Differential diagnosis of obstructive sleep apnea syndrome patients and snorers using cephalograms

Craniofacial risk factors for obstructive sleep apnea-systematic review and meta-analysis

Obstructive sleep apnea (OSA) is caused by temporary partial or complete constriction of the upper airway during sleep which leads to reduced blood oxygen and cardiovascular risks. Main symptoms vary between adults and children leading to misdiagnosis or delayed patient identification. To improve early diagnosis, lateral cephalograms can provide craniofacial measurements associated with a higher risk of OSA. In order to identify the most relevant craniofacial measurements, a systematic literature review with meta-analysis was conducted combining the terms 'orthodontic*', 'craniofacial', 'cephalometr*', 'cephalogram', 'OSA*', 'UARS', 'SDB', 'sleep disordered breathing', 'sleep apnea' and 'sleep apnoea'. Of 3016 publications, 19 were included in the systematic review and meta-analysis, 15 with adult patients and four with children. A total of 16 measurements (six angles, 10 distances) were compared, nine showed a possible influence in patients with OSA compared to controls: NSBa angle (-0.28°), ANB angle (+0.33°), ML-NSL angle (+0.34°), Me-Go-Ar angle (+0.33°), SN distance (-0.70 mm), N-ANS distance (-0.36 mm), MP-H distance (+1.18 mm), uvula length (+1.07 mm) and thickness (+0.96 mm). Posterior airway measurements were not sufficiently described or comparably measured to be statistically analysed. There is some evidence for altered craniofacial anatomy in patients with OSA compared to controls. Lateral cephalograms should be screened for these aspects routinely to improve early diagnosis of OSA and craniofacial orthopaedics should complement the interdisciplinary treatment plan for young patients with OSA.

Correlation between Apnea Severity and Sagittal Cephalometric Features in a Population of Patients with Polysomnographically Diagnosed Obstructive Sleep Apnea

Background and Objective: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder featuring a repeated closure of the upper airway during sleep. Craniofacial anatomy is a potential risk and worsening factor for OSA. This study aims to assess the relationship between cephalometric features of craniofacial morphology and OSA severity in a population of patients with OSA. Material and Methods: A sample of forty-two patients (n = 42, M = 76%, mean age = 57.8 ± 10.8) with a polysomnographically (PSG) confirmed diagnosis of OSA were recruited and underwent cephalometric evaluation of 16 cephalometric variables. In addition, the apnea−hypopnea index (AHI), oxygen desaturation (SatMin), Epworth sleepiness scale (ESS), and body mass index (BMI) were assessed. Then t-tests were performed to compare the values of all cephalometric variables between two AHI severity-based groups (mild-to-moderate = AHI ≤ 30; severe = AHI > 30). Single- and multiple-variable regression analyses were performed to assess the associations between AHI scores and cephalometric features. Results: Mean AHI, SatMin, and BMI were 31.4 ev/h, 78.7%, and 28.1, respectively. The cephalometric variables were not significantly different between the two OSA-severity groups (p > 0.05). Multiple-variable regression analyses showed that gonial angle and nasopharynx space were negatively associated with AHI, explaining 24.6% of the total variance. Conclusion: This investigation reported that severity of AHI scores in patients with OSA showed a negative correlation with gonial angle and nasopharynx space. As a general remark, although maxillofacial anatomy can be a predisposing factor for OSA, disease severity depends mainly upon other variables.

An orthodontic-orthognathic patient with obstructive sleep apnea treated with Le Fort I osteotomy advancement and alar cinch suture combined with a muco-musculo-periosteal V-Y closure to minimize nose deformity

In some severe skeletal Class III patients, mandibular setback surgery using sagittal split ramus osteotomy (SSRO) is performed to correct mandibular protrusion. However, in patients diagnosed with obstructive sleep apnea syndrome (OSAS), the risk of OSAS worsening as a result of the SSRO is very high. Maxillary advancement could reduce the degree of mandibular retropositioning and expand the skeletal framework in the pharyngeal region, leading to enlargement of the airway. However, nasal deformity is an undesirable outcome of the procedure. This case report describes a 23-year-old man with a retruded maxilla and OSAS. The maxillary retrusion was treated using Le Fort I osteotomy with an alar cinch suture and a muco-musculo-periosteal V-Y closure (ACVY). After treatment, better occlusal relationships and improvement in OSAS were observed. Thus, an ACVY could minimize nasolabial deformity.

