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Developmental disturbances

What do we mean by it ?

Alteration that occur during development , these alteration are not related to viral

infection ,bacterial infection ,fungal infection or to any certain clear disease .

Sometime these alternation have no a known cause “ non-known cause”

Generally we know that trauma maybe the cause

Developmental changes affect oral and maxillofacial region, so the changes will

affect the hard tissue {teeth and bone} and the soft tissue” mucosa, muscle “

[1] Developmental alteration affecting the teeth

What are the changes that could happen to teeth due to disturbance during the

development ?

-we have

A] changes in the size of the tooth “ so the tooth may be big or it may be small “

When we say big/small that’s bigger than normal or smaller than normal

B] Regarding the number if teeth

we may have extra teeth , or decreased in the number of normal teeth

C] time of eruption

Some time we will have premature eruption , some time we have delayed eruption

D] the shape of the tooth some teeth may look up normal

E] change in the structure of enamel, dentine or the structure of cemantum

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Disturbance of the size

the teeth which are smaller than normal we will call it microdontia

The teeth which are bigger than normal we will call it macrodontia

Microdontia

Could be true or relative, true means that the tooth is truly smaller than normal in

dimensions

Ex. the lateral incisor have a width of 7. Mm if we have 3 or 4 mm lateral incisor

this is true microdentia

What do we mean by relative ?

The tooth has normal dimensions but it look small relatively.

Ex. If we have lateral incisor measures 7 or 8 mm but it looks small these may be

relative , because the tooth is normal but the jaw is wide “maybe the patient

inherited a wide jaw but a normal teeth “

so normal tooth in a large jaw is relatively small

the microdonutia is usually localized and the teeth which are most commonly

effected are the lateral incisors

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this is called peg lateral “ وتد”

examples of localized microdontia

peg lateral which considered familial” occur in some family more than

others” . and it’s an example of localized microdontia

the third molars , third molar some time are smaller in size if u check your

upper 8 it may look conical and smaller in size so it’s effected by

microdontua

if we have an extra tooth this extra tooth is most likely to have microdontia

Macrodontia

May be true or relative it may be localized or may be generalized.

If its true so there is really increase in the size of the tooth.

it’s very rare to have localized macrodontia except for some cases like when

we have hemi facial hypertrophy , so teeth in the effected side will be

macrodontia “larger in size “ this is an example of the localized “ just a

number of teeth”

generalized are more common like when the patient have gaintesim for

example {have increase in growth hormone or certain hormones

disturbances } so everything in the body will be affected including the teeth .

some time we have increase in the size of the root “previously we were

talking about the crown (micro/macro – dontuoa) “ but radiographly the

root also may be effected by macrodontia we call it radimegaly and usually

for the canine teeth

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Disturbances in the number of teeth

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There may be decrease in the number of the teeth “hypodontia” , complete

absence” anodontia” or the maybe increase in the number of teeth “supernumerary

teeth” .

and another situation there maybe clinically you think that the patient doesn’t

have some teeth but acutely when you take a radiograph you will see that the

patient is having the normal number of teeth but the are un-erputed

so if u examine a patient and u don’t see 4 or 5 teeth u should take a radiograph

first to see if the teeth are present but not erupted, OR they are completely absence

and then you say that the patient have hypodontia

Hypodontia is the absences of tooth , the tooth germ itself is not there .

anodontia complete absence of teeth . Which occur in ectodermal dysplasia.

ectodermal dysplasia : is a genetic disease it has several types one of it types is

called hypohydrotic [a variant of ectodermal dysplasia which is x-linked recessive

occur more in the males. In which the males have more than one thing effected

“the hair , swet gland missing , and the teeth , protuberance of the upper lip,

absences of eye brows “]

the number if tooth is obuvisoly reduced and if we take a radiograph we will not

see teeth there “they are not formed ASLN” and even the shape of the teeth is

abnormal “taper teeth ,small and absence “ so the condition here will be both

microdontia and hypodontia “number & size”

the problem in this disease is in the keratinocyte in the epithelium the defect is in

the membrane of the epithelium there is a transmembrane protein in the membrane

of keratinocyte is defected which lead to this findings

so a defect in a single transmembrane protein in one type cell could cause a life-

threaten disease !

and for those patient who don’t have sweat gland the will not tolerate high

temperature they will die !

