90% of Biochem is unnecessary. As a practicing dentist you do not need to know how prostaglandins, fatty acids, ketone bodies, etc are made. You do not need to know how pyrimidines and purines are made.
I would argue that Histology to a certain extent is unnecessary. As a practicing general dentist how often would you break out your microscope and look at at a sarcomere, blood vessel enothelium, a thyroid gland, a thymus, a pancreas, a Hassel's Corpusle, the cap and bell stage of a developing tooth, a epiphyseal plate, an osteon??? Never. Unless you are doing some kind of research in with case you can go get a phd and learn all that.
For Anatomy, I would argue that as a dentist I don't need to know about every back muscle, every muscle of the hand and arm, blood vessels and muscle layers of the thoracic cavity. If its not head and neck we don't need to know it. Thats half the semester eliminated right there. How often is a dentist going to trace a problem in the oral cavity to the hemiazygous vein???? Never.
Its little irrelevant things like this in every class that you can trim down. If I had syllabi from every class i could name more things. Give me an example of a time when a practicing general dentist will absolutely need to know any of the things i mentioned above and I will shut up.