Oral-Path-Lec-M1.pdf

m1-m2 oảl pathology

2. ORAL PATHOLOGY 1
DR.GEORGE S. NAVARRA

3. Module 1
DEVELOPMENTAL ANOMALIES OF TEETH
Lesson 1
Alterations in Size
Alterations in Number and
Eruption

Lesson 2
Alterations in Shape / Form

Lesson 3
Defects of Enamel and
Dentin

4. Alterations in Size
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MACRODONTIA (MEGADONTISM, HYPERPLASIA OF THE
TEETH)
Overdevelopment or gigantism of the teeth wherein teeth are
excessively larger than normal
Varieties:
A. true generalized or proportional macrodontism
All teeth are affected and proportional to the development of the jaws
B. relative generalized or disproportional macrodontism
teeth are large and disproportional to the jaws
C. macrodontia of single tooth
Involves only 1 tooth

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Etiology
Hormonal
hyperpituitarism
Cross inheritance
heredity
Overactive odotogenesis
Nutritional deficiencies or diseases

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MICRODONTIA (HYPOPLASIA OF THE TEETH)
Underdevelopment of teeth and abnormally smaller than normal
Varieties:
True generalized or proportional microdontism
Teeth are smaller than normal and found on small jaws
Relative generalized or disproportional microdontism
Teeth slightly smaller than normal and found on large jaws
Microdontia of single tooth
Involves only 1 tooth

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Etiology
Dwarfism
Cross inheritance
Atavism (cone-shaped or haplodont form)
Evolution
Aplasia (poor development of teeth)

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Clinical feature
Teeth are small
Dwarfed crowns/short
No cusps
Reduced number and size of cusps
Peg shaped teeth

11. ANOMALIES IN NUMBER
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ANODONTIA (HYPOPLASIA OF DENTITION)
Tooth or teeth are missing congenitally
Failure of germ development
True anodontia
Pseudo-anodontia (multiple unerupted teeth)
Teeth are missing clinically but failed to erupt
Associated with systemic disturbances (hypofunction of pituitary or thyroid gland,
cleidocranial/craniofacial dysostosis)

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Varieties:
Total anodontia
Failure of entire dentition to develop
Hypodontia
Few or specific teeth are missing
Oligodontia
Many teeth are missing and the remaining are smaller

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Etiology
Congenital disturbances
Hereditary ectodermal dysplasia and malformations


Frequency of missing teeth:
3
rd
molars
2
nd
premolars lower
upper lateral incisors
central incisors lower
lower lateral incisors

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SUPERNUMERARY TEETH
Extra teeth or teeth above the normal number of teeth in a set
Varieties:
Supernumerary teeth resembling the normal tooth form
Small peg-shaped teeth that bear no resemblance to any normal tooth form also called as
accessory or rudimentary teeth
Locations:
Common in the region of upper central incisors like MESIODENS – supernumerary teeth in
between of two central incisors
Common also on bicuspids, less common on canine and molar region
Generally erupts outside the dental arch - PERIDENTES
Those found on molars – DISTOMOLAR/ MESIOMOLAR
Found on buccal of posterior teeth – PARAMOLAR
Fused with permanent molar – PARAMOLAR TUBERCLE

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Clinical findings:
Crowding and malocclusion of normal teeth
Unerupted or embedded may result to diastema
Rotation of normal teeth
Etiology:
Remnants of dental lamina (glands of serres)
Theory of atavism
Recurrence of teeth which has been lost due to the process of evolution especially the supernumerary
premolars, the 4
th molar and mesiodens
Hyperactivity of the dental lamina
Instead of producing two buds, additional bud maybe produced either in between the temporary and
permanent buds or after the permanent bud
Dichotomy/division
If equal, the extra tooth will resemble the neighboring tooth
If unequal, the additional tooth is malformed or conical
SCHIZOGENESIS (fission of enamel organ) – term used to designate splitting into two or more parts

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Histopathology:
Rudimentary type of supernumerary tooth consist only of thin later of enamel
with underlying dentin of coarse structure

