landmarks of max. & mand

8/2/2019 Landmarks of Max. & Mand.

1/69

Landmarks of the Maxilla& Mandible


2/69

Maxillary Incisor

Nasal septum

Inferior concha

Nasal fossa

Nasal spineIncisive foramen

Nose

Median palatine suture


3/69

ef

a = nasal septumb = inferior conchac = nasal fossad = anterior nasal spine

e = incisive foramenf = median palatal

suture

b

ad

c

facial view palatal view


4/69

Nasal septum

facial view


5/69

a

Inferior concha

facial view


6/69

Nasal fossa

facial view


7/69

Anterior nasal spine

facial view


8/69

Incisive foramen

palatal view


9/69

Median palatal suture

palatal view


10/69

Soft tissue of the nose


11/69


12/69

Red arrow = mesiodens(supernumerary tooth);

d

f

Blue arrow = chronic periapicalperiodontitis. Tooth # 9 is non-

vital (trauma) and needs endo.

d: anterior nasal spine; f: median palatal suture


13/69

The red arrows point to the soft tissue of the nose.The green arrows identify the lip line.


14/69


15/69

a = floor of nasal fossab = maxillary sinusc = lateral fossa

(a & b form inverted Y)

a

cb

a

c

b

facial view


16/69

Floor of nasal fossa (red arrows) and anterior borderof maxillary sinus (blue arrows), forming the inverted

(upside down) Y.

facial view


17/69

Lateral fossa. The radiolucency results from adepression above and posterior to the lateral incisor.To help rule out pathology, look for an intact lamina

dura surrounding the adjacent teeth.

facial view


18/69

Soft tissue of the nose

Red arrows point to nasolabial fold.Also note the inverted Y.


19/69

The maxillary sinussurrounds the root of thecanine, which may bemisinterpreted aspathology.

The white arrows indicate thefloor of the nasal fossa. Themaxillary sinus (red arrows)has pneumatized between the2nd premolar and first molar


20/69

The red arrow identifies the lateral fossa. The pinkarrow points to CPP (chronic periapical periodontitis =abscess, granuloma, etc.).


21/69

Zygomaticprocess

Sinus septumSinus recess

Maxillary sinus

Maxillary Premolar


22/69

a = malar processb = sinus recessc = sinus septumd = maxillary sinus

b

a cd

bdca

facial view


23/69

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 thezygomatic bone.

facial view


24/69

Sinus septum. This septum is composed of folds of

cortical bone that arise from the floor and walls of themaxillary sinus, extending several millimeters into thesinus. In rare cases, the septum completely divides thesinus into separate compartments.

facial view


25/69

Sinus recess. Increased area of radiolucency causedby outpocketing (localized expansion) of sinus wall. Ifsuperimposed over roots, may mimic pathology.

facial view


26/69

Expansion of sinus wall into surrounding bone(Pneumatization), usually in areas where teethhave been lost prematurely. Increases with age.


27/69

Maxillary Molar

Maxillary sinusSinus recess

Zygoma

Pterygoid plate

Hamularprocess

Coronoid process Maxillary tuberosity


28/69

g

d

a

e

f

a = maxillary tuberosity* e = zygoma (dotted lines)b = coronoid process f = maxillary sinusc = hamular process g = sinus recessd = pterygoid plates

* image of impacted third molar superimposed

c

b

facial view

d

ba

e

c f

g


29/69

Maxillary Tuberosity. The rounded elevationlocated at the posterior aspect of both sides ofthe maxilla. Aids in the retention of dentures.

facial view

f i l i


30/69

Coronoid process. A mandibular structure

sometimes seen on the maxillary molar periapicalfilm when using the bisecting angle techniquewith finger retention (The mouth is opened wide,moving the coronoid down and forward).

facial view


31/69

Hamular process (white arrows) and pterygoid plates

(purple arrows). The hamular process is an extensionof the medial pterygoid plate of the sphenoid bone,positioned just posterior to the maxillary tuberosity.

facial view


32/69

Zygomatic (malar) bone/process/arch. The zygomatic

bone (white/black arrows) starts in the anterioraspect with the zygomatic process (blue arrow),which has a U-shape. The zygomatic bone extendsposteriorly into the zygomatic arch (green arrow).

facial view


33/69

The zygomatic process (green arrows) is a prominent U-shaped radiopacity. Normally the zygomatic bone

posterior to this is very dense and radiopaque. In thispatient, however, the maxillary sinus has expanded intothe zygomatic bone and makes the area moreradiolucent (red arrows). The coronoid process (orangearrow), the pterygoid plates (blue arrows) and the

maxillary tuberosity (pink arrows) are also identified.


34/69

This film shows the expansion of the borders of themaxillary sinus through pneumatization (red arrows). Thisexpansion increases with age and it may be accelerated asa result of chronic sinus infections. It is most commonly

seen when the first molar is extracted prematurely, as inthe film at right (the second and third molars havemigrated anteriorly to close the space). The coronoidprocess is seen in the lower left-hand corner of each film.The green arrow identifies a sinus recess. Note the twodistomolars in film at right (blue arrows).


