Upload
soni-bista
View
162
Download
8
Embed Size (px)
Citation preview
ANATOMY, DEVELOPMENT
,APPLIED ANATOMY OF
MAXILLA
PRESENTED BY –Dr.SONI BISTA (1st year PG student)Periodontology and Oral Implantology
UNDER THE GUIDANCE:Prof.DR.C.S. SAMBI(H.O.D)DR.VIKASH KUMAR(ASST.PROF)
CONTENTS INTRODUCTION
DEVELOPMENT
FEATURES OF MAXILLA
MAXILLARY SINUS
AGE CHANGES IN MAXILLA
VASCULATURE
MAXILLARY SINUS ELEVATION AND
AUGMENTATION
RESOURCES
INTRODUCTION 2nd largest bone of face Paired bone 2 maxillae forms whole of upper jaw Hollowed out by the maxillary sinus
and nasal cavity.
Each maxilla contributes in formation of –
1. Face2. Nose3. Mouth 4. Orbit5. Infratemporal fossa6. Pterygopalatine fossa
DEVELOPMENT OF MAXILLA MAXILLA develops from ossification in mesenchyme of
maxillary process of 1st arch. No arch cartilage / primary cartilage Center of ossification: close to the cartilage of nasal capsule in angle between division of infraorbital nerve. From this center the bone formation spreads
Posteriorly – below the orbit toward the developing maxillaAnteriorly – toward the future incisor regionSuperiorly – to form frontal processMedially – to form palate
According to B.D. Chaurassia’s human anatomy 4th edition vol. 3 The Head & Neck
MAXILLA ossifies from 3 centers in the membrane –1. 1 center for maxilla proper – 6th week of IUL,
above the canine fossa2. 2 centers for premaxilla
Of 2 premaxillary centers-o Main center above the incisive fossa - 7th week of
IULo Second center – ventral margin of nasal septum -
10th week of IUL soon fuses with palatal process of maxilla.
Premaxilla begin to fuse with alveolar process almost immediately after the ossification begins.
Bony trough for infraorbital canal is formed . From this trough a downward extension of bone forms the lateral alveolar plate.
Medial alveolar plate – from junction of palatal process & main
body of forming maxilla…..
These plates forms a trough of bone around the maxillary
tooth germ.
There is contribution of secondary cartilage.
Zygomatic / malar cartilage adds in development of maxilla.
Development continues….
FEATURES OF MAXILLA Each maxilla has –
1. A body2. 4 processes – frontal zygomatic alveolar palatine
BODY OF MAXILLA Shape – pyramidal It has –
4 surfaces – anterior / facial posterior / infratemporal medial / nasal superior / orbital Encloses a cavity – maxillary sinus
Nasal surface
Zygomatic process
MAXILLARY SINUSAlso called as antrum of Highmore(1651).Occupy the body of the maxillaLargest of the paranasal sinus, communicates
with other sinus through lateral nasal wall.
Air filled cavity.pCO2: 110 mmHg
.
BORDERS
Floor of the orbit
Lateral wall of the nasal
cavityLateral wall of the maxilla, alveolar process and the
zygomatic arch
Average measurement:Height: 3.5 cmWidth: 2.5cmDepth: 3.5 cm
oPyramidal in shape; Base directed medially towards the lateral wall of nose and Apex directed laterally into the zygomatic process of maxilla.oIts roof is formed by the floor of the orbit and is traversed by the infraorbital nerve.oIts floor is formed by the alveolar process of maxilla and lies about 1 cm below the level of the floor of the nose.oThe roots of maxillary 1st and 2nd molar are often close to the floor of the sinus Less frequently: roots of premolars and 3rd molars.
STRUCTURE
MAXILLARY NASAL SEPTA• Subdivided (incompletely) into recesses by one or more septa.• Frequently present(upto 39% of sinuses)_Ella B et al(2008)• CT scans are prefered more to detect septa than panoramic
radiograph• Septa are found in anterior (24%), middle(41%), posterior(35%)
of the maxillary sinus,with the most common location between 2nd premolar and 1st molar_Kasabah S et al
(2002)• The height of the septa vary as well, ranging from 0 to 20.6mm•Only 0.5% of septa form complete separation of the sinus spaces
into separate chambers.
