Sleep-Disordered Breathing – A Dental Perspective

Abstract

What is Sleep Disordered Breathing? What are the causes of Sleep Disordered Breathing? What role does an Orthodontist play? The article aims at answering such questions and spreading the ideology and seriousness of this disorder. Normal sleep involves air passing through and going directly down to the lungs. With an obstructed airway, the structures in the back of the throat occlude the airway due to an inadequate motor tone of the tongue and airway dilator muscles, and thus, prevent the air from passing.

INTRODUCTION

What is sleep-disordered breathing? What are the causes of sleep-disordered breathing? What role does an orthodontist play?

The article aims at answering such questions and spreading the ideology and seriousness of this disorder.

Normal sleep involves air passing through and going directly down to the lungs. With an obstructed airway, the structures in the back of the throat occlude the airway due to an inadequate motor tone of the tongue and airway dilator muscles and thus prevent the air from passing.

WHAT IS SLEEP-DISORDERED BREATHING?

Sleep-disordered breathing refers to a range of issues, from simple snoring to severe obstructive sleep apnea (OSA). Significant arterial hypoxemia and hypercapnia are caused by sleep-disordered breathing (SDB), which is described as transient, often cyclical cessations in breathing followed by a prolonged reduction in breathing [Figure 1]. These disorders are a group of symptoms consisting of upper airway dysfunction, snoring, effortful breathing secondary to decrease in airway volume, and pharyngeal obstruction.[1]

Figure 1.

The difference between normal airway and collapsed airway

PREDISPOSING FACTORS

There are various factors contributing to the development of OSA in Table 1. Sleep apnea is also a concern for people with Down's syndrome, Marfan syndrome, Prader–Willi syndrome, etc.

Table 1.

Factors contributing to sleep apnea

sl. no	Factors contributing to sleep disordered breathing
1	Anatomical abnormalities resulting in upper airway obstruction
2	Adenoids
3	Smoking and alcohol consumption
4	Retrognathic mandible
5	Enlarged tonsils, tongue, elongated soft palate
6	inferiorly positioned hyoid bone

Role of dentist

By detecting a narrow and anatomically affected upper airway, dentists can have a critical role in recognizing OSA during routine dental examinations. Using a simple questionnaire can be of great help to a dentist. Malocclusion is a form of maxillofacial abnormality that has been linked to breathing through the mouth as a main cause.[2,3,4]

Role of orthodontist in sleep-disordered breathing

Despite the fact that malocclusion is a major problem with serious health consequences in a developing nation such as India with inadequate health resources, the significance of malocclusion in SDB is frequently neglected, resulting in the condition being underdiagnosed and untreated. In such a situation, the responsibility of a professional orthodontist in early evaluation, preparation of an individualized treatment plan, and implementation of proper therapy becomes critical.[5] An orthodontist can clearly evaluate the anatomic variables that contribute to breathing problems. Anatomic traits include maxillary or mandibular retrognathism and a higher lower jaw.[6]

DIAGNOSTIC TOOLS FOR MALOCCLUSION ASSESSMENT AS RELATED TO OBSTRUCTIVE SLEEP APNEA

With orthodontic diagnosis and treatment planning, a detailed functional, positional, and structural examination of the dentofacial pattern is required, as well as an assessment of the pharyngeal structures. Some of the factors contributing to sleep apnea is shown in Table 1.

Cephalometric observation

The alterations in anatomic structure can be identified by an orthodontist using adequate radiological screening. Lateral cephalometry is a simple, low-cost, and repeatable technique for evaluating the pharyngeal airways. It provides precise measurements of skeletal and soft tissue components [Figure 2].

Figure 2.

Standard cephalometric planes and angulations are recorded

Increased Frankfort mandibular plan angle or maxillary mandibular plan angle are cephalometric characteristics linked with SDB.[1]

CLINICAL PREDICTION MODELS

Measurements are taken from the maxillary cast using a pair of digital calipers to measure the interdental width [Figure 3]. The presence of a posterior transverse discrepancy is recorded as a buccal crossbite.[6]

Figure 3.

Diagram of the maxillary dental arch illustrating the linear measurements taken from study models. ICD, intercanine distance; IP1D, first interpremolar distance; IP2D, second interpremolar distance; IMD, intermolar distance; MD, molar depth

Three-dimensional volumetric analysis

In the comprehensive assessment of craniofacial morphology, three-dimensional volumetric reconstructions and analyses, such as cone beam computed tomography (CBCT), are critical.[3]

However, CBCT does not provide information on neuromuscular tone, collapse susceptibility, or airway function. Depending whether the patient is asleep or awake, there are variations in position and function of airway.[7]

According to the International Classification of Sleep Disorders, OSA can be diagnosed by either of two sets of criteria.

The first set of diagnostic criteria for OSA includes the presence of at least 1 of the following:

1. The patient has sleepiness, fatigue, or insomnia symptoms

2. The patient wakes with gasping or choking

3. During a PSG, the patient has been diagnosed with hypertension, coronary artery disease, congestive heart failure, and type 2 diabetes mellitus; and polysomnography (PSG) shows at least 5 predominantly obstructive events per hour of sleep.

