Prevalence and Risk of Obstructive Sleep Apnea and Association with Orofacial Symptoms in Patients Attending the Dental Clinics.

BACKGROUND: Dentists have a vital role in detection of the signs and symptoms of obstructive sleep apnea (OSA) as it modifies in anatomy of orofacial structures. AIMS AND
OBJECTIVES: This study aims to assess the prevalence of OSA risk in patients attending dental department and explore the factors related with high-risk OSA.
MATERIALS AND METHODS: The study was carried in the Al-Farabi Dental College, Jeddah, Saudi Arabia, on 200 consecutive dental patients from June 1, 2018, to July 31, 2019. Demographic details and the OSA risk were evaluated based on the Berlin questionnaire (Arabic version). Two qualified investigators independently did anthropometric measurements, medical and dental examination.
RESULTS: About 3.7% of males and 13.8% of females were found to be at high risk of OSA. Obese individuals almost had twice more likely chance to have OSA symptoms.
CONCLUSION: Our findings confirm that dentists have an important role in recognizing the OSA signs and symptoms. Copyright:

INTRODUCTION

The word apnea means without breath in Greek. Obstructive sleep apnea (OSA) is a chronic condition denoting as a repetitive upper airway obstruction while sleeping.[1] As dentists are experts in the field of craniofacial growth and development, and also have knowledge about oral devices, they are part of a multidisciplinary team along with physicians in treating OSA. In individuals with OSA, as there is upper airway collapsibility, there is an increased effort in respiration for maintenance of airflow through a constricted airway, resulting in hypercapnia and hypoxemia. There is also cortical arousal from sleep, raising sympathetic neural activity, which leads to tachycardia and cardiac arrhythmias. The entire process might occur several times per hour during sleep.[23]

OSA is a complex condition epitomized by its multifactorial etiology. The risk factors include obesity (body mass index [BMI] more than 30 kg/m2), males, and increasing age. Craniofacial factors that might predispose to OSA are macroglossia, micrognathia, hypertrophy of palatine tonsils, and enlarged uvula. Majority of the OSA patients are ignorant of this phenomenon owing to lack of knowledge and guidance from their family physicians and dental surgeons.

Literature search regarding the relevance of OSA gives varied reports, commonly shown as 14% in men and 5% in women. The higher prevalence rates have been reported in obese individuals and poststroke patients. BaHammam et al. in their two studies in Saudi Arabian population found OSA prevalence as 39% in females and 33.3% in males.[45]

Polysomnography (PSG) is considered as the gold standard confirmatory test in diagnosis of OSA. If OSA is untreated, it leads to several consequences such as excess daytime sleepiness resulting in increased risk of motor vehicle accidents, decreased scholastic and occupational performance. The systemic effects of OSA may cause hypertension, coronary artery disease, cardiac arrhythmia, myocardial infarction, and sudden cardiac death.[345]

Very few studies were carried out regarding prevalence and risks of OSA symptoms among dental patients in Saudi Arabia.[45] This study is carried to find out the prevalence of OSA risk in adult dental patients and also to investigate the factors associated with high-risk OSA.

MATERIALS AND METHODS

This study was carried at Al-Farabi Dental College, Jeddah, Saudi Arabia. The study included 200 consecutive dental patients from June 1, 2018, to July 31, 2019, after attaining Institutional Ethical Committee clearance and informed consent in accordance with the Helsinki Declaration.

Inclusion criteria

Adult patients, 18–65 years, who visited dental clinics, were included in the study.

Exclusion criteria

Patients with craniofacial anomalies such as cleft lip and palate

Patients unable to read.

A structured Arabic version of the Berlin questionnaire with demographic details, medical and dental history, and objective variables such as BMI, hypertension, Epworth Sleepiness Scale (ESS), was used by two trained investigators. The height (cm) and weight (kg) were measured by a digital scale (Detecto 6129, MO, USA) and neck circumference (NC, cm) at cricothyroid membrane level. Obesity was considered if BMI was ≥30 kg/mm2. Blood pressure (BP) was recorded with a digital sphygmomanometer. Oxygen saturation (SpO2) was recorded with a pulse oximeter (OxyTrue® S, Selmsdorf, Germany). Upper airway examination encompassed: tonsil size, modified Mallampati classification, tongue size (normal, tongue indentations), size and shape of uvula and soft palate, and depth of palatal vault. Dental occlusion examination was done by the presence of enamel wear by Basic Erosive Wear Examination index. A total of 200 were included, out of which 188 were eligible (12 did not meet inclusion criteria).

