A retrospective cohort study was set up to analyse the prevalence and treatment of obstructive sleep apnoea (OSA) in relation to the severity of the deformity in patients with craniofacial microsomia (CFM). This study included a population of 755 patients with CFM from three craniofacial centres. Medical charts were reviewed for severity of the deformity, types of breathing difficulty, age at which breathing difficulty first presented, treatment for OSA, and treatment outcome. In total, 133 patients (17.6%) were diagnosed with OSA. Patients with Pruzansky IIB/III classification or bilateral craniofacial microsomia were significantly more often diagnosed with OSA than unilaterally affected patients of Pruzansky I/IIA classification. The initial treatment of OSA consisted of adenotonsillectomy, tracheotomy, or non-invasive positive pressure ventilation. Thirty-seven patients received more than one treatment (range 1–3). In this study, the prevalence of OSA in patients with CFM was higher than the prevalence in the healthy population described in the literature. Although several treatment modalities are available for the treatment of OSA in patients with CFM, treatment should be individualized and based on clinical symptoms, the severity of the deformity, and comorbidities.
Craniofacial microsomia (CFM) is a facial anomaly characterized by asymmetric underdevelopment of structures derived from the first and second branchial arches, including the mandible, maxilla, ears, soft tissues, and facial nerves . With an occurrence of 1 in 3500 to 5000 live births, CFM is the second most common congenital malformation of the head and neck. CFM is most often regarded as a unilateral malformation; however facial structures are involved bilaterally in 10% of cases .
CFM is a clinical diagnosis. The dysmorphology of CFM ranges from mild to severe. Several classification systems have been designed to define the spectrum of anomalies seen in CFM . Mandibular hypoplasia can be classified into four types based on the Pruzansky classification, modified by Kaban et al. . The OMENS classification of Vento et al. proposes a grading system based on severity and anatomical involvement in each category of the acronym: orbit, mandible, ear, nerves, and soft tissue .
Bilateral mandibular hypoplasia is seen in several facial malformations (e.g. Pierre Robin sequence, Treacher Collins syndrome) and can be associated with obstructive sleep apnoea (OSA) . The term obstructive sleep-disordered breathing (SDB) describes a syndrome of upper airway dysfunction during sleep that is characterized by increased upper airway resistance and pharyngeal collapsibility. Obstructive SDB is associated with snoring and/or increased work of breathing while the patient is sleeping. Obstructive SDB includes a spectrum of clinical entities with variable severity ranging from primary snoring to OSA . OSA is characterized by snoring, laboured breathing during sleep, and periods of complete or partial obstruction. Since OSA is associated with neurocognitive, metabolic, and cardiovascular consequences, accurate diagnosis and identification of at-risk groups is important .
The prevalence of OSA in lean children without facial malformations is 2.2–3.8% . However, in patients with mandibular hypoplasia, the prevalence of OSA is higher, e.g. 12.5% in patients with Treacher Collins syndrome .
Previous studies on the incidence of OSA in patients with CFM (bilateral and unilateral cases) showed wide variability, from 7% to 67% . The results of these studies were based on samples of nine to 124 patients, and OSA was only objectively diagnosed by polysomnography (PSG) in a small proportion of the study groups . According to Cohen et al., patients with more severe orbital and mandibular deformities and/or bilateral involvement are at greater risk of OSA . Patients suspected for or diagnosed with OSA also more often have extracranial anomalies. The treatment of OSA in patients with CFM has varied from prone positioning and non-invasive positive pressure ventilation to various surgical treatments, such as tracheostomy, (adeno)tonsillectomy ((A)TE), and mandibular distraction osteogenesis (MDO). Both clinical symptoms and respiratory parameters with PSG outcomes have been shown to improve after surgical and non-surgical treatment . So far, no studies have reported long-term results.
The aim of the present study was to retrospectively analyse the prevalence of OSA in patients with CFM in a large group of patients by combining the cohorts of three major craniofacial centres. It was sought to determine the relationship between the severity of CFM and the risk of OSA, as well as to analyse the chosen treatment modalities and their respective clinical outcomes.
Materials and methods
This retrospective study was conducted in a population of patients diagnosed with CFM at the craniofacial centres of Erasmus University Hospital, Rotterdam, the Netherlands; Great Ormond Street Hospital, London, UK; and Boston Children’s Hospital, Boston, USA.
Following institutional review board approval, patients diagnosed with CFM were reviewed. As CFM is a clinical diagnosis, patients with clinical and/or radiographic images, i.e. panoramic X-rays and/or computed tomography scans of the head, were included for analysis. Following the identification of patients, a chart review was performed to collect information on age, sex, affected side, severity of the deformity, and presence of breathing difficulties.