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*Ectodermal dysplasia patient

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we can see hypodontia in lateral incisors “congenitally missing”

so the lateral incisors maybe ]absence “hypodontia” , peg shape “ microdotia” ,

present normally[

third molar maybe congenitally missing and some time the second molar

some children retain “E” because the don’t have “5” to push it to erupt the

“5” is congenitally missing so we retain E

the lateral incisors could be missing in the primary teeth also

supernumerary teeth

increase in the number of teeth.

different types, different location , it could be single and it could be multiple it can

erupt in the maxilla or the mandible

one well-known supernumerary tooth is called mesiodense , meso- because

it is in the mesial aspect to the upper central incisors “between the central

incisors “

mesodense shape is tapper “look like the peg shape lateral “

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some research said that the supernumerary teeth could be more associated with

Clift lip or Clift palate and with certain syndromes , but the mesodinse could be

present without any syndromes”

mesodenis may erupt or it could erupt in the floor of the nose upside down , or

maybe horizontal impacted and in this case it may effect the surrounding teeth

cause pressure , repsorbtion ,interfere with the normal eruption, impaction in the

surrounding teeth

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any supernumerary teeth will lead to problem in eruption , repsortpion and another

complication it may cause tumor in association with supernumerary tooth

it shows 4 premolar , so we have two extra premolar

when supernumerary tooth look exactly very similar to the normal tooth we call it

supplemental “similar morphology to the normal teeth “

in the maxilla the most common is the mesiodense

in the mandible the most common in the premolar area and sometimes we

have a forth molar .. or any tooth

it could be conical in shape like mesiodense or normal in shape like the premolar

“supplemental tooth”

in deciduous teeth we may have more lateral incisors “in the maxilla”

so the lateral maxillary incisor it could be effected with hypodontia and

supernumerary on the shape of lateral incisors for the deciduous

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we may have multiple supernumerary and impacted supernumerary in

satution were we have two syndrome Cleidocranial dysplasia and Gardner

syndrome

in these syndrome we may have multiple supernumerary and multiple impactions

because they have no space to erupt actually the may interfere with normal

eruption of the surrounding teeth

so when the patient come to your clinic and you examine him you will found that

he doesn’t have premolars or lateral incisors or lower canine several teeth are not

there so you take a radiograph and then you see several extra teeth present but

there is no eruption >

disturbances in the timing of eruption

i. premature eruption the teeth erupt earlier than the normal expected date,

and these may be due to hormonal changes in the children

ii. delayed eruption like in multiple supernumerary teeth , another cause for

interference of eruption early extraction of deciduous teeth (because they

aid in the eruption of permanent teeth) , tumors or mass or cyst present over

the tooth may delay the time of eruption .

premature eruption is most likely to be in the deciduous mandibular incisors , it

could be familial more than a disease for example in a family maybe the time of

eruption for the permanent teeth is 4 years instead of 5 or 6

natal teeth children born with teeth if the teeth erupts within the first 30 days of

life we call it neonatal teeth

most of the time the natal teeth are true deciduous teeth “ so we don’t go straight

forward for extraction, except when the interfere with feeding , or if they cause

trauma to the tongue

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in this pic we can see redness and ulceration in the tongue due to natal or neonatal

tooth while the infant move his tongue

so any reason for chronic ulcer we don’t like it , so we go for extraction ,and any

patient who have sharp tooth or broken he at least should have smoothed and then

filed or replaced so we avoid chronic source of trauma

delayed eruption

due to Cleidocranial dysplasia, could be tretanism “ عكس العملقه” , may be the

patient have gingival fibromotisis “which mean that the Geneva is sick so the teeth

couldn’t erupt normally through the gingiva so they need surgical exposure ….

Unless it is familial in this case the gingeva will keep thickened unless the teeth are

extracted then it will be normal

now for the impaction the tooth cannot erupt , the tooth is willing to erupt but there

is abstraction on the way like physical barrier “crowding, there are no

supernumerary teeth but the normal teeth are crowded when we have crowded

teeth when the jaw is smaller than normal or the teeth are bigger than normal or

the case together “ or if we have supernumerary teeth or cysts or tumors

the most common tooth that get impacted is the third molar due to physical

barrier some time the tooth is mesio angular so it can’t erupt , and some

time it’s disto angular it can’t erupt through the ramous .

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Eruption sequestram

is a small isolated bone island that present over the erupting tooth ,,, that mean

when the tooth in the process of eruption there should be bone resorption, some

times a small pieces of the bone remained if it doesn’t reorsoped completely , so

when the tooth enters the oral cavity the mother may fell that there’s a small piece

of bone on the tooth ,, and it’s normal

so eruption sequestram small specula of calcified tissue that go through the alveolar

mucosa overlying the erupting tooth which is usually the molar “because the molar

have wide occlusal surface compared to the incisors or bicuspid” so in the center

small peace of bone may remain

it’s require NO treatment

Disturbances in the shape

The shape of the teeth will change look at the root how does it look like

There is curvature in the root over here we call this dilacerations

Done by : Mohammad F. Elwir