June 21, 2021
Primitive man had teeth with flatter biting surfaces. Upon biting, the upper and lower teeth close in line with each other. The development in diet, cooking patterns and facial morphology changed with evolution, leading to the formation of cusps on the biting surfaces. These cusps are small hilly areas on the surface of teeth. The growth of the face horizontally and development in speech led to a new bite form. Instead of edge-to-edge, a normal bite pattern now sees the maxillary teeth slightly ahead of the lower teeth and the cusps of the back teeth interlock with each other. The distance we have today between the upper and lower front teeth is called the overjet. This is a major determinant in establishing a normal bite (occlusion).
A malocclusion is anything other than the normal bite form. Skeletal changes like excessive forward or excessive backward growth of the mandible, dental anomalies like crowding of teeth, missing teeth, improper eruption of teeth and certain genetic syndromes are responsible for the development of various types of malocclusions. One such malocclusion is the edge-to-edge bite. This form of malocclusion sees the absence of overjet. This means, that the tips of the upper and lower front teeth meet each other upon biting.
At the age of 2 years, the relation of the upper and lower front teeth is such that the overjet is between 2 to 5 mm. By the age of 5 years, the mandible grows downwards and forwards to compensate with the growth of the upper arch. This is when an edge-to-edge bite develops for the first time. However, this malocclusions is temporary and soon ends when the permanent incisors erupt between 6 to 8 years of age. The real concern arises when the edge-to-edge bite occurs after the all permanent teeth have erupted in the oral cavity. The patient can experience wearing away of the biting surfaces of the upper and lower front teeth. This gives these teeth an attrited look which is certainly not aesthetic upon smiling. An edge-to-edge bite will exert unnecessary forces on these front teeth, which can damage the periodontium. The periodontium is the tissue complex around each tooth that supports it functionally.
An edge-to-edge bite might be present along with a posterior open bite or a crossbite. A posterior open bite is when the back teeth do not meet each other upon closure. This can reduce the chewing efficacy of the patient. A crossbite is when one or more upper teeth find themselves locked within the lower arch teeth. Treatment of edge-to-edge bites needs to be done through an orthodontic approach. This involves assessing the arch length, the severity of malocclusion, the reason behind the malocclusion (dental or skeletal) and other systemic factors.
If the cause of the edge-to-edge bite is skeletal, than an extraoral appliance might be needed to move the mandible backwards in order to create an overjet. Simultaneously, there might be a need of expanding the upper arch in order to attain the proper intercuspation. If the cause of the edge-to-edge bite is dental, then braces or aligners can help in aligning the teeth to the desired areas.
An adverse effect of an edge-to-edge bite is pain in the temporomandibular region. This is the area near the region where the mandible (lower jaw bone) fits in the depression in the skill. This is the joint, whose movement allows us to speak, chew and move our lower jaw with ease. A temporomandibular disorder (TMD) can develop in case of an edge-to-edge bite due to the excessive force. This pain or discomfort can be relieved upon the correction of the bite.
The front teeth may become extremely sensitive and are at a risk of fracturing themselves in cases of edge-to-edge bite. In such cases, a root canal treatment might need to be carried out before carrying out any orthodontic intervention. This is because orthodontic treatment exerts forces on the surrounding bony architecture. Since edge-to-edge bite can hamper the tooth's bony architecture, it is necessary to reinforce its strength through such endodontic (involving the root canals) treatments.
An edge-to-edge bite must be corrected as soon as it is recognized. Since this form of malocclusion can have direct effects on the vertical height of the face, it is important to restore the normal functionality of the orofacial structures.