Oral pathology sheet # 2 - Shatha Al Saudi

بسم الله الرحمن الرحيم
In this lecture we will talk about developmental disturbances of teeth
Disturbances in the size of the teeth …
Microdontia






Teeth size is smaller than normal.
Commonly seen in .. 3rd molars , upper lateral incisors.
Microdontia could be ….. Generalized or Localized … Bilateral or Unilateral.
Localized : peg shape lateral & affect upper 3rd molar ( smaller than normal )
Generalized : may be
characterized by spaces btwn the teeth ….
Relative :
(false microdontia) large jaw .. teeth size is normal , this may be associated with inheretence " i.e the pt inherit the size of the jaw from one parent & the size of teeth from another "
True microdontia: the size of jaw is normal but the size of teeth is smaller than normal. Seen in patient with systemic diseases like endocrine disorders … e.g. hypopituitarism which result dwarfism .
Also can be seen in patients with Congenital Heart diseases or Down syndrome.
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Macrodontia :
The presence of teeth larger than normal.
Could be :
Localized , Isolated , Unilateral " affects only one tooth" .… seen in case of HEMIFACIAL HYPERATROPHY affecting one side of the face including all teeth of that side .
Generalized : ALL teeth are larger than normal .
Generalized Macrodontia may be :
True .. seen in HYPER pituitary function, Gigantism.
False ( relative ) .. due to micrognathia , smaller jaw .
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Developmental disturbances in teeth Number :
Anodontia :


Complete failure of development of all teeth .
There is no teeth at all.
Rare condition
Usually it is associated with syndrome such as Ectodermal Dysplasia .

Hypodontia :



Reduce the number of the teeth.
More common than anodontia .
Explanation : when u see the pt you must know wither the missing teeth are extracted or failure to develop so the Radiograph is v.imp to detect that there r teeth not erupted ( impacted ) & u must take a history to know if there's any tooth that is extracted .

Mooost commonly affected teeth …
1) 3rd molars( 20 _30 % ) of people , mostly the upper 2 3rd molars .
2) lower 2nd premolars ( 2-3 % ) of people
3) upper lateral incisors the most common congenitally missing teeth .

Hypodontia may be :
Symmetrical : e. g missing lateral incisor on the left & right side
Haphazard
More common in Permanent teeth than Primary .
= = in Females than males .

Etiology for the hypodontia is unclear but there are :
Hereditary component : certain gene mutation lead to the disturbance
Note : Mutations of PAX9 gene & MSX1 gene are inherited as an autosomal dominant trait . these genes are inherited are involved in the development of structures other than teeth including face & other structures . Thus, mutations in these in these genes may lead to many other abnormalities & syndromes.
Acquired :
Maternal age ( increase w\ the mother age )
Low birth weight ( increase incidence for hypodontia )
Radiation & chemotherapy
Certain endocrine disturbences e.g hypoparathyroidism
Primary teeth are uncommonly affected by hypodontia ( 0.9 – 1 % ) , and most frequently involves the maxillary lateral incisors .
Q.. if a child has amissing primary tooth , what do you expect to the permenant tooth ???
ANS .. the absence of the deciduous tooth is associated strongly with an Increased prevalence of the missing permanent tooth ( 30 – 35 % ) .

if u see a missing lateral incisor don't think that he has systemic disease or syndrome but if u see a multiple missing teeth u must think about syndrome .
Syndromes associated with with Hypodontia :
Hypohydrotic ectodermal dysplasia
Crouzon's syndrome
Cleft lip\palate
Down syndrome
Chondroectoderma (Ellis-Van-creveled syndrome) …. Patients with extra digits

Hypohydrotic Ectodermal dysplasia :
Inherited as X-linked recessive trait…. Affects males .
Suffering from congenital absence of the ectodermal structures.
Few teeth are present (hypodontia), but they are small , deformed with abnormal shape "conical shape".
Delay in teeth eruption .
Other features ; Smooth shiny dry thin skin , Fine scanty hair , Partial or total absence of sweat glands (causing Hyperthermia .. heat intolerance ), Nails are abnormal (dystrophic and brittle) , Midface hypoplasia , Saddle nose.