All medical charts of patients with CFM and breathing difficulties were categorized as suspected for OSA and were reviewed further for OSA, age at which OSA first presented itself, treatment for OSA, and treatment outcome. The diagnosis of OSA was based on PSG, the presence of a tracheostomy, or was based on the use of treatment for OSA without preceding PSG. The severity of OSA was based on PSG outcomes. When a tracheostomy was present, the severity of OSA was noted to be severe. When the diagnosis of OSA was based on the use of treatment for OSA without a preceding PSG, the severity of OSA was noted to be unknown. When no clinical signs of OSA were found in the medical charts, the patients were categorized as not suspected for OSA.
The severity of OSA was determined using the obstructive apnoea–hypopnoea index (oAHI). For children (0–18 years), OSA was defined as an oAHI ≥1 per hour. An oAHI score of 1–5 was defined as mild OSA, a score of 5–24 as moderate OSA, and an oAHI of ≥25 as severe OSA, in accordance with Goroza et al. and Guilleminault et al. . For adults (age >18 years), OSA was diagnosed when the apnoea–hypopnoea index (AHI) was >5. An AHI of 5–15 was defined as mild OSA, 15–30 as moderate OSA, and an AHI of >30 as severe OSA . In the case where PSG was performed but no oAHI was reported, the severity of OSA was drawn from the conclusion of the PSG report. When the oAHI was not available and the conclusion on the chart did not mention the severity of OSA, the result of the PSG was noted as unknown.
The assessment of mandibular hypoplasia in CFM was based on the classification of Pruzansky, modified by Kaban et al. . The Pruzansky classification was scored on both sides in patients with bilateral CFM. However, only the most severe score was used in the analyses.
When radiographic images were not available, the diagnosis of CFM was assessed on clinical pictures with the help of the pictorial global, detailed and radiographic Phenotypic Assessment Tool − Craniofacial Microsomia (PAT-CFM) .
Statistical analyses were performed using IBM SPSS Statistics for Windows, version 20.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were used. Equality of groups was tested with the Pearson χ 2 test. A P -value of <0.05 was considered to be statistically significant.
In total, 955 patients were diagnosed with CFM. Clinical pictures and/or radiographic images were available for 755 patients and these patients were included for further analysis ( Table 1 ).
|Affected side a|
Presence of obstructive sleep apnoea
Of the 755 patients, 181 were suspected of having OSA and 574 were not suspected of having OSA. PSG outcomes were found to be negative for OSA in 48 patients suspected of having OSA. In total, 133 patients (17.6%) were diagnosed with OSA: 74 based on positive PSG outcomes, 35 based on the need for a tracheostomy, and 24 based on treatment for OSA without a preceding PSG ( Fig. 1 ).
Characteristics of patients with obstructive sleep apnoea
OSA was diagnosed at a median age of 2.4 years (range 0–25.8 years). OSA was diagnosed before the age of 1 year in 35.3% of the patients ( Fig. 2 ).
OSA was significantly more often diagnosed in patients with bilateral CFM than in patients with unilateral CFM (Pearson’s χ 2 (1) = 7.026, P = 0.008) ( Table 1 ). Patients with Pruzansky IIB/III, both unilateral and bilateral cases, were more often diagnosed with OSA than patients with Pruzansky I/IIA ( Table 2 ). Severe OSA was mostly seen in patients with Pruzansky IIB/III, in both unilateral and bilateral cases. Of the 11 patients with Pruzansky IIB and severe OSA, six patients were diagnosed with unilateral CFM and five patients with bilateral CFM. For the patients with Pruzansky III and severe OSA this was 15 patients and nine patients, respectively. When patients with Pruzansky III were diagnosed with OSA, 52.2% were diagnosed with severe OSA. Mild OSA was more commonly diagnosed in patients with Pruzansky I and IIA, in 30.8% and 50% of the cases, respectively ( Table 3 ).
|Pruzansky score||OSA suspected clinically||OSA not suspected clinically||Total (Unilat./Bilat.)|
|Unilat.||Bilat.||Unilat. + Bilat. (%)||Unilat.||Bilat.||Unilat. + Bilat. (%)||Unilat.||Bilat.||Unilat. + Bilat. (%)|
|I||10||3||13 (9.3%)||10||1||11 (7.9%)||112||4||116 (82.9%)||140 (132/8)|
|IIA||16||6||22 (15.8%)||5||1||6 (4.3%)||107||4||111 (80.4%)||139 (127/11)|
|IIB||15||10||25 (21.4%)||8||3||11 (9.4%)||77||4||81 (68.6%)||117 (100/17)|
|III||30||16||46 (41.4%)||8||0||8 (7.2%)||50||7||57 (51.4%)||111 (88/23)|
|Unknown||19||8||27 (10.9%)||11||1||12 (4.8%)||191||18||209 (84.3%)||248 (221/27)|
|Severity of OSA||Pruzansky I||Pruzansky IIA||Pruzansky IIB||Pruzansky III||Unknown||Total|
|Unilat. + Bilat.||Unilat. + Bilat.||Unilat. + Bilat.||Unilat. + Bilat.||Unilat. + Bilat.|