Managements:
1. extraction
2. if no disturbance or symptoms, no treatment

20. Anomalies in dentition
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DECIDUOUS DENTITION
PREMATURE ERUPTION (DENTITIA PRECOX)
DELAYED ERUPTION (DENTITIA TARDA)
PREMATURE LOSS OF DECIDUOS TEETH
PERSISTENCE OF ENTIRE GROUPS OF DECIDUOS DENTITION

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PREMATURE ERUPTION (DENTITIA PRECOX)
Early eruption of deciduous teeth
Clinical feature
Common on mandibular central incisors (at birth)
Rare in maxillary teeth
Short roots and mobile
Due to hyperactivity of the dental lamina
Etiology
Excessive or over secretion of certain ductless glands (thyroid, gonads and thymus)
Heredity
Congenital syphilis
Exanthemata (fever)

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DELAYED ERUPTION (DENTITIA TARDA)
Retardation in eruption of deciduous teeth
Etiology
Cretisnism – thyroid hormone deficiency
Cleidocranial dysostosis
Rickets – due to thickening of the fibers of the dental follicles
Presence of eruption cyst
Impacted between two teeth
Local complication
Acute localized inflammation of the mucosa, resistance of overlying mucosa, eruption
cyst (occur as small circular bluish swelling over the tooth and it delays its final
emergence, stomatitis (due to fusospirochetal type which is associated with dirty
feeding bottles and neglected oral hygiene.

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Systemic complications:
Pyrexia
Anorexia
Vomitting
Diarrhea
Salivation
Irritability
Convulsions
Erythema of the face
Cough
Anuria, polyuria and dysuria

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PREMATURE LOSS OF DECIDUOS TEETH
Due to dental caries
Systemic conditions leading to early loss are acrodynia and hands-schuller
Christian disease
Clinical findings:
Early loss of deciduous teeth lead to closing of space which causes the permanent
tooth to become impacted or to erupt in lingo or bucco version
May also lead to early eruption of permanent teeth

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PERSISTENCE OF ENTIRE GROUPS OF DECIDUOS DENTITION
Etiology
Anodontia of the permanent dentition
Malpositon of the succedaneous teeth
Delayed development and eruption of succedaneous dentition
Presence of infection around the roots of deciduous teeth
Ankylosis of permanent teeth

29. Anomalies in dentition
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PERMANENT DENTITION
PREMATURE ERUPTION OF ALL OR MANY PERMANENT TEETH
Etiology:
Early loss of deciduous teeth
Hypergonadism (tumors of adrenal glands)
DELAYED ERUPTION OR RETARDED ERUPTION OF PERMANENT TEETH
Dwarfism due to endocrine dysfunction (hypogonadism, hypopituitarism)
Cleidocranial dysostosis or crowzon’s disease – causes retardation of deciduous teeth
Rickets, cretinism and infantile myzedema
IMPACTION
IMPACTED TEETH – eruption is prevented by the adjacent teeth or bone
EMBEDDED TEETH – teeth are locked against adjacent teeth or bone
COMPLETELY EMBEDDED TEETH – completely covered with bone
PARTIALLY ERUPTED TEETH – crown is partially visible
MULTIPLE IMPACTION – several teeth are impacted

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Causes of impaction
Local causes
Irregularity in the position and the pressure of an adjacent tooth
Density of the surrounding tissues
Chronic inflammation
Lack of space
Retention of deciduous teeth
Premature loss of temporary teeth
Acquired diseases
Inflammatory changes in the bone like pathologies

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Systemic causes of impaction
Prenatal
Heredity, miscegenation(mixed genesis, mixed marriages), syphilis, tuberculosis,
malnutrition
Postnatal
Rickets, anemia, hereditary syphilis, tuberculosis, pathologies of the jaw, lack of space,
endocrine dysfunction
Rare conditions
Cleidocranial dysostosis – defective ossification of cranial bones and complete or partial
absences of clavicle, delayed shedding of deciduous teeth, unerupted permanent teeth and
rudimentary teeth
Oxycephaly (steeple head)
Progeria – premature old age form of infantilism
Achondroplasia – cartilage failed to develop
Cleft palate – congenital fissures

