Maxilla Anatomy and Development

BY: DR. KOMAL SHARMA
PG 1ST YEAR
ANATOMY OF MAXILLA AND
ITS DEVELOPMENT

CONTENTS
 INTRODUCTION
 DEVELOPMENT OF MAXILLA
 FEATURES OF MAXILLA
 ARTICULATION OF MAXILLA
 AGE CHANGES
 PERIODONTAL CONSIDERATIONS
 CONCLUSION

INTRODUCTION
 Maxilla is the 2nd largest bone of
the face.
 The 2 maxillae form the whole of
the upper jaw.
 3 cavities: the roof of the mouth,
the floor & lateral wall of the nose
& the floor of the orbit.
.

 2 fossae, the infratemporal &
pterygopalatine.
 2 fissures, the inferior orbital &
pterygomaxillary.

DEVELOPMENT OF MAXILLA:
PRENATAL EMBROYOLOGY OF MAXILLA:
 4th week of IUL a prominent
bulge appears on the ventral
aspect of the embryo.
 Shallow depression primitive
mouth stomodeum
 Separated from the foregut by
the buccopharyngeal membrane
 5 branchial arches form in the
region.
 1st branchial arch is mandibular
arch – responsible for the
development of nasomaxillary
region.

 The mesoderm covering the
developing forebrain proliferates
to form the frontonasal process.
 The stomodeum is overlapped
superiorly by frontonasal process
& laterally by mandibular arches
of both sides.
 Formation of nasal pits divides
frontonasal process into 2 parts :
a) The medial nasal process
b) The lateral nasal process

•The mandibular arch gives off a bud from its
dorsal end called the maxillary process which
grows ventro-medio-cranial to the mandibular
process.
•At this stage the stomodeum is overlapped
from above by the frontal process, below by
the mandibular process & on either side by
the maxillary process.
•The two mandibular processes grow
medially & fuse to form the lower lip & the
lower jaw.

•Maxillary process undergoes
growth, frontonasal process becomes
narrower so that 2 nasal pits come
closer.
•Line of fusion of maxillary process
& the medial nasal process
corresponds to the nasolacrimal
duct.

DEVELOPMENT OF PALATE:
 Palate is formed by:
A. Maxillary process
B. Palatal shelves
C. Frontonasal process
The frontonasal process premaxillary region while palatal shelves
form rest of the palate.
 Medial growth of palatal shelves & their union is prevented by the
presence of the tongue, thus palatal shelves grow vertically downwards
initially.

 7th week - IUL transformation in
the position of palatal shelves
occurs i.e from a vertical to a
horizontal position.
 8 ½ weeks- IUL c/t of palatal
shelves intermingle with each
other resulting in their fusion
 Initial palatal contact occurs in the
central region of the secondary
palate posterior to the premaxilla.
 Mesial edges of the palatal
processes fuse with the free lower
end of the nasal septum & thus
separates the 2 nasal cavities from
each other & the oral cavity.

OSSIFICATION OF THE PALATE:
 It occurs from the 8th week of intra-uterine life.
 Its an intramembranous type of ossification.
 The palate ossifies from a single centre derived from the maxilla.
 The most posterior part of the palate does not ossify & forms the soft
palate.
 The mid-palatal suture ossifies by 12-14 years.

Tongue
 5th week , rapidly proliferating
mesenchymal swellings, covered
with a layer of epithelium, appear
on the internal aspect of the
mandibular arch known as the
lateral lingual swellings
 Between the swellings arises a
small medial projection, the
tuberculum impar
 Caudal to the tuberculum impar,
the copula unites the 2nd & the 3rd
branchial arches to form a mid
central elevation extending
backward to the epiglottis

 Mesodermal tissue from the 2nd, 3rd & 4th arches grow on either side of the
copula & form the tongue structure
 Point at which the 2nd & 3rd branchial arches merge marked by the foramen
caecum just behind the sulcus terminalis, which marks a boundary between
root of the tongue and its active portion
 Mucosal sac or covering of the body of the tongue originates from 1st lateral
lingual swelling of the mandibular arch.
 11th week of fetal age papillae of the tongue are seen .
 By 14 weeks the taste buds can be observed in the fungiform papillae, & they
appear in circumvallate papillae at about 12 weeks

DEVELOPMENT OF
MAXILLARY SINUS:
 The maxillary sinus forms
sometime around the 3rd month of
intrauterine life.
 It develops by expansion of the
nasal mucous membrane into the
maxillary bone.
 Later sinus enlarges by resorption
of the internal wall of maxilla.

