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بسم الله الرحمن الرحيم

#The first lec. In ORAL PATHOLOGY…

Firstly Dr. Rima started the lecture by illustrating that:

-You haven't to be absent more than 10% of lectures without medical excuse because you will be out of this course… so keep attendant.

-If you have any comment or problem you can communicate with Dr.Rima in the DEANSHIP in sun. and wed. afternoon because the Dr. will be adviser to us as 3rd dental student year.

-The first three lec.s will not be from the reference book…. There will be handouts and slides which will be on e-learning.

So let's start the first lec.

Slide # 2

What does developmental disturbance mean-?

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Developmental disturbances

It means that the disturbances and changes due to development without specific cause; without infection, neoplasia,tumor,reactive changes or soft tissue tumor.

What are the main structures which are in the oral cavity?

Teeth, soft tissue and bone.

So we will talk about disturbances that will affect teeth , soft tissue and bone of oral and maxillofacial region.

So you have to be able to differentiate developmental changes and pathological changes.

Slide #3

So starting by teeth… disturbances in teeth might be occurring in:

Size: macrodontia Vs. microdontia-;

Macrodontia: increasing in the tooth size.

Microdontia: decreasing in the tooth size.

Number: hypodontia Vs. Supernumerary- ;

Hypodontia : the number of teeth is less than the normal number.

Supernumerary: the number of the teeth is more than the normal number.

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Eruption: premature eruption Vs. delayed eruption-.

Shape: there are a lot of changes which affect the tooth shape-.

Structure: tooth is composed of three parts; enamel, dentine and pulp.

The changes of structure of every normal part will cause different developmental disease than the other part.

Slide # 4

Changes in tooth size will be either microdontia or macrodontia.

Firstly, what is the difference between localized and generalized microdontia?

Localized microdontia: some of the teeth are affected, but in generalized microdontia most of the teeth are affected.

Generalized microdontia might be true or relative:

-Relative generalized microdontia: if the teeth are normal in size but the jaw is abnormally big.

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-But true generalized microdontia: when the dimension of the teeth is less than the normal sizes of normal teeth.

Note: Be careful when deciding if it's true or relative, because it may look as true microdontia, but by taking measurements then using charts or tables specific for teeth size you might be wrong.

As you can see in this slide... As an example of localized microdontia : max. Lateral incisor is taper , it's smaller than normal one, and even its shape is abnormal, so it's called peg lateral. 3rd molar especially max. 3rd molar could be seen rounded, small and conical, so they may be very small compared to adjacent molars.

Supernumerary teeth : ( super: extra , numerary : referred to the number ) these additional teeth are usually microdontia so these are microdontia and super numerous

Slide# 5

Again… macrodontia is increasing in the tooth size.

And it will be true (if teeth size is more than normal sizes of normal teeth) or relatives (If the jaw is small

and the teeth are normal.(

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True macrodontia could be occurred due to hormone changes (increasing in growth hormone) and other endocrine changes.

So it's rarely to see one big tooth , in this case you can see half of the teeth.

When we will discuss ENSHALLA developmental changes affecting the bone we will discuss hemifacial hypertrophy.

Hemifacial hypertrophy: condition in which half of the teeth will be increased in the size, so there will be increasing in the size of half of the face, including: bone, soft tissue, teeth and tongue ( one half of the

tongue will be bigger than the other half.(If size of the root of the tooth is increased it's called radiculomegaly and this usually occurred in mand. Canine …. So there roots will be bigger than normal ones.

slide # 7

Firstly these are some notes:

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Note: Localized microdontia is more common than localized macrodontia.

An: prefix that indicate negation.

Hypo: prefix that indicate decreasing.

Hypodontia Vs. anodentia-.

-Anodontia: complete absence of teeth (for example … 6 yr. pt. without having teeth.(

Hypodontia: decreasing in teeth number (less than normal-.(

Syndrome in which there are no teeth (anodontia) is known as ectodermal dysplasia; abnormality in epithelium in some components of the body especially which are related to teeth, we know that teeth are formed by interaction between epithelium (which gives enamel) and mesenchyme ( which gives dentine, pulp and periodontal ligament)so epithelium is important in teeth formation.