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Frequency of impacted teeth
1. mand 3
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molar
2. max 3
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molar
3. max cuspid
4. mand cuspid
5. mand bicuspid
6. max bicuspid
7. max central incisor
8. max lateral incisor

34. Classification of third molars:
(mandibular)
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A. relation of impacted third molar to the ramus of the mandible
and second molar:
Class I – sufficient amount of space bet. Ramud and distal of the
second molar for the accommodation of the mesiodistal diameter of
the crown of the third molar
Class II – space bet ramus and distal of the 2
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molar is less the the
mediodistal diameter of the crown of the third molar
Class III – all or most of the third molar is located within the ramus

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B. relative depth of the third molar in bone:
Position A – highest portion of the impacted teeth is in level with or
above the occlusal line of the second molar
Position B – highest portion of the tooth is below the occlusal plane
but above the cervical line of the second molar
Position C – highest portion of the teeth is below the cervical line of
the second molar

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C. The position of the long axis of the impacted mand third
molar in relation with the second molar/angulation (from
winter’s classification):
Vertical
Horizontal
Inverted
Mesioangular
Distoangular
Buccoangular
linguoangular

38. Classification of third molars
(MAXILLARY)
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A. relative depth of the impacted max third molar in the bone
Class A – lowest portion of the crown of the impacted third molar is in
line with the occlusal plane of the second molar
Class B – lowest portion of the crown of the impacted third molar is
between the occlusal plane of the second molar and cervical line
Class C – lowest portion of the crown of the imp maxillary third molar
is at or above the cervical linme of the second molar

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B. the positon of the long axis of the impacted maxillary third
molar in relation to the long axis of the second molar/
angulation:
Vertical
Horizontal
Mesioangular
Disto angular
Inverted
Buccoangular
linguoangular

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C. relation of the impacted maxillary third molar to the maxillary
sinus
With Sinus Approximation (SA)- no bone or very thin partition of bone
exist between the maxillary third molar and maxillary sinus
Without Sinus Approximation (NSA) – 2mm or more of bone exist
between the impacted maxillary third molar and the maxillary sinus

42. Classification of maxillary impacted
cuspids
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Class I – impacted cuspid located in the palate (horizontal, vertical,
semivertical)
Class II – impacted cuspids located in the labial or buccal surface of the
maxilla ( horizontal, vertical, semivertical)
Class III – located both the pataline and maxillary bones, crown is on the
palate while root passes through betweenm the roots of the adjacent teeth
in the bone
Class IV – located in the bone usually vertically between incisor and first
bicuspid
Class V – impacted cuspid located in an edentulous maxilla
Class VI – in unusual position
Class VII – migrated canine

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Clinical pathology of impacted teeth
Tissues surrounding an impacted teeth may become inflamed and develop:
Pus – pericoronitis, pericoronal abscess
May result in difficulty of swallowing, trismus, inflammation of lymph tissues, fever due to
bacteremia and worst cases fatal difficulty of breathing

Complications:
a. resorption of impacted teeth due to infection
b. inflammatory process – pericoronitis and pericoronal abscess
c. resorption and displacement of adjacent teeth
d. development of tumors and cystic oral pathology
e. systemically, may cause headache, fever, facial paralysis and trismus
f. third dententition (post permanent dentitition) – supernumerary teeth that delayed in its
eruption

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46. Anomalies in Position in the Dental Arch
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Types and classification
1. general malalignment of the teeth
Due to undervelopment of the mandible resulting to crowding of permanent teeth
2. diastema between the teeth
Due to acromegalic gigantism or hyperplasia of the jaw
due to hyperthropied lip
due to retained deciduous roots or supernumerary tooth
3. individual malposition of teeth
Labioversion, buccoversion, linguoversion, mesioversion, distoversion, torsoversion
(rotated), supraversion, infraversion, transposition (interchange between 2 teeth),
migration (teeth migrated to abnormal position such as in cranial bones and even to
the other side of the jaw, floor of mouth, ramus and center of palate)