POST-NATAL GROWTH OF MAXILLA
 Maxillary complex is attached to the cranial base it influences the
development of this region.
 The growth of the maxilla is dependent on the spheno-occipital & spheno-
ethmoidal synchondroses.
 The growth of the nasomaxillary complex is produced by the following
mechanisms:
 Displacement
 Growth at Sutures
 Surface Remodeling

 Displacement
 Growth of the cranial base
passive /secondary displacement
of nasomaxillary complex in
downward & forward direction.
 As middle cranial fossa grows it
moves the nasomaxillary
complex to a more anterior
position.
 Growth of the maxillary
tuberosity primary type of
displacement in a forward
direction,due to the enlargement
of the bone itself.

 Growth At Sutures :
Maxilla is connected to the cranium
& cranial base by a number of
sutures:
 The fronto-nasal suture
 The fronto-maxillary
suture
 The zygomatico-temporal
suture
 The zygomatico-maxillary
sututre
 The pterygo-palatine
suture

 Surface Remodeling :
 Massive surface remodeling by
bone deposition & resorption
increase in size; change in shape
of bone; & change in functional
relationship.
 Resorption occurs on lateral
surface of the orbital rim
lateral movement of the eyeball,
to compensate for this
resorption there is bone
deposition on the external
surface of the lateral rim.

 Bone deposition occurs along
the posterior margin of the
maxillary tuberosity,
lengthening of dental arch &
enlargement of antero-posterior
dimension of entire maxillary
body & helps to accommodate
developing molars.
 Bone resorption on the lateral
wall of the nose leads to an
increase in the size of the nasal
cavity.

 Bone resorption on floor of the
nasal cavity compensated by
deposition on palatal side,
downward shift an increase
in maxillary height.
 The zygomatic bone moves in
posterior direction, which is
achieved by resorption on
anterior surface & deposition on
posterior surface.

 Face enlarges in width by bone
formation on lateral surface of
zygomatic arch & resorption on
its medial surface.
 As teeth start erupting, bone
deposition occurs at alveolar
margins.
 Increases the maxillary height
& depth of palate: the
expanding “V” principle.

Anatomy of maxilla
BODY OF MAXILLA:
 Body of maxilla is pyramidal in
shape, with its base directed
medially at the nasal surface, and
the apex directed laterally at the
zygomatic process.
 It has four surfaces and encloses a
large cavity; the maxillary sinus.
(1)Anterior or facial
(2)Posterior or infratemporal
(3)Superior or orbital
(4) Medial or nasal

Four Processes of Maxilla:
 Zygomatic Process
 Frontal Process
 Alveolar Process
 Palatine Process

The Maxillary Sinus or Antrum of Highmore
(sinus maxillaris)
 Large cavity in body of maxilla.
 Pyramidal in shape, with base :
 Medially towards lateral wall of
nose
 Apex directed laterally into
zygomatic process of maxilla.
 Roof formed by floor of orbit and
traversed by infraorbital canal.
 The floor is formed by alveolar
process of maxilla ,lies about 1.2
cm below level of floor of nose.

FUNCTIONS :
 Speech and voice resonance
 Reduce the weight of scull
 Filtration of inspired air
 Immunological barrier
 Regulation of intranasal pressure

Articulations of Maxilla
 Superiorly, it articulates with- 3 bones
1) Nasal
2) frontal
3) lacrimal.
 Medially : 5 bones
1) Ethmoid
2) Inferior nasal concha
3) Vomer
4) Palatine
5) Opposite maxilla

 Laterally : 1 bone
1) Zygomatic bone

Age Changes
 At birth :
 Transverse and anteroposterior diameters >vertical diameter;
 Frontal process is well marked
 Body consists of a little more than the alveolar process;
 The tooth sockets close to floor of orbit
 Maxillary sinus is a mere furrow on the lateral wall of the nose.
 In Adults:
 Vertical diameter is greatest due to developed alveolar process
 increase in the size of the sinus.
 In Old
 Infantile condition
 Its height is reduced as a result of absorption of the alveolar process.

