Common Orthodontic Problems
Medically Reviewed by Dr. Duane S. Shank, DDS, Board-Certified Orthodontist
Most orthodontic treatment addresses one of a short list of problems: crowding, spacing, overbite, underbite, crossbite, open bite, protruding teeth, or impacted teeth. Most affect how you chew, how well you can clean your teeth, and how they wear over decades.
Orthodontists group bite problems into three classes. Class I is a normal jaw relationship with crowding, spacing, or rotation among the teeth, and it accounts for roughly three quarters of cases. Class II is an overbite. Class III is an underbite.
Crowding and spacing
Crowding is the most common problem there is. The jaw does not have room for all the teeth, so they overlap, twist, or get pushed out of the arch. Crowded teeth are the hardest to clean, which makes crowding a decay and gum-disease problem rather than only an appearance one. Treatment is space creation: expanding the arch, and in more severe cases removing teeth.
Spacing is the opposite, and gaps trap food and leave gum tissue exposed. Braces or aligners close them, and where a tooth is genuinely missing, space is either closed or held open for a restoration.
Overbite and protruding teeth
An overbite is a Class II relationship, where the upper front teeth sit too far forward of the lower. A deep overbite means they cover too much of the lower teeth vertically, sometimes biting into the gum behind them. Protruding upper front teeth are also far more likely to be broken in an accident, which is a real reason to correct them in a child who plays sports.
Underbite
A Class III relationship, where the lower teeth sit ahead of the upper, usually because the lower jaw grew further forward or the upper jaw is underdeveloped. Underbites make chewing inefficient and get harder to correct as growth finishes, which is why they are the classic case for early treatment. Severe adult underbites sometimes require jaw surgery.
Crossbite
One or more upper teeth sit inside the lower teeth rather than outside. Crossbites often push the lower jaw sideways when the teeth meet, so the jaw functions off-center. In a growing child that asymmetry can become built in, and correcting it early with an expander is far simpler than correcting it later.
Open bite and impacted teeth
In an open bite the front teeth do not touch when the back teeth are together. Thumb sucking, tongue posture, and skeletal growth pattern all contribute, and open bites are among the harder problems to hold once corrected.
An impacted tooth has not erupted because it is blocked or growing the wrong way, most often an upper canine. An oral surgeon exposes the tooth and orthodontic traction brings it into the arch over months.
TMJ and TMD
The temporomandibular joints connect your lower jaw to your skull, and you use them for every word, bite, swallow, and yawn. When they hurt, the condition is called temporomandibular disorder, or TMD.
Symptoms include jaw pain, clicking or popping, headaches or neck aches, ringing or fullness in the ears, muscle spasm, facial swelling, a limited or locking jaw, and a bite that suddenly feels different.
Causes are often multiple: the cushioning disc inside the joint moving out of position or wearing, arthritis, a blow to the jaw, and above all clenching and grinding.
What helps, in order. Conservative measures first, and they work for most people. Rest the jaw, keep lips together and teeth apart, avoid gum, chew evenly on both sides, and stop cradling a phone against your shoulder. Soft food during a flare, heat, and over-the-counter anti-inflammatories. If clenching and grinding are involved, a custom nightguard or splint takes the load off the joint and is usually the next step.
Where orthodontics comes in. A bite in which the teeth meet badly can load the jaw joints unevenly, and correcting it is sometimes part of managing TMD. The relationship between bite alignment and joint pain is not settled in the research, and no responsible orthodontist should promise braces as a cure for jaw pain. Dr. Shank will examine the joints and the bite, tell you whether the way your teeth meet is plausibly contributing, and say so plainly if it is not.
