palate anatomy
TRANSCRIPT
PALATE
PRESENTED BY-Dr. I Krishna chetan Post Graduate student,Department of Prosthodontics,
PRESENTED BY-Dr. I Krishna chetan, Post Graduate student,Department of Prosthodontics
Content
IntroductionDevelopment of palateHard palateSoft palateMusclesFunctionsClinical consideration
Introduction Palate is the roof of the mouth. It separates the oral cavity from the nasal cavity
Lies in the roof of the oral cavity Has two parts:
Hard (bony) palate anteriorly Soft (muscular) palate posteriorly
Development of the Palate
Initially, during the 6th week of intrauterine development, there is a common oro-nasal cavity bounded anteriorly by the primary palate and occupied mainly by the developing tongue
The medial part is also known as the primary palate because it develops first and is a floor to the nasal pits.Lateral palatine process develop from the maxillary processes laterally & grow to midline.
The primary palate is formed by the merging of the two median nasal processes
Between the 7th and 8th weeks of development, formation of the secondary palate occurs
Hard palate
Primary palate
Soft palate
Secondary palate
The primary palate represents only a small part lying anterior to the incisive fossa, of the adult hard palate
Formation of the palate involves the fusion of two processes: the right and left maxillary processes and the medial nasal process
The median nasal process grows downward and forward to form the nasal septum
In the beginning, the lateral palatine processes project inferomedially on each side of the tongue
As a result of the enlargement of the mandible and a change in the degree of flexion of the fetus head, the tongue moves inferiorly.
When the tongue is removed from the path of the growing lateral palatine processes, the processes are straightened to a horizontal position.
Then the lateral palatine processes grows medially at the midline and fuse with each other and with the posterior part of the primary palate and nasal septum to give rise to the hard and soft palate
Hard Palate
The hard palate separates the oral cavity from the nasal cavities. It consists of a bony plate covered above and below by mucosa:
Above, it is covered by respiratory mucosa and forms the floor of the nasal cavities (superior surface)
Below , it is covered by a tightly bound layer of oral mucosa and forms much of the roof of the oral cavity (inferior surface)
The posterior margins gives attachment to soft palate.
The anterolateral margins are continuous with alveolar arches and gums.
Vesssels And Nerves ARTERIES- Greater palatine branch of maxillary artery.
VEINS- Drains into pterygoid plexus of veins. NERVES- Greater palatine & nasopalatine branches of pterygopalatine ganglion suspended by the maxillary nerve.
LYMPHATICS- Upper deep cervical nodes
SOFT PALATE
movable muscular fold suspended from posterior border of hard palate
Separates nasopharynx from oropharynx Traffic controller 2 surfaces 4 borders
Covered on its upper and lower surfaces by mucous membraneoComposed of:
Muscle fibers An aponeurosis Lymphoid tissue Glands Blood vessels Nerves
Palatine Aponeurosis
Fibrous sheathIs flattened tendon of tensor velli palatine
Attached to posterior border of hard palate
Splits to enclose musculus uvulae
Gives origin & insertion to palatine muscles
Muscles
Tensor veli palatine Origin: lateral side of auditory tube,
Greater wing and scaphoid fossa of sphenoid bone.Insertion: forms palatine aponeurosis which is attached to(a) Posterior border of hard palate(b)Inf surface of palate behind palatine crestAction: Tenses soft palate,opens auditory tube
Levator veli palatiniOrigin: inferior aspect of auditory tube,Adjoining part of inf. surface of petrous temporal bone.Insertion: upper surface palatine aponeurosisAction: Raises soft palate and closes the pharyngeal isthmus,also opens auditory tube
Musculus uvulaeOrigin: posterior nasal spine,Palatine aponeurosisInsertion: mucosa membrane of uvula Action: Elevates uvula
Palatopharyngeus Origin: Ant Fasciculus-Post border of hard palatePost fasciculus-palatine aponeurosisInsertion: posterior border of thyroid cartilage,wall of the pharynx and its median raphe.Action: Elevates wall of the pharynx
PalatoglossusOrigin: oral surface of palatine aponeurosisInsertion: side of tongue at the junction of oral and pharyngeal partsAction: pulls root of tongue upward, closes oropharyngeal isthmus
Blood Supply
Arteries- Greater palatine branch of the maxillary artery Ascending palatine branch of the facial artery Palatine branch of Ascending pharyngeal,
branch of the external carotid artery
Veins- Pterygoid and tonsillar plexus of veins Lymphatics- Upper deep cervical & retropharyngeal nodes
Sensory Nerve Supply
General Sensory: Mostly by the maxillary nerve through its branches:◦ Middle lesser palatine nerve◦ Posterior lesser palatine nerve
Special Sensory: For taste sensations: lesser palatine nerves, greater petrosal nerve geniculate ganglion of facial nerve nucleus of solitary tract.
Secretomotor;Lesser palatine nerves Derived from sup. salivatory nucleus travel through greater petrosal nerves.
Motor Nerve Supply
All the muscles, except tensor veli palatini, are supplied by the:◦ Pharyngeal plexus, it is derived from cranial part of the
accessory nerve through vagus.
Tensor veli palatini supplied by the:Nerve to medial pterygoid, a branch of the mandibular nerve.
Passavant’s RidgeUpper fibers of palatopharyngeus pass deep to the mucous membrane of the pharynx and form a sphincter internal to the sup. Constrictor.These fibers constitute passavant’s muscle which on contraction raises passavant’s ridge on posterior wall of nasopharynx.When soft palate is elevated it comes in contact with the ridge and close the pharyngeal isthmus between nasopharynx and oropharynx.
Movements & functions of Soft palateControls 2 gatesIsolates mouth from Oropharynx during chewing.Separates Oropharynx from nasopharynx by locking into passavant’s ridge during second stage of swallowing.By varying the degree of closure of pharyngeal isthmus, quality of voice can be modified.During sneezing , the air is appropriately divided and directed through the nasal and oral cavities.During coughing, the air and sputum is directed into the mouth.
Clinical Considerations
Cleft palate – is the result of the non-fusion of the 2 palatine processes and the inferior border of the nasal septum
◦ Unilateral◦ Bilateral◦ Median
Torus palatinus- Is a bony protrusion on the palate. Palatal tori are usually present on the midline of the hard palate.
Staphyloschisis –bifid uvula, with or without cleft of soft palate.
Paralysis of the soft palate-The pharyngeal isthmus can not be closed during
swallowing and speechNasal regurgitationNasal twangFlattening of Palatoglossal arch
Incisive canal cyst- These are usually present as asymptomatic palatal swellings.These are the most common non-odontogenic cyst of the oral cavity.
Smoker’s palate/ Stomatitis nicotina-It is a diffuse white patch on the hard palate, usually caused by tobacco smoking, pipe or cigar smoking.It is a painless, and it is caused by a response of the palatal oral mucosa to chronic heat
Reference's Grays human anatomy, 14th edition: Elsevier publications
B.d churasia’ human anatomyvol:3
Shafers text book of oral pathology & microbiology, 6th edition
Davidson’s text book of general medicine 18th edition