broken jaws always come in pairs

Monday, August 17, 2015

That Geno Smith, Jets quarterback, broke his mandible in two places, is not a testament to the severity of the blow that struck him, but instead, a result of the physics and anatomy and design. There are many circles found throughout the human body and whether it is the mandible (jaw bone), the tibia and fibula (shin bone), the radius and ulna (forearm) or pelvis, it is tough to break a circle in just one spot. Just imagine breaking a pretzel.

Mr. Smith was in a locker room altercation when he was punched in the face and sustained a fractured mandible (jaw). Just to be clear with word, fractured and broken mean the same thing. The jaw is a common facial bone to break, second only to broken noses and the most common causes are motor vehicle crashes and altercations. Most people know that something is wrong almost immediately. Aside from the pain, there is a sense that the teeth don’t quite fit properly. The muscles that attach to the mandible, and allow us to open and close our mouths, shift the bone fragments and the lower teeth that are attached don’t quite align with the upper teeth in the maxilla. And as with any injury, swelling and spasm occurs gradually making it difficult to open the mouth. This is called trismus.

LatMandible Mandible-front-with-orientation-01

For the doctor, though, the important thing to remember is anatomy and physiology and how the body absorbs force. If there is one fracture found in the jaw, the search must happen for the second break. Most often, a fracture of the body of the jaw is associated with a fracture of the condyle on the opposite side. The condyle is the thin bone that connects the jaw to the skull.

Even before worrying about the broken bone, other issues need to be thought of. If there is enough bleeding and swelling, breathing can become an issue. Associated broken teeth or dentures can fall into the back of the throat, trachea or lung, obstructing the airway, so making certain breathing happens is always job one.

In boxing, the one goal of the sport is to inflict a concussion and knock out the opponent. If there is enough force to break the jaw, there is also enough potential force to cause a head injury or break a neck. With most trauma resuscitation, the obvious injuries are appreciated but take second stage to the injuries that are lethal or permanently disabling. Even if takes just a minute or two to consider what badness might occur, that time is invaluable in caring for the patient.

The diagnosis of a broken jaw is often made clinically by appreciating the swelling, pain and disfigurement that is associated with the broken jaw. X-ray and CT scan then confirm the location of the break. Sometimes special dental x-rays are required to assess damage to individual teeth and their roots, especially if the fracture line goes into the tooth socket and that might affect treatment options.

Treatment is almost always surgery to align the bone fragments, especially those that are teeth bearing. Some children or elderly patients without teeth may be spared the scalpel. The teeth must be aligned as perfectly as possible so that bite is maintained. Fractures that heal with poor alignment can cause wear and tear on the temporomandibular joint (TM joint). This is the joint where the mandible attaches to the temporal bone of the skull. Like any joint that is placed under stress; it can develop arthritis, inflammation and pain. There are many surgical options but often titanium plates are screwed in place across the fracture site to hold it in place. Not only does the fracture needs to be plated, but in some cases, the jaw needs to be wired shut s the bone heals.

The use of wiring depends upon the clinical situation, the stability of the fracture and the discretion of the surgeon. There are different wiring techniques but, in general, wires are tightened from the upper teeth to the low teeth preventing the jaw from moving and opening. Just like any other bone, a mandible fracture needs about 6-8 weeks to start to heal and that means the jaw will be wired shut for that long as well. There are exceptions, especially with condyle fractures, where the wires are kept in place for only a couple of weeks.

If the mandible fracture is an isolated injury, then there is little reason to limit activity. Geno Smith was seen playing catch shortly after surgery and for a football player that seems like a pretty reasonable thing to do… as long as he avoids helmets, pads and the risk of getting hit in the jaw again.

It goes without saying that when it comes to trauma, prevention is always the best treatment. From seatbelts to bicycle helmets, it’s what is done before the accident that can help minimize damage. Unfortunately, in Mr. Smith’s case, turning the other cheek didn’t quite work out.

 

 

This entry was tagged , , , , , , ,


the broken jaw

Monday, December 16, 2013

The violence that is football does not exempt any player on the field. The crushing block on Cincinnati Bengal punter, Kevin Huber, is a reminder that even helmets and pads may not adequately protect the body. Mr. Huber ay on the field for more than a few minutes before walking off the field with blood soaked gauze in his mouth. The initial injury report was of a broken jaw and only later was it found that he also broke a vertebra in his neck. There are lessons to be learned from his injuries. The first is that mandible fractures (a broken jaw) tend to happen in pairs and the second is that a broken neck does not equal a spinal cord injury.

The mandible is a semicircular bone that attaches to the temporal bone of the skull. When hit, the bone tends to break (fracture and crack mean the same thing) at the site of the blow, but another fracture often occurs on the opposite side. It is the same physics principle that makes it tough to break a pretzel in only one place. Understanding the way force is transmitted helps diagnosing where other injuries might exist. Mandible fractures often occur in the weakest and thinnest part of the bone, where the teeth are located and the subcondylar area, just beneath where the mandible attaches to the skull.

MandibleFx

The diagnosis is often made clinically. Aside from pain, all broken bones hurt, the patient may complain that their bite is off, their teeth don’t fit right or that they cannot fully open their mouth. Often, the fracture causes the gum or the lining of the mouth to tear and bleeding may occur.

The treatment of a mandible fracture depends where the bone is broken and whether the teeth alignment is affected. Oral surgeons are the doctors who deal with repairing the bone and aligning the teeth. Plain x-rays including a panorex (think a panorama pic of the jaw) and CT may be done to visualize any or all breaks. Restorative dentistry may be needed if teeth are lost are broken, but the goal is to end up with a jaw that works, teeth that chew and a nice cosmetic result.

The second lesson that comes from being hit in the jaw is that other structures in the head and neck can be affected. In boxing, the goal is to knock out the opponent, effectively causing a concussion. For that reason, a concussion should be suspected with any blow to the face. Similarly, the head swivels on the neck and if there is enough force to fracture the mandible, there may be enough force to fracture a vertebra or bone in the neck. Once again broken bones hurt and relatively quickly, the muscles that help support the neck go into spasm. For that reason, it is important to consider a neck fracture with any head injury. The spinal cord may not be damaged initially, but if the neck injury is not stable, there is potential that the spinal cord can be put at risk.

Some neck (cervical spine) injuries are stable and need no more than a stiff collar to provide support and pain control, but most often, a neurosurgeon is involved in reviewing the situation, either directly, or by reviewing x-rays and CT scans. Not too long ago, Jermichael Finley of the Green Bay Packers lay on the field with a spinal cord contusion. The cervical spine was not fractured but the cord was injured, the reverse situation for Mr. Huber. It is a reminder that the diagnosis of a patient requires both high touch and high tech. Radiology needs history and physical exam to accurately assess a patient.

While Mr. Huber has been placed on injury reserve ending his season, the good news is that the prognosis is positive for him to play again next season. The bad news is that Christmas dinner may be a little difficult to chew.

Image attribution: rad.washington.edu

 

This entry was tagged , , , , ,