landmarks of max. & mand (1)

8/14/2019 Landmarks of Max. & Mand (1)

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One of key factor in the differential diagnosis is the recognition of anatomical landmarks

Today we will start by the most common landmarks seen on either extra or intra oral

radiographs for the maxilla.

Starting from maxillary central incisors (next slide)

Landmarks of the Maxilla &

Mandible

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Maxillary Incisor

We have Nasal septum

Sometimes Inferior concha may be

seen in radiographs

Nasal fossa or nasal cavity

Nasal spine

Incisive foramen

Shadow of Nose

Median palatine suture

Shadow of

the lip

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e

f

a = nasal septum

b = inferior concha

c = nasal fossa(cavities)

d = anterior nasal spinee = incisive foramen

f = median palatalsuture

b

ad

c

facial view palatal view

(if you go backward in positioning of your film

either in perapical or occlusal film you may

see

Imagine the skull

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Nasal septum radiopaque line dividing 2 cavities in the

middle & if you draw a line from midline up to floor of the nose

you will find radiopaque line that what we called nasal septum

facial view

Going to periapical radiographs

what we see on skull how we can see it on radiographs

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a

Inferior concha can be seen within a radiolucent

area (which is nasal cavity ) sometimes mistaken byforeign body or supernumerary tooth or any type of

pathology so such radioopacity seen within

radiolucent area it is a normal structure

facial view

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Nasal fossa(cavities ) sometimes present in relation with

apices of the 2 central incisors so when we see

radiolucent area (which is well defined , well corticated )

does not mean pathology associated with central incisor

facial view

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Anterior nasal spine radio-opaque structure in front

part of nasal septum sometimes mistaken with certain

pathology which may appear radio-opaque

facial view

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Incisive foramen dividing the root of the central

incisors well defined radiolucent area might be

mistaken with nasopalatine cyst (which appear in this

area ) so , when you see such anatomical structure

you should included in the differential diagnosis of

any type of pathology which may appear within this

area

palatal view

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Median palatal suture it appear at radiograph as aradiolucent line dividing the palate into equal pieces

it may be mistaken by line of fracture (which appear

also radiolucent

palatal view

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Soft tissue of the nose all the time in anterior we see

a radio-opaque shadow at neck of crown of anterior

teeth (at CEJ) again this does not mean any shadow ofpathology

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Red arrow points to periapical lesion (post-endo). There is

no anatomical structure appear at this area so this is a

pathology even if it appears similar to other structure here

treatment in this tooth that we have endo &post ---so bcz

we did endo so we expect to had ossifying osstietis either

radicular cyst or periapical abcess or granuloma (bcz tt forthese 3 is similar) so when we see such a radiographic

appearance it could be either pathology or process of healing

(that means we made the treatment but the radiolucency

will not disappear right away following the treatment )so we

will know if it is pathology or healing based on patient

complain if there is no pain on percussion ,no sinus tract, noabscess so this is a sign of healing rather than pathology

ab

e

a

db

Red arrows = lip line

Sometimes lip may appearmid part of the crown it loo

again slightly opaquer than

area above it

a: nasal septum; b: inferior concha(appear more opaque ); d:

anterior nasal spine; e: incisive foramen

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Red arrow = mesiodens (supernumerary tooth);

we know that nasal septum appears radio-

opaque here theres radio-opaque structure

but more dense than usual & in the mid of this

radio-opaque structure theres Radiolucent line

So this is supernumerary tooth ( mesodense )

So , when we see radiolucency in the middle ofa radio-opaque structure it is the shadow of

root canal pulp so, if we see radiolucent area

in the middle of radio-opaque structure it is

more commonly to be unerupted tooth

(impacted tooth) or Supernumerary tooth &

mesiodens (most common site for it btw 2

central incisor&sometime it overlaps on nasalseptum)

d

f

Blue arrow = chronic periapical periodontitis.

Tooth # 9 is non-vital (trauma) and needs endo.

(as we said that nasal cavities may appear very

close to central incisor depend on angulation of

cone so, If vertical angle is decreased well

see nasal cavities very close to apices of central

incisor so, when we see such radiographic

appearance & I cant see it in other side so,

its not a nasal cavity its a sign of pathology

associated with this central incisor

d: anterior nasal spine; f: median palatal suture

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The red arrows point to the soft tissue of the nose it is not a Sign of pathology

at all, it appears at apical 1/ 3 of the root .

