A baby born with two mouths? Case report describes 'extremely rare' case of craniofacial duplication

This image shows the infant's face and "right mandibular lesion at 5 weeks of age". (BMJ Case Reports / MUSC)

TORONTO — A baby girl was born with an “extremely rare” complication: a second mouth protruding from the side of her face, complete with teeth and a tongue that moved in synchronicity with her normal tongue.

This unique case of “craniofacial duplication” was described in a case report published online in mid-May by BMJ Journals, a database for medical journals.

Doctors first noticed an unusual mass on the right side of the infant’s face during an ultrasound in the third trimester of the mother’s pregnancy, but were unsure what it was.

It wasn’t until the baby was delivered successfully that doctors realized the 1-2-centimetre mass of tissue on the side of the baby’s chin appeared to be a “rudimentary duplicated mouth.”

Photos of the baby at five weeks show a lump of flesh protruding from the right side of the baby’s face, underneath the corner of her mouth. The mass has what appears to be a shiny strip of lip, as well as a tiny opening.

But did the baby actually have two mouths? Yes, and no.

Inside the mass, there was an opening in the tissue called a sinus tract, the report describes, but it was only 13 millimetres deep, and didn’t connect to the baby’s regular oral cavity, or airways. The baby’s other mouth also had no issues.

But a CT scan of the baby’s skull at two weeks revealed a bone structure for the additional mouth, and showed that there were extra teeth inside the soft tissue of the mass. The second mouth even had its own tongue, which seemed to move in parallel to the baby’s actual tongue.

“A small accessory tongue appeared to protrude from the opening of the sinus tract and was noted to move in synchronisation with the oral tongue when the infant was feeding,” the journal stated.

Occasionally, the additional mouth would weep a clear fluid, but no tests were performed to figure out if it was saliva, as was the guess.

Essentially, the mass had many of the characteristics of a mouth, but without a connection to the rest of the respiratory system, it couldn’t function the way the main mouth could; no breathing, drinking, eating or speaking.

Duplication of facial features or structures, such as noses, mouths or ears, is very rare, the report said. Around 35 cases of partial or complete facial duplication have been reported since 1900. Although some have involved structures in the brain, the mildest of which being a pituitary gland duplication, partial duplication most often involves the top and bottom halves of the jaw or the oral cavity itself.

This specific phenomenon was first reported in 1948, the report said, when a two-day old infant was found to have a “duplication of the mouth and tongue” very similar to this new case.

At two weeks old, the baby with two mouths seemed to have no idea that she was a medical marvel: she was healthy, feeding well, and gaining weight without any issues. Having an additional mouth didn’t seem to disrupt any of these regular functions.

At six months old, the baby was taken into surgery to correct the second mouth.

Doctors removed the bone and tissue making up the additional mouth, and closed up the opening in the soft tissue by transferring over adjacent tissue. During the surgery, they discovered the second mouth had salivary glands and a mucosal lining. When they peeled the mucosal lining off of the mandible, they uncovered yet more teeth “facing towards the duplicate oral cavity.”

The teeth were pulled, and the sockets were “drilled down” to contour the lower jaw back to a normal size. Doctors took care to preserve the facial nerves as they closed up the opening with other tissue.

A photo taken one month after the infant's surgery shows a slight swelling on the right side of the face where the mouth used to be. At her six-month followup after surgery, the incisions were healed and she could feed without difficulty, but doctors noted that she had some trouble moving her bottom lip.

There are numerous causes for craniofacial duplication, according to the report. Often it’s part of another syndrome. This recent case, the report said, appeared to be an “isolated anomaly” on an otherwise healthy baby.