Crouzon's syndrome :
Caused bcoz of Craniosynostosis or Premature closing of the cranial sutures .
Autosomal Dominant .
Defects of the Maxilla ,,, small in size .
Features :
Ocular proptosis due to shallow orbits
Midface hypoplasia
Hearing defects
Visual impairment or total blindness
Hyperobitalism ; larg distances btwn the eyes
Concave face due to the small maxilla
Hypodontia

Cleft lip \ palate :
More common in males
Cleft usually passes btwn maxillary canine & lateral incisor
The affected side may suffer from missing teeth where the other side may have extra teeth .
Q.. what are the complications ??
Feeding difficulties , sucking difficulties , Gag reflux or nasal regurgitation
Ear infections and hearing loss ; more susceptible to middle ear infection .
Dental problems ; A pediatric dentist should monitor tooth development and oral health from early age.
Speech difficulties ; bcoz both the lips & palate are used in forming sounds.
Psychological challenges .
Down syndrome :
Suffering from hypodontia & microdontia .

Chondroectodermal dysplasia (ellis-van creveld syndrome )
Patients with extra digits and other cardiovascular abnormalities .

Q.. What's the difference btwn Hypodontia & Oligodontia ???
ANS.. Hypodontia describes a situation where the patient is missing 6 teeth or less , excluding 3rd molar . Oligodontia ..is the condition of the missing over 6 teeth excluding 3rd molar .
Q.. If the pt has a multiple missing teeth he has a syndrome ??? !!!!!



* the female who has ovarian cancer has increase the risk of multiple teeth missing
( 8.1 time )

Hyperdontia :
The development of teeth is increased in number of teeth
The additional teeth are called supernumerary .
More common in Permenant teeth and Females.
Most common site .. Maxilla ( 80-90 % ) & half of this % is on anterior maxilla.
Most common supernumerary tooth ..
Mesiodens ( the tooyh btwn the central incisor & it's wedge shape like the peg shape lateral ) .
** only 25 % of supernumerary r erupted so that most of the supernumerary teeth ( 75%) not clinically examinated so we need radiograph .
Other sites …
(b) Paramolars – beside the molar either palatal or buccal & it may be smaller than normal
(c) Distomolar ( 4th molar ) found after the third molar , normal size or small redmentary . there's a supposed that people may have 5th molar .
Supernumerary tooth are usually Smaller in size , Conical in shape as the mesiodens .
Mostly occurs unilaterally ,although they may occur bilaterally .
1\3 of supernumerary teeth in the primary dentition is followed by supernumerary teeth in the permanent dentition .

*** Complication of hyperdontia ..
) failure of the eruption of the permanent teeth , (bcz the Mesiodens r the most common so the most affected teeth is the central incisors )

** supplemental teeth is a supernumerary teeth similar to the normal but sometimes smaller in size .
Late therapy & diagnosis may lead to:
Delayed eruption
Resoption of the adjacent teeth
Displacement of teeth with associated crowding
Dilacerations
Diastema formation
May predispose the area to subacute pericoronitis , gingivitis , periodontitis…etc.
Supernumerary teeth are divided into:
Supplemental : normal shape and size (resembeles the adjacent tooth)
Rudimentary: abnormal shape and smaller size.
Multiple supernumerary teeth are associated with syndroms …
Cleidocranial dysplasia … more common in females,, defects in the clavicles & cranium.
Gardner syndrome ( multiple supernumerary teeth & bone osteoma & polyp in GI tract )
Cleft lip\ palate
Q.. are there any reported cases of super numerary teeth occurring in sites other than the jaw???
Ans.. Yes, may erupt in :
Nasal cavity
Maxillary sinus
The chin

Disturbances in the form of teeth
As in peg-shped laterals .
May affect crown or root.
The number of cusps may be abnormal or the cingulum may be too prominent .
1 ** Dilacerations ;
It's a deformity in which the crown of the tooth is displaced from it's normal alignment with the root , so that the tooth is severly bent along it's long axis.
Mainly results from Acute Mechanical Trauma
According to the stage of tooth development –if trauma occurs - The bent 'angulation' may occur .. btwn crown & root or any area in the root or crown.
Most commonly affects Permanent Maxillary Central Incisors .
Complications :
teeth impaction or eruption in improper alignment so difficulty in extraction .
problem in RCT .

2 ** Taurodontism :
Or called Bull-like tooth.
Features:
Elongated crown with apically placed furcation .
Elongated pulp chambers .
Short root canals
Etiology : Faluire of Hertwing's sheath to invaginated at the proper horizontal level .
Dosen't associated with underlying disease or represent any disease.
Associated with certain syndromes such as disturbances in sex chromosomes
Most commonly seen in Permanent Molars / mandibular 2nd molar.
3 ** Double teeth :
Called Connated teeth
These teeth are joined by the crown .. root .. or both .
Most common in permanent central incisors
Includes 2 forms … Gemination .. Fusion .
Germination : it’s the partial development of teeth from a single tooth bud following incomplete division .
There is NO decrease in the teeth number .

