire results.

Materials and Methods: Prospective study of 203 patients who required interceptive treatment. Two sleep questionnaires (the Paediatric Sleep Questionnaire (PSQ) and the Sleep Disturbance Scale for Children (SDSC)) were used which were completed by the parents at baseline (T1) and after completion of interceptive treatment (T2). The results of the questionnaires were analysed, grouped according to the type of treatment received and related to 12 cephalometric variables on cephalometric radiography at T1 and T2.

Results: The prevalence of SDB at T1 was 21.2% according to PSQ and 33% according to SDSC. The mean age at T1 was 8.5 years and the mean duration of treatment was 13.8 months. Between 10.8% (PSQ) and 17.2% (SDSC) of patients showed improvement in SDB after interceptive treatment (p<0.05). Treatment led to statistically significant cephalometric changes in the variables of mandibular length, maxillary length and overbite, with no significant differences between treatment groups or in relation to questionnaire results.

Conclusion: Interceptive treatment achieves significant improvements in SDB. The type and duration of treatment do not affect the prevalence of SDB, although RPE is associated with a higher rate of improvement. The improvement in SDB is independent from the type of treatment and the cephalometric changes effected.

Keywords: Sleep-disordered breathing; Paediatric sleep questionnaire; Cephalometry; Interceptive treatment Orthodontic appliances


Sleep-Disordered Breathing (SDB) is a syndrome of upper airway dysfunction characterised by snoring and/or increased respiratory effort secondary to increased upper airway resistance and pharyngeal collapsibility [1]. It has a high prevalence in childhood. The childhood prevalence of snoring is 3 to 27%, and that of sleep apnoea 1 to 10% [2]. Risk factors include tonsillar hypertrophy and the presence of craniofacial abnormalities, since a small maxilla and/or mandible may predispose children to sleep-disordered breathing.

The diagnostic gold standard for the diagnosis of Obstructive Sleep Apnoea-Hypopnoea Syndrome (OSAHS) is polysomnography, but due to its complexity and high cost, questionnaires have been developed as a screening method. Some of those most widely used in children are the “Paediatric Sleep Questionnaire” (PSQ, by Chervin et al.) [3] and the “Sleep Disturbance Scale for Children” (SDSC, by Bruni et al.) [4]. Cephalometry is also considered as an appropriate method to assess skeletal and soft tissue characteristics, and as a screening procedure for the diagnosis and investigation of predisposing factors for OSAHS [5,6].

The PSQ, developed by Chervin [3] (and translated to Spanish by Tomas Vila et al. [7], in 2007) for the diagnosis of sleep-disordered breathing, has a high diagnostic sensitivity and specificity (0.78 and 0.72, respectively), and a 91% agreement with diagnosis by polysomnography. It was subsequently validated in 2015 by the study by Bertran et al. [8] which reported a sensitivity of 0.714 and specificity of 0.521. Meanwhile, the Sleep Disturbance Scale for Children (SDSC) for the diagnosis of all sleep disorders was developed by Bruni in 1996 (sensitivity of 0.89 and specificity of 0.74) and validated by the Association of Sleep Disorders Centers (ASDC) [4], correctly identifying 73.4% of the control group and 89.1% of the group with SDB.

The first-line therapy is tonsillectomy and adenoidectomy; however, this approach does not eliminate sleep apnoea in all patients. A recent study [9] found that craniofacial abnormalities are a greater risk factor for OSAHS than obesity; it therefore makes sense to correct craniofacial abnormalities to improve the child’s growth and to reduce snoring and sleep apnoea. Preliminary studies suggest that orthodontic treatment such as maxillary expansion or mandibular advancement with functional appliances may be effective for the treatment of sleep apnoea. Rapid maxillary expansion was first described in 1860, but only associated with OSAHS once it was found to reduce nocturnal enuresis, a sign and symptom of OSAHS in children [10]. Mandibular advancement appliances, which enhance mandibular growth, were introduced by Dr. Kingley in 1879. These treatment options are suitable alternatives for patients who are not eligible for surgery or cannot tolerate other methods: The first is maxillary expansion, which is used in patients diagnosed with a narrow upper jaw. The main benefit of this approach is that it reduces nasal resistance and repositions the tongue, thereby reducing the risk of obstruction. The second treatment option is mandibular advancement in order to correct skeletal and dental retrognathia and redirect mandibular growth downward and forward, this mandibular displacement can increase the oropharyngeal airway space [2]. Another option is maxillary advancement with or without maxillary expansion, as proposed by Stacey Quo [11] in 2019 and Sayionsu [12] in 2006; both conducted a pilot study in which they noted a slight improvement in SDB post-treatment.

In a previous study carried out by Vázquez et al. [13] in the Department of Orthodontics of Hospital Sant Joan de Déu in Barcelona, the prevalence of SDB in paediatric patients was 21.2% according to the PSQ and 33% according to the SDSC. Along these lines, we decided to continue the research with 3 main objectives: to reassess the prevalence of SDB by means of questionnaires in patients who received interceptive treatment; to determine whether there is a relationship between the nature and duration of treatment and the prevalence of SDB; and to correlate cephalometric changes with the type of orthodontic treatment received and questionnaire results.

Materials and Methods

The initial sample consisted of all the patients who visited the Department of Orthodontics of Hospital Sant Joan de Déu and required interceptive treatment between April 2016 and December 2017. Patients with craniofacial malformations, respiratory disorders, neurological disorders and a prior history of SDB were excluded from the sample.

