Musculoskeletal System in Dentistry Practice Questions
20 free Musculoskeletal System in Dentistry practice questions for the CDA. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which muscle is primarily responsible for elevating the mandible during chewing?
- A Lateral pterygoid
- B Masseter
- C Buccinator
- D Orbicularis oris
Correct answer: Masseter
The masseter is one of the strongest muscles of mastication. Its primary action is to elevate the mandible to close the jaw.
Which muscle depresses and protrudes the mandible?
- A Temporalis
- B Lateral pterygoid
- C Medial pterygoid
- D Zygomaticus major
Correct answer: Lateral pterygoid
The lateral pterygoid opens the mouth by depressing the mandible and also protrudes it forward. It is essential for wide mouth opening.
Temporomandibular joint (TMJ) movement is classified as which type of joint action?
- A Hinge and gliding
- B Ball-and-socket
- C Saddle
- D Pivot
Correct answer: Hinge and gliding
The TMJ combines hinge rotation with gliding translation movements. This allows complex jaw motions such as opening, closing, and lateral excursion.
Which bone forms the only movable joint of the skull with the temporal bone?
- A Maxilla
- B Mandible
- C Zygomatic bone
- D Palatine bone
Correct answer: Mandible
The mandible articulates with the temporal bone at the TMJ. It is the only freely movable bone of the skull.
Which muscle assists in retracting the mandible?
- A Masseter
- B Temporalis
- C Medial pterygoid
- D Buccinator
Correct answer: Temporalis
The posterior fibers of the temporalis muscle retract the mandible. Its anterior fibers elevate it.
Which muscle compresses the cheeks and helps keep food on the occlusal surfaces during chewing?
- A Masseter
- B Buccinator
- C Orbicularis oris
- D Temporalis
Correct answer: Buccinator
The buccinator compresses the cheeks, preventing food from accumulating in the vestibule. It is essential for efficient mastication.
Which ligament helps prevent excessive posterior movement of the mandible?
- A Stylomandibular ligament
- B Temporomandibular ligament
- C Pterygomandibular raphe
- D Sphenomandibular ligament
Correct answer: Temporomandibular ligament
The temporomandibular ligament limits posterior movement of the mandible. It also reinforces the lateral aspect of the TMJ.
TMJ dysfunction most commonly affects which associated structure?
- A Articular disc
- B Mandibular canal
- C Mental foramen
- D Hyoid bone
Correct answer: Articular disc
The articular disc can become displaced or inflamed, causing TMJ dysfunction. Disc displacement with reduction is a common issue.
Which muscle is responsible for elevating the shoulders and assisting in neck posture during dental procedures?
- A Sternocleidomastoid
- B Trapezius
- C Masseter
- D Platysma
Correct answer: Trapezius
The trapezius elevates the shoulders and stabilizes the upper back and neck. Prolonged activation during dental work can cause neck strain.
Which muscle allows for side-to-side (lateral) movement of the mandible?
- A Temporalis
- B Medial pterygoid
- C Masseter
- D Sternohyoid
Correct answer: Medial pterygoid
The medial pterygoids work with the lateral pterygoids to create lateral jaw movement. This motion is essential for grinding food.
Which structure cushions the TMJ and allows smooth articulation?
- A Synovial membrane
- B Articular disc
- C Glenoid fossa
- D Mandibular condyle
Correct answer: Articular disc
The articular disc absorbs shock and allows smooth movement between the mandibular condyle and temporal bone. It divides the joint into two compartments.
Which bone serves as the attachment point for many tongue and neck muscles?
- A Mandible
- B Palatine bone
- C Hyoid bone
- D Zygomatic bone
Correct answer: Hyoid bone
The hyoid bone is a unique bone that does not articulate with other bones. It anchors muscles of the tongue, floor of the mouth, and neck.
Which muscle is primarily activated when a patient protrudes the mandible forward?
- A Masseter
- B Temporalis
- C Lateral pterygoid
- D Orbicularis oris
Correct answer: Lateral pterygoid
The lateral pterygoid is the main protruding muscle of the mandible. It pulls the condyle and disc forward.
Which joint structure produces synovial fluid to lubricate the TMJ?
- A Articular cartilage
- B Fibrous capsule
- C Synovial membrane
- D Retrodiscal tissue
Correct answer: Synovial membrane
The synovial membrane secretes synovial fluid that lubricates and nourishes the joint. This fluid reduces friction during movement.
Which muscle tenses the skin of the neck and can be visible when clenching the jaw?
- A Platysma
- B Trapezius
- C Sternocleidomastoid
- D Masseter
Correct answer: Platysma
The platysma is a thin muscle that tenses neck skin and assists in depressing the mandible. It becomes pronounced during jaw clenching.
Which cervical vertebra supports the skull at the occipital condyles?
- A C1 (Atlas)
- B C2 (Axis)
- C C3
- D C7
Correct answer: C1 (Atlas)
The atlas (C1) articulates with the occipital condyles to support the skull. It allows nodding movements of the head.
Which cervical vertebra contains the dens, enabling rotation of the head?
- A C1 (Atlas)
- B C2 (Axis)
- C C3
- D C5
Correct answer: C2 (Axis)
The axis (C2) contains the odontoid process (dens), enabling head rotation. It works closely with C1 to allow significant mobility.
Which muscle is commonly strained in dental professionals due to static posture during procedures?
- A Temporalis
- B Sternocleidomastoid
- C Trapezius
- D Masseter
Correct answer: Trapezius
The trapezius is frequently strained due to prolonged forward head posture. This can lead to chronic neck and shoulder pain.
Which structure forms the upper limit of movement for mouth opening?
- A Articular disc
- B Coronoid process
- C Articular eminence
- D Glenoid fossa
Correct answer: Articular eminence
The articular eminence guides and limits the forward movement of the TMJ. The condyle slides along this surface when opening the mouth.
Which muscle group works together to close the jaw?
- A Lateral pterygoid, buccinator, and digastric
- B Masseter, temporalis, and medial pterygoid
- C Orbicularis oris, platysma, and masseter
- D Digastric, mylohyoid, and geniohyoid
Correct answer: Masseter, temporalis, and medial pterygoid
The masseter, temporalis, and medial pterygoid form the primary jaw-closing muscles. They elevate the mandible to occlude the teeth.