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ANATOMY OF THE MAXILLA AND ITS SURGICAL IMPLICATIONS
INDIAN DENTAL ACADEMYLeader in continuing Dental Education
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CONTENTS Gross anatomy Surgical anatomy Development Maxilla in fractures Maxillary osteotomies Maxillectomy Infections of maxilla
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INTRODUCTION
Paired bone Second largest bone of face Contributes to formation of several
structures Whole of upper jaw Roof of oral cavity Floor and lateral wall of nasal cavity Floor of each orbit Infratemporal and pterygopalatine
fossae Inferior orbital and pterygomaxillary
fissures
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Indian Dental academy
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GROSS ANATOMY OF MAXILLA Body Processes :
Frontal Zygomatic Alveolar Palatine
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BODY OF MAXILLA Incisive fossa Canine fossa Canine eminence Infraorbital foramen Nasal notch Anterior nasal spine
Posterior dental canals
Maxillary tuberosity
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Infra orbital groove and canal Inferior orbital fissure
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Maxillary hiatus Greater palatine
groove Inferior meatus
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PROCESSES OF MAXILLA Frontal Zygomatic Alveolar
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PALATINE PROCESSwww.indiandentalacademy.com
SURGICAL
ANATOMY
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SURGICAL LAYERS
SMAS is a meshwork of fibrous septae Which envelopes fat lobules Overlies fascia Blends into facial muscles
Acts as a distributer of forces
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MUSCLE GROUPSwww.indiandentalacademy.com
BLOOD VESSELS ENCOUNTERED IN MAXILLAwww.indiandentalacademy.com
MAXILLARY ARTERYwww.indiandentalacademy.com
VENOUS DRAINAGE IN MAXILLAwww.indiandentalacademy.com
INNERVATION OF MAXILLARY REGION - MOTOR
Predominantly zygomatic and buccal branches of facial nerve
Proximal trunks located relatively deep to skin
Several anastomoses of branches
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INNERVATION OF MAXILLARY REGION - SENSORY
Infra orbital nerve
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DEVELOPMENT OF MAXILLA Develops from the mesenchyme of the
maxillary process (derivative of first arch)
Cartilages: No primary cartilage seen Associated closely with cartilage of nasal
capsule Secondary cartilage: zygomatic or malar
cartilage aids in growth
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Centre of ossification appears at angle between anterior superior alveolar nerve and infraorbital nerve
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CENTRE OF OSSIFICATION(B/W 2 NERVES)
FRONTAL PROCESS
TOWARD DEVELOPING ZYGOMA
TOWARD FUTURE INCISOR REGION
LATERAL ALVEOLAR PLATE
BONY TROUGH FOR NERVE
PALATINE PROCESS
MEDIAN ALVEOLAR PLATE
Sinus – develops by sixteenth week by pneumatization
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FRACTURES OF MAXILLA Maxilla varies from mandible in
geometric distribition of bone Thin laminae Increased surface area : bone volume
ratio Good blood supply – excellent healing
potential
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BUTTRESSES OF MIDFACE ARCHITECTURE
Was elucidated by Le fort in fracture lines
Sicher and Tandler in 1928 gave concept of vertical buttresses
These help in transmission of forces 3 buttresses are identified:
Pterygomaxillary Zygomatic nasomaxillary
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Nasomaxillary buttress:
From maxillary canine area Through lateral piriform rim Through frontal process of maxilla To superior orbital rim
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Zygomaticomaxillary buttress:
From zygomaticoalveolar crest Through the zygoma To posterior aspect of superior orbital rim and
temporal bone
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Pterygomaxillary buttress:
Through palatine bone To pterygoid plates Base of sphenoid
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SURGICAL APPROACHES FOR # FIXATION Intra oral approach preferred –
esthetics Vestibular Palatal Midface degloving approach
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VESTIBULAR
Access to anterolateral aspect of maxilla Extent can vary – unilateral or bilateral
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PALATAL
Midline split of maxilla – severe injuries
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MIDFACE DEGLOVING APPROACH
Le fort II fractures
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Lower eyelid/ subciliary incision
Transconjunctival/ lateral canthotomy approach
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Upper eyelid blepharoplastywww.indiandentalacademy.com
Coronal approachwww.indiandentalacademy.com
FIXATION OF MAXILLARY # Le fort I :
lateral and medial buttress
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Le fort II :
nasofrontal suture,
orbital rim
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Le fort III : nasoethmoid
, fronto -
zygomatic suture,
orbital rim, zygoma
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PATHOLOGIES OF MAXILLA Squamous cell carcinoma of sinus and oral
mucosa
Desmoplastic ameloblastoma Adenomatoid odontogenic tumor Squamous odontogenic tumor
Melanotic neuroectodermal tumor Osteosarcoma – secondary to Paget’s disease Chondrosarcoma
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LATEARL RHINOTOMY APPROACH Tumors of lower
part of nasal cavity/maxilla
Polyps, papillomas Starts at philtrum
Around vestibule, ala
Nasolabial crease
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WEBER FERGEUSON INCISION (DIEFFENBACH)
More exposure partial/total maxillectomy Midline upper lip
Philtrum columella
Around vestibule, ala
Nasolabial crease
Medial canthus
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LYNCH EXTENSION Exposure of
ethmoid air cells Extends till
medial edge of eyebrow
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LATERAL SUBCILIARY EXTENSION SUBCILIARY AND SUPRACILIARY EXTN.
