Ch 8 Dentistry

Enamel

Enamel

• hardest material of the body

• makes up the anatomical crown of the tooth

Dentin

• makes up the bulk of the tooth

• covered by enamel on the crown and cementum on the root

Cementum

• rigid connective tissue that covers the root of the tooth

• anchors tooth to the bony socket

Pulp

• made of blood vessels and nerves

• blood supply derived from branches of dental arteries

Periodontium

• supports, nourishes, and protect the teeth

• consists of cementum, alveolar bone, and periodal ligaments

Apical foramen

the hole at the tip of the root where nerves and blood vessels enter the tooth

Apex

situated just above the apical foramen

Pulp horns

elongations of the coronal pulp

Coronal pulp

connected with the accessory canal and lies in the crown portion of the tooth

Bud (initation) stage

tooth formation begins

Cap (proliferation) stage

cells of the developing tooth increases ; tooth increases in size

Bell (histodifferentiation) stage

different tissues of the tooth form

Morphodifferentiation

development of different tooth types or shape

Anterior mandibular region

site of earliest signs of tooth development at 5 to 6 weeks

Tooth and jaw size

genetic factor that is most often concerned in prenatal development

Succedaneous teeth

• also known as decidous teeth

• permanent teeth

Eruption

movement of the tooth into its functional position in the oral cavity

Exfoliation

normal process by which the primary teeth are lost

Osteoblasts

cells that form bone

Osteoclasts

cells that resorb bone

Osteocytes

a bone cell, formed when an osteoblast becomes embedded in the matrix it has secreted

Fibroblasts

• cells that produce collagen and other fibers

• permit continuous and rapid remodeling of periodontal ligament

Odontoblasts

cells that form dentin

Cementoblasts

cells that form cementum

Ameloblasts

cells that form enamel

Attrition

a wearing down over time

Remodeling

occurs in response to forces placed on the tooth in its socket

Teratogens

• environmental agents that harm the embryo or fetus

• infections, radiation exposure, drugs

Preimplantation

• first period of prenatal development

• first week to second week

Embryonic period

• most critical stage of prenatal development, from second to eighth week

• face and related tissues begin to form

• ectoderm, mesoderm, and endoderm are produced

• branchial arches have formed

Fetal phase

• eight weeks to birth

• all primary teeth develop by 17th week

• about 44 teeth developing by birth

Clinical crown

part of the tooth that is visible in the mouth

Anatomical crown

portion of the tooth that is covered with enamel

Ectoderm

• outermost embryonic layer

• enamel of teeth

Mesoderm

• middle layer

• cementum, dentin, and pulp form

Endoderm

innermost layer

Lining mucosa

• soft, moist, can stretch and compress

• lines inside of cheeks and underside of tongue

Masticatory mucosa

• rubbery and resilient

• lines attached gingiva and upper surface of tongue

Specialized mucosa

located on the top surface of the tongue as papillae

Yellow to grayish white

colors of enamel

Primary dentin

• formed before eruption

• forms bulk of the root

Secondary dentin

• begins forming after eruption

• continues very slow formation throughout tooth's lifespan

Tertiary (reparative) dentin

• formed in response to irritation

• appears as a localized deposit on the wall of the pulp chamber