Simple mechanisms which predispose the mouth to trauma and ulceration are xerostomia (dry mouth – as saliva usually lubricates the mucous membrane and controls bacterial levels) and epithelial atrophy (thinning, e.g., after radiotherapy), making the lining more fragile and easily breached. : 7  Stomatitis is a general term meaning inflammation within the mouth, and often may be associated with ulceration.Pathologically, the mouth represents a transition between the gastrointestinal tract and the skin, meaning that many gastrointestinal and cutaneous conditions can involve the mouth. Some conditions usually associated with the whole gastrointestinal tract may present only in the mouth, e.g., orofacial granulomatosis/oral Crohns disease.Similarly, cutaneous (skin) conditions can also involve the mouth and sometimes only the mouth, sparing the skin. The different environmental conditions (saliva, thinner mucosa, trauma from teeth and food), mean that some cutaneous disorders which produce characteristic lesions on the skin produce only non specific lesions in the mouth. The vesicles and bullae of blistering mucocutaneous disorders progress quickly to ulceration in the mouth, because of moisture and trauma from food and teeth. The high bacterial load in the mouth means that ulcers may become secondarily infected. Cytotoxic drugs administered during chemotherapy target cells with fast turnovers such as malignant cells. However, the epithelia of the mouth also has a high turnover rate and makes oral ulceration (mucositis) a common side effect of chemotherapy.Erosions, which involve the epithelial layer, are red in appearance since the underlying lamina propria shows through.
The American Academy of Sleep Medicines protocol for obstructive sleep apnea (OSA) recommends oral appliances for those who prefer them to CPAP and have mild to moderate sleep apnea or those that do not respond to/cannot wear a CPAP. Severe cases of OSA may be treated with an oral appliance if the patient has had a trial run with a CPAP. Oral appliances should be custom made by a dentist with training in dental sleep medicine.Mild obstructive hypopnea can often be treated by losing weight or by avoiding sleeping on ones back. Also quitting smoking, and avoiding alcohol, sedatives and hypnotics (soporifics) before sleep can be quite effective. Surgery is generally a last resort in hypopnea treatment, but is a site-specific option for the upper airway. Depending on the cause of obstruction, surgery may focus on the soft palate, the uvula, tonsils, adenoids or the tongue. There are also more complex surgeries that are performed with the adjustment of other bone structures - the mouth, nose and facial bones. Central hypopnea
People with neuromuscular disorders or hypoventilation syndromes involving failed respiratory drive experience central hypoventilation. The most common treatment for this form is the use of non-invasive ventilation such as a bilevel positive airway pressure (BPAP) machine. Etymology
The word hypopnea uses combining forms of hypo- + -pnea, from the Greek roots hypo- (meaning low, under, beneath, down, below normal) and pnoia (meaning breathing). See pronunciation information at dyspnea. See also
List of terms of lung size and activity
Bradypnea

References

http://www2.merriam-webster.com/cgi-bin/mwmednlm?book=Medical&va=hypopnea
http://www.emedicine.com/neuro/TOPIC419.HTM
http://www.sleepdex.org/dyssomnias.htm
https://www.sciencedaily.com/releases/2007/10/071015081737.htm
http://www.aasmnet.org/Resources/PracticeParameters/PP_MedicalTherapyOSA.pdf
Alcohol and health