PERIODONTAL CONSIDERATIONS
 Palatal flaps and donor sites for
gingival grafts should be carefully
performed and selected to avoid
invading these areas, as profuse
haemorrhages may ensue, if
vessels are damaged at palatine
foramen.
 Severance of greater palatine
artery must be avoided as it is very
difficult to stop the hemorrhage by
local clamping or by tamponade.
In certain instances stoppage has
only been accomplished by
ligation of external carotid artery.

ANATOMIC SPACES
 Spaces contain loose c/t , can be
easily distended by inflammatory
fluid and infection. Surgical
invasion of these areas may result
in dangerous infections and should
be carefully avoided.
 Canine fossa contains varying
amounts of c/t & fat and is
bounded
 Infection of this area results
in swelling of upper lip,
obliterating nasolabial fold,
& of upper and lower eyelids,
closing the eye.

Infection of this area results in swelling of the cheek but
may extend to the temporal space or the submandibular
space, with which the buccal space communicates.

ANTERIOR FACIAL REGION
 Maxillary incisor teeth
eccentrically placed in the
alveolus, Facial alveolar bone
being very thin or absent over
prominent incisor or canine roots.
selecting a surgical procedure
which leaves bone covered with
periosteum & c/t, one may prevent
p.o osseous and gingival recession.
 Alveolar process have clinical
importance in periodontal surgery
because of several muscle
attachments.

 During periodontal surgery in the
canninus muscle attachment arise
from canine fossa below
infraorbital foramen should not
damage infraorbital nerve and
vessels.

POSTERIOR FACIAL REGION
 Severe bone loss in this region could result in the base of the periodontal
pocket approximating both zygomaticoalveolar ridge of the zygomatic process
of the maxilla and the attachment of the buccinator muscle. Each could
complicate any surgical attempt to deepen the vestibule or increase the zone of
attached gingiva.
 Attachment of buccinator muscle may also limit the apical extent to which
one could establish the mucogingival junction and an adequate width of
attached gingiva.
 Alveolar bone overlying buccal roots of maxillary molar teeth is frequently
found to be very thin or absent. As in anterior facial region of the maxilla, a
surgical technique may be employed which prevents exposure of the bone and
possible postoperative recession.

PALATE
 Nasopalatine nerve emanates from
incisive foramen to supply the
sensory innervation for palatal
mucosa from canine to canine.
 Surgery to eliminate periodontal
pockets in this region often
requires removing or undermining
the incisive papilla, which could
result in servering the nasopalatine
nerve and a temporary paresthesia
of the area supplied.

 Osseous considerations in the
palate include the presence of tori
and the shape of the palatal vault.
 Prominent exostoses or a flat,
shallow palatal roof make osseous
interproximal ramping either
impossible or difficult to
accomplish.

 In gingivectomy procedures on the
palate, If the alveolar process is
very short due to a shallow palatal
vault, it would be very difficult to
achieve a properly beveled result
without making an extremely wide
incision with its probable
postoperative discomfort.

IMPLANTS:
Age as compromising factor for implant insertion:
Transverse growth:
 The width of ant. portion of the arch is completed prior to the adolescent growth spurt,
but for post. portion, the width increase is closely tied to the increasing jaw length.
 The width in the ant. portion ses mainly by growth at the midpalatal suture ,a growth
is 3x larger in 1st molar area than in front.
 The intercanine distance will change only little after the age of 10 (0.9 mm)
 Thus if a central incisor was replaced with an implant shortly after eruption, diastema
could develop between the implant and the adjacent natural central incisor ,resulting in
subsequent shifting of the midline to the implant side.
 In most post. area changes can occur until complete tooth eruption.
 The midpalatal suture usually closes after puberty around the age of 15 .

Sagital growth:
 Maxilla ses in length due to both sutural growth & bone apposition at
maxillary tuberosity.
 The ant. part of max. is rather stable.
 When max. is displaced & during growth ,up to 25% of
displacement is lost via resorption at anterior site, latter could result in an
implant gradually losing labial bone.
 Teeth have a spontaneous mesial drift. The lat. segment moves on average 5 m
mesially but max. incisors move only 2.5 mm buccally ,causing net loss in
space ,lead to crowding.
 Implant does not take part in spontaneous tooth migration. Thus an implant in
lat. region could stop the mesial drift resulting in asymmetric arch.
Vertical growth:
 Occurs via displacement and drift.
 An implant inserted in ant. part at age of 7 will 9 years later be located 10 mm
more apically than the neighbouring teeth.