Craniofacial and upper airway morphology in adult obstructive sleep apnea patients: A systematic review and meta-analysis of cephalometric studies

Obstructive sleep apnea (OSA) is one of the common sleep breathing disorders in adults, characterised by frequent episodes of upper airway collapse during sleep. Craniofacial disharmony is an important risk factor for OSA. Overnight polysomnography (PSG) study is considered to be the most reliable confirmatory investigation for OSA diagnosis, whereas the precise localization of site of obstruction to the airflow cannot be detected. Identifying the cause of OSA in a particular ethnic population/individual subject helps to understand the etiological factors and effective management of OSA. The objective of the meta-analysis is to elucidate altered craniofacial anatomy on lateral cephalograms in adult subjects with established OSA. Significant weighted mean difference with insignificant heterogeneity was found for the following parameters: anterior lower facial height (ALFH: 2.48 mm), position of hyoid bone (Go-H: 5.45 mm, S-H: 6.89 mm, GoGn-H: 11.84°, GoGn-H: 7.22 mm, N-S-H: 2.14°), and pharyngeal airway space (PNS-Phw: -1.55 mm, pharyngeal space: -495.74 mm² and oro-pharyngeal area: -151.15 mm²). Significant weighted mean difference with significant heterogeneity was found for the following parameters: cranial base (SN: -2.25 mm, S-N-Ba: -1.45°), position and length of mandible (SNB: -1.49° and Go-Me: -5.66 mm) respectively, maxillary length (ANS-PNS: -1.76 mm), tongue area (T: 366.51 mm²), soft palate area (UV: 125.02 mm²), and upper airway length (UAL: 5.39 mm). This meta-analysis supports the relationship between craniofacial disharmony and obstructive sleep apnea. There is a strong evidence for reduced pharyngeal airway space, inferiorly placed hyoid bone and increased anterior facial heights in adult OSA patients compared to control subjects. The cephalometric analysis provides insight into anatomical basis of the etiology of OSA that can influence making a choice of appropriate therapy.

Obstructive sleep apnea prevents the expected difference in craniofacial growth of boys and girls

OBJECTIVES

It was to compare cephalometric measures of mouth-breather boys and girls and with the cephalometric pattern observed in obstructive sleep apnea syndrome (OSAS) patients.

METHODS

Craniofacial measurements of lateral cephalometric radiographs obtained from 144 children aged 7-14 years were compared between boys and girls, and both were compared to cephalometric pattern of OSAS patients.

RESULTS

Mouth-breather boys and girls had no gender differences regarding to craniofacial morphology while nose-breather boys and girls showed those expected differences. Nose-breather boys presented a more retruded mandible and proinclined upper incisor when compared to nose-breather girls, but mouth-breather boys and girls had no differences. The measure NS.GoGn was the only variable with an interaction with gender and breathing.

CONCLUSIONS

There were no cephalometric difference in mouth breather-boys and girls related to normal growth, suggesting that oral breathing make the same craniofacial morphology and both have craniofacial morphology close to that of OSAS patients.

Mouth breathing children have cephalometric patterns similar to those of adult patients with obstructive sleep apnea syndrome

OBJECTIVE

To determine whether mouth breathing children present the same cephalometric patterns as patients with obstructive sleep apnea syndrome (OSAS).

METHOD

Cephalometric variables were traced and measured on vertical lateral cephalometric radiographs. The cephalometric measurements of 52 mouth and 90 nose breathing children were compared with apneic patients. The children had not undergone adenoidectomy or tonsillectomy and had not had or were not receiving orthodontic or orthopedic treatment.

RESULTS

Mouth breathing children showed same cephalometric pattern observed in patients with OSAS: a tendency to have a retruded mandible (p=0.05), along with greater inclination of the mandibular and occlusal planes (p<0.01) and a tendency to have greater inclination of the upper incisors (p=0.08). The nasopharyngeal and posterior airway spaces were greatly reduced in mouth breathing children, as observed in patients with apnea (p<0.01).

CONCLUSION

Mouth breathing children present abnormal cephalometric parameters and their craniofacial morphology resembles that of patients with OSAS.

Facial patterns and primary nocturnal enuresis in children

PURPOSE

Aims of our study are evaluating: (1) the prevalence of dolicofacial pattern among enuretic and control-group children, (2) the prevalence of an abnormal head posture in bedwetters, and (3) the correlation with sleep-related breathing disorders (SRBD) identified by polysomnography (PSG) recording. Nocturnal enuresis is a multifactorial disease, but has been related also to obstructive sleep-disordered breathing in both adults and children. Anatomical factors recognized to predispose to SRBD include adenotonsillar hypertrophy, neuromuscular disorders, craniofacial abnormalities associated with macroglossia, retrognathia or maxillary hypoplasia, and obesity.