The second criterion was whether PSG revealed 15 or more primarily obstructive events.

The number of apnea, hypopneas, and respiratory effort-related arousals per hour of sleep are measured using the respiratory disturbance index.

The apnea–hypopnea index, which counts the number of apnea and hypopneas per hour of sleep, was the other index [Table 2].

Table 2.

Types of sleep apnea.

Forms of OSAHS	AHI Score
Mild	AHI 5-14/hrs
Moderate	AHI 15-30/hrs
Severe	AHI>30/hrs
Very Severe	AHI>40/hrs

QUESTIONNAIRES USED

Berlin questionnaire

In 1996, during a symposium of sleep apnea specialists in Berlin, the Berlin questionnaire was adopted having a series of questions about the risk factors and symptoms of sleep apnea. They are divided into three types in general.

There are five snoring questions (category 1), four daytime sleepiness questions (category 2), one blood pressure question, and basic questions regarding age, social background, gender, body weight, height, and neck circumference.

Category 3 is positive if the body mass index is >30 kg/m². If any two categories are positive, then the patient is at high risk.[8]

Polysomnography

The purpose of PSG is to quantify the amount of time spent sleeping at night and sleep variations. PSG can assess sleep time, stages of sleep, respiratory effort and airflow, heart rhythm, pulse oximetry for blood oxygen saturation, and abdominal, using multichannel recordings when performed under standardized settings.[9]

MANAGEMENT OF SLEEP-DISORDERED BREATHING

Behavioral modification

The first stage in treatment is to change one's behavior or lifestyle.[8] Patients will benefit from sleeping in a 30-degree inclined posture because it prevents the tongue and palate from slipping backward and the airway from collapsing due to gravity.

Nasal expiratory device

It is ideally useful in position-dependent SDB as it creates a free passage for air to pass by increasing nasal expiratory resistance.

PHARMACOLOGICAL MANAGEMENT

Behavioral modification

Avoiding alcohol, drugs, and sleeping pills might reduce airway dilator function and aggravate the illness.[5]

According to the American Academy of Sleep Medicine, Modafinil is a routine treatment for people with excessive daytime sleepiness. Protriptyline is used as a second-line treatment and has been approved by the FDA.[8]

Nonsurgical interventions

Continuous positive airway pressure

Continuous positive airway pressure (CPAP) during sleep has been the gold standard of therapy.[9] For moderate-to-severe cases, CPAP is the best therapy choice.

During sleep breathing, CPAP functions by keeping the airway clear. Its flow generator provides positive pressure through air tube to a nasal mask of the patient. This prevents interrupted breathing by replacing normal oxygen levels.

Oral appliance therapy

The purpose of these equipment is to anteriorly advance jaw and tongue creating more space in the lower pharynx for uninterrupted breathing while asleep.

Tongue retention devices and mandibular advancement appliances are two examples.[5] The lower jaw and tongue are brought forward with the aid of a mandibular advancement splint or mandibular retention device (Snore Guard, Herbst appliance, tongue retaining device), which keeps the airway open. A soft palate lifter is used, as well as a combination of an oral appliance with CPAP [Figure 4].[8]

Figure 4.

Continuous positive air pressure

Oral appliance [Figure 5] is indicated in patients with,

Figure 5.

Mandibular advancement devices

1. Snoring or mild disturbed breathing pattern who do not respond for treatment with behavioral measures

2. Moderate to severe disturbed breathing who decline to use nasal CPAP.

Advantage of oral devices

• Decrease in breathing interruptions

• Increase airflow

• Good patient compliance.

Disadvantages of oral appliances

• Reciprocal forces on other teeth and jaw

• Dry mouth

• Dental pain

• headache, and

• TMJ disorders.

Headgear therapy

Orthopedic growth modification headgear, which helps to change the direction of the maxilla's growth, has long been a part of some orthodontic procedures. Since the changes produced by headgear on maxilla is minor, no significant changes in upper airway volume or morphology would be predicted.

Surgical interventions

When noninvasive treatments such as CPAP and oral appliances have failed, surgery may be considered [Figure 6]. It is performed when there are anatomic defects.

Figure 6.

Consequence of not treating sleep-related breathing disorders

Tracheostomy

It is a surgical procedure that repairs SDB more successfully and can be used as a preventative step in high-risk individuals before other airway procedures. In individuals with chronic obstructive lung disease, congestive heart failure, or obesity with hypoventilation, it is not recommended.[8]

• Uvulopalatopharyngoplasty

• It is the removal of the soft palate's posterior edges as well as any undesired mucosa on the pharyngeal walls to reconstruct the throat.

SUMMARY

The demand for incorporating routine sleep checks into orthodontic practice is driven by societal preference, as patients who are aware of SDB will visit dental clinics. A casual interaction with a patient could lead to a good discussion about how an orthodontist can assist in the diagnosis and treatment of this problem. It is time for orthodontists to take a lead role and responsibility in screening patients for this disease and, if need arises, oral devices should be advocated.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.