The green arrows identify the lip line (shadow of lip )appears at coronal 1/ 3 ofcrown .

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in area of MaxillaryCanine

Floor of nasal fossa

Maxillary sinus extend to

premolar area so, we are able to

see Some radiolucent area Some

where here

Lateral fossa appear btw Canine &Lateral

so,bcz we have lat fossa so , bone here

in this area not as dense as at this area or

thatso , amount of radiation travel

through this area more than this area orthat areaso, well see at radiograph a

radiolucent area

Always when we see radiolucency well say

that it is sign of pathology unless theres

anatomical structure so, When we know that

the bone is thin here so, radiolucency that we

see it associated with lateral Incisor is shadowof lateral fossa rather than pathologyShadow of nose appear at apical 1 /3of root in canine area

(cavity )can be see

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a = floor of nasal fossa

b = maxillary sinus area that has less bone than inother area (means more Radiolucent than other area)

but this doesnt mean that we have pathology it is

normal structure .

c = lateral fossa

(a & b form inverted Y)its connection btw floor

of nose ( or floor of nasal cavity ) with max sinus

which will give us inverted y

a

c

b

a

c

b

facial view

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Lateral fossa. The radiolucency results from a depression above and posterior to

the lateral incisor. To help rule out pathology, look for an intact lamina dura

surrounding the adjacent teeth.

This is lat fossa (more radiolucent than this area) but once we can see bonetrabiculation within radiolucent area means that its a healthy bone

but if its pathology we cant see any radio-opaque line present within radio-

lucent area

So, here there is Bone trabiculation So, its anatomical structure

facial view

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Soft tissue of the nose

Red arrows point to nasolabial fold. Also note the

inverted Y.

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The maxillary sinus surrounds

the root of the canine, which

may be misinterpreted as

pathology.The white arrows indicate the floor of

the nasal fossa. The maxillary sinus

(red arrows) has pneumatized between

the 2ndpremolar and first molarHere max sinus is very close to 5 even it

extends btw 5 & 6we call this condition

pneumatizedwhen there were early lose

of posterior teeth associated with

expansion of max sinus btw remainingteeth

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The red arrow identifies the lateral fossa. The pink arrow points to CPP (chronic

periapical periodontitis = abscess, granuloma, etc.).

Lat fossa ( radio-opaque structure within radiolucent area)so, bone trabeculation

intactso, its not a pathology at all.

Here , at this arearadiolucent areatheres loss of lamina duraso, we are

dealing with pathology in this case -we have post in lateral we dont have RCT so,

this radiolucency is a sign of pathology

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a = malar process

b = sinus recess

c = sinus septum

d = maxillary sinus (lower border of max sinus)close to molar &premolar

b

a cd

b

dca

facial view

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Malar (zygomatic) process. U or j-shaped radiopacity, often superimposed over the

roots of the molars, especially when using the bisecting-angle technique. The red

arrows define the lower border of the zygomatic bone.

facial view

Max sinus

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This is 1 this is the


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Sinus septum. This septum is composed of folds of cortical bone that arise from the

floor and walls of the maxillary sinus, extending several millimeters into the sinus. In

rare cases, the septum completely divides the sinus into separate compartments.

when we see this, it doesnt mean that this is max sinus& this is not or it may be a

radiolucent area associated with 5 or 4 ,no this is wrong

So, When there is a Straight line (which should be vertical)it is most probably a

septa rather than pathology

facial view

This is 1

compartment

this is the

other

compartment

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Sinus recess. Increased area of radiolucency caused by outpocketing (localized

expansion) of sinus wall. If superimposed over roots, may mimic pathology.

Sinus recess radiolucency increased so, when we see within radiolucent area a

more lucent than against structure this doesn`t mean that this is pathology

associated with one of those teeth .

In order to determine if it is pathology or recess ,Always we have to retain to clinical

examination to see if there `s a sign of pain at against teeth or not

facial view

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Expansion of sinus wall into surrounding bone (Pneumatization), usually in areas where teeth

have been lost prematurely. Increases with age.