Now let's discuss hypohydrotic dysplasia

Defenition: subtype of the syndrome in which sweet glands are also defective so the pts. Will be abnormal by missing normal sweating so they won't tolerate high temperature.

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Note:

We are concerned with hypohydrotic as a subtype of ectodermal dysplasia because of having more than

one type.

Features: as you can see in slide # 9 you can notice abnormal hair ( very thin hair , protruded upper lip, bulging in frontal bone, no eyedraw, very thin eyelashes and there will be defective sweat glands and anodontia and hypodontia( in which there are decreasing in both number and size; hypodontia and microdontia(

Slide # 8

Causes : the defect in this syndrome is transmembrane protein in keratinocytes affecting teeth, sweat glands and hair follicles.

Q & A

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In other syndromes may there will be no teeth, but there will be impacted in the jaw and may will be supernumerary in this case it is not hypodontia because they are present but interrupted.

Slide # 11

This slide talks about teeth that will be missed congenitally; means that if the parent congenitally missing later incisor (for example) some of the

children will also have congenitally missing lateral .

For the permanent teeth: lateral incisor, 3rd molar,(not of us have four third molars), second premolar especially upper.

For the deciduous teeth: maxillary laterals are the most common congenitally absent teeth.

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Q1: In anodontia , Are the teeth missing from the beginning ? Are they impacted in the bone?

Q2: Does calcium level affect the teeth to be missed ?

A1: there are no teeth from the beginning, and even in the bone so to make sure make OPG (ortho pantomograph) or radiograph for the whole jaw.A2: Ca level affects on structure of teeth not the number or the size.

Slide # 12

Supernumerary teeth:

Single or multiple; single: one extra tooth-.

Multiple: more than one extra tooth

Erupted or impacted-.

*A common location of supernumerary tooth is in the midline of maxilla between two central incisors and it may erupt adversely like in the floor of the nose or may be impacted.

Think about this case??????????

If the supernumerary tooth is impacted in the bone, what are changes could be happen?

It will resorb the adjacent teeth, it may have odontogenic tumor or odontogenic cyst, it may develop anything ( cyst , tumor,…) like any other normal teeth.

-Maxilla is much more common to have supernumerary teeth compared to mandible.

In maxilla :

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-Mesiodens: supernumerary tooth that erupt in the midline of maxilla (mesio; it erupted mesially to both central incisors(

-Paramolar : extra molar (fourth molar) which erupts distally to the last molar.

-Patients with cleft palate may develop supernumerary teeth in later incisor region, so these patients develop hypodontia ,or hyperdontia

( supernumerary tooth.(

In mandible :

Premolars ,fourth molars and incisors.

In deciduous :

Maxillary lateral incisor may have supernumerary teeth.

The shape is conical (indicates microdontia )or normal-.

Note: supernumerous teeth which are normal in shape are called supplemental.

From the book: supplemental teeth: supernumerous teeth which morphologically resemble those of normal series.

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Slide # 13

This slide shows supernumerous teeth:

1-what do we call this supernumerous conical tooth that is in the midline (between incisors) #1 ? mesiodens.

2-if you look to lateral incisor tooth, you will see (mesially ) supernumerous tooth,is it conical or supplemental #2?

It's supplemental because of its normal shape.

3 -how many supernumerous teeth are there?

Three supernumerous teeth.

Slide # 14

How many supernumerary teeth do you see?-1

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111

2

They are 2 (3rd and 4th premolars.(

2-Are they conical or supplemental?

They are supplemental because of their normal shape.

Slide # 15

What are syndromes in which there are multiple and impacted supernumerous teeth?

Cleidocranial dysplasia: (taken later) there will be no clavicle-.

-Gardner syndrome: serious syndrome in which all the patients will develop adenocarcinoma of the colon.

Firstly, Dr. asked us if we took multiple osteoma, intestinal poly-p, intestinal adenoma in general pathology, then she asked: What is the difference between adenoma and poly-p in intestine ?

