Halitosis – the medical term for bad breath.

Hard Palate – the roof of the mouth.

Heat-Sterilizing – the use of an autoclave or dry-heat sterilizer to kill all potential disease-causing agents that remain on dental instruments following patient treatment.

Heterodont – different types of teeth within the same dentition (e.g., incisors, canines, molars, etc.).

Histo-Differentiation – development into a specialized tissue.

Histology – the study of tissues.

Homodont – the presence of only one type of tooth in the dentition.

Hygienist – dental hygienists are licensed medical professionals specializing in preventive oral health care.

Hyperplasia – the over-growth of a part or area; an increase in the number of cells.

Hypersensitivity – a sharp, sudden, painful reaction in teeth when exposed to hot, cold, chemical, mechanical, or osmotic (sweet or salty) stimuli.