Abnormalities of teeth

Abnormalities of Teeth
Dr. Arsalan Malik
Assistant Professor & HOD (Oral Pathology)
ِ‫يم‬ ِ‫ح‬َّ‫الر‬ ِ‫من‬ْ‫ح‬َّ‫الر‬ ِ‫هللا‬ ِ‫م‬ْ‫س‬ِ‫ب‬
1

Environmental Alterations of Teeth
 Developmental tooth defects
 Post developmental structural tooth loss
 Discoloration of teeth
 Localized disturbances in eruption
2

Factors Associated with Enamel Defects
Systemic
◦ Birth related trauma
◦ Chromosomal abnormalities
◦ Chemicals
◦ Infections
◦ Inherited diseases
◦ Malnutrition
◦ Metabolic disorders
◦ Neurological disorders
Local
◦ Acute mechanical trauma
◦ Local infection
◦ Electrical
◦ Irradiation
3

Enamel Defects
 Matrix Formation
 Mineralization
 Maturation
4

Enamel Defects
Enamel Hypoplasia
Occurs in form of pits, grooves or larger areas of missing enamel
Diffuse Opacities
Variation in the translucency of enamel. Normal thickness with white opacities and no boundary
Demarcated Opacities
Variation in the translucency of enamel. Normal thickness with white opacities and clear boundary
5

Turner’s Hypoplasia
It is caused by periapical inflammatory
disease of the overlying deciduous tooth.
Most commonly noted in permanent bicuspids
due to overlying deciduous molars
6

Turner’s Hypoplasia
Degree of damage depends upon stage of development, length of time of infection,
virulence of organism and the host resistance factors
If the primary tooth develops caries, the successor is twice likely to develop caries
If the primary tooth is extracted for some reason other than trauma, prevalence of
demarcated enamel is increased 5 folds.
7

Molar Incisor Hypomineralization
o Enamel defects of one or more first permanent molars
o The altered enamel is white, yellow or brown and often
soft and porous.
o Affected teeth are sensitive to cold and warmth and
enamel chip off easily
o Difficult to anesthetize during dental procedures
8

Dental Fluorosis
 The integration of excess amount of fluoride can also
result in enamel defects known as dental fluorosis
 The integration of fluoride into the enamel reduces the
incidence of caries
 Pre-eruptive as well as post eruptive supply of fluoride is
equally effective however the 2nd & 3rd decade is critical for
application of fluoride
9

Dental Fluorosis
 A definitive diagnosis requires bilateral presence
of defects, evidence of prior fluoride intake and
elevated levels of fluoride in enamel
 The antibiotic administration during development
reduces the expression of enamel proteins genes
10

Post Developmental Loss Of Structure
Attrition
Abrasion
Erosion
Abfraction
11

Attrition
Loss of tooth structure caused by tooth to tooth
contact during occlusion and mastication
Main factors are
◦ Poor quality or absent enamel
◦ Premature contacts
◦ Intra oral abrasive, erosions and grinding habits
12

Abrasion
Pathological loss of tooth structure or restoration secondary to the
mechanical action of an external agent
Common causes are
◦ Hard tooth brush with abrasive tooth paste
◦ Chewing tobacco, biting nails or pencil
When tooth wear is accelerated by chewing an abrasive
substance, the process is termed as Demastication and it
exhibits features of abrasion and attrition
13

Erosion
o Loss of tooth structure caused by non bacterial chemical
process. The gradual destruction of surface by the chemical
or electrolytic process
o Erosion from dental exposure to gastric secretion is termed
as Primolysis
14

Abfraction
o It appears as wedge shaped defects limited to
the cervical area of the teeth and may closely
resemble cervical abrasion or erosion
o Clues to the diagnosis are deep, narrow and
v shaped defects that predominantly affects
facial surfaces of bicuspids and molars
15

Resorption
 Destruction of tooth can also occur through resorption, which is accomplished by cells
located in the pulp (Internal resorption) or in the periodontal ligament (External
resorption)
 Internal resorption is a relatively rare occurrence and mostly it develops after trauma to
the pulpal tissues of the tooth
 It continues as long as vital pulp tissue remains and may result in communication of
pulp with the PDL.
16

Factors Associated with External Resorption
 Cysts
 Dental trauma
 Excessive mechanical forces
 Excess occlusal forces
 Hormonal imbalance
 Peget’s disease of bone
 Periodontal treatment
 Tumours
 Reimplantation of teeth
17

Clinical Features
 Inflammatory resorption
The resorbed dentin is replaced by inflamed granulation tissues. Most commonly cervical portion is
involved and resorption continues as long
 Replacement resorption
Portion of the dentinal walls are resorbed and replaced with bone or cementum like material.
Radiographically it appears as enlargement of the pulp canal and filled with a material that is less
radiodense as compared to surrounding zone.
After re-implantation of tooth, extensive resorption starts without rapid intervention
18