Bone density Description Tactile analog Typical anatomical
location
D1 Dense cortical Oak or maple wood Anterior mandible
D2 Porous cortical and coarse
trabecular
White pine or spruce wood Anterior mandible, posterior
mandible, Anterior maxilla
D3 Porous cortical and fine
trabecular
Balsa wood Anterior & posterior maxilla
D4 Fine trabecular Styrodoam Posterior maxilla
Misch bone density classification

IMPLANTS
 In maxilla,7 mm of bone height is
sufficient to accommodate short
implants.
 Use of 7-10 mm long implants is a
greater concern in the maxilla
because implant failure rate is
higher in the maxilla.Therefore,13
mm recommended minimum
occlusocervical bone dimension in
maxilla.
 In case of not having enough bone
height can opt for sinus lift, which
is a surgical procedure, aims to
increase amount of bone in the
posterior maxilla.

AUTOGENOUS BONE GRAFT
 Osseous coagulum:
 Sources were:
 Exostoses
 Edentulous ridges
 Bone distal to terminal tooth
 Lingual surface of maxilla at least 5 mm from the roots.

 Cancellous bone marrow transplants obtained from:
 Maxillary tuberosity
 Edentulous areas
 Healing sockets
 Maxillary tuberosity contains good amount of cancellous bone, care should be
taken not to extend the incision (made distally from last molar) too far distally
to avoid sectioning the tendons of the palatine muscle

A) radiographic appearance, showing the possibility of removing bone
from the right maxillary tuberosity, B) in the dry skull, the presence of
medullary bone C) tuberosity detached for graft removal.

Radiographic considerations:
 Here shown radiographic anatomy of maxillary area in the periapical,
panoramic, occlusal, cephalometric radiographs and finally in
volumetric computed tomography.
Periapical radiographs-incisor area

Cephalometric radiographs Panoramic radiographs

Occlusal radiographs Periapical radiographs – canine area

Computed tomography: Maxillary Central area

ANESTHESIA
Posterior superior alveolar
nerve: (PSA)
 Descends from the main trunk
of the maxillary division in the
pterygopalatine fossa just
before the maxillary division
enters the infraorbital canal.
 Passing downward through the
pterygopalatine fossa, they
reach the inferior temporal
surface of maxilla .

Nerve block: Commonly used,
Successful technique.
 Technique:
 Advance needle slowly
upward: Superiorly at a 45
degree angle to occlusal plane
Inward: Medially toward
midline at 45 degree to occlusal
plane.
Backward : Posteriorly at 45
degree angle to long axis of 2nd molar
in one movement.

 Alternative: Supraperiosteal injections: requires multiple needle
penetrations , provides shorter duration of anesthesia.
 When combined with anterior superior alveolar block –entire maxillary
arch on one side can be anesthetized (except palatal tissues).
 Prevention: the risk of hematoma can be minimized by using a short
25 or 27 gauge needle, aspirating in two planes multiple times before
and during the slow deposition of anestheic.
 If anesthesia of posterior palate is needed, greater palatine block should
be provided in addition to psa block.

 Middle superior alveolar nerve :
(MSA)
 Nerve branches off the main nerve
trunk(V2) within the infraorbital canal to
form a part of superior dental plexus,
composed of posterior, middle, and
anterior superior alveolar nerve.
Nerve block:
 SITE OF ORIGIN: from posterior
portion of infraorbital canal to anterior
portion ,near the infraorbital foramen.
 Insertion: at the height of mucobuccal
fold above max.2nd premolar.
 If deposition too low, only 2nd pm will be
anesthetized.
 Alternative: infraorbital nerve block.