Lined with a thin mucosal membrane called the schneiderian membrane.Entrance: through the orifice or maxillary duct(orifice:3-6mm in length and diameter. located at the superior medial aspect the cavity) occasional accessory opening is found inferior and posterior to the main opening.Drains: into the middle meatus (orban’)of the main cavity through maxillary duct, which passes secretions medially to the semilunar hiatus of lateral nasal cavity. Normal amount of secretion are moved from the sinus by the spiral pattern of beating (respiratory)cilia surrounding the orifice. Inflammation/Infection: Impairs the drainage…….The floor of the maxillary sinus extends down below the nasal cavity into alveolar process.
overview
BLOOD SUPPLYSuperior alveolar branches of
maxillary arteryGreater palatine artery
Infraorbiatl arteryFacial artery
VENOUS DRAINAGEVia the pterygoid plexusFacial vein
NERVE SUPPLYSuperior alveolar nerve(anterior,middle,posterior),Branches of maxillary arteryInfraorbital nerve
BLOOD SUPPLY AND INNERVATIONS
LYMPHATIC DRAINAGESubmandibular lymph nodes
ANTERIOR / FACIAL SURFACE
Directs laterally Incisive fossa -depressor septi, 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 labii superioris
Medially – the nasal notch - anterior nasal spine
POSTERIOR / INFRATEMPORAL SURFACE
Concave Directed – backward & laterally Forms – anterior wall of
infratemporal fossa Separated from anterior surface 2-3 alveolar canals for – posterior
superior alveolar nerve Posteroinferiorly – maxillary
tuberosity & superficial head of medial pterygoid muscle
Above maxillary tuberosity -anterior wall of infratemporal fossa, grooved by maxillary nerve
SUPERIOR / ORBITAL SURFACE Smooth, triangular & slightly concave Forms – Greater Part Of Floor Of Orbit Anterior border forms – part of inferior orbital margin continues with lacrymal crest of frontal process.
Posterior border – smooth & rounded Forms most anterior margin of inferior orbital fissure In middle – infraorbital groove
Medial border – Anteriorly lacrymal notch, converted into nasolacrymal
canal Behind the notch, articulation with -
Lacrymal Labrynth of ethmoidOrbital process of palatine bone
The superior surface presents – Infraorbital groove & canal Canalis sinosus Inferior oblique muscles
THE MEDIAL /NASAL SURFACE Part of lateral wall of nose Posterosuperiorly – maxillary hiatus Above the hiatus – air sinuses Below the hiatus – anterior part of inferior meatus Behind the hiatus – articulates with perpendicular plate of palatine bone & encloses greater & lesser palatine canals
THE MEDIAL /NASAL SURFACE
Infront of the hiatus – nasolacrymal groove articulates with
descending process of lacrymal bone & lacrymal process of inferior nasal concha to forms nasolacrymal canal
THE MEDIAL /NASAL SURFACE
More anteriorly – conchal creast for articulation with inferior nasal concha.
Above the conchal crest – atrium of middle meatus.
PROCESSES OF MAXILLA
1. FRONTAL2. ZYGOMATIC3. ALVEOLAR4. PALATINE
FRONTAL PROCESSProjects upward & backwards
to articulate above – nasal margin of frontal
bone in front – nasal bone behind – lacrymal boneLateral surface – divided by
anterior lacrymal crest into anterior smooth & posterior grooved
Medial surface – forms lateral wall of nose
ZYGOMATIC PROCESSPyramidal lateral projectionAnterior, posterior & superior surfaces converge
hereSuperiorly – rough, to articulate with zygomatic
bone
ALVEOLAR PROCESSForms half of alveolar archBears socket for maxillary teeth In adults = 8 socketsBuccinator arises from posterior part of its outer
surface upto 1st molar tooth.Maxillary torus (occasionally)
PALATINE PROCESSThick horizontal plateProjecting mediallyForms largest part of roof & floor Inferior surface – concave & forms anterior 3/4th
of bony hard palate.
Various foramina & pits
Posterolaterally – greater & lesser palatine foremen
Superior surface –concave from side to side & forms floor of nasal cavity.
Medial border – Thicker anteriorly Groove between nasal crest of 2 maxilla receives lower border vomer Anterior part of ridge – incisal crest & anterior nasal spine,
Incisive canal
Posterior border articulates with horizontal plate of palatine bone
Lateral border is continuous with alveolar process.
