In plain words
rush into Your fearsome mouths, terrible with fangs. Some are seen caught between Your teeth, their heads crushed.
Word for word
[they] enter in haste Your mouths, terrible with fangs, fearful; some, caught in the gaps between the teeth, are seen with [their] heads crushed.
The commentators
Bhagavadgītābhāṣyam
किञ्च —
वक्त्राणि मुखानि ते तव त्वरमाणाः त्वरायुक्ताः सन्तः विशन्ति, किंविशिष्टानि मुखानि ? दंष्ट्राकरालानि भयानकानि भयङ्कराणि । किञ्च, केचित् मुखानि प्रविष्टानां मध्ये विलग्नाः दशनान्तरेषु मांसमिव भक्षितं सन्दृश्यन्ते उपलभ्यन्ते चूर्णितैः चूर्णीकृतैः उत्तमाङ्गैः शिरोभिः ॥ २७ ॥
In plain words
And there is more —
They rush headlong into your mouths, your faces. And what kind of mouths are they? Fearsome, bristling with tusks, terrifying to see. And more than that — some of those who have already gone in are caught there, wedged between your teeth, looking for all the world like meat being chewed, their heads crushed to powder.
Close to the Sanskrit
And what more —
Mouths, faces, of you, your, hastening, endowed with haste, being so, they enter — of what particular kind are the mouths? Fearsome with tusks, frightful, terrifying. Moreover, some, among those who have entered the mouths, stuck in the midst, in the gaps between the teeth, like flesh being chewed, are seen, are perceived, with their heads crushed, ground to powder.