Histopathological Features
 Pulp tissues are vascular and exhibit increased cellularity.
 Numerous multinucleated dentinoclasts are present adjacent to
the dentinal walls.
 Inflammatory infiltrate is present
 In replacement resorption, the normal pulp tissues are replaced
by woven bone that is fused to adjacent dentine.
 Areas of resorption are often repaired by deposition of
osteodentine
 Extensive bone deposition in external resorption may lead to
ankylosis
20

Teeth Discoloration (Staining)
EXTRINSIC
 Bacterial stains
 Iron
 Tobacco
 Food & beverages
 Medications
 Restorative materials
 Gingival haemorrhage
INTRINSIC
 Amelogenisis imperfect
 Dentinogenisis imperfect
 Dental fluorosis
 Trauma
 Localised RBC breakdown
 Medications
21

Localized Disturbances in Eruption
 Impaction
 Teeth that cease to erupt before emergence are called Impacted
 Ankylosis
 Eruption continues after emergence of teeth to compensate for masticatory wear and the growth of
jaws. The cessation of eruption after emergence is termed Ankylosis
24

Impaction
In permanent dentition, the most frequently impacted tooth is
mandibular 3rd molar followed by maxillary 3rd molar and cuspids
Factors associated with impaction are
 Overlying cysts or tumours
 Trauma
 Reconstructive surgery
 Thickened overlying bone
 Systemic disorders
25

Ankylosis
Associated factors
 Disturbances from changes in local metabolism
 Trauma
 Injury
 Irritation
 Local failure of bone growth
 Abnormal pressure from the tongue
26

Developmental Alterations of Teeth
 Number
Hypodontia
Hyperdontia
 Size
Microdontia
Macrodontia
 Shape
Gemination
Fusion
Concresence
Taurodontism
Hypercementosis
Dilaceration
Dens invaginatus
Dens Evaginatus
 Structure
Amelogenisis Imperfecta
Dentinogenisis Imperfecta
Dentin Dysplasia type I
Dentin Dysplasia type II
Regional Odontodysplasia
27

Hypodontia
 Lack of development of one or more
teeth is referred as Hypodontia
 Total lack of tooth development is
called Anodontia
 Lack of development of 6 or more
teeth is called Oligodontia
28

Hyperdontia
 Development of increased number of teeth
is referred as Hyperdontia
The additional teeth are referred to as
Supernumerary teeth.
The Supernumerary teeth in the midline is
called Mesiodense
29

Supernumerary Teeth
Supplemental Teeth
Normal size & shape
Rudimentary Teeth
Abnormal Size & Shape
30

Supernumerary Teeth
Natal Teeth
Teeth present in newborns
Neonatal Teeth
Teeth erupt within 30 days of life
31

Microdontia
 When the teeth are physically smaller
than normal then it is termed as
Microdontia
 Normal size teeth may appear smaller
when they are widely spaced within large
size jaws. This is termed as Relative
Microdontia but it is actually
macrognathia
 Maxillary lateral incisors are most
commonly effected and appear as peg
shaped crown.
32

Macrodontia
 When the teeth are physically larger
than normal then it is termed as
Macrodontia
 Normal size teeth may appear larger
when they are crowded within small
size jaws. This is termed as Relative
Macrodontia but it is actually
micrognathia
 Diffuse macrodontia has been
observed in pituitary gigantism and
otodental syndrome
33

Gemination
 It is defined as an attempt of a single
tooth bud to divide with the resultant
formation of a tooth with bifid crown and
usually a common root and root canal.
 The tooth count remains normal when
the anomalous tooth is considered as
one.
34

Fusion
It is considered to be the union of two
normally separated teeth buds with the
resultant formation of a joined tooth with
confluence of dentin.
In this condition the tooth count shows one
missing tooth when the tooth count is
considered as one.
35

Concrescence
It is described as two fully formed teeth
joined along the root surfaces by cementum.
More commonly present in posterior &
maxillary teeth.
The development pattern often involves
second molar tooth where roots are in close
proximity to 3rd molar tooth.
36

Dens Evaginatus
 It is a cusp like elevation of enamel located in the central groove or lingual ridge of the buccal
cusp of premolar or molar tooth.
 The accessory cusp usually consist of enamel & dentine with pulp present in half of the cases
 The accessory cusp creates occlusal interference that are associated with clinical problems.
 Pulp necrosis is common and may occur through a direct exposure or invasion of patent,
immature dentinal tubules.
37

Dens Invaginatus
Deep surface invagination of the crown or root that is lined by enamel.
The depth of invagination varies from a slight enlargement of the cingulum pit to a deep
infolding that extends to apex.
Occasionally the invagination may be large and resemble a tooth within tooth appearance
called den in dente.
39

Taurodontism
 Enlargement of the body & pulp chamber of a
multirooted tooth with apical displacement of the pulpal
floor & bifurcation of the root.
 It may be unilateral or bilateral affecting permanent
dentition.
Classified into mild, moderate and sever forms
41

