Human health and medicine

OptiMed trial

OptiMed trial: Swiss-Portuguese pre-post, multisite pilot and feasibility study (NCT06688591, withdrawn) of an interprofessional medication management program for polymedicated home-dwelling older adults; distinct from the Dutch Opti-Med cluster randomized trial.

OPTIMISE trial

OPTIMISE trial (NCT06444711), University of Leeds randomised trial testing cardiology-led GP-practice reviews against NICE guidelines in 138 high-risk community-dwelling adults with cardiovascular, renal, metabolic, and pulmonary disease; distinct from OPTIMISE II and OPTIMISE Your Health.

Optoelectronic plethysmography

Optoelectronic plethysmography (OEP) is a noninvasive motion-capture method, introduced in 2001, that tracks infrared-reflective markers on the chest wall to measure breathing volumes, mainly in research.

Optometrists

Optometrists are eye care professionals holding the Doctor of Optometry (O.D.) degree who examine eyes, prescribe lenses and medications, and refer complex disease; scope of practice varies by jurisdiction.

Optometry

Optometry is the eye care profession of examining eyes, diagnosing vision problems and eye disease, and prescribing corrective lenses; practitioners are optometrists (OD degree in the US), distinct from ophthalmologists, who are physician surgeons.

Optoretinography

Optoretinography (ORG) is a dye-free optical imaging method that measures how photoreceptors in the living retina respond to light, detecting dysfunction in diseases such as retinitis pigmentosa.

Oral administration

Oral administration (per os) is giving drugs by way of the mouth, the most convenient and widely used route. Key facts: lower bioavailability than IV due to first-pass metabolism; Spansule 1952 began oral controlled release; food effects and poor solubility limit it.

Oral allergy syndrome

Oral allergy syndrome, also called pollen-food allergy syndrome (PFAS), is an IgE-mediated cross-reaction between pollen and plant foods causing itchy, swollen mouth and throat, usually mild, rarely anaphylactic, managed by avoiding raw foods.

Oral and maxillofacial surgery

Oral and maxillofacial surgery (OMFS, OMS) is the surgical specialty treating diseases, injuries, and defects of the mouth, jaws, and face, bridging dentistry and medicine through single or dual degree training pathways worldwide.

Oral appliance therapy

Oral appliance therapy (OAT) is a dental treatment for obstructive sleep apnea and snoring in which a removable device worn during sleep holds the lower jaw forward to keep the airway open.

Oral cancer

Oral cancer: squamous cell carcinoma of the lips and mouth (oral cavity), related to HPV-driven oropharyngeal cancer. Key facts: tobacco, alcohol, betel quid, HPV-16; 389,846 global cases 2022; 69% US 5-year survival.

Oral candidiasis

Oral candidiasis (thrush), Candida albicans overgrowth of the oral mucosa; occurs with dentures, antibiotics, steroids, diabetes, HIV; treated with topical nystatin, clotrimazole, miconazole, or oral fluconazole for 7-14 days.

Oral Diagnosis

Oral diagnosis: dental specialty of identifying oral diseases via history, conventional oral examination (visual inspection and palpation), radiographs, and biopsy. COE shows 71-88% sensitivity for oral cancer; biopsy is definitive.

Oral diseases

Oral Diseases (Oral Dis) is a Wiley peer-reviewed journal of oral medicine and head and neck disorders, founded 1995, ISSNs 1354-523X and 1601-0825, edited by Giovanni Lodi.

Oral fibroepithelial polyp

The oral fibroepithelial polyp, also known as an irritation fibroma, is a common benign growth of fibrous tissue in the mouth, usually caused by cheek biting or dentures.

Oral food challenge

An oral food challenge is a medical test in which a patient eats increasing amounts of a suspected food under supervision to confirm or rule out a food allergy.

Oral hexavalent reassortant rotavirus live attenuated vaccine (Vero cell)

Oral hexavalent reassortant rotavirus live attenuated vaccine (Vero cell), brand 武生儿轮宝: Wuhan Institute of Biological Products' oral live vaccine against rotavirus G1, G2, G3, G4, G8, G9 in infants 6–36 weeks; NMPA-approved August 2025, first hexavalent rotavirus vaccine globally.

Oral hygiene

Oral hygiene: daily cleaning of the mouth by brushing with fluoride toothpaste, flossing, and limiting sugar to prevent cavities and gum disease; tools from Babylonian chew sticks to the Tang-dynasty toothbrush and modern fluoride products.

Oral hygiene index

The Oral Hygiene Index (OHI) is a clinical dental index introduced by Greene and Vermillion in 1960 that scores debris and calculus on tooth surfaces, giving a total from 0 to 12.

Oral immunotherapy

Oral immunotherapy (OIT) is an allergy treatment in which gradually increasing swallowed doses of a food allergen raise the reaction threshold, protecting against accidental exposure while daily dosing continues.

Oral Medicine

Oral medicine, also called stomatology, is the dental specialty diagnosing and nonsurgically managing oral, facial, and jaw disorders and oral manifestations of systemic disease; founded 1925, US specialty recognition 2020.

Oral mucocele

Oral mucocele (mucous cyst, ranula when on the floor of the mouth): benign mucus-filled cyst of minor salivary glands, usually on the lower lip, caused by trauma; extravasation and retention types; often self-healing.

Oral mucosa

The oral mucosa, also called the mouth mucosa, is the moist tissue lining the inside of the mouth, protecting it from mechanical, chemical, thermal, and microbial damage.

Oral mucositis

Oral mucositis: painful inflammation and ulceration of the mouth lining caused by chemotherapy and radiotherapy, affecting 40-80% of chemotherapy patients, with five-phase pathobiology and MASCC/ISOO guidelines.

Oral Pathology

Oral pathology, in its modern form called oral and maxillofacial pathology, is the dental specialty diagnosing diseases of the mouth and jaws through biopsy-based histopathology.

Oral recombinant Helicobacter pylori vaccine

Oral recombinant Helicobacter pylori vaccine (口服重组幽门螺杆菌疫苗), a Chinese UreB-LTB fusion oral vaccine by Zou Quanming's Third Military Medical University team; first H. pylori vaccine to complete phase 3 (71.8% one-year efficacy in children), class 1 new drug certificate 2009, but never marketed.

Oral rehydration therapy

Oral rehydration therapy (ORT), using oral rehydration salts (ORS) solution, treats diarrhoeal dehydration by mouth via glucose-sodium absorption; WHO low-osmolarity formula (75 mEq/L sodium, 75 mmol/L glucose) since 2003, credited with saving about a million children yearly.

ORAL STRATEGY trial

ORAL Strategy (Oral Rheumatoid Arthritis triaL Strategy), NCT02187055: a 2017 Pfizer-funded phase 3b/4 head-to-head trial in 1146 methotrexate-inadequate responders showing tofacitinib plus methotrexate non-inferior to adalimumab plus methotrexate; tofacitinib monotherapy was not.

Oral submucous fibrosis

Oral submucous fibrosis (OSF, OSMF): chronic potentially malignant fibrosis of the oral mucosa caused by areca (betel) nut chewing, causing trismus and burning, with 3-10% oral cancer risk.