Fusion : the union btwn dentine & /or enamel of 2 or more Separate developing teeth . e.g. when the central and lateral incisors joined together .
There is a DECREASE in the number of teeth .

4 ** Concresence : an acquired disorder .
The roots are joined by cementum only after the formation of crowns .
The teeth have separate dentine and root canals.
The most common sites of concrescence :
Upper permanent molars bcz the root r v.close to each other so if there is a hypercemintosis there's a greeter tendency for fusion .
Lower permanent molars
Causes …
during teeth development , the roots were too close to each other as molars .
the roots were separated but hypercementosis has occurred btwn adjacent teeth ,thus concrescence takes place.
May be due to inflammation of the tooth … bone loss… lesions connecting two teeth … hypercementosis /formation of exta cementum… Concrescence .

Q.. what are the complications of concrescence ???
extraction difficulties , fracture of the jaw may result in no radiographs were taken before the extraction .
post inflammatory concrescence
NO problems in RCT.

Disturbances in the structure of the teeth:
Defects in enamel structure depends on many factots :
Local causes
Systemic causes
Sever or mild
Duration of occurrence

### Enamel hypoplasia :
Formation of organic matrix is followed by calcification then a 3rd stage takes place which is the maturation and all of that occur in normal situation , but if any defect occurs in the 1st stage( formation) that will result in defect in the amount of enamel y3ni; clinically there's defect in the thickness of enamel ( pits & grooves )but the calcification occurs normally .

### Enamel hypomineralization :
Normal thickness of enamel & the defect occur in the calcification stage
So result in abnormal color of the tooth when erupt ( white chalky appearance & affected easily by attrition ) .

These defect depend on many factor :
The cause of disturbance
Duration & also in the stage .
Age of occurrence .

There r 2 types depending on the extent " localized & generalized "
Localized enamel hypoplasia :
Etiology …
Idiopathic : seen on the labial surfaces of anterior teeth as white spots ,,, its due to hypomineralized subsurface, with age it becomes yellow to brown spots… its called FOCAL ENAMEL OPACITY .
Florosis : tooth discoloration , appears as white to brown spots.
Infection or trauma : for the primary tooth during permenant tooth development (trauma causes intrusion of the root affecting the developing permanent tooth ) … causing enamel hypoplasia . ,,, such teeth called TURNER TEETH.
The most affected teeth the upper permanent incisors having grooves & abnormal color .

If the child has caries on his 1ry teeth and extend to result in pulpitis , this inflammation will affect permenant teeth during maturation .
Most common affected teeth by infection permenant lower premolars ( bcz they develop under 1ry molars .

Radiotherapy.

Generalized enamel hypoplasia:
Affects multiple teeth.
Could be … systemic (acquired)causes: affects permanent OR primary ,,, Horizontal line .
or hereditary : Permanent & primary ,,, Vertical grooves .


Q .. what are the systemic disorders ???
Serios nutritional deficiencies .. e.g. vit D deficiency
Sever viral infection
Maternal disease
Premature birth
Congenital heart disease chemotherapy exposure or treatment with excess floride
Hemolytic disease of newborn
GI disturbances inhibet ameloblast during tooth development , horizontal lines of small pits or grooves on enamel surface, affect teeth formed in the first teeth.
Endocrine disease

*** Congenital Syphilis ***
Spirochetes affect the developing tooth germ maily the enamel of the permanent incisors & the 1st molars .
# The central incisors: mesial & distal surfaces taper towards the incisor edges rather than toward the cervical margin giving a "Screw-Driver" appearance ,,, its called Hutchinsons Incisors(there's a notch on incisal edge) .
# Mulberry Molars : Occlusal surfaces of the 1st molars are covered by small globular masses of enamel (multiple tubercles) .
Q .. does the conginetal syphilis affect the primary teeth????
Ans.. yes , if the mother when was pregnant have syphilis .

***Excess Floride***
Whitish to brownish color .
Causes mottiling of the teeth … less susptiple to caries due to Higher conc. Of floride on the teeth
Leads to Enamel Hypoplasia
Widely seen in Jordan.
Mostly affects permanent teeth .
Upper incisors , 2nd molars are commonly affected.
Affect the upper teeth more than lower teeth .
The reccommeneded amount of florid is 0.7 .





Floride mottling :
Depends on floride conc.
Can be either … Mild (Smooth enamel with white patches) ,,, Sever (yellow..brown or dark enamel,, pits & grooves may , hyperplasia).

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Special thanks to Mays Smadi for the usefuuuUl notes , and Amneh Shdaifat "keep smiling " .


Done by : Shatha Al Saudi..