Total and radical maxillectomy Along tarsal margin of lower eyelid to lateral canthus Along upper eyelid
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MIDFACE DEGLOVING INCISIONwww.indiandentalacademy.com
PARTIAL MAXILLECTOMY Tumors in floor of
sinus Lower half of maxilla Intra oral incision Antral lining is
removed to prevent chronic inflammation
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SUBTOTAL MAXILLECTOMY
Tumors extending to superior part of sinus Tumors extending beyond the sinus borders Weber fergeuson approach Palatine vessels and maxillary artery
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MEDIAL MAXILLECTOMY Tumors of:
lateral wall of nasal cavity medial wall of maxillary
sinus Infra orbital nerve is
preserved Medial canthal ligament is
detatched Lacrimal duct transected Anterior ethmoidal artery
ligated
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TOTAL MAXILLECTOMY Complete
removal Primary
mesenchymal tumors
Subciliary extension
Periosteum elevated from floor of orbit
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RADICAL MAXILLECTOMY Orbital exenteration is done For tumors that have spread into orbit
through orbital periosteum Weber fergeuson approach with
subciliary and supraciliary extension
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MAXILLARY OSTEOTOMIES
Le fort I osteotomy Segmental osteotomy High level osteotomies – le fort II and
III
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ANATOMICAL CONSIDERATIONS IN LE FORT 1 OSTEOTOMY
Incision – intraoral from zygomaticomaxillary buttress anteriorly across the midline
Posterior maxilla – dissection is tunneled to preserve an intact mucosal pedicle
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Infra orbital nerve exposed on subperiosteal dissection
Descending palatine vessels – usually ligated as they are source of bleeding
Internal maxillary artery – may be damaged during downfracture. Posterior osteotomy is directed inferiorly to prevent this.
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SEGMENTAL OSTEOTOMIES
Wunderer method – buccal pedicle intact
Wassmund method – both buccal and palatal pedicle intact
Cupar method
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WUNDERER METHOD Incisions –
transpalatal buccal
vertical incisions Midline incision
over anterior nasal spine
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WASSMUND METHOD
Two buccal verical incision No transpalatal incision
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CUPAR METHOD
Only vestibular incision Non vitality of teeth – minimum 1mm of bone over roots Oronasal & oroantral communication.
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LE FORT II OSTEOTOMY Indications :
Cleft palate, binder’s syndrome
Dish face deformity due to trauma
Incision – mucogingival Anatomical structures :
Infraorbital nerve Nasolacrimal duct
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LE FORT III OSTEOTOMY Total midface hypoplasia:
craniofacial synostosis Degree of proptosis and
hypoplasia Incision – coronal Anatomical structures:
Infraorbital nerve Lacrimal apparatus and
orbit Pterygoid venous plexus
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INFECTIONS OF MAXILLA
Sinus infections Space infections Infantile osteomyelitis
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CHRONIC MAXILLARY SINUSITIS Approaches:
Caldwell Luc approach incision over canine fossa Exposes anterolateral wall of sinus Above – infraorbital foramen and nerve Below – apex of premolar teeth, middle
superior alveolar nerve Posteriorly – zygomatic buttress
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Intranasal antrostomy: Antrum punctured through inferior meatus The inferior turbinate must be protected
Denker’s procedure: Antrum exposed via caldwell luc approach The lateral nasal wall is trephined and nasal mucosa sutured to
the sinus
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SPACE INFECTIONS Canine space
Infected maxillary canine
Between maxilla and muscles of face
Drainage – intraoral through vestibule
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INFANTILE OSTEOMYELITIS Rare but involves maxilla Etiology :
Due to perinatal trauma use of suction bulb or contaminated
fingers May involve eye, dural sinuses and
teeth Maxilla is swollen both buccally and
palatally
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