chapter 2 Flashcards
anodontia
zero teeth
hypodontia
too few teeth
-uncommon in deciduous dentition, but common in permanent dentition
what syndromes are associated with hypodontia?
- downs
- Crouzon
- ectodermal dysplasia,
- ehlers-danlos
hyperdontia
too many teeth (supernumerary teeth)
what is the most common hyperdontia?
Mesiodens (between 8-9)
followed by distomolar=4th molar, paramolar
hyperdontia is often associated with what syndroms?
- Apert
- Cleidocranial dysplasia
- Crouzon
- gardner
what are the most common areas of hypodontia?
3rd molars 20-23%
2nd premolars
then lateral incisors
hypodontia is more common in what sex and what is the ratio?
more common in females, 1.5:1
hyperdontia is more common in what sex and what is the ratio?
males, 2:1 ratio
which arch is more affected by hyperdontia?
maxilla
natal teeth
teeth present at, or soon after, birth
- prematurely erupted deciduous teeth
- only remove if extremely mobile or causing traumatic ulcerations (Riga-Fede disease. ie the teeth makes ulcerations on infants tongue and moms breast)
which are the most common natal teeth?
mandibular incisors and maxillary incisors
Microdontia
- small teeth
- more common in females
- diffuse (heredity, down, dwarfism) is rare
- isolated is common “peg laterals” then 3rd molars
macrodontia
- more common in males
- diffuse (heredity, gigantism) is rare
- Isolated is also rare
Gemination
attempt of a single tooth bud to divide into two
fusion
union of two normally separated tooth buds into one
-bifid crown with separate root canals
concrescence
union of two adjacent teeth by their cementum
- occurs after development, secondary to inflammation, trauma or nearness during eruption
- often occurs in maxillary molar area
accessory cusps
- cusp of carabelli (ML cusp of 1st max)
- talon cusp
- dens envaginatus
talon cusp
cingulum enlargement on maxillary incisors
dens envaginatus (dens in Dente)
central tubercles on mandibular premolars
- deep invagination of the crown into itself
- most common affected teeth are permanent lateral incisors
- needs to be restored quickly or caries and pulpal pathosis will occur
ectopic enamel
- presence of enamel in unusual location
- “enamel pearls” are on the root surface, usually maxillary molars
- “cervical enamel extensions” are from CEJ into furcation, usually mandibular molars
Taurodontism
enlargement of the pulp chamber with increased occlusal-aplical dimensions
- resembles the pulp of a bull-“tauro”
- no treatment necessary
Hypercementosis
- non-neoplastic excessive cementum on the root
- Usually in adulthood and may be the result of trauma, infection or lack of occlusion
- PDL surround the hypercementosis
- may be seen in Acromegaly, arthritis, paget’s disease and others
Dilaceration
- abnormal bend in the root
- possible due to injury to the tooth bud
supernumerary roots
abnormal number of roots on a tooth
developmental abnormalities:
- amelogenesis imperfecta (AI)
- dentinogenesis imperfecta (DI)
- Dentin dysplasia
- Regional Odontodysplasia
Amelogenesis Imperfecta
- “enamel formed imperfectly”
- 14 different hereditary subtypes exist, thus a lot of variety in appearance
- problem can occur during the enamel matrix phase, the mineralization phase, or the maturation phase
- therefore classified as hypoplastic AI, Hypocalicifed AI, hypomaturation AI
Dentinogenesis imperfecta
- autosomal dominant
- hereditary opalesent dentin
- increased water content and lack of D-E scalloping
- thus the enamel does not stay attached and the exposed dentin wears away quickly
- both deciduous and permanent dentitions are affected
types of dentinogenesis imperfecta
- Type I: associated with osteogenesis imperfecta
- type II: known as hereditary opalesent dentin
- type III: known as shell teeth or bradywine type
what do the radiographs look like for DI?
- bulbous crown, cervical constriction, thin roots, and early obliteration of the root canals and pulp chambers (won’t see a pulp canal)
- root fractures are common
what else should you check for in a patient with DI
Osteogenesis imperfecta
- look for a blue sclera
- ask if they have had any long bone fractures, they will have a history of fractures
- differentiate between type 1,2, and 3
dentin dysplasia
- Type 1 (“radicular dentin dysplasia”; rootless teeth): crown enamel and dentin are normal but root is short and malformed, Root will stop forming, or decrease its formation
- Type 2 (“Coronal dentin dysplasia”): pulp stones in enlarged pulp chambers. I think he said something about “lava”
Regional odontodysplasia, “ghost teeth”
-where?
- NOT HEREDITARY
- localized abnormality of tooth possibly due to vascular problem during development
- maxillary anterior segment is common
- “teeth” are conglomerates of enamel and dentin
ameloblasts are sensitive to insults during…
matrix formation, mineralization and maturation
when does the deciduous dentition develop?
develops from 14th week of gestation thru one year after birth
if there is a short lived insult during development of deciduous and permanent teeth, what occurs?
-only a small horizontal band of ameloblasts are injured
when does permanent dentition develop?
from 6 months thru age 15
childhood fever
- if you look hard enough, 68% of children will have some degree of defect. about 3.6 teeth per individual
- presents as horizontal rows of pits, bilaterally symmetric and correspond to the stage of development at the time of insult: 0-2 years affects anterior teeth and 1st molars; 4-5 yrs affects cuspids, bicuspids and 2nd molars
enamel hypoplasia
-secondary to A childhood Fevrile Illness
Turner’s tooth
- enamel defects in the permanent teeth due to periapical infection of the overlying deciduous tooth, or trauma.
- hypoplasia varies based on timing, duration and severity of the insult
where is turner’s tooth most commonly found?
in the bicuspids, followed by the anterior teeth
-may also be caused by trauma rather than infection. In these cases, the most commonly affected teeth are the maxillary central incisors.
Dental fluorosis
- ingestion of excess amounts of fluoride in drinking water (>4ppm), pediatric vitamins, toothpastes, etc
- defects are dose dependent.
- affected teeth appear lusterless, white with white/brown flecks
syphilitic hypoplasia
- congenital syphilis is the transmission of the Treponema organisms across the placenta to infect the developing fetus
- incisors and 1st molars are affected and misshapen
hutchinson’s triad
hutchinson’s teeth
interstitial keratitis
eighth nerve deafness
associated with congenital syphilis
-mulberry molars
how would you correct environmental structural defects?
- acid etched composite resins
- labial veneers
- full crowns
attrition
-the loss of tooth structure caused by tooth to tooth contact
abrasion
pathologic loss of tooth structure secondary to external abrasive agents: tooth brushing with abrasive “whitening toothpastes”, tobacco, excessive flossing…
how can you know if the staining is from tetracycline?
shows a bright yellow fluorescence under UV light exposure
what are the types of intrinsic staining?
- tetracycline
- minocycline
what is minocycline?
- prescribed for acne
- can discolor teeth, bone and soft tissue
- causes a blue-gray discoloration
ankylosis
- fusion of cementum or dentin to the alveolar bone
- abrupt cessation of eruption
- most commonly seen in children and with the primary first molar
- will cause infraocclusion (submerged)
- CLINICALLY will make a SHARP, SOLID SOUND on percussion.
