Question

Which of these is the only movable bone in the skull is –
a)Mandible
b)Maxilla
c)Ethmoid
d)Sphenoid

Answer 1

Hint:It is a single bone forming a temporomandibular joint with the temporal bone and responsible for the chin shape.

Complete answer:
Out of Mandible, Maxilla, Ethmoid, and Sphenoid the only movable bone in the skull is Mandible. Mandible bone constructs the lower jaw of the skull and acts as a collecting cabin for the lower teeth, mandible can be located beneath the maxilla. The strongest and largest bone of the face is the mandible. With the help of the temporomandibular joint, it is connected to the temporal bone on either side of the skull.
So the correct answer is (a), i.e. the mandible
Additional information
The structure of mandible bone is a curved shape depicting a horseshoe. The two borders it comprises are:
- Alveolar process– superiorly located, lower teeth are held up by these 16 sockets.
- Base –In the inferior area of the jaw and digastric muscle is attached to it.

The shape of the chin is formed by mental protuberance. During developmental stages, a ridge-like structure develops due to the fusion of two halves of the mandibular known as Mandibular symphysis. The neurovascular structures pass by the mental Foramen, which is located below the second premolar tooth on either side (present laterally to the mental protuberance).

Hence option ‘a’ is the correct answer

Note: The maxilla bone constructs the upper jaw of the skull. Irregularly shaped, right and left halves of the maxilla fuse together, in the midline, this area is known as an intermaxillary suture (can be located below the nose).
The nasal cavity is separated from the brain through the ethmoid bone. They are unpaired bones and can be located between the two orbits in the skull.
In the middle of the skull, unpaired bone of the neurocranium is present. This bone is known as the sphenoid bone located in front of the basilar part of the occipital bone.