METHODS

Two hundred seventy enuretic children aged 7-12 years (mean 9.62 ± 2.31) were compared with a control-matched group of 274 children. To screen nocturnal sleep habits, all subjects' mothers filled out the Sleep Disturbance Scale for Children. Among these scales, only SBD scale was taken into account. Sleep breathing disorders (SBD) scale is composed of three items: sleep breathing difficulties, sleep apnea, and snoring. Cephalic index was calculated for each patient in order to identify facial patterns. An overnight PSG was performed in 28 (15 males, 13 females), randomly chosen, enuretic children and in 38 healthy volunteer controls (18 males, 20 females) matched for age (8.73 ± 0.79 vs. 9.12 ± 1.23; p = 0.147) and sex distribution (chi-square = 0.062; p = 0.803).

RESULTS

Bedwetters show different sleep habits, higher prevalence of dolicofacial pattern, and abnormal head posture more than controls.

CONCLUSIONS

Our preliminary study support further investigation of usage of the cephalic index as a predictor of SRBD.

Sleep architecture and the apnoea?hypopnoea index in children with obstructive-sleep apnoea syndrome

This study aimed to examine the sleep architecture and craniofacial morphology in a group of children divided by different levels of apnoea-hypopnoea index (AHI), 5, 4.5, 4, 3.5, 3 and 2.5, and to determine an AHI threshold value at which sleep architecture is most affected. 23 children, who were selected from a preliminary questionnaire survey about sleep-related breathing disorders, were evaluated with cephalometric radiographs and overnight polysomnography. The findings indicated that the children with AH1 > or = 2.5 and > or = 3 showed significantly larger numbers of waking (p < 0.005) and desaturation index (p < 0.01) than those with AHI <2.3 and <3, respectively. Significantly (p < 0.05) higher amounts of waking and lower amounts of REM as a percentage of total sleep time (TST) were also found in the children with AH1 > or = 3. In the subgroups with AHI > or = 3.5 and > or = 4, only the percentage of REM was found to be significantly (p < 0.05) lower. No significant differences were found at the AHI threshold of 4.5 and 4. AHI correlated significantly (p < 0.05) with the number of awakenings, amount of waking as a percentage of TST, desaturation index and oxygen saturation nadir. Higher incidence of skeletal Class II pattern was found in children with AHI > or = 2.5 and > or = 3, and Class III in those with AHI <2.3 and <3, respectively. The effects on polysomnographic characteristics demonstrated to be the greatest on children at the AHI threshold of 3. In addition, the evaluation of oxygen saturation can be used to provide some information concerning the severity of sleep-related breathing disorders.

Ethnicity and obstructive sleep apnoea

There is a scarcity of adult prevalence studies of OSA outside the Caucasian populations of North America, Europe and Australia, and comparisons have been complicated by methodological differences in sleep study settings, respiratory events definition, measured risk factors and clinical outcomes, and the lack of objective parameters for the measurement of ethnicity itself. Comparing studies with the same methodological design and respiratory events definition, recent large-scale prevalence studies from Hong Kong, Korea and India show similar OSA rates to populations of mainly Caucasian composition. OSA is a very complex disorder determined by several phenotypes such as obesity, craniofacial structure and abnormalities in neuromuscular and ventilatory control. Genetics may partially explain some of the ethnic clustering of these phenotypes, modulated by cultural and environmental factors. The exact contribution of these component phenotypes to overall OSA risk will be determined by their varying prevalence and relative risk conferred across ethnic groups. For lesser degrees of obesity, Asians are at risk for a more severe degree of illness compared with Caucasians. Inter-ethnic studies suggests that African-American ethnicity may also be a significant risk factor for OSA. The increased prevalences of OSA among American Indians and Hispanic adults, and increased severity among Pacific Islanders and Maoris, were mainly explained by increased obesity parameters. Most cephalometric studies have largely been conducted without specific regard to ethnicity and comparisons of findings across studies have been mainly limited by differences in sampling methods and the varying selection and definition of measured cephalometric variables. The limited number of studies with inter-ethnic comparative data suggest cephalometric variables and their degree of contribution to OSA vary across ethnic groups.