PERHAPS IT is a measure of our social backwardness that we permit a silly thing like a table to stand in the way of normal comforts. At a table, I'm told, it is impolite to pick your teeth.

This is a bothersome and unhealthful restriction, as people south of the equator will tell you. There, diners are allowed a time-honored practice of carrying specially chosen sticks so they can pick and clean their teeth wherever they go. I offer this only as an explanation for the absence of tables in those parts. People of more refined customs such as theirs have a much keener eye for the narrower, unmarked paths that can otherwise lead man to disgrace.

My father, a northerner, has always been a great tooth picker. But then, he has always been a successful social aberrant.

For many years a traveling salesman, he had almost daily occasion to savor the cuisines of backwater Illinois, Iowa, Indiana and Michigan. Being a meat-and-potatoes man, he had his share of shards that found their intractable way into the fleshly netherworld twixt gum and tooth.

His great luxury was the many hours spent alone in his car, where he could pick away to his heart's content at the remains of a brisket, a fried chicken or even a carefully gnawed rack of spare ribs. And for the memory of those hours of quiet deviant pleasure he reserved a place of honor.

Before an expanding waistline forced him to switch to the "diet special," he saved his toothpicks and stuck them neatly in a row above the window on the driver's side. Today they stand as a reminder of his noble defiance -- and also as a reserve, should ever the need arise.

This talk of spare ribs demands once again we address the question of where, when, how and if to pick. The more squeamish among you may want to retreat to the lavoratory to extract those stringy morsels. And though it is beyond me why anyone would want to use anything other than a good, hard, pointy toothpick for the job, I will even open the discussion to an expert -- my dentist.

John Conaghan, who practices in the District of Columbia, has had his share of apres-diner customers begging for the removal of an errant food bit. "Boy, I'll tell you," he says, "that'll give you a fit." a

Left to its own ways, food between the teeth will not only give you bad breath, Conaghan says, but can "break down the gum between the teeth and leave a pocket dentists always want to charge you to fill."

Conaghan, however, cautions against using those toothpicks you find wrapped in pairs at better roadhouses ("They cause a little halfmoon erosion below the dental line"), recommending instead the "dental stimulators" sold for about $1.30 a pack in drug stores.

These triangular pieces of balsa wood also come to a point at one end. Allowed to moisten in the mouth, however they become maleable and fit better, Conaghan said, to the natural space between the teeth.

Now Conaghan and most other dentists will tell you to use dental floss, which comes in packages -- waxed or unwaxed -- at the drugstore for about a buck. How you are supposed to floss your teeth and drive at the same time is beyond their professional expertise. And be assured that many rib houses don't have flossing facilities.

To my mind, dental floss should be kept at home, or at least reserved for those "special" occasions. Mint-flavored floss is an exceptional accompaniment to, say, roast of lamb. Save the cinnamon-flavored floss for breakfast.

Beware of such faux-picks as matchbook covers. These are a poor substitute, wilting quickly under pressure and apt to leave behind traces of cardboard and strange addresses. Tubular plastic picks bend hopelessly almost at the first insertion.

"Flat" toothpicks sold in grocery stores break easily, their primary function being to spear stuffed mushrooms.

For the upwardly mobile, gold toothpicks, with a diamond stud and a handy leather carrying case, are available at such catalogue stores as W. Bell & Co. for as little as $35. The sterling silver model is a mere $15.

But I return to the round, pointed toothpick, advising its use be limited to brief moments of pleasure in dislocating those larger chunks. The "dental stimulator" is a wise concession to dentistry. Its smaller size allows almost unlimited action around the rear molars.

Either would add admirably to a collection of your own.