MDS PREP
The nerve to masseter passes
1. deep to the medial pterygoid muscle
2. posterior to temporomandibular joint
3. superior to zygomatic arch to enter the muscle on its medial surface
4. through the mandibular notch to enter the muscle on its medial surface
Anatomy
Answer: 4
The nerve to masseter passes through the mandibular notch to enter the muscle on its medial surface
The nerve to the masseter muscle is the masseteric nerve, which is a branch
of the mandibular nerve (CN V3), the largest division of the trigeminal nerve
(cranial nerve V). The masseter muscle is one of the muscles of mastication that
lifts the lower jaw, contributing to the action of biting and chewing.
The masseteric nerve originates from the anterior division of the mandibular
nerve and typically passes:
1. Deep to the medial pterygoid muscle: The medial pterygoid muscle is located
in the infratemporal fossa, which is the space deep to the zygomatic arch and
medial to the temporomandibular joint (TMJ). The masseteric nerve runs in a deep
position relative to the medial pterygoid muscle as it travels towards the
masseter muscle. This muscle is involved in the side-to-side movement of the
jaw, known as lateral excursion.
2. Posterior to the temporomandibular joint: The TMJ is the articulation between
the mandible and the temporal bone of the skull. It is a synovial joint that
allows for the hinge movement of the jaw, such as opening and closing the mouth.
The masseteric nerve passes behind the TMJ to reach the masseter muscle. This
nerve does not actually cross the joint itself but runs in a position posterior
to it.
3. Superior to the zygomatic arch: The zygomatic arch is the bony structure that
extends from the zygomatic process of the temporal bone to the zygomatic bone of
the skull. It forms the prominence of the cheek. The masseteric nerve runs
superior to the zygomatic arch to reach the masseter muscle. The arch serves as
a landmark for the nerve's course, and the nerve typically does not pass through
the arch itself.
4. Through the mandibular notch: This statement is not entirely correct. The
masseteric nerve does not pass through the mandibular notch, which is a
depression on the medial surface of the ramus of the mandible, but rather it
passes above (superior to) the notch. The mandibular notch is the location where
the masseteric nerve and the other branches of the mandibular nerve leave the
infratemporal fossa and enter the submandibular space to innervate the muscles
of mastication, including the masseter. The nerve then runs along the lateral
surface of the lateral pterygoid plate and enters the deep surface of the
masseter muscle.
In summary, the masseteric nerve passes deep to the medial pterygoid muscle,
posterior to the TMJ, and superior to the zygomatic arch. It does not pass
through the mandibular notch; instead, it runs superior to it before reaching
the masseter muscle. The anatomical pathway of this nerve allows it to
effectively innervate the masseter muscle, which is crucial for the function of
the muscle in mastication.
The auriculotemporal nerve carries some fibers which are .
1. motor to masseter muscle
2. secretory to parotid gland
3. afferent from the carotid body
4. sensory to lining of tympanic cavity
Anatomy
Answer: 4
The auriculotemporal nerve carries some fibers which are sensory to lining of tympanic cavity
Malformation of the coronal portion of the permanent anterior teeth is most frequently encountered in the
1. maxillary central incisor
2. maxillary lateral incisor
3. maxillary canine
4. mandibular lateral incisor
Dental Anatomy
Answer: 2
Maxillary lateral incisor agenesis:
This is the most common congenital absence of a permanent tooth in the maxillary
anterior region, accounting for about 20% of all dental anomalies.
Coronal developmental invagination (DI):This is a common anomaly in the
permanent maxillary lateral incisor, usually appearing as an accentuation of the
lingual pit.It's often bilateral.
Peg-shaped crown:This is a common alteration in the maxillary lateral incisor.
Which of the following is TRUE regarding the attachment of the mylohyoid muscle?
1) It attaches superiorly at the lateral border of the mandible and inferiorly at the body of the hyoid.
2) It attaches superiorly at the medial border of the mandible and inferiorly at the lesser horn of the hyoid
3) It attaches superiorly at the medial border of the mandible and inferiorly at the greater horn of the hyoid
4) It attaches superiorly at the medial border of the mandible and inferiorly at the body of the hyoid
Anatomy Answer: 4
It attaches superiorly at the medial border of the mandible and inferiorly at the body of the hyoid
The most common site for CSF rhinorrhea
1. frontal bone
2. ethmoid bone
3. tegmen tympani
4. none
Anatomy
Answer: 2
Cerebrospinal fluid (CSF) rhinorrhea occurs when there is a leak of CSF through the nasal cavity, often due to a defect in the skull base. The ethmoid bone is the most common site for such leaks because of its thin structure and proximity to the nasal cavity.
Which muscle of the soft palate is not supplied by the pharyngeal plexus?
1. Palatoglossus
2. Musculus uvulae
3. Palatopharyngeus
4. Tensor veli palatine
Anatomy
Answer: 4
muscle of the soft palate is not supplied by the pharyngeal plexus is Tensor veli palatine
9 months of age, is the usual eruption time for
1. primary mandibular canines
2. primary maxillary canines
3. primary maxillary first molars
4. primary lower lateral incisors
Dental Anatomy
Answer: 4
9 months of age, is the usual eruption time for primary lower lateral incis
The largest and longest root canal of the maxillary second molar is the
1. lingual
2. mesiobuccal
3. distobuccal
4. distal
Dental Anatomy
Answer: 1
The largest and longest root canal of the maxillary second molar is the lingual