Statistical analysis

Data were analyzed by Microsoft Excel, GraphPad Prism, and SAS university edition open source software. Mean ± standard deviation was recorded for continuous normal data (one-way ANOVA) and median ± interquartile range for continuous nonnormal data (Kruskal–Wallis test). The association between variables was done by Chi-square test for categorical data. P < 0.05 was regarded as statistically significant.

RESULTS

Out of total 188 patients, 108 (57%) were male. Majority of them were highly educated (138, 73%) and in the low-to-middle-income groups. Fifty-nine (31.2%) patients were obese. About 15% were on medications for systemic conditions such as diabetes, hypertension, and hyperthyroidism [Table 1].

Table 1

Demographic profile of the patients

Variable	Value
Male/female ratio, n (%)	108 (57)/80 (42)
Age (years), mean±SD (median, IQR)	32.1±10.5 (28, 25-36)
Education, n (%)
College or higher	138 (73.0)
High school or less	46 (24.3)
Marital status
Married	78 (41.3)
Not married or widowed	100 (52.9)
Monthly income (SR), n (%)
High (≥15,000)	60 (31.8)
Middle (5000-14,999)	63 (33.3)
Low (<5000)	61 (32.8)
BMI (kg/m2), mean±SD	26.9±5.8
BMI categories, n (%)
Normal weight (18.5-24.9)	66 (34.9)
Underweight (<18.5)	10 (5.3)
Overweight (25-29.9)	52 (27.5)
Obese (≥30)	59 (31.2)
Height (cm), mean±SD	167.6±9.9
Weight (kg), mean±SD	76.6±21.9
Height corrected NC (cm), mean±SD	37.1±4.3
Habitual smoking, n (%)	58 (30.7)
SPO2 (%), mean±SD	96.8±4.4
Pulse rate (bpm), mean±SD	82.2±9.7
History of last dental visit, n (%)
Within the last year	118 (62.4)
More than a year ago	70 (37.0)

SPO2: Percutaneous oxygen saturation, NC: Neck circumference, BMI: Body mass index, bpm: Beats per minute, IQR: Interquartile range, SD: Standard deviation

We found that there is a significant association between risk of OSA and gender, with more number of male patients in moderate risk and more females in high-risk category [P < 0.0001, Table 2].

Table 2

Distribution of risk of obstructive sleep apnea in patients attending the dental clinics

Outcomes value	Female (n=80)	Male (n=108)	P
Risk of OSA
Low	67 (83.8)	50 (46.3)	<0.0001+
Medium	2 (2.5)	54 (50.0)
High	11 (13.8)	4 (3.7)

+Significance level P<0.05 using Chi-square test. OSA: Obstructive sleep apnea

There is a significant difference between risk of OSA and age, male, BMI, obese (≥30 kg/m2), height corrected neck circumference, habitual smoker, systolic BP, diastolic BP, SPO2, ESS score, Mallampati, Class III or IV, tongue indentations, and down sloping soft palate; and remaining all are not significant [Table 3].

Table 3

Clinical differences between low, medium, and high risk of obstructive sleep apnea

Variables	Risk of OSA			P
	Low(n=118)	Medium (n=56)	High (n=15)
Age (years)	30.2±9.7	34.0±9.6	40.6±15.2	0.0004*
Male, n (%)	50 (42.4)	54 (96.4)	4 (26.7)	<0.0001+
BMI (kg/m2)	24.6±4.4	31.4±5.3	28.9±6.9	<0.0001*
Obese (≥30 kg/m2), n (%)	19 (16.1)	34 (60.7)	8 (53.3)	<0.0001+
Height corrected neck circumference	36.0±3.3	39.2±5.2	38.1±5.0	<0.0001*
Habitual smoker, n (%)	25 (21.2)	30 (53.6)	3 (20.0)	<0.0001+
Systolic BP (mmHg)	122.5±8.7	129.2±8.7	124.0±13.6	<0.0001*
Diastolic BP (mmHg)	79.3±7.6	82.4±7.9	78.8±11.5	0.045*
SPO2	97.5±1.7	96.0±3.9	94.3±12.9	0.0002*
Pulse rate (bpm)	82.8±10.7	80.4±6.6	85.1±10.9	0.366
Epworth sleepiness scale score	5.4±3.3	9.8±3.0	10.5±4.2	<0.0001$
Convex facial profile, n (%)	32 (27.1)	10 (17.9)	4 (26.7)	0.403
Mallampati (Class III or IV), n (%)	5 (4.2)	12 (21.4)	2 (13.3)	0.002+
Tonsil size (Grade III or IV), n (%)	6 (5.1)	1 (1.8)	1 (6.7)	0.712
Tongue indentations, n (%)	4 (3.4)	9 (16.1)	3 (20.0)	0.005+
High vaulted palate, n (%)	39 (33.1)	9 (16.1)	5 (33.3)	0.059
Down sloping soft palate, n (%)	29 (24.6)	25 (44.6)	5 (33.3)	0.028+
Molar angle classification, n (%)
Class I	89 (75.4)	37 (66.1)	13 (86.7)	0.091
Class II	22 (18.6)	10 (17.9)	1 (6.7)
Class III	7 (5.9)	9 (16.1)	0
Mean over jet, mm	2.5±1.5	2.1±1.8	3.0±1.0	0.237
Overbite (mm), n (%)
<0	2 (1.7)	4 (7.1)	0	0.629
0-2	49 (41.5)	40 (71.4)	3 (20.0)
>2	12 (10.2)	11 (19.6)	1 (6.7)
BEWE, medium or high risk, n (%)	11 (9.3)	12 (21.4)	3 (20.0)	0.073
Last dental visit more than a year ago	37 (31.4)	28 (50.0)	5 (33.3)	0.056