Anterior superior alveolar nerve: (ASA)
 Relatively large branch ,is given off the infraorbital nerve approx. 6-10 mm
before latter’s exit from infraorbital foramen.
 Descending within the anterior wall of maxillary sinus ,provides pulpal
innervations to central and lateral incisors and the canine, and secondary
innervations to periodontal tissues, buccal bone and mucous membranes.
 ASA nerve communicates with MSA nerve and gives off a small nasal branch
that innervates the anterior part of nasal cavity along with branches of
pterygopalatine nerves.
Nerve block:
 Target area : Infraorbital foramen

Precautions:
 For pain on insertion of needle and
tearing of the periosteum, reinsert
the needle in a more lateral way
(away from bone) position or
deposit solution as the needle
advances through soft tissues.
 For overinsertion of
needle,estimate the depth of
penetration before injection and
exert finger pressure over
infraorbital foramen.

Greater palatine nerve:
 Descends through the
pterygopalatine canal emerging on
the hard palate through the greater
palatine foramen.
Nerve block:
 Technique:
 27 gauge short needle recommended
 Locate the greater palatine foramen:
 By using a cotton tipped applicator
to firmly palpate from 1st molar
region at the junction of alveolar
process and the hard palate towards
third molar
 Small depression will be felt
between distal of 1st molar and
mesial to 3rd molar

Nasopalatine nerve:
 Passes across the roof of nasal cavity downward and forward ,where it lies
between the mucous membrane and the periosteum of nasal septum.
 It continues downward, reaching the floor of the nasal cavity and giving
branches to anterior part of nasal septum and floor of nose.
 It then enters the incisive canal through it passes into oral cavity via incisive
foramen located in midline of the palate about 1 cm posterior to maxillary
central incisiors.

Nerve block: Highly traumatic
 Technique:
 A 27 gauge short needle recommended.
 Approach the injection site at a 45 degree angle towards the incisive papilla.
 Apply enough pressure to bow the needle slightly.

CONCLUSION
 Consideration of the surgical anatomy serves as a basis for surgical procedures
involving periodontal tissues and implants. damage to nerves can be avoided
with proper technique and treatment planning that should include three
dimensional radiographs when these structures are likely to be within vicinity
of surgical approaches.
 Inadvertent surgical incision of major blood vessels, such as the greater
palatine artery and the middle and posterior superior alveolar artery, can be
avoided by knowledge of their anatomic positioning.

REFERENCES
 B.D Chaurasia’s Human Anatomy 4TH ed vol.3.THE HEAD AND NECK.
 Carranza’s clinical periodontology. Michael G. Newman, Henry H. Takei,
Fermin A. Carranza .11th ed. Elsevier publication 2012.
 Grey’s anatomy of the human body.20th ed. philadelphia 1918
 Orthodontics THE ART AND SCIENCE. S.I Bhalajhi. 5TH ed. Arya Medi-
2012.
 Human Embryology. Inderbir Singh. 10TH ed. Jaypee Brothers 2014.
• Orban’s B. Oral Histology & Embryology. 7th ed. St. Louis. Mosby Inc – 1972
 Carl.E.Misch. Contemporary implant dentistry.3rd ed. Elsevier 2011
 Michael A. Clarke, D.D.S., M.S, Kenneth W. Bueltmann, D.D.S., M.S.
Anatomical Considerations in Periodontal Surgery. j. Periodont, 42:610-625,
1971.

 Handbook of local anesthetics. Stanley F. Malamed.6th ed. Elsevier publication
2012
 Normal Radiographic Anatomy – Maxillary Central Area. Carmen Elena
Georgescu, Gabriela Tãnase, Augustin Mihai. OHDMBSC - Vol. VI - No. 3 -
September, 2007
 Leonardo Perez Faverani , Gabriel Ramalho-Ferreira , Paulo Henrique
Dos Santos , Eduardo Passos Rocha , Idelmo Rangel Garcia Júnior , Cláudio
Maldonado Pastori , Wirley Gonçalves Assunção .Surgical techniques for
maxillary bone grafting - literature review.. Rev. Col. Bras. Cir. Rio de Janeiro
41:1,Jan./Feb. 2014.
 Laura J. Webb. Anesthesia during perio: Maxillary injections useful for adult
nonsurgical periodontal therapy. June 12, 2015
 Danny G. op heij, Heidi opdebeeck, Daniel van steenberghe,Mark quirynen.
Age as compromising factor for implant insertion.periodontology
2000,33:172-184;2003

Maxilla Anatomy and Development

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