Lockjaw refers to the condition of having difficulty opening your mouth due to spasms in the muscles that you use for chewing (mastication). You can most likely open your mouth somewhere between 40-60 mm or 1.5 to 2.3 inches. While the distance you open your mouth isn't enough to diagnose lockjaw, if you are experiencing lockjaw, you may only be able to open your mouth less than 35 mm (1.4 inches).
A good way to look for a restricted mouth opening is to try the three finger test.
- Place your index, middle, and ring finger together.
- Turn your three fingers so that they are vertical
- Try to place your three fingers between your front teeth.
If your fingers fit between your front teeth comfortably, then you most likely do not need to be concerned with trismus.
With vaccinations, the incidence of tetanus has declined, and in the United States from 2001 to 2008, there were only 233 reported cases. While rare, lockjaw is a common symptom Experienced if you have tetanus.However, if you have had treatment for cancer of the head and neck (surgical or radiation) you stand a 5 to 38 percent chance of developing lockjaw. Improved techniques in both surgical and radiation therapies are helping to improve the incidence of lockjaw. Temporomandibular Joint (TMJ) disorders can also result in lockjaw in as many as 86 percent of the cases.
Other Symptoms Associated with Lockjaw
While the most common symptom related to lockjaw is the inability to open your mouth fully, there are several other symptoms associated with the condition. These include:
• Xerostomia (dry mouth)
• Jaw pain
• Hard of hearing
• Speech difficulties
• Swallowing difficulties
• Dental issues related to hygiene
• Malnourished associated with difficulty eating
Treatment for Lock Jaw
Early intervention is very important if you are experiencing lockjaw. Procrastinating treatment can result in contractures which are rigid and deformed joints that will not function appropriately. Common therapies include dental treatments, physical therapy, tools or devices to assist in range-of-motion. If you are experiencing difficulties talking or swallowing, you should also have speech therapy.
The most common and effective treatments for lockjaw are tools or devices that assist you in improving range-of-motion. These can range from using your own fingers to assist in opening your mouth to devices that continually open and close your jaw according to the parameters which you can set. Manually opening and closing your mouth using your fingers is the least effective method for treating lockjaw.
The continuous passive motion (CPM) machines are the most costly of the devices. These machines are programmable to operate within the range that you specify. It is recommended that you use these machines for 4-6 hours a day for 4-6 weeks, as determined by your physician or physical therapist.
A very inexpensive tool is a tongue depressor. You can insert tongue depressor blades stacked on top of each other until you have a comfortable stretch. You gradually can then increase the number of tongue depressors that you use to gain a stretch. While this method is considered "old-school" studies still show that it has benefits over some other methods.