+Significance level P<0.05 using Chi-square test, *significance level P<0.05 using Kruskal–Wallis test, $significance level P<0.05 using one-way analysis of variance test. BEWE: Basic erosive wear examination index, SPO2: Percutaneous oxygen saturation, BMI: Body mass index, bpm: Beats per minute

There is association between risk of OSA and BMI (kg/m2), neck circumference (in cm), tongue indentations, high ESS score, and age (in years); and remaining all are no association. Analysis showed that obese patients were more likely (almost twice) to have OSA symptoms (odds ratio: 0.61, 95% confidence interval: 0.31–1.20) [Table 4].

Table 4

Logistic regression of the risks of obstructive sleep apnea symptoms

Variable	Univariate analysis, OR (95% CI)	P
Obese (≥30 kg/m2)	0.61 (0.31-1.20)	0.1533
BMI (kg/m2)	0.84 (0.75-0.94)	0.003
Neck circumference, (cm)	0.84 (0.72-0.98)	0.031
Tongue indentations	7.14 (1.44-35.39)	0.016
High ESS score	0.68 (0.49-0.94)	0.021
Age (years)	0.91 (0.86-0.96)	0.001

*Significance level P<0.05. OR: Odds ratio, CI: Confidence interval, ESS: Epworth Sleepiness Scale, BMI: Body mass index

DISCUSSION

Dentists are helpful in screening OSA by identifying abnormalities in dentofacial components that may cause the condition. Thus, they assist physicians in managing the disease. As in most of the situations, they are the ones who are first to identify this condition, referring these patients to physicians or sleep specialists are vital.[56]

About 17.5% of samples were at high risk of OSA. This finding is lower than 26% in a survey of 1506 adults carried out by the National Sleep Foundation in America.[7] Our findings differed from two studies on Saudi population, which reported a prevalence percentage of 39% and 33.3% OSA in females and males, respectively. Levendowski et al. reported the prevalence of OSA to be 33% in males and 6% in females.[8]

We found high-risk OSA to be more common in females. Our findings are in contrast to Bixler et al. who found OSA to be three times more common in males. This might be due to gender hormones, fat distribution, and neurochemical mechanisms.[9] However, medium-risk OSA was found to be more common in males. Obesity was the strongest independent risk factor for OSA in our study (twice more). Peppard et al. reported that for approximately 10% increase in body weight, there is 32% increase in OSA symptoms, and also for 10% body weight loss, there is 26% reduction in the OSA severity.[10]

Worldwide and especially in Saudi Arabia, obesity is a serious public health concern irrespective of age. Al-Quwaidhi et al. stated that the obesity prevalence in adults of Saudi Arabia has increased considerably from 22% to 36% between 1990 and 2005 and might reach 78% in females and 41% in males by 2022.[11] This high percentage of obese females in Saudi population reflected in our study also.

We found that tongue indentations and tonsil size were the statistically significantly associated intraoral features with OSA. Lee et al. found a significant relation of increased tonsil size and risk of OSA in 20–23-year-old male Korean soldiers, confirming the role of upper airway anatomy on the incidence of OSA.[12]

We found that the severity of OSA increases significantly with age. This is in accordance with Deng et al. and contrary to Al-Jewair et al.[613]

Limitations of the study

Less sample size

Subjective nature of our assessment

Objective diagnosis of OSA with PSG should have been done

Gender equality in sample should have been maintained

Only adults were considered.

Hence, there is a need for future studies on a larger sample.

CONCLUSION

OSA can lead to serious consequences if left untreated. All dental surgeons are expected to be familiar with this condition and must consider to incorporate OSA screening while examining any dental patients. The management of this life-threatening condition needs a combined effort by a sleep medicine physician and dental surgeon.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.