Adenoma: pre-malignance. - Poly-p: benign-.

As a dentist you are supposed to be the first one to discover if your patient has Gardner syndrome or not, by taking radiograph then you notice that there are a lot of impacted and multiple supernumerous teeth, What will your diagnosis be since both of cleidocranial dysplasia and Gardner syndrome have this feature( multiple and impacting supernumerous

teeth ?

In cleidocranial dysplasia Pts. There will be NO clavicle, so there is approximation between

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shoulders, if not your diagnosis will be Gardner syndrome, and then genetic diagnosis will be done, then Pts. Start to treat their intestinal adenoma.

Slide # 16

Disturbances in eruption will be either pre-mature or delayed eruption or impacted teeth.

What's the difference between natal teeth and neonatal teeth?

Natal teeth: one or more tooth that present in infant mouth at birth.

Neonatal teeth: one or more tooth that present in the first month of birth.

The deal Q is: Are these teeth supernumerous (that could be extracted) or deciduous ?

They are deciduous, so there are no associated problems with this tooth, NO ulceration, NO feeding problems, so we keep them without extraction.

Note: any chronic irritant is not acceptable in oral cavity, like fractured tooth or sharp cusp and fractured restoration because they will induce chronic irritation.

-If you remember when we took neoplasia in 2nd year, we took chronic irritation it's a chronic inflammation which has a lot of inflammatory mediators and chemokines which induce proliferation of cells and then mutation will be more.

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-Chronic irritation is a questionable not confirmed cause of oral carcinoma.

Slide # 18

Causes of impacted teeth :

Physical barrier-:

Impacted tooth is one of the other disturbances of eruption, actually there must be a barrier; it could be soft tissue like in gingival fibromatosis or very thick gingiva or the adjacent tooth is inclined or there are impacted supernumerous teeth or impacted adjacent tooth…. So it's something obstruct the way of the tooth or the tooth itself is inclined so the path of

eruption may be abnormal .

-Crowding, odontogenic cyst ,supernumerous tooth ,or the tooth itself has odontogenic tumor.

Examples :

-3rd molars; sometimes it's inclined mesially or distally so abnormal path of eruption, or the adjacent tooth prevent the normal path.

-Maxillary canines: if they are horizontally lying in maxilla so they will be impacted.

Treatment: in need to surgical TM then orthodontic TM to pull canines down.

Delayed eruption is another disturbance of eruption,

Causes :

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-Cleiodocranial dysplasia : because of the presence of multiple and impacted supernumerous teeth they will delay the eruption of normal adjacent teeth.

- Gingival fibromatosis : so Pts. Need surgical TM to allow teeth to erupt .

Slide # 19

-If you are asked from your relatives about a case in an infant mouth that there is a small piece of bone over an erupting 2nd deciduous molar (for example) sure you will

answer quickly!!

It's a bone sequestrum …. When the tooth is erupting it resorbs the bone, so may will still a small unresolved bone on the occlusal surface of this erupting molar.

It's normal condition and it will be lost by itself, it is not pathological so there is no need to TM.

Note: this condition is different from sequestrum osteomyelitis so you have to be accurateالتهاب).

العظام(

AS A SUMMARY: eruption sequestrum is a specule of calcified tissue that is extruded from the alveolar mucosa, and it has strange appearance, it requires no TM.

Slide # 20

Disturbance in the shape of the tooth:

Dileceration:

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Definition: disturbance in the shape of the tooth, it's a curve in its root and this curve occurs before mineralization, because if it occurs after mineralization ( like in trauma) fractures may occur because it's hard and brittle … but before mineralization a sharp curve may occur and mineralization may follow.

"When I asked the Dr. if dileceration just involves in the root without the crown she answered that just in severe

cases crown is involved" …

As a summary: dileceration involves variable severity and location along the root and just in severe case crown is involved.

Causes:

Trauma during teeth development-.

Continued root formation-.

Idiopathic- .

Complication :

Difficult extraction-.