Expansion of max sinus that we said it may extend btw 2 remaining teeth following

premature lose of 1 of the molar & we may see that max sinus `ll reach the level of crestal

bone

So, it`s not a sign of pathology at all

So,when we ask pt when did u lose ur 1stmolar? he `ll say when he was at 8 or 9 yrs

So, this is normal appearance.

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MaxillaryMolar

Maxillary sinus

Sinus recess

Zygoma

Pterygoid plate

Hamular

process

Coronoid process

especially with bisecting

angle technique

Maxillary tuberosity appear at periapical to molar

area

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g

d

a

e

f

a = maxillary tuberosity* usually appear post to 3rdmolar, I can`t see it clearly at radiograph bcz we have impacted 3rdmolar ( tuberosity

overlay on impacted 3rdmolar )

e = zygoma (dotted lines)

b = coronoid process (radio-opaque structure beneath 3rdmolar that we can see it here when pt open his mouth widely)

When u give infiltration at molar area , u ask pt to close the mouth slightly, to avoid contact with coronoid process

the same in radiograph technique, when pt open his mouth widely we see coronoid process ,so pt opens mouth widely only at

bisecting technique only but at long cone parallel technique , pt bite on biteblock , so we can`t see coronoid process

But in bisecting we can see it, so, if we dont know that coronoid may appear , we may thought that it`s radio-opaque pathology

within this area , then we `ll take panorama, then when we make panorama, we can`t see this radiographic appearance, so we over

exposed pt

f = maxillary sinus always appear

c = hamular process may appear periapical g = sinus recess always appear

d = pterygoid plates may appear periapical

* image of impacted third molar superimposed

c

b

facial view

d

b

a

e

c f

g

b

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Maxillary Tuberosity. The rounded elevation located at the posterior

aspect of both sides of the maxilla. Aids in the retention of dentures.Tuberosity - that didn t appear in last slide bcz of impacted 3rdmolar .

Here it appear& it`s not a residual cyst

facial view

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f i l i


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Coronoid process. A mandibular structure sometimes seen on the maxillary

molar periapical film when using the bisecting angle technique with finger

retention (The mouth is opened wide, moving the coronoid down andforward).

facial view

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Hamular process (white arrows) and pterygoid plates (purple arrows). The hamular

process is an extension of the medial pterygoid plate of the sphenoid bone,

positioned just posterior to the maxillary tuberosity.

facial view

Hamular process

pterygoid plates

We can see them in

panorama more clear

than periapical but

sometimes may appear

in periapical 31


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Zygomatic (malar) bone/process/arch. The zygomatic bone (white/black arrows)

starts in the anterior aspect with the zygomatic process (blue arrow), which has a

U-shape. The zygomatic bone extends posteriorly into the zygomatic arch (greenarrow).

facial view

Coronoid

process

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The zygomatic process (green arrows) is a prominent U-shaped

radiopacity. Normally the zygomatic bone posterior to this is

very dense and radiopaque. In this patient, however, themaxillary sinus has expanded into the zygomatic bone and

makes the area more radiolucent (red arrows). The coronoid

process (orange arrow), the pterygoid plates (blue arrows) and

the maxillary tuberosity (pink arrows) are also identified.

zygomatic process- U

shapeas we said that it

appears in bisecting

technique overlay on

palatal root of 1st&or 2ndmolar

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Impacted molarMax sinus


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This film shows the expansion of the borders of the maxillary sinus through

pneumatization (red arrows). This expansion increases with age and it may be

accelerated as a result of chronic sinus infections. It is most commonly seen when

the first molar is extracted prematurely, as in the film at right (the second and third

molars have migrated anteriorly to close the space). The coronoid process is seen in

the lower left-hand corner of each film. The green arrow identifies a sinus recess.Note the two distomolars in film at right (blue arrows).

