Nevertheless , unless its excessive :
Yawning is considered as Natural breathing technique that will improve your overall health and Well-being!
Dan Brule in his Book : Breath Work: states as below:
"Yawning energizes you, while also triggering the relatation response!
It helps with sleep, mood and anxiety, and it discharges, Stress and Tension. "
Yawning is associated with precuneus , a tiny structure hidden ,
within the folder of parietal lobe
and it appears to play a role in the consciousness, self-reflection and memory retrieval.