Application of Berlin questionnaire in obstructive sleep apnea syndrome through soft palate morphology types

Abstract

Background: Obstructive sleep apnea (OSA) is a sleep disorder characterized by intermittent complete and partial airway collapse, resulting in frequent episodes of apnea and hypopnea. The Berlin questionnaire (BQ) is a simple, inexpensive instrument used to screen for OSA, which is about risk factors for sleep apnea, namely, snoring behavior, daytime sleepiness or fatigue, and the presence of obesity or hypertension. This 10-question test has since then become well known for its accuracy in predicting the presence of sleep apnea in patients. Cephalometry is a relatively inexpensive method and it permits a good assessment of the soft tissue elements that define the soft palate and its surrounding structures. Therefore, the present study aims to study the morphology of the soft palate using lateral cephalometry and classify it into various types. And to identify the individuals with OSA syndrome through a particular type of soft palate and correlate it with the BQ.

Material and methods: This prospective study was conducted in the Department of Oral Medicine and Radiology of D.Y.Patil Dental College, Pune. About 150 subjects for the study were selected by random sampling from the outpatient department of Oral Medicine and Radiology and the patients were referred from the orthodontics department. Lateral cephalograms were assessed for soft palate morphology types, and all participants filled the BQ. A Chi-square test was applied. The level of significance was set at P < 0.05.

Results: Among six types of the soft palate, the maximum number of participants had type 2 (rat-tail type) of the soft palate (26.0%). A highly significant association was found between the BQ (positive and negative response) and soft palate morphology types (i.e., P < 0.01). A maximum number of participants who responded to the BQ had type 5 (S type) of the soft palate (76.47%).

Conclusion: The type 2 (rat-tail) soft palate was the most frequent type, while the type 4 (straight-line) shape was the least common among all the six types. The persons with type 5 (S-shape) soft palate responded more positively to the BQ as compared to other types of soft palate. This shows that a particular type of soft palate could be responsible for causing OSA syndrome.

Clinical significance: Lateral cephalogram and BQ, which are relatively inexpensive and widely available, can be used in resource-limited and thickly populated countries like India to correctly identify patients with OSA syndrome.

Keywords: Berlin questionnaire; lateral cephalogram; obstructive sleep apnea syndrome; soft palate.

Figure 1

Berlin questionnaire format (part-1)

Figure 2

Berlin questionnaire format (part-2)

Figure 3

Berlin questionnaire format (part-3)

Graph 1

Distribution and proportion of soft palate morphology types

Graph 2

Berlin questionnaire and soft palate morphology types