Astanga Hrudaya
विधुरे मातृकाश्चाष्टौ षोडशेति परित्यजेत्। हन्वोः षोडश, तासां द्वे सन्धिबन्धनकर्मणी॥२७॥
two vidhura, and eight matraka should be avoided in the hanu (lower Jaw) there are sixteen; of them, the two which binds the joints (of the lower jaw with the skull, should not be cut)
english translation
vidhure mAtRkAzcASTau SoDazeti parityajet। hanvoH SoDaza, tAsAM dve sandhibandhanakarmaNI॥27॥
hk transliteration by Sanscript