Anatomy of the maxilla and its surgical implications /cosmetic dentistry courses

ANATOMY OF THE MAXILLA AND ITS SURGICAL IMPLICATIONS

INDIAN DENTAL ACADEMYLeader in continuing Dental Education

www.indiandentalacademy.com

CONTENTS Gross anatomy Surgical anatomy Development Maxilla in fractures Maxillary osteotomies Maxillectomy Infections of maxilla


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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GROSS ANATOMY OF MAXILLA Body Processes :

Frontal Zygomatic Alveolar Palatine


BODY OF MAXILLA Incisive fossa Canine fossa Canine eminence Infraorbital foramen Nasal notch Anterior nasal spine

Posterior dental canals

Maxillary tuberosity


Infra orbital groove and canal Inferior orbital fissure


Maxillary hiatus Greater palatine

groove Inferior meatus


PROCESSES OF MAXILLA Frontal Zygomatic Alveolar


PALATINE PROCESSwww.indiandentalacademy.com

SURGICAL

ANATOMY


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


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


INNERVATION OF MAXILLARY REGION - SENSORY

Infra orbital nerve


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


Centre of ossification appears at angle between anterior superior alveolar nerve and infraorbital nerve


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


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


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


Nasomaxillary buttress:

From maxillary canine area Through lateral piriform rim Through frontal process of maxilla To superior orbital rim


Zygomaticomaxillary buttress:

From zygomaticoalveolar crest Through the zygoma To posterior aspect of superior orbital rim and

temporal bone


Pterygomaxillary buttress:

Through palatine bone To pterygoid plates Base of sphenoid


SURGICAL APPROACHES FOR # FIXATION Intra oral approach preferred –

esthetics Vestibular Palatal Midface degloving approach


VESTIBULAR

Access to anterolateral aspect of maxilla Extent can vary – unilateral or bilateral


PALATAL

Midline split of maxilla – severe injuries


MIDFACE DEGLOVING APPROACH

Le fort II fractures


Lower eyelid/ subciliary incision

Transconjunctival/ lateral canthotomy approach


Upper eyelid blepharoplastywww.indiandentalacademy.com

Coronal approachwww.indiandentalacademy.com

FIXATION OF MAXILLARY # Le fort I :

lateral and medial buttress


Le fort II :

nasofrontal suture,

orbital rim


Le fort III : nasoethmoid

, fronto -

zygomatic suture,

orbital rim, zygoma


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


LATEARL RHINOTOMY APPROACH Tumors of lower

part of nasal cavity/maxilla

Polyps, papillomas Starts at philtrum

Around vestibule, ala

Nasolabial crease


WEBER FERGEUSON INCISION (DIEFFENBACH)

More exposure partial/total maxillectomy Midline upper lip

Philtrum columella

Around vestibule, ala

Nasolabial crease

Medial canthus


LYNCH EXTENSION Exposure of

ethmoid air cells Extends till

medial edge of eyebrow


LATERAL SUBCILIARY EXTENSION SUBCILIARY AND SUPRACILIARY EXTN.

Total and radical maxillectomy Along tarsal margin of lower eyelid to lateral canthus Along upper eyelid


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


SUBTOTAL MAXILLECTOMY

Tumors extending to superior part of sinus Tumors extending beyond the sinus borders Weber fergeuson approach Palatine vessels and maxillary artery


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


TOTAL MAXILLECTOMY Complete

removal Primary

mesenchymal tumors

Subciliary extension

Periosteum elevated from floor of orbit


RADICAL MAXILLECTOMY Orbital exenteration is done For tumors that have spread into orbit

through orbital periosteum Weber fergeuson approach with

subciliary and supraciliary extension


MAXILLARY OSTEOTOMIES

Le fort I osteotomy Segmental osteotomy High level osteotomies – le fort II and

III


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


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.


SEGMENTAL OSTEOTOMIES

Wunderer method – buccal pedicle intact

Wassmund method – both buccal and palatal pedicle intact

Cupar method


WUNDERER METHOD Incisions –

transpalatal buccal

vertical incisions Midline incision

over anterior nasal spine


WASSMUND METHOD

Two buccal verical incision No transpalatal incision


CUPAR METHOD

Only vestibular incision Non vitality of teeth – minimum 1mm of bone over roots Oronasal & oroantral communication.


LE FORT II OSTEOTOMY Indications :

Cleft palate, binder’s syndrome

Dish face deformity due to trauma

Incision – mucogingival Anatomical structures :

Infraorbital nerve Nasolacrimal duct


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


INFECTIONS OF MAXILLA

Sinus infections Space infections Infantile osteomyelitis


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


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


SPACE INFECTIONS Canine space

Infected maxillary canine

Between maxilla and muscles of face

Drainage – intraoral through vestibule


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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