There is pneumatization happen to max sinus btw 5 &7 due to extraction of 6 very

earlyso, 5 take place of 1stmolar

Impactedmolar

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M dib l I i


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MandibularIncisor

Mental ridge

mainly we can see

it in bisecting

angle technique &

it is difficult to see

it in long coneparallel technique

Genialtubercles Lingualforamen

Mental fossahere amount of

bone is thinner ( we have

depression in this area)so ,

radiographically it will appear

more lucent than left or right

side of canine --- so, this

radiolucency due to

anatomical structure rather

than pathology

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f i l ili l i


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b = genial tubercles will appear radioopaque

a = lingual foramen (radio lucent area) Surrounded

by bone

c = mental ridge ,more dense so ,it

appears more opaque in radiograph

d = mental fossa( depression or thinning

of bone in this area ) (appear more radiolucent )

a

b

cd

facial viewlingual view

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li l i


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Lingual foramen. Radiolucent hole in center of genial tubercles. Lingual nutrient

vessels pass through this foramen.

lingual view

Shadow of

lower lip

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lingual view


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Genial tubercles. Radiopaque area in the midline, midway between the inferior

border of the mandible and the apices of the incisors. Note double rooted canine (redarrows).

lingual view

here we can not see mental foramen (Radiolucency ) due to angulation of xray beam . So only

Genial tubercles can be seen

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facial view


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Mental ridge. These represent the raised portions of the mental protuberance on

either side of the midline. More commonly seen when using the bisecting angle

technique, when the x-ray beam is directed at an upward angle through the ridges.

facial view

Mental ridge appear

opauer

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facial view


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Mental fossa. This represents a depression on the labial aspect of the mandible

overlying the roots of the incisors. The resulting radiolucency may be mistaken for

pathology.

facial view

Mental fossa (bonethinner,more

radiolucent than

against area ,more gray

than bone beneath)

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Nutrientthe radiolucency

increase in this area so


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The radiolucent area above corresponds to the location of the

mental fossa. However, this slide represents chronic periapicalperiodontitis; these teeth are non-vital, due to trauma.

The orange arrows above

identify nutrient canals. They

are most often seen in olderpersons with thin bone, and in

those with high blood pressure

or advanced periodontitis.

Nutrient

canal1-

when pt get

older we can

see them

more also 2-

with pt with

high bld

pressure

they are more

ovious at

lower

structureit

is not

pathology it

may appear

with pt withhigh bld

pressure

increase in this area so

it is not Mental fossa

so , we should expect a

pathology here if there

is pain on percussion or

teeth not vital

but there is other

pathologies appear at

lower ant without

pulpal involvement like

periapical cemental

dysplasia

If teeth are vital ,no

painso, it is not apathologyno, u

should keep in mind

that periapical

cemental dysplasia

appears at this area

with vital teethso,

bcz there is no

treatment for itso ,

we monitor this fibro-osseous lesionit

appear in mix stage as

radiolucent & radio-

opaquein next stage

as radio-opaque

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M dib l C i


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MandibularCanine

Mental ridge part of it

will appear

Genial tubercles

Lingual foramen

Mental foramen btw4&5

Cortical bone (Lower border of mand) 42

facial view lingual view


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b2

a = mental ridge

c = mental foramen

b2 = lingual foramen

b1 = genial tubercles

g

dc

da

db1

db2

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facial view


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Mental ridge. The raised portions of the mental protuberance, sloping

downward and backward from the midline.

Shadow of mental

ridgeit is not a

foreign bodyit is

anatomical

structure

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lingual view


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Lingual foramen/genial tubercles btw central incisor . (See

description under mandibular incisor).

lingual view

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f i l i


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The red arrows identify the mandibular canal; the blue arrow points to

the mental foramen; the green arrows identify the cortical bone at the

lower border of the mandible.

facial view

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M dib l P l


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MandibularPremolar

Mylohyoid ridge

Mandibular canal start to appear in radiograph at PM area

-usually floored by radio-opaque line &roofed by another

radio-opaque line which reaches backward posteriorly to area

of 3rdmolarthen mylohyoid ridge or IOR start to appear

Mental foramen appear obvious

Submandibular

gland fossa appear more

radiolucency than ant

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c

b = mandibular canal

d = mental foramen

a = mylohyoid ridge

(internal oblique)

c = submandibular gland

fossa(thickness of bone here thinner

than above or beneath (more radiolucent ))


c

add b

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li l i


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Mylohyoid (internal oblique) ridge. This radiopaque ridge is the attachment for the

mylohyoid muscle. The ridge runs downward and forward from the third molar region

to the area of the premolars.

lingual view

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facial view

Mandibular canal. (Inferior alveolar canal). Runs downward from the mandibular

foramen to the mental foramen, passing close to the roots of the molars. More

easily seen in the molar periapical.

