anatomy of maxilla and mandible

1. Anatomy of Maxilla

2. Maxilla
 It is the second largest bone of the face
 It forms the upper jaw with the fellow of the opposite side
 It also contributes to the formation of
1. Floor of the orbit
2. Roof of the mouth
3. Lateral wall of the nose
4. Pterigopalatine and infratemporal fossae
5. Pterigomaxillary and infraorbital fissures

3. Anatomy of the maxilla
 The anatomy of the maxilla has two main parts:
1. Body(pyramidal shape)
 Anterior surface
 Posterior surface
 Orbital surface
 Nasal surface
2. Processes
 Zygomatic
 Frontal
 Alveolar
 Palatine

5. Anterior Surface:
 Incisive Fossa:
 Depressor septi nasi
 Orbicularis oris
 Canine fossa:
 Levator anguli oris
 Infraorbital foramen
(above canine fossa)
 Infraorbital nerves and vessels
 Above sharp border between
anterior and orbital surface:
 Levator labi superioris
 Nasal notch: Dilator Naris
 Ant Nasal Spine

6. Posterior Surface
 It is directed backwards and laterally
 It forms anterior wall of the infratemporal fossa
 Anterior and posterior surfaces are seperated by ridge which leads to the
socket of 1st molar tooth
 Near the centre of posterior surface 2 to 3 openings of dental canal for
posterior superior alveolar vessels and nerves
 At the lower end there is a raised maxillary tubrosity which is rough in the
upper part of its medial end for tubercle of the palatine bone which has the
attachment of superficial fibres of the medial pterigoid muscles
 Above this smooth surface which forms the boundry of the pterigopalatine
fossa is grooved for the maxillary nerve, this groove is continuous with the
infra orbital groove

7. Orbital surface
Smooth and triangular
 Medial border
 Notch: lacrimal notch
 Behind this it articulates with the
 Lacrimal
 Orbital plate of ethmoid
 Orbital process of palatine
 Posterior border: Smooth, rounded and it forms greater part of infraorbital
fissure in middle infraorbital groove
 Anterior border: forms orbital margin ,infraorbital groove and canal; a little
lateral to this is lacrimal canalis which passes in the anterior wall of the
maxillary sinus and reaches in the nasal cavity and opens in the side of the
nasal septum in front of incisive canal
 A little lateral to the lacrimal groove there is attachment of inferior oblique
muscle of eveball

8. Nasal Surface
 In its upper posterior part there is a large maxillary hiatus which leads into
the maxillary sinus
In articulated skull this hiatus is completed by ethmoid and lacrimal bones
 Behind this there is a rough impression for the perpendicular plate of
palatine bone
 More anteriorly concal crest for articulation with inferior nasal concha
The upper jaw inside view
1 - frontal process;
2 - lacrimal groove;
3 - cleft maxillary sinus;
4 - infratemporal surface;
5 - palatine process;
6 - alveolar bone

10. Maxillary Sinus
 Large pyramidal cavity with its apex directed laterally towards the zygomatic
process
 Base is towards the lateral wall of the nose
 In articulated skull it is reduced by
Above
 Process of ethmoid
 Desending part of lacrimal bone
Below: inferior nasal concha
Behind: perpendicular plate of palatine
 It opens into the middle meatus of the nose.
 Occasionally there are projections in the maxillary sinus from roof to anterior
wall

12. Processes
 Zygomatic: it is rough and pyramidal
 Front:it is contineous with the anterior surface of body
 Behind(concave):in continuity of the posterior surface
 Above: articulates with zygomatic bone
 Below(arched border) which anterior and posterior surface of
the body

13.  Frontal Process:
 Lateral Surface:
 Vertical ridge (Lacrimal crest)
 Groove for the lacrimal sac
 Medial surface: It is rough and uneven and articulates with the ethmoid and also
closes the anterior ethmoidal sinus below ethmoidal crest
 Upper end: Articulates with the frontal bone
 Anterior border with the nasal bone
 Posterior border with the lacrimal bone

14.  Alveolar processes: It has thick arched border behind and
contains sockets to receive roots of teeth which vary in size
and depth
 Canine deepest
 Molar widest and subdivided into 3 minor sockets by septae

15.  Palatine Process: Thick strong horizontal
 Inferior surface is concave and presents numerous foramina for passage of
nutrient vessels and contains depressions for lodgement of glands
 Groove for grater palatine Vessels and nerves
 Incisive fossa leads into the incisive canal
 Sometimes anterior and posterior incisive foramen for long sphenopalatine nerve
which communicates with the greater palatine nerve
 Upper surface: forms the floor of the nasal cavity
 Lateral Border fuses with rest of the bone
 Posterior border fuses with the horizontal plate of the palatine

