Tooth Histology and Biomineralization: Structures, Tissues, and Processes 낱말 카드

What are teeth composed of?

Teeth are composite organs made of multiple hard and soft tissues.

What are the two anatomical parts of a tooth?

Crown and root.

What percentage of the mouth's surface do teeth constitute?

About 20%.

What are primary teeth also known as?

Baby teeth, milk teeth, or deciduous teeth.

When do primary teeth typically begin to erupt?

Around 6 months to 3 years.

How many primary teeth are there?

20 teeth.

What are secondary teeth also called?

Adult teeth or permanent teeth.

When do secondary teeth typically arrive?

Between 6 to 18 years.

How many secondary teeth are there?

32 teeth.

What is mixed dentition?

The presence of both primary and secondary teeth at the same time, typically from ages 6 to 13.

What is the outermost layer of the tooth crown?

Enamel.

What is the primary function of enamel?

To break down food and resist forces of chewing, wear, and acids.

What type of cells produce enamel?

Ameloblasts.

What is unique about the origin of enamel?

It is the only dental tissue that is ectodermal/epithelial in origin.

What is the hardest substance in the body?

Enamel.

What is dentin?

The bulk of the tooth, providing a tough, flexible layer beneath enamel.

What cells produce dentin?

Odontoblasts.

What is the structure of dentin?

Porous and hydrated due to dentinal tubules.

What is the role of odontoblasts?

They maintain long cell processes that extend through dentinal tubules, delivering nutrients and keeping dentin hydrated.

What does dental pulp contain?

Blood vessels, nerves, stem cells, and more.

What is the role of the periodontal ligament (PDL)?

It attaches and supports the tooth.

What is cementum?

A tissue that covers the root of the tooth.

What is the significance of the biomineralization process in teeth?

It is essential for the formation and maintenance of dental and periodontal tissues.

What happens to enamel over time?

It is supposed to last a lifetime as it has no cells to repair or replace it.

What are odontoblasts and where do they live?

Odontoblasts are cells that live in the dental pulp, at the pulp-dentin border.

What is the primary function of dentin?

Dentin is secreted at the inner edge and contains dentinal tubules, which are a key feature of its ultrastructure.

What is the composition of the pulp in teeth?

The pulp is rich in blood vessels and nerves.

What structures make up the periodontium?

The periodontium consists of cementum, periodontal ligament (PDL), alveolar bone, and gingiva.

What is gomphosis?

Gomphosis is a unique joint called a tooth socket, where the periodontal ligament connects bone to tooth.

What is cementum and where is it located?

Cementum is a tissue that covers the root surface of the tooth and attaches it to the jawbone via the periodontal ligament.

What are the functions of cementum?

Cementum attaches the tooth to the jawbone, grows by slow apposition, and has some capability for repair after damage.

What is the role of the alveolar bone?

The alveolar bone supports teeth and distributes occlusal forces.

What cells are responsible for the formation of alveolar bone?

Alveolar bone is made by osteoblasts and is home to osteocytes, while being resorbed by osteoclasts.

What is the oral mucosa and its function?

The oral mucosa, including gingiva and junctional epithelium, provides a physical barrier and serves as an outpost for immune cells.

What is biomineralization?

Biomineralization is the process where living organisms produce minerals, forming hard, mineralized tissues like bones and teeth.

What are the four unique mineralized tissues in the oral cavity?

The four mineralized tissues are enamel, dentin, cementum, and bone.

What is the primary component of the extracellular matrix in dentin, cementum, and bone?

Type I collagen composes 90% of the matrix in dentin, cementum, and bone.

What is the difference between geologic and biologic hydroxyapatite?

Geologic hydroxyapatite forms under high heat and pressure, while biologic hydroxyapatite forms under mild conditions conducive to life.

What is the role of collagen fibers in the periodontal ligament?

Collagen fibers in the PDL extend between cementum and bone, providing structural support and facilitating tooth attachment.

How does the oral cavity respond to tooth use and loading?

The alveolar bone remodels rapidly in response to tooth use and loading, demonstrating a great capacity for repair.

What is the significance of junctional epithelium?

Junctional epithelium is a specialized epithelium that seals underlying tissues and allows for immune surveillance.

What is the composition of enamel?

Enamel is primarily composed of enamel-specific proteins and hydroxyapatite.

What are the main cells involved in the formation of cementum?

Cementoblasts are the main cells responsible for the formation of cementum.

What is the role of fibroblasts in the periodontal ligament?

PDL fibroblasts are responsible for the formation and maintenance of the periodontal ligament.

What is the primary mineral found in dentin?

Dentin is primarily composed of hydroxyapatite.

What is the relationship between collagen and mineral deposition?

Gap zones in collagen fibers are thought to initiate mineral deposition, which can then spread throughout the fibers.

What is the primary function of the oral mucosa?

The oral mucosa provides a physical barrier and facilitates immune cell activity.

What is the significance of Sharpey's fibers?

Sharpey's fibers are collagen fibers from the PDL that integrate into cementum and alveolar bone, providing stability.

What is the primary inorganic component of enamel?

Hydroxyapatite (HA): Ca10(PO4)6(OH)2

What unique proteins are used in the mineralization of enamel?

A suite of unique proteins that are almost completely removed by the time enamel is mature.

What happens to collagen during enamel formation?

No collagen is involved in directing enamel formation.

What is the shape of hydroxyapatite crystals in bone and dentin?

Plate-like 'habit' or shape, measuring 12-20 nm in width and 20-50 nm in length.

How do hydroxyapatite crystals in enamel differ from those in bone?

Enamel crystals are elongated and greater than 10 times the width and length of those in bone.

What must organisms do to control biomineralization?

Prevent spontaneous precipitation of calcium and phosphate, ingest and transport ions, deposit extracellular matrix, and regulate hard tissue removal/remodeling.

What are the consequences of hypomineralization?

Poor bone growth, rickets, thin and weak bones and teeth, fractures, dental abscesses, and defective enamel.

What is hypermineralization?

Too much mineral or mineral in the wrong places, leading to inappropriate mineralization of soft tissues.

What syndrome is associated with a mutation in the MGP gene?

Keutel syndrome.

What condition is linked to the AMELX, AMBN, ENAM, and MMP20 mutations?

Amelogenesis imperfecta (AI).

What role does vitamin D play in mineral metabolism?

It regulates calcium and phosphate metabolism and promotes intestinal absorption of these ions.

What are the effects of chronic vitamin D deficiency?

Decreased calcium and phosphate levels.

What dental condition can result from childhood vitamin D deficiency?

Enamel hypoplasia and structural defects.

What is the impact of reduced phosphate in childhood?

It can lead to rickets and poorly mineralized bone.

What are the implications of enamel hypoplasia?

Increased prevalence of caries due to structural and mineralization defects.

What is the significance of the timing of vitamin D deficiency?

It affects the mineralization of both deciduous and permanent teeth.

What is the role of negatively charged amino acids in biomineralization?

They help regulate mineral initiation and growth, particularly in bones and teeth.

What is Winchester syndrome associated with?

Loss of control in biomineralization leading to various skeletal issues.

What mutation is linked to hypophosphatasia (HPP)?

ALPL mutation.

What condition is characterized by calcification of joints and arteries?

Generalized arterial calcification in infancy (GACI) associated with ENPP1 mutation.

What is the mutation associated with fibrodysplasia ossificans progressiva (FOP)?

ACVR1 mutation.

What is the outcome of ectopic mineralization in soft tissues?

It can lead to debilitating or lethal conditions.

What is the relationship between dental mineralization defects and caries?

Defects in mineralization can lead to an increased risk of dental caries.