The dental arch is the length and width of the line in which a person's teeth are set into their upper and lower jaws. The depth and diameter of this arch are vital to the long-term health of the teeth in particular and the mouth in general. If the arch does not conform to satisfactory standards, it may result in dental and health problems.
Since there are a standard number of teeth in humans, the size of the dental arch is of vital importance in determining how the teeth are positioned when they appear. While the arch can expand as a child grows, a small arch will force the teeth to grow close together. This can result in overlapping and improperly positioned teeth. Teeth may tilt at an awkward angle, putting pressure on gums when food is being chewed. This can ultimately lead to compromised gums or infections.
If the dental arch is too narrow, some teeth may be selected for extraction. This will allow more room for the other teeth; in young patients with teeth that are still in the process of growing, teeth may to some degree correct themselves with the new space. At other times, braces or other corrective measures, such as the insertion of spacers, can be taken. Many individuals have their wisdom teeth removed to prevent crowding in the back of the mouth, at the very ends of the dental arch. Failure to remove them can result in impaction and considerable pain for many.
Alternately, if the dental arch is too long or too wide, teeth may come in with large spaces between them. This is fairly common, and can easily be seen in individuals with gaps between their front teeth; in these cases, the front portion of the dental arch may be too wide. Braces can often be applied in order to shift the teeth forward into the proper position.
The dental arch also determines the proper placement of the teeth around the tongue; improperly formed arches can force teeth to interfere with speech. Consequently, some speech problems can be solved by adapting teeth to better fit the space available in the individual's mouth. A narrow arch can also present an individual with difficulties chewing and make thorough brushing difficult.
Problems with the arch are most common in very young or older individuals. The proper fitting of dentures requires that plates be molded to the exact specifications of an individual's mouth. A shortened arch may result in difficulties fitting dentures, and can cause abnormal pain in the face, jaw, or gums.