ARTICULATIONS OF MAXILLA
Superiorly – 3 bones1. Frontal 2. Nasal3. Lacrymal Laterally – 1 bone1. Zygomatic boneMedially – 5
bones1. Ethmoid2. Inferior nasal
concha3. Vomer 4. Palatine5. Opposite
maxilla
AGE CHANGES IN MAXILLA AT BIRTH –
1. Transverse & anterioposterior diameter > vertical diameter2. Well marked frontal process3. Body consists of little more than alveolar process4. Tooth sockets – close to orbit5. Maxillary sinus is a mere furrow on the lateral wall of nose
IN ADULTS – Vertical Diameter Is More due to –
1. Developed alveolar process2. Increased size of maxillary sinus
IN OLD –1. Infantile condition2. Resorption of alveolar
bone
MAXILLARY SINUSWith increasing age , it expands, becoming more and more pneumatized down around the roots of the maxillary teeth, sometimes resulting in exposure of the roots through the bony floor into the sinus
Terminal branch of nasopalatine nerve and vessels pass through the incisive canal,which opens in the midline anterior area of the palate.
The greater palatine foramen opens 3 to 4 mm anterior to the posterior border of the hard palate. Greater palatine nerve and vessels emerge through this foramen and run anteriorly in the submucosa of the palate, between palatal and alveolar processes. Palatal flaps and donor sites should be carefully performed and selected to avoid invading these areas because profuse hemorrhage may ensue, particularly if vessels are damaged at the palatine foramen. Vertical incisions in the molar regions should be avoided.
The submucous layer of the palate protects the vessels and nerves. The area distal to the last molar called maxillary tuberosity consists of the
posterior-inferior angle of the infratemporal surface of the maxilla. Medially it articulates with the pyramidal process of the palatine bone. It is covered by dense, fibrous connective tissue and contains the terminal branches of the middle and posterior palatine nerves. Excision of the area for distal flap surgery may reach medially to the tensor palati muscle.
VASCULATURE
CLINICAL SIGNIFICANCEPERIODONT
AL SURGERY
MAXILLARY SINUS ELEVATION AND BONE AUGMENTATION Rehabilitation of the edentulous posterior maxilla with
endosseous dental implants often represents a clinical challenge because of insufficient bone volume resulting from pneumatization of the maxillary sinus along with resorption or loss of alveolar crestal bone.
In 1980, Boyne and James first described a procedure to graft the maxillary sinus floor with autogenous marrow and bone for placing an implant(blade type)Access to the maxillary sinus was gained through a “Cardwell-Luc” procedure(i.e., an opening is created at the anterior-superior aspect)Since then, several other techniques have beendescribed,including variations on the lateral window osteotomy and a variety of techniques to lift the sinus floor from a crestal approach.
Various bone graft materials have been used to augment the maxillary sinus.
The 1996 Consensus Conference on maxillary sinus bone grafting reviewed available data and concluded that allografts,alloplasts,and xenografts, alone or in combination with autogenous bone, can be effective as bone substitute graft materials for sinus bone augmentation. Conclusion:
The sinus graft procedure with implant placement is effective treatment modality for the rehabilitation of the posterior maxilla.
INDICATIONS:An alveolar bone
height in posterior maxilla is less than
7mm
CONTRAINDICATIONS
LOCAL FACTORS:1. Tumors or pathologic growth in
the sinus2. Maxillary sinus infection3. Severe chronic sinusitis4. Surgical scar/deformity of sinus
cavity5. Dental infection involving in or
proximity to sinus 6. Severe allergic rhinitis/sinusitis7. Chronic topical steroid use
SYSTEMIC FACTORS:8. Radiation therapy involving sinus9. Metabolic diseases(e.g.,
uncontrolled diabetes mellitus)10.Excessive tobacco use11.Drug/alcohol abuse12.Psychological/mental impairment
RISKS AND COMLICATIONS
1. Technique sensitive, requiring meticulous surgical skills
2. Tearing /perforation
of the schneiderian
membrane3. intraoperative/postoperative
bleeding4.Loss of bone graft
or implant
RESOURCES
TEXT BOOK –1. B.D. Chaurassia’s human anatomy 4th edition vol. 3 The Head & Neck.2. CARRANZA’ clinical periodontology 11th edition3. GRAY’ anatomy 379h edition4. TEN CATE’ oral histology 6th edition5. The maxillary sinus and its dental implications Killey and Key.
Which of the following tooth is very close to the maxillary antrum:
(a)Third molar(b)Second molar(c)Premolar (d)Canine