Hypercementosis
Non neoplastic deposition of excessive
cementum that is continuous with the normal
radicular cementum.
Radiographically affected tooth show thinking or
blunting of root but the exact amount of extra
cementum is difficult to estimate
42

Associated Factors
Local
 Abnormal occlusal trauma
 Adjacent inflammation
 Repair of vital root fracture
 Unopposed teeth
Systemic
 Acromegaly
 Arthritis
 Calcinosis
 Thyroid goiter
 Gardner Syndrome
 Vitamin A deficiency
43

Dilaceration
 Abnormal angulation or bend in the root or less
frequently in the crown
 A number of teeth having dilacerations arises
after injury that displaces the calcified portion of the
tooth germ and remainder of the tooth is formed at
an abnormal angle
44

Supernumerary Roots
It refers to the development of an increased
number of roots on a tooth compared with that
classically described in dental anatomy.
Most commonly affected teeth are permanent
molars from either arch and mandibular cuspids
and premolars
45

Amelogenisis Imperfecta
 A complicated group of conditions that demonstrate
developmental alterations in the structure of enamel in
the absence of any systemic disease.
 Different classification systems were proposed but
Witkop’s Classification is widely accepted.
 It is based on phenotype and pedigree (clinical
appearance & apparent mode of inheritance)
46

Amelogenisis Imperfecta
 Formation of enamel is a multistep process and
problem may arise in any of these them.
1) Elaboration of the organic matrix
2) Mineralization of the matrix
3) Maturation of the enamel.
47

Hypoplastic Amelogenisis Imperfecta
o The basic alteration centres on inadequate deposition of
enamel matrix.
o The matrix present is well mineralized and
Radiographically contrasts well with the underlying dentine
o In generalized pattern pinpoint to pin head pits are
scattered on the surface.
o Staining of the pits may occur.
48

Hypoplastic Amelogenisis Imperfecta
o In localized pattern, the affected teeth demonstrate horizontal rows of pits, linear
depression or one large area of hypocalcification.
o In other patterns of this disorder, enamel may appear smooth, thin, hard and glossy.
o Radiographically demonstrate a thin radio-opaque line of enamel.
49

Hypomaturation Amelogenisis Imperfecta
• Enamel matrix is laid down properly and begin to mineralize but there is defect in
maturation of enamel crystal structure
• Affected teeth are normal in shape but show mottled appearance and tend to chip easily
• Radiographically its density is similar to dentine
50

Hypomaturation Amelogenisis Imperfecta
51

Hypocalcified Amelogenisis Imperfecta
o Enamel matrix is laid down properly but failed to mineralize properly
o Affected teeth are proper in shape but very soft & easily lost
o It has more tendency of calculus deposition on it
o Radiographically the density of enamel & dentine is similar
o After some duration time of eruption, cuspal enamel is lost leaving occlusal surfaces
irregular
52

Hypocalcified Amelogenisis Imperfecta
53

These are not evident in routine preparations because decalcification of the teeth is
necessary before processing and all the enamel is lost in it
Ground sections of Non decalcified teeth are prepared for examination
The alterations are highly diverse and depend upon the type of variation in enamel structure
54

Treatment
o Main problems are aesthetics, dental sensitivity and loss of vertical dimension
o In some types, increased prevalence of caries, anterior open bite, delayed eruption and associated
gingival enlargement are observed
o Crown placement
o Full dentures
o Veneers
oGlass Ionomer Cements restorations
55

Dentinogenesis Imperfecta
o It is a hereditary developmental disorder of the dentine in the absence of any systemic
disease.
o It is associated with mutation in DSPP gene.
Shields Clinical Presentation
Dentinogenesis Imperfecta I Osteogenesis imperfect with opalescent dentine
Dentinogenesis Imperfecta II Isolated opalescent teeth
Dentinogenesis Imperfecta III Isolated opalescent teeth
56

Clinical Features
o All teeth in both dentitions are affected
o The severity of problem depends upon the
age at which teeth developed
o Deciduous teeth are affected more
intensely followed by permanent incisors
and 1st molars
58

Clinical Features
o Blue to brown discoloration often with
distinctive translucence
o Enamel easily gets separated form
underlying dentine leading to rapid attrition
oUsually the pulp is obliterated by excessive
dentine formation but sometimes shell teeth
are observed having small dentine and large
pulp chambers.
59

Radiographic Features
o Teeth have bulbous crowns, cervical
constrictions, thin roots and early
obliteration of the root canals and pulp
chambers.
60

o Dentine adjacent to enamel are similar to
normal dentine but the remainder is
significantly different
o Scanty atypical odontoblasts line the pulp
surface and cells can be seen entrapped
within defective dentine
o1/3rd of the patients have hypoplastic
enamel
61

Treatment
o Teeth are not good candidates for crown placement because of cervical fractures
o Overly dentures placed on teeth with fluoride releasing material is being practiced in
some cases
o In cases with lose of vertical dimension, metal crowns are used with adhesive bonding
agents
o On occlusal surfaces composites are being used
62

Abnormalities of teeth

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