16. Maxillary Artery

17. Veinous drainage

18. Nerve Supply

19. Lymphatics

20. Mandible
 Largest and strongest bone of the face
 Curved horizontal body; convex forwards
 It has two rami which project upward from posterior end of
the body
 The body is horse shoe shaped

23. External Surface
 Faint ridge: symphisis menti
 Mental protuberance in the triangular area below sympisis
menti
 Mental tubercle on each side of mental protruberance
 Mental foramen between premolar teeth
 Oblique line

25. Internal Surface
 Myelohyoid line
 Sub mandibular fossa
 Sub lingual fossa
 Genial tubercle
 Myelohyoid groove

26. Borders
 Upper boder:
 Sockets for the mandibular teeth are present
 Lower border(Base) presents a digastric fossa
 Ramus
 Lateral Surface
 Medial Surface
 Mandibular foramen canal
 Lingula- mylohyoid groove
 Inferior border is continuous with the angle of mandible
 Upper Border: Mandibular Notch

27. Arterial Supply of Maxilla and
Mandible

29. Nerve supply of Mandible

31. Veinous drainage of Mandible

32.  Processes:
 Condylar
 Coronoid
 Mandibular canal

33. Age changes in mandible

34. Applied Anatomy
Muscle injuries: Its cause and
effects
 Incisivus labii Superioris:
 During the exposure of the bone of
premaxilla between the canines ,a
mucoperiosteal flap reflection may
detach the muscle and if the muscle
gets damaged the the drooping of the
septum and ala of the nose may occur

35.  Mylohyoid muscle
 Surgical manupulation of the floor of the mouth may result in edematous
swelling of the sublingual space (above the mylohyoid muscle )and
submandibular space(below the mylohyoid muscle)
 Cellulitis of this sublingual space in quiet common however excessive bilateral
cellulitis of the sublingual spaces may push the tongue backwards and compress
the pharynx and may result in airway obstruction

36.  Genoiglossus muscle
 During the elevationof the lingual
mucosa before making an
impression for a subperiosteal
implant a portion of the muscle may
be reflected from te genial tubercle,
however if the muscle is completly
detached from the tubercle it may
lead to retrusion of the tongue and
airway obstruction

37.  Medial pterigoid
 The medial pterigoid muscle binds
the pterigomandibular space medially
,during surgical procedures involving
the area of pterigomandibular space
infection may occour and may be
dangerous due to its closed proximity
to the pharyngeal space
 Surgical exposure of the tissue
posterior to the maxillary tubrosity
may also involve the medial pterigoid
muscle as a part of the muscle
originates from the maxillary tubrosity

38.  Lateral pterigoid muscle
 The lateral pterigoid muscle fibres are placed in an angulated manner and
because of this there may be pain in patients with a full arched subperiosteal
implant or prosthetic splint

39.  Mentalis muscle:
 Complete reflection of the mentalis
muscle for the purpose of extension
of a subperiosteal implant may result
in a condition known as witch’s chin
There is failure of the mentalis muscle
reattachment following the
implantation. An external bandage is
applied for four days to help in the
reattachment of the muscle

40.  Buccinator muscle:
 Myositis of the detached buccinator muscle in patients with subperiosteal
implants may cause swelling and pain at the site of origin of the muscle

41. Nerve injuries
 Inferior alveolar nerve:
 The nerve may be damaged
easily when making an incision
or reflection of the mucosa in
its area therefore position of
the inferior dental canal in
vertical and buccolingual
dimension is of great
importance during site
preprations for implants

42.  Lingual nerve
 The position of the nerve is lateral
to the retromolar pad the incision
should remain lateral to the pad
and the mucosal reflection should
be done with a periosteal elevator
in constant contact with the bone
to prevent injury to the nerve

43.  Nerve to mylohyoid:
 The nerve lies in closed relation to the ramus of mandible hence it is prone to get
damaged during surgical intervention

44.  Long buccal nerve:
 When the ramus is accessed for
the purpose of a block graft
excision great care must be take
to protect this nerve from injury

45. Injury to vessels
 Maxillary vessels:
 During the surgical orthognathic
procedures the major nutrient artery
of the maxilla are sometimes
damaged, but the blood supply is
maintained by anastamosis present
in the soft palate

46. Thank You