Both stick to the teeth and promote decay.
Starchy foods and boiled sweets, something they are very fond of but that this tribe would not have had much access to are also "sticky" foods.
Some Brits and Irish hold a sugar cube in their teeth while they sip tea. And those front teeth rot out first. Kind of scary how the sugar destroys the teeth where it is actually held, in those few seconds of sipping. You’d think the bad effects would be a little more evenly distributed among the teeth. I see teenagers drinking sodas with sugar—and I’ve discovered that they’ve been told in government school that Splenda and Equal are dangerous poisons! Lefty Commie Red Maoist Democrat teachers!