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Etiology:
Hereditary
Disease
Habit – thumb sucking, thumb biting, mouth breathing
Other factors
Drifting of teeth due to absence of teeth or restorations of teeth
Abnormal occlusion
Delayed shedding of deciduous teeth
Premature extraction
Thickening of tissue

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management:
Orthodontia
Oral medicine
Operative restorative dentistry

50. Anomalies in shape and form
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1. Anomalies in crown
Fusion – two normally separate tooth germs become united
Gemination – single tooth germ divides during tooth formation and forms
double crown with a single root and canal, aka twin formation
Taurodontism – body of the tooth is enlarged at the expenses of the root, aka
bull-like teeth (hypotaurodont, mesotaurodont, hypertaurodont)
Dens invaginatus – deep invagination of the lingual pit of an incisor
Supernumerary cusps – accessory cusps like TALON cusps arising from the
cervico-lingual ridge
Leong’s premolar – premolar with an occlusal turbercle by Leong Ming Ong
1946
Peg tooth – cone-shaped incisors or canines
Hutchinson’s teeth – notched incisors and mulberry moalrs

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2. Anomalies of the root
1. Large or small roots – maybe caused by trauma, short roots seen
due to systemic disturbances, extra long roots are usually seen on
cuspids and molars
2. accessory roots – extra roots
3. fusion of roots – two or three roots are fused into one and function
as one root
4. concrescence - secondary union of fully formed teeth by cementum
only, occurs in originally separate teeth at late period in development
5. enamel pearls/enamel drops/enameloma – islands of enamel found
at the root surface

61. Anomalies in Enamel Structures
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Amelogenesis imperfecta – defective enamel calcification and formation
Enamel Hypoplasia – decificent enamel formation
Enamel hypocalcification – enamel is undercalcified

Clinical Features
White, opaque or chalky enamel
Corrugated or wrinkled enamel
Fissured enamel
Pitted enamel
Gnarled enamel (whorl)
Turner’s tooth (small, brownish and irregularly shaped crowns)
Fluorosis – due to fluorine disturbances

Management: restorations and jacket crowns

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Etiological factors of enamel and dentin defects:
A. local causes
Trauma, infection
B. general causes
Heredity, idiopathic dentinogenesis imperfect, systemic diseases
Syphilis (hutchinsons teeth, moon’s molar, mulberry molar, bud molars- dome shaped)
Hutchinson’s triad – interstitial keratitis, atypical teeth and otitis media
Trophic disturbances
GIT disease
Infantile tetany - hypocalcemia
Vitamin deficiency – vit C and D
Exanthemata – severe fever
Fluorosis

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Mechanisms of enamel hypoplasia
1. collapse theory
Enamel collapsed due to delay in calcium depositon
2. degenerative theory
Degeneration and actual necrosis of ameloblasts – Bauer and Kliex

Management: proper diet and remove infected teeth

66. Defects in the Structure of Dentin
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A. Dentinogenesis Imperfecta
Dentin hypoplasia
Dentin hypocalcification
Clinically brownish discoloration, caused by disturbance due to aplasia and dysfunction of the cell
producing ground substance of dentin.
Histologically, canals containing blood in the dentinal tubules that may account for discoloration
B. Shell teeth
Enamel is normal, but dentin is extremely thin and pulp chambers are large
Insufficient amount of dentin
Roots of teeth are short
C. Odontodysplasia (ghost teeth, odontogenesis imperfecta)
Shape of teeth is irregular
Defective mineralization
Xray shows marked reduction in radiosensitivity hence “ghost appearance”
Enamel and dentin are thin with enlarge pulp chambers

69. Defects in Cementum
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A. hypercementosis – overgrowth cementum
B. cementicles – small calcified areas found in the
periodontium, may appear near the epithelial rest
C. Concrescence – resorption of alveolar bone between 2 teeth
caused the roots to progress and be in contact therefore union
of 2 teeth