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lingual view

Submandibular gland fossa. The depression below the mylohyoid ridge where the

submandibular gland is located. More obvious in the molar periapical film.

Submand gland fossa (radiolucent ) confused us with traumatic bone cyst ,which is most

commonly appear at lower posterior &at scalloping btw root of teeth ,

so ,if we don`t know that we have anatomical structure in this area look radiographically

like this it could mislead us in differential diagnosis

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Sometimes due to slight


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Mental foramen. Usually located midway between the upper and lower borders ofthe body of the mandible, in the area of the premolars. May mimic pathology if

superimposed over the apex of one of the premolars.

This Radiolucency due to fossa more lucent than above or ant , so , when u see it

it`s not a sign of pathology

facial viewmodification at horizontal angle ,might lead to radiolucent area

superimposed at apex of 5 or 4

,so, it mislead us in

interpretation toward ossifying

ossities rather than anatomical

structure especially when we see

tooth heavily restored ,if it `s

sound it`s easy to say that it `s

anatomical structure, but if we

see heavily restored teeth &we

see radiolucent area overlap on

apexbe carefultry to follow

lamina duraif u can followlamina dura so , it is not

pathologyif u can not follow

lamina dura in apical 1/3- so , it is

pathology rather than anatomical

structure

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b

c

ab

a = external oblique ridge

c = mandibular canal

b = mylohyoid ridge

d = submandibular glandfossa

dd

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facial view


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External oblique ridge. A continuation of the anterior border of the ramus, passing

downward and forward on the buccal side of the mandible. It appears as a distinct

radiopaque line which usually ends anteriorly in the area of the first molar. Serves as

an attachment of the buccinator muscle. (The red arrows point to the mylohyoid

ridge).

facial view

Lower border of mandSOME PEOPLE thought that this is lower border of mand especially

when there is cone cut but that is wrong , when there is 2 opaque line

parallel to each other one at level of CEJ &other at apical 1/3 of root

so, one( Internal )&other (External )

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li l i


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Mylohyoid ridge (internal oblique). Located on the lingual surface of the

mandible, extending from the third molar area to the premolar region. Serves as

the attachment of the mylohyoid muscle.

lingual view

Lower border of mand

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The external oblique ridge (red arrows) and the mylohyoid ridge (blue arrows)

usually run parallel with each other, with the external oblique ridge always

being higher on the film.

Lower border of

mand

There are 3 RADIOOPAQUE LINES PARALLEL to each other might be se

-1st is external oblique ridge

-2ndmylohyoid ridge

-3rdLower border of mand

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facial view

Mandibular (inferior alveolar) canal. Arises at the mandibular foramen on the lingual side

of the ramus and passes downward and forward, moving from the lingual side of the

mandible in the third molar region to the buccal side of the mandible in the premolarregion. Contains the inferior alveolar nerve and vessels.

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Slide # 1


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Slide # 1

A. The red arrows identify the ?

Floor of the nasal fossa

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Slide # 2


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Slide # 2

A. The red arrow points to the ?

B. The white arrows identify the ?

C. The blue arrow points to the ?

D. The yellow arrow identifies the ?

Coronoid process

Maxillarysinus**

Sinusseptum

Zygomaticprocess

*(pneumatized into maxillary tuberosity)

Usually

superimpose

d on palatalroot of 7

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Slide # 3


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Slide # 3

A. The small radioluceny identified by

the green arrow is the ?

Lingual foramen

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Slide # 4


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Slide # 4

A. The radiopacity identified by theblue arrows is the ?

B. The orange arrow identifies the ?

Mylohyoid ridge=internal oblique line

Submandibular

gland fossa

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Slide # 5


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Slide # 5

A. The yellow arrows point to the ?

B. The red arrows identify the ?

Zygomatic process(U shape )

Maxillary sinus

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Slide # 6


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A. The red arrow points to the ?B. The orange arrow points to the ?

C. The blue arrows point to the

radiolucent line known as the ?

Inferior conchaNasal septum

Median palatal suture

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Slide # 7


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A. The red arrows point to the ?

Mental ridge

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Slide # 8


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A. The red arrows identify the ?

B. What is the name of the radiolucent

area surrounding this structure?

Mandibular canal

Submandibular

gland fossa

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Done by: Duha ghassankhasawneh

landmarks of max. & mand (1)

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