Difficult RCT (root canal treatment-(

There is Q. which I couldn't hear but Dr. answered that normal procedures (caries, composite filling,…)could done easily but the problem in RCT and extraction because it needs special consideration …. Apexectomey could be done by cutting apex then fill it.

Slide # 21

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The other disturbance in shape is Taurodontism :

If you compare the two teeth at this radiograph at the furcation site; in the normal tooth there is furcation site then two roots, but in the other tooth there are two short roots, so the problem here is apical placement ( the

furcation site is downward to the apex.(

Complication :

Difficult RCT : difficulty in finding canals orifices.

Difficult extraction: special care when using forceps to extract the tooth from its furcation site which is downward.

Association :

This disturbance is associated with:

Amelogenesis imperfect-.

Down syndrome-.

Klinefilter syndrome- .

slide #23

The third change is dense invaginatus

Firstly what is the difference between invagination and evagination?

In invagination: downward growth occurs… the growth goes inside the tooth or the organ … BUT in evagination: it goes outside.

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First of all to get the idea of dense invaginatus you have to know that enamel has the highest opacity comparing to other parts of tooth.

If you look at tooth on the left in slide # 24 … you will notice high radio density for enamel, in other words… enamel is more opaque compared to dentine… so what happens is: before mineralization there is invagination of enamel through crown or root so enamel will be in abnormal site and we can guess that by high radio density of enamel or aesthetic problem of the tooth ( I think it will be bulgy in severe cases) so enamel will move to the pulp champer or ( sometimes) to the pulp canal then goes up.

So you can guess that pit has an open side ( in oral cavity) and closed side( in the pulp) which is lined by enamel( so you will notice high opacity site comparing to

adjacent dentine.(

What is the significance of this pit-?

By this pit, food and bacteria will be accumulated and caries will occur, then the lining of the pit may perforate (perforation due to the analysis of food debris by bacteria so acids will be formed) and that will cause pulpitis (inflammation of the pulp) by the entrance of the bacteria, then the pulp may will be necrotic or the products of the bacteria will go in the apical area then form abscess or granuloma or inflammation in the alveolar bone.

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So as a summary: the significance of the dense invaginatus is the exposure of the pulp silently (because this process is gradual) then forming an abscess then

your patient may come with draining abscess. Prevention: with fissure sealant to prevent pulp exposure.

Detection: by making radiograph and by using prop or thin file so it will reach variable ways.

Causes: idiopathic or trauma.

The tooth may will be extracted to aesthetic reasons only in severe cases.

If you look at the same slide on the right … in this case dense invaginatus is severe because it reaches the apex so this invaginatus is severe , dilated , has calcified mass, changing in crown shape and doesn't look as pit or canal this case is called dilated odontume ( so named because it's wide and reaches the pulp and has a

collection of enamel and dentine and some pulp .(

So the most severe form of dense invaginatus is dilated odontome .

Dr. asked us if there is congenitally absent decidous lateral incisor …. Will there be congenitally absent permanent lateral incisor? The answer is YES.

Dr.Rima reminds us about cusp of carabelli that it's additional cusp in mesiolingual surface of the upper first

molar ( as in slide # 25.(20 | P a g e

Slides # 26 & 27

Dense evaginatus…. In this case extra cusp will usually on premolars especially lower ones.

???Why is this extra cusp considered as significant case???

-It may interfere with occlusion because it's simply extra cusp.

-If it's fractured, dentine will be exposed then sensitivity will happen, and even pulp exposure because of the presence of pulp horn inside this cusp.

So patients with this case ( dense evaginatus) can't treated by just trimming because that will expose dentine or pulp but instead of this RCT could be done.

Another cusp which is talon cusp, extra cusp( has enamel, dentine and pulp) that's usually on the upper anterior teeth ( usually central incisors and sometimes lateral incisor) it interferes with the occlusion and it can't be just trimmed, RCT could be done.

This cusp could have grooves in either sides or pits so food and bacteria could be accumulated and caries could happen, so fissure sealant could be used to prevent food accumulating.

