Actually, it should read "biting up" because it's our mandible that works while our skull stays in place.
"Bread of deceit is sweet to a man; but afterwards his mouth shall be filled with gravel." (Proverbs 20:17)
I had a dream once where my mouth was full of gravel. And I dreamt it prior to reading and knowing this scripture. Solomon's right, though. As I had lived my life in a shallow expression of my faith, there were (not too deep) depths to my person that needed cleaned from the stain of deceit. Like a spiritual root-canal. I once heard someone on the radio (a call-in show featuring a dream interpreter) say that a dream where your teeth fall out means that the dreamer is lying during their waking life in some way, shape or form. You have to be careful in taking dream interpretation from anyone other than the Holy Spirit, though. As He is the one in charge of the believer's dream life, we'd do well to consult him with dreams and their interpretations. "And Joseph said unto them, Do not interpretations belong to God? tell me them, I pray you." (Genesis 40:8) But we all have teeth. Best not to bite down (or up, for that matter) on a rock. You're bound to break something.
"Break their teeth, O God, in their mouth: break out the great teeth of the young lions, O Lord." (Psalm 58:7)
To masticate means to "chew". I suppose praying something like the above would prevent that from continuing. Much of the Bible is written in a symbolic mood. Metaphor, analogy, symbolism. Numerous times in the New Testament does Jesus "speak to them in parables" (Matthew 13:13) "because they seeing see not". As an aside, my wisdom teeth came in straight. They're still there. Doesn't mean I'm any wiser for it, just that I haven't had to inconvenience myself with dental bills and a liquid diet, however temporary, etc. Whenever I see teeth spoken of in the Bible, I think of confidence though. Wisdom does bestow confidence but I don't go around thinking about it. With the exception of when they grew in, I don't expend much thought in their direction. Don't get me wrong, I'm glad I still have them. I have a friend who, when the time came to have his removed, found out he had eight. Both my brother and my dad have had theirs' removed. My dad doesn't have his tonsils either but my brother does. So do I. All this aside, looking at the above verse and seeing "teeth" as pointing to "wisdom-based confidence", is an interesting, if apt, interpretation. All of what you see behind a simple smile belying a not-so-simple construct.
"He saved others; Himself He cannot save. If He be the King of Israel, let Him now come down from the cross, and we will believe Him. He trusted in God; let Him deliver Him now, if He will have Him: for He said, I am the Son of God. The thieves also, which were crucified with Him, cast the same in His teeth." (Matthew 27:42-44)
The next verse details the three-hour midday darkness over the land. David in Psalm 22 (verses 7-8) foretells the defamation that everyone present throws up at Jesus. "All they that see me laugh me to scorn: they shoot out the lip, they shake the head, saying, He trusted on the Lord that He would deliver Him: let Him deliver Him seeing He delighted in Him." All of this points to the definition of "casting in one's teeth". To deride and defame and slander. Usually in public. And Jesus definitely delighted in His father. Notice how the onlookers qualify God's "deliverance" with "if He will have Him". How sad to assume that they know the Father better than does the Son. As an aside, Jesus comes from the tribe of Judah. He's spoken of by one of the elders in Revelation (5:6) as "the Lion of the tribe of Juda". Rewind to the beginning of the Bible and see Israel's prophecy over Judah:
"Judah, thou art he whom thy brethren shall praise: thy hand shall be in the neck of thine enemies; thy father's children shall bow down before thee. Judah is a lion's whelp: from the prey, my son, thou art gone up: he stooped down, he couched as a lion, and as an old lion; who shall rouse him up? The sceptre shall not depart from Judah, nor a lawgiver from between his feet, until Shiloh come; and unto him shall the gathering of the people be. Binding his foal unto the vine, and his ass's colt unto the choice vine; he washed his garments in wine, and his clothes in the blood of grapes: His eyes shall be red with wine, and his teeth white with milk."
Jesus was crucified on the hill Golgotha. In Hebrew it means "skull". The prophecy of Israel has indeed come true, and "unto [Jesus] shall the gathering of the people [was]" and is. Some were there to testify to the truth of who He was and others wanted to kick Him in the teeth, drawing out His suffering and shame. I should add that they were lying, simple as that.
"I cried unto the Lord with my voice, and He heard me out of His holy hill. Selah. I laid me down and slept; I awaked; for the Lord sustained me. I will not be afraid of ten thousands of people, that have set themselves against me round about. Arise, O Lord; save me, O my God: for thou hast smitten all mine enemies upon the cheek bone; thou hast broken the teeth of the ungodly. Salvation belongeth unto the Lord: Thy blessing is upon Thy people. Selah." (Psalm 3:4-7)
They say the way to tell if a pearl is real is to bite down on it. If it has a rough texture, it's real. If smooth, counterfeit. Furthering the teeth analogy, it says later on in Revelation (21:21) that each of the twelve gates is "one pearl". That might be a bit of a stretch but consider also that anyone outside those same gates, as Jesus said many times, would be weeping and gnashing their teeth.