专业术语—口腔生理学术语S2(英文详解)（在线收听）

    Sesamoid bone - a small bone which appears at the age of thirteen, adjacent to the carpo-metacarpal joint of the thumb and is of use in determining the skeletal age of a child.

    Sharpey's fibres. - are collagen fibres which have been trapped in bone or cementum in order to anchor them. see also extrinsic fibres.

    Sialoproteins - a family of adhesion molecules which include osteopontin. Bone sialoprotein is formed by cells lining the root surface and influences cementoblast differentiation which encourages mineralisation. Dentine sialoprotein appears to inhibit mineralisation. Osteoclasts adhere both to bone sialoprotein and osteopontin.

    Sinus - a curved out hollow space in side the skull which is lined by respiratory epithelium and drains into the back of the throat. For example, maxillary s., ethmoid, s., sphenoids.

    Solubility-product - a value found by multiplying the concentration of positive IONS by the concentration of negative ions in a solution of a salt, hence [Ca]+ x [P04]- = Ksp(solubility product). The value for Ksp is constant when the solution of ions is saturated and in balance with its solid crystalline form. Acid helps increase the solubility of a weakly soluble salt.

    Sphenomandibular ligament - a ligament which joins the lingula of the mandible to the spine of the sphenoid bone.

    Spongy-bone - the bone beneath the cortical bone which has been thinned out by bone remodelling to form a spongy inner core. Also called cancellous (lace-like) bone.