DENTAL ANATOMY, PHYSIOLOGY & OCCLUSIONdental.subharti.org › oral_path › Introduction to DADH.pdf · Anatomy –Greek word- Anatome •Ana- apart Tome- To cut open /apart •Deals

DENTAL ANATOMY, PHYSIOLOGY &

OCCLUSION

Dr Vijay Wadhwan

Prof. & Head

Oral & Maxillofacial Pathology

Dr. Vijay Wadhwan, Subharti Dental College, SVSU

• The morphology of various teeth in the human dentitions.

• Shape, form, structure, color, & function of teeth in relation with each other, in the same arch & in opposite arch.


Anatomy

– Greek word- Anatome

• Ana- apart Tome- To cut open /apart

• Deals with structure of living things

• Importance related to basic sciences Physiology, Microbiology and Pathology and applied sciences like Medicine & Surgery


Physiology

• Deals with the normal functions of living organisms and their parts.

• All the physical and chemical processes that take place in organisms


occlusion

• Simply means contact between teeth.

• Technically, it is the relationship between the maxillary and mandibular teeth when they approach each other, as occurs during chewing or at rest.

• Occlusion is also termed as articulation.


components of oral cavity Hard tissues

• Perioral bones

– Mandible

– Maxilla

– Skull bones

– Aveolus/Alveolar process

• Dentition

– Primary

– Permanent

– Mixed dentition

• Soft tissues

– Tongue

– Cheeks

– Soft palate

– Lips

– Salivary glands


Classification of dentition & Cusp forms

• Monophyodont

• Diphyodont

• Polyphyodont


Based on kind of teeth found

• Homodont or Isodont

• Specialized homodont

• Heterodont


HOMODONT

• Functionally & Anatomically similar but size may vary. Eg Amphibian, Reptiles

SPECIALIZED HOMODONT

• Functional specialization is required like venomous fangs. Eg Venomous snakes

HETERODONT

Four different types for cutting, tearing, grinding Eg Mammals


Based on attachment to bone

• Acrodont

• Pleurodont

• Thecodont


ACRODONT

• Teeth attached on top surface of jaw bone by fibrous membrane. No roots. Lost easily Eg. Fish, Amphibians

PLEURODONT

• Teeth attached on inner side and upper side. Stronger attachment Eg Lizards

THECODONT

Root is fixed firmly to the jawbone in socket with the help of cementum. Eg Mammals


Development

• Primary dentition

Development : 6-7 weeks IU –postnatal age of 3

Eruption : 6 month of age -28 ± 4 months

• Transition /Mixed dentition: 6-12 years of age

• Permanent Dentition:6 – 18-25 years of age


Formulae for mammalian teeth

• Four classes of teeth: Denominations

• Incisors :( I )

• Canines :(C)

• Premolars: (P)

• Molars :(M)


Formula for primary teeth

• I 2 C 1 M 2

2 1 2 =10


Formula for permanent teeth • I 2 C 1 P 2 M 3

2 1 2 3 =16


Crown & Root

• Crown-The portion of tooth visible in the oral cavity

• Root –the portion of tooth embedded in the bone


Anatomical & Clinical Crown

• Anatomical crown-from the incisal edge /tip of cusp to the cervical line

• Clinical crown -from the incisal edge /tip of cusp to the gingiva (exposed portion)


Tissues of tooth

• Enamel

• Dentin Hard/Mineralised

• Cementum tissues

• Pulp Soft tissue


• Crown covered by Enamel

• Root covered by Cementum

• Crown & root joined at cemento-enamel junction (CEJ) /Cervical line


Other supporting tissues

• Periodontal ligament

• Alveolar bone

• Gingiva (Oral Mucous Membrane)


Surfaces & Ridges

According to their positions & uses: • Facial surfaces Labial surfaces- towards the lip Buccal surfaces- towards the cheek • Lingual surfaces-towards the tongue • Proximal surfaces-towards adjoining teeth Mesial Distal • Occlusal –towards opposite jaw (occlusion)


Division into thirds

Crown

• Cervico-Occlusally

• Faciolingually

• Mesiodistally

Root

• Cervicoapically

• Faciolingually

• Mesiodistally


Line angle

• Formed by Union of Two surfaces

• Anterior 06 Line angles

• Posterior 08 Line angles


Point angle

• Formed by Union of Three surfaces

• Anterior 04 Point angles

• Posterior 04 Point angles


Landmarks

• Cusp • Tubercle • Cingulum • Ridge Marginal ridge Triangular ridge Transverse ridge Oblique ridge

• Fossa • Sulcus • Groove Developmental groove Supplemental groove • Pit • Lobe


Cusp

• A cusp is an elevation or mound on the crown portion of a tooth making up a divisional part of the occlusal surface.


Mamelon

• Any one of the three rounded protuberances on the incisal ridges of newly erupted incisor teeth.


Tubercle

• It is a smaller elevation on the crown produced by extra formation of enamel.


Cingulum

• A cingulum or girdle is the lingual lobe of an anterior tooth & makes up the bulk of the cervical third of the lingual surface.


Lobe

• It is one of the primary section of formation in the development of the crown.

• Cusps & mamelons are representative of lobes.


Ridge

• A ridge is any linear elevation on the surface of a tooth & is named according to its location. (buccal, marginal, or incisal)


Labial ridge

• Running cervicoincisally at the centre of the labial surface

• Prominent in maxillary canines


Buccal ridge

• Running cervico-occlusally in premolars buccal aspect

• Prominent in first premolar


Lingual ridge

• Running cervicoincisally at the centre of the lingual surface


Linguoincisal ridge

• Running mesiodistally in the lingual surface at incisal third


Cusp ridge

• Inclined surface that forms an angle at cusp tip

• Also known as Cusp Arm


Marginal ridges

• Marginal ridges are those rounded borders of enamel that form the mesial & distal margins of the occlusal surfaces of premolars & molars,& lingual surfaces of incisors & canines.


Triangular ridge

• Ridges that descend from the tips of the cusps of molars & premolars toward the central part of the occlusal surfaces.

• Slopes of each side of the ridge are inclined to resemble two sides of a triangle.


Transverse ridge

• A transverse ridge is the union of two triangular ridges transversely crossing .the surface of a posterior tooth .

• Form by joining buccal & lingual triangular ridges.


Oblique ridge

• A ridge obliquely crossing the occlusal surfaces of maxillary molars & formed by the union of


Fossa

• It is an irregular depression /concavity .

Lingual fossae

Central fossae


Sulcus

• It is a long depression or valley on the surface of a tooth between ridges & cusps, the inclines of which meet at an angle


Developmental groove

• It is a shallow groove or line between the primary parts of the crown or root.

Supplemental grooves

Buccal groove

Lingual groove


Pit

• It is a small pinpoint depression located at the junction of developmental grooves


Documents

DENTAL ANATOMY, PHYSIOLOGY & OCCLUSIONdental.subharti.org › oral_path › Introduction to DADH.pdf · Anatomy –Greek word- Anatome •Ana- apart Tome- To cut open /apart •Deals