Little kids often put things into their mouths that don't belong there, from coins and jewelry to small toys and batteries. Even though grownups know better, they sometimes accidentally swallow items they shouldn't either -- and these objects may get stuck in their throats or lodged in their digestive tracts.

A review study from Germany, published in the journal Deutsches Arzteblatt International, recently identified the three items most likely to be inadvertently swallowed by adults. First on the list was fish bones followed by chicken bones, neither of which seem that unusual. The third most common item was dentures, which may loosen up in an older person's mouth while eating. 

Although the researchers didn't speculate beyond these three items, I asked Dr. Ram Chuttani, a gastroenterologist and director of endoscopy at Beth Israel Deaconess Medical Center in Boston to do so. He was not involved in the study, but described some of the most frequent objects he's known to unintentionally slide down an adult's throat during his medical career.

"Coins are a big one," says Chuttani. "How they get there is difficult to say, but they're not uncommon." Toothpicks are also common, he suggests, and they're one of the more dangerous because they are long, thin, pointy, and wooden.

Wooden objects, such as pencils and toothpicks, are not easily picked up on X-rays, Chuttani explains. Also tough to see are broken pieces of glass whose sharp edges can damage your insides. So can swallowing an open safety pin, and Chuttani says that sometimes prisoners purposely swallow sharp items like razor blades because they know it will temporarily get them out of jail and into the hospital.

The German study also recommends seeking prompt medical attention if items such as batteries and magnets are accidentally swallowed. A battery stuck in the esophagus needs to be removed immediately because it might leak alkaline substances. It can also put pressure on the wall of esophagus, or generate electrical currents that can short-circuit its function. Batteries that make their way into the stomach might corrode the lining there.

Magnets can be especially risky when you swallow more than one of them, points out Chuttani. He says that if one magnet winds up in the stomach while another is in the small intestine, they can attract each other causing the walls of the intestine to get trapped in between. Pressure can build up and puncture a hole in the intestine.

Sometimes people do dumb things and an object glides down their gullet -- whole. Chuttani once removed a ping pong ball that a drunk college student chugged during a memorable game of beer pong. He's also retrieved a latex glove that a psych patient stuck down his throat, and has drudged up swallowed condoms.

The study shows pictures taken after folks accidentally swallowed a toothbrush, spoon, or dental drill bit, while other case reports have described women who have mistakenly sent a butter knife or pen down their throats.

Chuttani says most of the time these foreign objects pass by themselves.

According to the study, about 80 percent of the time an item winds its way through the curvy GI tract without causing any trouble. It typically comes out in your poop within 4 to 6 days. In rare instances, an object may take up to 4 weeks to pass through a person's body safely.

Roughly 20 percent of cases need endoscopy, in which doctors look inside the body, locate the item, and then gently remove it. 

A very small minority -- less than 1 percent of cases -- require surgery to retrieve the object.

Related: 

How a tooth got lodged in this guy's foot

Engineer lived with bullet in his head for 8 decades

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Not much good can happen when you send a bare foot smashing into someone's jaw. But during a summer beach brawl, a kick to the face caused one man to get part of his opponent's tooth stuck in his right foot.

Published in the Journal of Foot and Ankle Surgery, this case is the first to report a tooth "traumatically implanted in the foot." 

The case describes a 29-year-old Croatian man who came to the hospital emergency room complaining of swelling and severe pain in his right foot. At first, he claimed he had stepped on a piece of glass while walking on the beach.

The man had a wound on the sole of is right foot in the gap of skin between his third and fourth toe. When doctors x-rayed the foot, they didn't find a shard of glass but saw "an opaque object" that resembled a human tooth.

So, they questioned the patient again and this time he came clean.

He admitted that two weeks earlier he had been involved in a fight with another guy on the beach. He had been wearing flip-flops but they flew off during the scuffle as he kicked his opponent in the jaw with his right foot.

That strike to the jaw broke off one of his opponent's teeth, which then embedded itself beneath the man's right foot.

Ten days after the brawl when pus from the wound started to ooze out, the man went to see his doctor about his injury. But he didn't fess up to the fight, and his doctor cleaned the wound and prescribed an antibiotic to reduce the risk of infection.

When the pain did not let up, he headed to the emergency room and that's when the tooth was discovered. The doctors decided to surgically remove it because the skin had developed an abscess.

"We consider all foreign body puncture wounds to be 'dirty,' " says Zenon Pogorelić, MD, the case study lead author and a pediatric surgeon at the University Hospital Split in Split, Croatia. Dr. Pogorelić removed the tooth from the patient's foot, and says that because human saliva contains nearly 200 different species of micro-organisms, this can also increase a person's risk for infection.

From the looks of it, the surgeon's suspect the tooth was an incisor from the front part of his opponent's mouth.

Stepping on toothpicks, sewing needles, glass, metal, and insect stingers are the most common objects to cause deep cuts to the sole of the foot. Finding a human tooth there is a rarity, although the medical literature describes unusual cases where a tooth has been found in the tongue, throat, sinuses, and ear canal.

The wound eventually healed, and "the patient returned to his regular activities 15 days after the operation." Let's hope those regular activities didn't include putting his foot into another person's mouth.

More tales of misplaced things:

• Engineer lived with bullet in his head for 8 decades
• Swallowed pen still works 25 years later
• Woman's breast implant disappears during Pilates

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New England Journal of Medicine

This image shows the bullet that was lodged in an 85-year-old man's head -- specifically, his foraman magnum -- for more than 80 years.

When a Russian man was only 3, his older brother accidentally shot him with a pistol. More than eight decades later, the bullet was still there, according to a case report just published online in the latest issue of the New England Journal of Medicine. 

The bullet hit the little boy right below the nose and eventually lodged itself in his foramen magnum, the opening in the bottom of the skull that allows the spinal cord to pass through and connect to the brain. The 3-year-old lost consciousness for several hours. At the time, a doctor examined the poor kid, but didn't remove the bullet for fear of causing more harm than good, says Dr. Marat Ezhov of Moscow's Cardiology Research Center, who examined the patient more than 80 years later. Incredibly, the boy recovered completely. 

"The body has an amazing ability to 'get used to' things," explains Dr. Richard O'Brien, a spokesman for the American College of Emergency Physicians. "Also, children have a great ability to overcome hardship and rebuild themselves when injured."

Eighty-two years later, Ezhov and Dr. Maya Safarova were treating the man at the cardiology center for his coronary heart disease. His patient history included the story of the accidental shooting, so doctors did a CT scan to check it out, which revealed the stowaway bullet. But the bullet had left no sign of neural damage -- further evidenced by the man's successful career as an award-winning engineer. 

"High-speed missiles, like a bullet, can cause great damage and usually do," explains Dr. David Ross, an emergency physician at Penrose Hospital in Colorado Springs, Colo. "However, because they are high-speed, they generate a lot of heat. That heat usually means the missile is sterile -- meaning it is unlikely to serve as a basis for infection if it stays in one place for many years. So if it did not cause much damage, which it apparently didn't, it was unlikely to cause him ongoing troubles."

A weird little detail: Ezhov notes that the during his engineering career, the man oversaw construction of ballistic missles.

Doctors at the Russian cardiology center decided that at this point, the bullet didn't need to be removed -- after all, he was in good condition, Ezhov noted, and he had been doing well for decades. Besides, even his scar wasn't affecting his life negatively -- the bullet did leave a scar under his nose, but his curved, Roman nose keeps it invisible, Safarova said in an email. 

Related:

• Swallowed pen still works 25 years later
• Woman's breast implant disappears during Pilates

Want more weird health news? Find The Body Odd on Facebook.