Thanks for sharing your concern.
sleeping actually makes you feel relaxed and also fresh.As the extraction process, itself is very painful and uncomfortable, therefore its nice if you get good sleep and relax for sometime.
Also pain and effect of anesthetic
also plays role here.If there is more pain and discomfort you cannot relax yourself and again this adds to your tiredness
Therefore it is good to take adequate rest post extraction.
Hope i have answered your query.
For further query please let us know.
Wish you good health.