Halitosis
Bad breath of oral or gastrointestinal origin.

Heimlich Maneuver
Techinque employed by rescuer for obstruction of victim's airway.

Hematoma
Swelling of effused blood beneath tissue surface.

HMO or DMO
Health (dental) maintenance organization which specifies a health care (dental) provider a patient may see. Profitability depends on minimization of treatment.

Hydrogen Peroxide
Disinfecting solution used in dental irrigation procedures or as mouth rinse.

Hygienist
Dental auxiliary who cleans teeth and provides patient education; administers local anesthetic, nitrous oxide and performs periodontal scaling.

Hyperemia
Increased blood flow; may cause dental sensitivity to temperature and sweets;
may precede an abscess.

Impaction
Partial or completely unexposed tooth that is wedged against another tooth, bone, or soft tissue, precluding the eruption process.