Mandible, temperomandibular joint & muscle of mastication (M.C.Qs.)

By

Prof. Samir Malik

Dental students

M.C.Qs.The muscles attache to the both surface of the mandible are one of the following?A-5 muscles.B-6 muscles.C-7 muscles.D-9 muscles.

Answer:The muscles attache to the both surface of the mandible are one of the following?A-5 muscles.B-6 muscles.C-7 muscles.D-9 muscles.

Short account:Mention four muscles attached to the mandible &their nerve supply?

Answerplatysma n.supply: facial nerve.Mentalis ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Buccinator ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, Temporalis Trigeminal nerve.

M.C.Qs.The condylar process of the mandible showing all the following are true except one sentence is wrong?A-neck.B-pterygoid fovea.C-HeadD-shaft.

AnswerThe condylar process of the mandible showing all the following are true except one sentence is wrong?A-neck.B-pterygoid fovea.C-HeadD-shaft.

Mention the nerve related to the mandible?

Answer :Lingual nerveInferior alveolar nerveNerve to mylohyoidMental nerve.Mandibular branches of facial nerve..Auriculotemperal nerve.

Two glands: submandibular& Sublingual. Two muscles: platysma & anterior belly of the digastric.

Mention two structure above or superior to diaphragma oris & two below?

Answer:Abovegenohyoid musclesublingual glandbelow;anterior belly of the digastric muscle& submandibular gland

The temporal fossa above zygomatic arch? A-true B-false.The infratemporal fossa above the zygomatic arch? A-true B-false

AnswerThe temporal fossa above zygomatic arch? A-true B-false.The infratemporal fossa above the zygomatic arch? A-true B-false

What are the ligaments of the temperomandibular joint?

Answer:1-stylomandibular ligament.2-Sphenomandibular ligament3-temperomandibular ligament

M.C.QsWhich structure dividing the temperomandibular joint into two cavities; upper &lower?A-intrarticular disc.B-tendon.C-ligamentsD-menisci.

Answer:Which structure dividing the temperomandibular joint into two cavities; upper &lower?A-intrarticular disc.B-tendon.C-ligamentsD-menisci.

M.C.Qs.The mental foramen of the mandible in the extremity of the age lying near?A-alveolar processB-lower borderc-near the ramusd-near the symphysis menti

Answer The mental foramen of the mandible in the extremity of the age lying near?A-alveolar processB-lower borderc-near the ramusd-near the symphysis menti

M.C.Qs.The elevation of the temperomandibular joint (T.M.J.) is done by the following muscle except one muscle doesnot charing in elevation?A-Temporalis Muscle .B-Masseter muscle .C-Medial pterygoid muscleD-Auricularis superior muscle

Answer:The elevation of the temperomandibular joint (T.M.J.) is done by the following muscle except one muscle doesnot charing in elevation?A-Temporalis Muscle .B-Masseter muscle .C-Medial pterygoid muscleD-Auricularis superior muscle

M.C.Qs.The protrusion of the mandible is caused by one of the following ? A-lateral pterygoid muscle assisted by medial pterygoid . B- posterior belly of digastric muscle & stlyohyoid muscle.C-orbicularis oris & mentalis muscle D-mylohyoid & genohyoid

Answer.The protrusion of the mandible is caused by one of the following ? A-lateral pterygoid muscle assisted by medial pterygoid . B- posterior belly of digastric muscle & stlyohyoid muscle.C-orbicularis oris & mentalis muscle D-mylohyoid & genohyoid

M.C.Qs.The depression of the mandible is done by the following factor except one is wrong?A-Gravity.B-mylohyoid & genohyoid muscles.C-masseter muscle.D-Digastric muscle

Answer:The depression of the mandible is done by the following factor except one is wrong?A-Gravity.B-mylohyoid & genohyoid muscles.C-masseter muscle.D-Digastric muscle

retromoandibularfossa

pterygopalatinefossa

• 2- Masseter :

origin inner surface &lower border of zygomatic arch.

Insertion outer surface of ramus .

Nerve supply:massetric n.(first branchial arch)

1-TEMPRALIS MUSCLE

• Origin temporal fossa ,fascia & inbetween 2 temporal lines

• Insertion: cronoid process

• Nerve supply from deep temporal nerves; 1st branchial arch.

