How do the skull joints change after birth?

After birth, the skull undergoes several changes in its joints to accommodate brain growth, facial development, and sensory organ function. These changes are essential for the proper development and function of the head and its associated structures.

1. Fontanelles: At birth, the skull is not completely ossified, and there are several gaps between the skull bones called fontanelles. The most prominent fontanelles are the anterior fontanelle (located at the top of the head) and the posterior fontanelle (located at the back of the head). These fontanelles allow for the rapid growth of the brain during infancy. As the brain grows, the fontanelles gradually close and the skull bones fuse together. The anterior fontanelle usually closes by 18-24 months of age, while the posterior fontanelle closes by 2-3 months.

2. Sutures: The skull bones are connected to each other by sutures, which are flexible joints that allow for some movement. The sutures allow the skull to expand as the brain grows and to absorb shock from impacts to the head. Over time, the sutures gradually become less flexible and eventually fuse together, resulting in a more rigid skull.

3. Temporomandibular Joints (TMJ): The TMJ are the joints that connect the lower jaw (mandible) to the skull. These joints allow for movement of the jaw, which is essential for functions such as chewing, speaking, and yawning. The TMJ undergo significant changes after birth to accommodate the growth and development of the mandible and the associated facial structures.

In summary, the skull joints change after birth to allow for brain growth, facial development, and proper function of the sensory organs. The fontanelles close, the sutures fuse, and the TMJ adapt to support the growing and changing structures of the head.