35/69

Mandibular Incisor

Mental ridge

Genial tubercles Lingual foramen

Mental fossa


36/69

b = genial tubercles

a = lingual foramen c = mental ridge

d = mental fossa

ab

cd

facial viewlingual view


37/69

Lingual foramen. Radiolucent hole in center of genial tubercles. Lingual nutrient vessels passthrough this foramen.

lingual view

lingual view


38/69

Genial tubercles. Radiopaque area in the midline,midway between the inferior border of the mandible andthe apices of the incisors. Note double rooted canine(red arrows).

lingual view

facial view


39/69

Mental ridge. These represent the raised portions of themental protuberance on either side of the midline. Morecommonly seen when using the bisecting angletechnique, when the x-ray beam is directed at an upwardangle through the ridges.

facial view

facial view


40/69

Mental fossa. This represents a depression on thelabial aspect of the mandible overlying the roots of theincisors. The resulting radiolucency may be mistakenfor pathology.

facial view


41/69

The radiolucent area abovecorresponds to the locationof the mental fossa. However,this slide represents chronicperiapical periodontitis; theseteeth are non-vital, due totrauma.

The orange arrows aboveidentify nutrient canals.They are most often seen inolder persons with thinbone, and in those with highblood pressure or advancedperiodontitis.

M dib l C i


42/69

Mandibular Canine

Mental ridge

Genial tubercles

Lingual foramen

Mental foramen

Cortical bone

facial view lingual view


43/69

b 2

a = mental ridge

c = mental foramen b 2 = lingual foramen

b 1 = genial tubercles

g

dc

da

db 1

db 2

facial view


44/69

Mental ridge. The raised portions of the mentalprotuberance, sloping downward and backwardfrom the midline.

lingual view


45/69

Lingual foramen/genial tubercles. (Seedescription under mandibular incisor).

lingual view

f


46/69

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


47/69

Mandibular Premolar

Mylohyoid ridge

Mandibular canalMental foramen

Submandibulargland fossa

facial ie ling al ie


48/69

c

b = mandibular canal

d = mental foramen

a = mylohyoid ridge

(internal oblique)c = submandibular gland

fossa


c

add b

li l i


49/69

Mylohyoid (internal oblique) ridge. This radiopaqueridge is the attachment for the mylohyoid muscle. Theridge runs downward and forward from the third molarregion to the area of the premolars.

lingual view


50/69

facial view

Mandibular canal. (Inferior alveolar canal). Runsdownward from the mandibular foramen to the mentalforamen, passing close to the roots of the molars.More easily seen in the molar periapical.


51/69

lingual view

Submandibular gland fossa. The depression below the

mylohyoid ridge where the submandibular gland islocated. More obvious in the molar periapical film.


52/69

Mental foramen. Usually located midway between the

upper and lower borders of the body of the mandible,in the area of the premolars. May mimic pathology ifsuperimposed over the apex of one of the premolars.

facial view


53/69

Mandibular Molar

External obliqueridge


Mandibular canal

Mylohyoid ridge(internal oblique)

f i l i li l i


54/69


b

c

a b

a = external oblique ridgec = mandibular canal

b = mylohyoid ridged = submandibular gland

fossa

dd


55/69

ab

cdd

a = external oblique ridgeb = mylohyoid ridgec = mandibular canald = submandibular gland fossa

facial view


56/69

External oblique ridge. A continuation of the anteriorborder of the ramus, passing downward and forward

on the buccal side of the mandible. It appears as adistinct radiopaque line which usually ends anteriorlyin the area of the first molar. Serves as an attachmentof the buccinator muscle. (The red arrows point to themylohyoid ridge).

facial view


57/69

Mylohyoid ridge (internal oblique). Located on the

lingual surface of the mandible, extending from thethird molar area to the premolar region. Serves asthe attachment of the mylohyoid muscle.

lingual view


58/69

The external oblique ridge (red arrows) and themylohyoid ridge (blue arrows) usually run parallelwith each other, with the external oblique ridgealways being higher on the film.


59/69

facial view

Mandibular (inferior alveolar) canal. Arises at the

mandibular foramen on the lingual side of the ramus andpasses downward and forward, moving from the lingualside of the mandible in the third molar region to thebuccal side of the mandible in the premolar region.Contains the inferior alveolar nerve and vessels.


60/69

The mandibular canal (red arrows identify inferior borderof canal) usually runs very close to the roots of the

molars, especially the third molar. This can be a problemwhen extracting these teeth. Note the extreme dilaceration(curving) of the roots of the third molar (green arrow) inthe film at left. The film at right shows kissingimpactions located at the superior border of the canal.


61/69

Identify the anatomical structureson the following eight slides.

Slide # 1


62/69

Slide # 1

A. The red arrows identify the ?

Floor of the nasal fossa

Slide # 2


63/69

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

Maxillary sinus*Sinus septum

Zygomatic process

*(pneumatized into maxillary tuberosity)

Slide # 3


64/69

Slide # 3

A. The small radioluceny identified bythe green arrow is the ?

Lingual foramen


65/69

Slide # 5


66/69

Slide # 5

A. The yellow arrows point to the ?

B. The red arrows identify the ?

Zygomatic process

Maxillary sinus

Slide # 6


67/69

Slide # 6

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

Slide # 7


68/69

Slide # 7

A. The red arrows point to the ?

Mental ridge

Slide # 8


69/69

Slide # 8

A. The red arrows identify the ?B. What is the name of the radiolucent

area surrounding this structure?

Mandibular canal


landmarks of max. & mand

Documents