Dental Implications - Sleep Apnoea
Snoring? Obstructive Sleep Apnoea?
Obstructive Sleep Apnoea is characterized by frequent episodes of stopped or very shallow breathing, each lasting 10 seconds or more. It’s caused by an obstruction of the upper airway because of inadequate motor tone of the tongue and/or airway dilator muscles. Diagnosis usually requires overnight polysomnography to detect the frequency of apnoea (stopped breathing) and hypoapnoea (very shallow breathing) events.
The apnoea- hypoapnoea index (AHI) is the average number of disordered breathing events per hour. Typically OSA syndrome is defined as an AHI of five or greater with associated symptoms (e.g., excessive daytime sleepiness, fatigue, etc.) or an AHI of 15 or greater, regardless of associated symptoms.
Incidences of sleep bruxism is higher in children and decreases with age. It is found in 8 percent of the general population and 14-20 percent of children. A constricted airway due to adenoid and tonsil hypertrophy is often the cause for a constricted airway in children, which opens up with age.
Sleep bruxism is the grinding or clenching of teeth during sleep, which is preceded by sleep arousals. Sleep arousal is a naturally occurring 3-10 second shift occurring during deep sleep, which is accompanied by an increase in muscle tone. This motor activity causing clenching and grinding of jaw muscles is believed to be an attempt to open the constricted airway. Sleep bruxism occurs in multiple episodic bursts throughout the night. Some episodes may produce audible grinding noise.
Increased muscle tone and micro arousals caused by sleep apnoea events are the trigger factors for sleep bruxism.
Sleep apnoea episodes are often implicated as a contributing aetiology of GERD and sleep bruxism. Increased negative pressure in intrathoracic space during an apnoeic episode causes gastric acid to expel into the oesophagus. This triggers micro arousals leading to sleep bruxism.
Evaluate the following:
- Tooth wear – Asymmetric wear on areas other than occlusal surfaces will suggest the presence of an erosive process.
- Hypersensitive teeth
- Tongue indentation – Linea alba on cheek along the occlusal plane
- Gingival recession (loss of gum tissue around the tooth)
- Hypertrophy (muscular enlargement due to over use) of muscles of mastication
- Criteria that would increase the risk for sleep apnoea:
- Body Mass Index of more than 35.
- Age more than 50.
- Neck size more than 40 cm.
- Gender is male.