Mandibular hypoplasia, better known simply as micrognathia, is a medical condition where babies are born with a lower jaw that is smaller or more retruded than normal. Micrognathia is a congenital condition that is present at birth but becomes more obvious the older a child gets, because their lower jaw does not grow at the same rate as the rest of the face. In other cases, however, the condition gets better and corrects itself as the child gets older.
In addition to giving your child an abnormal facial appearance, micrognathia can also cause breathing problems. If the jaw is too sunken, it can block the airway and make breathing, eating, and swallowing extremely difficult. Micrognathia can occur as a standalone condition or in conjunction with other syndromes and conditions.
The most common sign of micrognathia is that the lower jaw is noticeably smaller than the upper jaw. This size differential can then lead to a number of other signs and symptoms, including:
In some cases where micrognathia is pronounced enough, doctors will be able to detect it on ultrasounds. In particularly extreme cases, micrognathia is accompanied by excess amniotic fluid, a condition known as polyhydramnios. Polyhydramnios is linked to a number of birthing defects and difficulties, which means that if your child has micrognathia, your doctor will likely also check for polyhydramnios.
Most cases of micrognathia occur because of a genetic condition that is passed from one or both parents to their child. A few of these conditions include Pierre Robin Syndrome, Teacher Collins Syndrome, Stickler Syndrome, Trisomy 13 and 18, Cri-du-chat Syndrome, and others. Therefore, if you or your partner are worried that you carry any of the genes that could cause a genetic mutation resulting in micrognathia, it is important to get tested.
In rare cases, however, mandibular hypoplasia can happen because of non-genetic reasons. A few of these instances include if the child also has a cleft palate or lip, if they are crowded in the womb, or if there is a problem with the baby’s muscles or nerves.
Depending on how severe your child’s case of micrognathia is, there is a chance your doctor can diagnose it before they are born with an ultrasound. This will give you time to prepare mentally, as well as to prepare a treatment plan.
In other cases, however, when the condition is not detected before birth, here are a few ways your doctor can diagnose your child with micrognathia:
In addition to seeing whether or not your child has micrognathia, these tests will also help determine if their condition is putting them at risk.
Unfortunately, there is no way to prevent micrognathia or to treat it non-invasively. There are, however, surgical remedies that can correct the size of the lower jaw so that it aligns with the rest of the body. Until you have time to schedule corrective surgery, it will be necessary to position your child while they sleep and eat in a certain way.
They may also require a tracheostomy or tube inserted into their airway to help with breathing, eating, and swallowing. However, unless the jaw corrects itself with age, reconstructive surgery is the only way to repair micrognathia.