Radiograph in slide #26:

-Do you notice that dense invaginatus is the adverse of dense evaginates? In dense invaginatus the radiopaque (

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enamel) is toward the pulp, but in dense evaginatus it's toward the incisal edge.

Note: if we don't reach pulp in trimming there is no need to RCT, but if trimming makes exposed dentin in this case filling material could be used.

Supernumerary roots are rare, most common on premolars ,canines and 3 rd molars ….. and there significance will be in both RCT( we have to find the extra root to treat it because we can't treat infections by treating root and leave others) and in extraction because if we don't detect it, it may still without removing, so taking radiograph is important in both RCT and extraction even if the tooth is about to be extracted.

slide #28

Disturbances in the shape of the tooth:

Gemination-

Fusion-.

Concrescence-.

Hypercementosis-.

Cervical enamel projection-.

Double teeth include both gemination and fusion and if it's not gemination or fusion it will be macrodontia but it's rarely to see just one macrodontia tooth.

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Fusion: occurs when teeth germs are fused togother ( because teeth germs are present close to each other) , so one single big crown will form and it could be completely fused roots or not, but at least dentine should be fused to be named as fusion.

Fusion could be completed or not according to the stage of the development y3ni when fusion occurs it will just include structures which are not harden yet…so there will be no fusion between hard structures.

Gemination: one tooth germ gives two teeth ( twinning (

fusionGeminationUnion of teeth germs

One tooth germ gives two fused teeth

definition

Missing teethNo missing teethdifference

Gemination looks like fusion clinically but you can differentiate between these two disturbances by counting the teeth … if you find missing teeth it will be fusion, if not it will be gemination.

How could it look in radiograph-?

One big root and two fused crown (twinning.(

Concrescence: fusion by cementum which covers the roots so the fusion will be in the roots and there is special features in this disturbance that it's the only one which

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occur after tooth eruption so it could be developmental or occurring later.

Causes of concrescence:

Mal alignment of teeth-

-Hypercementosis: two adjacent teeth without concrescence then by caries or inflammation in the pre-apical area hypercementosis will happen because cementum is dynamic so it could deposit unlike enamel.

Significance : extraction of the two fused teeth in this case requires minor oral surgery by breaking the teeth then cut them and then extract them in pieces.

How does the cementosis look like in radiograph?

The normal roots are taper, not bulgy or rounded as in concrescence case… and we could see lamina durra and soft tissue( black line in the radiograph) which surround the cementum so that indicate the presence of hypercementosis.

Causes of hypercementosis :

-High occlusal load: if the tooth is exposed to high occlusal stress it will start to deposit cementum to withstand the forces, as in high filling or by stressing

on the teeth (bruxism .(

-Low occlusal load: if the tooth is under occlusion (infra occlusion) so there will be stimulation to the cementum to composite for a reason or another , as

in low filling .

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-Infection: low grade infection may will start to stimulate deposition of cementum when reaching the pulp instead of resorbing it.

Hormonal changes: as in hyperituitarism-.

Paget's disease of the bone-.

Significance :

Extraction: instead of having taper roots which are easily extracted, there will be rounded, bulgy roots so difficulty will be faced, or it could cause concrescence with

adjacent tooth which is impacted or horizontally lying.

Cervical enamel projection :

developmental change causing enamel to deposit over cementum; Normal location of the enamel is on the crown not on the root surface the significance is in the periodontal ligament …. PDL will be between cementum and alveolar bone and if the enamel covers cement there will be no insertion to PDL on the cementum (because enamel is much mineralized compared to cementum.

How could we detect it clinically?

By using prop you will notice that there is like a pocket between the gingiva and crown … it can't be seen but can be detected clinically.

Cause :

Developmental change causing enamel to deposit over cementum.

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Complication :

Accumulating food and bacteria so periodontitis will occur.

Another abnormal site either than over cementum is furcation area in molars; in which droplet of enamel will be formed either having dentine in it or not and it's called enamel pearl.

Significance of enamel pearl :

Abnormal PDL insertion in that site so loss of the PDL could be and so furcation involvement.

تم بحمد الله

DONE BY: Mays Jaradat.

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