Tarsus (eyelids) is a groove in the inner surface of each eyelid. Along the inner margin of the tarsus are modified sebaceous glands known as tarsal glands (or meibomian glands), aligned vertically within the tarsi: 30 to 40 glands in the upper lid, and 20 to 30 in the lower lid, which secrete a lipid-rich product which helps keep the lacrimal secretions or tears from evaporating too quickly, thus keeping the eye moist. Tarsus (eyelids) The tarsi (tarsal plates) are two comparatively thick, elongated plates of dense connective tissue, about in length; one is found in each eyelid, and contributes to its
Dental sealant on the tooth, rather than the decay experienced in sealed and unsealed teeth. The ability of a pit and fissure sealant to prevent dental caries is highly dependent on its ability to retain on the tooth surface. It has been demonstrated that the use of adhesive systems before applying dental sealants improves retention. Traditional retention of a sealant on tooth surface is through acid etching. The most common reason for sealant failure is salivary contamination during sealing placement. Other factors include clinician inexperience, lack of client co-operation, and less effective sealant material used. Sealants may be in conjunction with fluoride