4-MEDIAL PTRYGOID

• Origin:deep head inner surface of lateral (medial) ptrygopid plate

• Superficial head: tuberosity of maxilla

• Insertion :inner surface of angle of mandible; 1st pharyngeal arch.

3-LATERAL PTRYGOID

• Origin:upper head infratemporal surface of greater wing of the sphenoid bone.

• lower head outer surface of lateral ptrygoid plate.

• Insertion: neck of the condyle ,ptrygoid fovea & capsule of TMJ.

• Nerve supply from mandibular nerve.

The infratemporal fossa- The mandibular nerve

The infratemporal fossa- The mandibular nerve

Mandibular NerveMandibular Nerve•The largest division of the trigeminal nerve•A mixed nerve, sensory and motor root•leave through the Foramen Ovale•Below the foramen ovale, the 2 roots unite to form the trunk of the nerve•Divides into anterior & posterior divisions•The ant. is mainly motor•The post. is mainly sensory

Branches:From the trunk:• Nerve to medial pterygoid (motor):

supply the tensor palati and tensor tympani ms & medial pterygoid • Nervus spinosus (sensory) for meninges

Passes through Foramen spinosum into the cranial cavity

Motor & sensory rootsof mandibular n

Nervusspinosus

Lesserpetrosal n.

Auriculotemporal n.

Chorda tympani

Inferior alveolar n.

Mylohoid nerve

Medial pterygoid

Lingual n.

Tensor palati

Otic ganglion

Tensor tympani

Ant. Division:

3 motor branches for muscles of mastications

•Deep temporal nerves (temporalis ms)

•Nerve to masseter

•Nerve to lateral pterygoid

one sensory branch•Buccal nerve (sensory): supplies skin over the buccinator, and mucosal lining of buccinator ms.

Deep temporalnerves

Buccal nerve

Lingualnerve

Inferior alveolarnerve

Auriculotemporalnerve

Posterior division: sensory branches 1.Auriculotemporal nerve• arises by 2 roots (which embrace the middle

meningeal artery) and passes backwards deep to the neck of the mandible

• supplies the scalp• sensory the parotid gland and carries

postganglionic parasympathetic to the parotid gland

Deep temporalnerves

Buccal nerve

Lingualnerve

Inferior alveolarnerve

Auriculotemporalnerve

2. Lingual nerve• Joined by the chorda tympani• Carries general sensations from the anterior 2/3 of

the tongue• The chorda tympani carries taste sensations from

the anterior 2/3 of the tongue and preganglionic parasympathetic fibres to the submandibular and sublingual glands

3. Inferior alveolar nerve•Runs behind the lingual nerve to reach mandibular foramen•The inferior alveolar nerve continues through mandibular canal and divides into mental and incisive branches

•The mental branch comes out of the mental foramen to supply skin of the chin•Before it passes through the mandibular foramen it gives the mylohyoid nerve (motor)

•The mylohyoid nerve supplies the mylohyoid muscle and anterior belly of digastric

Lingual nerveInferior alveolarnerve

Mylohoid nerve& vessels Mylohoid m.

•deep temporal (dt)

• auriculotemporal (at)

•inferior alveolar (ia)

•nerve to the mylohyoid (nmh)

•lingual (l)

•buccal (b)

Mandibular NerveMandibular Nerve

The infratemporal fossa- The chorda tympani

Recall of relevant structures

Muscles of the masticatory apparatus

masseter muscle

temporalis muscle

pterygoid muscles, medial and lateral

Muscle of masticationtemporalismasseter

medial pterygoid &lateral pterygoid

Highlight

• Temporalis superficial temporal vessels auricular temporal nerve N B P

• Masseter parotid parotid duct

• Medial ptrygoid lingual&inferior alveolar nerves

• Lateral ptrygoid parts of maxillary artery

Highlight• The disc is avascular in the centre so ,the

regenerative power is low.

• The disc is composed of dense collagen fibers only in its centre but in posterior & anterior ends it contains elastic fibers

• Synovial membrane has 3 types of cells :type A(fibroblast like cell) ,type B(macrophage like ) and intermediate cell.

• The disc having two nodules