The initial study population included 249 patients (T1). Two sleep questionnaires (PSQ and SDSC) were evaluated for each patient along with their anthropometric characteristics. An orthodontic assessment was performed (oral examination and cephalometric study) and the orthodontic treatment was then evaluated. Treatment options included maxillary expansion, mandibular advancement, maxillary advancement and expansion, maxillary advancement only and other methods. Forty-six patients either did not complete treatment or did not complete the second set of questionnaires, so that the final sample consisted of the 203 patients (T2) who also completed the PSQ and SDSC upon completion of interceptive treatment between 2017 and 2019. Of those 203 patients, 89 started the second treatment phase and underwent a new cephalometry. They were then grouped by type of treatment and the findings compared with the questionnaire results.

Sleep questionnaires

• The questionnaires were completed by the patients’ parents and/or legal guardians before (n=249) and after orthodontic treatment (n=203). The questionnaires used were:

• The Paediatric Sleep Questionnaire (PSQ) [3]: a 22-item questionnaire evaluating the presence of respiratory symptoms, enuresis, excessive sleepiness, headache, symptoms of hyperactivity and inattention. Possible answers are ‘Yes’, ‘No’ and ‘Don’t know’. The total score is calculated by dividing the number of affirmative answers by the total number of answers. The validated cut-off score is 0.33.

The Sleep Disturbance scale for children (SDSC) [4]: a 26-item, five-point, Likert rating scale where 1 means “never” and 5 “always. Six of the items relate to sleep: difficulty initiating and maintaining sleep, respiratory symptoms, arousal disorders, night terror and nightmares, sleep/wake transition disorders, symptoms related to excessive daytime sleepiness and presence of hyperhidrosis. The total score ranges from 26 to 130 points, with a cut-off score of 39.

Parents were also asked whether the patients had undergone adenotonsillectomy either before or during orthodontic treatment.

Cephalometric analysis

The data were completed with a cephalometric study of the patients before (n=203) and after (n=89) interceptive treatment. All images were obtained using the same cephalometric X-ray equipment. Cephalometric analysis was performed using NemoCeph® software. A series of points and planes were used to make linear and angular measurements, all of which were carried out by the same technician. Twelve cephalometric variables were determined according to the Steiner, Tweed, Ricketts and McNamara analysis.

Facial axis angle (º): posterior-inferior angle formed by the basicranial axis (Ba-Na) and the facial axis (Pt-Gn). Describes the general facial growth pattern. The value obtained from this measurement allowed to classify the facial growth pattern of the patients into mesofacial, brachyfacial or dolichofacial.

Mandibular plane angle (º): angle formed by the tangent to the lower border of the mandible and menton (Me-Go) and the Frankfort plane (FH). Provides information about mandibular growth and mandibular anatomical shape.

Facial convexity (mm): distance from point A to the facial plane (Na-Pg).

ANB (º): A-point-Nasion-B-point angle: indicates the anterior-posterior discrepancy between the maxilla and mandible, indicating the skeletal class.

SNA (º): Angle formed by the Sella, Nasion and A-point. Indicates the anterior-posterior location of the maxilla with respect to the base of the skull.

SNB (º): Angle formed by the Sella, Nasion and B-point. Indicates the anterior-posterior location of the mandible with respect to the base of the skull.

Mandibular length (mm): determined from Condylion (Co), the most posterior and superior point of the contour of the mandibular condyle, to the anatomical Gnation (Gn), the most antero-inferior point on the mandibular symphysis.

Maxillary length (mm): linear distance from Condylion (Co) to point A of the maxilla.

Upper incisor to palatal plane angle (UIPP,º): angle formed by the upper incisor axis with the palatal plane

Lower incisor to mandibular plane (IMPA,º): angle formed by the long axis of the lower incisor and the mandibular plane.

Overjet (mm): distance between the incisal edge of the maxillary incisor and the vestibular aspect of the mandibular incisor measured along the occlusal plane.

Overbite (mm): distance between the incisal edge of the mandibular incisor and the incisal edge of the maxillary incisor, perpendicular to the occlusal plane.

Type of treatment

The patients were divided into five groups according to the treatment received: Patients treated by maxillary expansion (quadhelix, Hyrax Rapid Palatal Expander (RPE) or removable Hawley retainer), mandibular advancement (Sander Guides or Twin- Block appliance), Rapid Maxillary Expansion (RME) and maxillary advancement (RME with hybrid Hyrax RPE-facemask combination), maxillary advancement only (facemask), and the last group, called “other treatments” which grouped treatments such as extraoral headgear, brass wire, utility arches, traction of incisors, etc.

Statistical analysis

The data obtained were analysed using SPSS software (Armonk, NY: IBM Corp.). A descriptive statistical analysis of the data was performed. Baseline intergroup comparisons for age were performed using paired t-tests. A chi-square (χ²) test was used to compare the sex ratios between groups. Pre- and post-treatment sleep questionnaires were correlated using the Kappa index. Analysis of Variance (ANOVA) was used to analyse the differences between treatment groups according to the type and duration of treatment. Since the cephalometric values showed normal distribution, parametric tests (Student’s t-test for quantitative data) were used for analysis. A p value <0.05 was considered significant.

Ethical approval and informed consent

The study was approved by the ethics committee of Hospital Sant Joan de Déu in Barcelona under number PIC-84-17 [13]. All patients who participated in the study and whose data were used in the writing of this article gave their informed consent.


The initial study sample consisted of 249 patients and the final study sample of 203 patients, 96 boys and 107 girls, with a mean age of 8.52±1.30 years. Most of them (95.6%) were of Caucasian ethnicity. The time between T1 and T2 was two and-a-half years (Table 1).