A mesiodens is the most common type of supernumerary, or extra, tooth that develops in the midline of the upper jaw between the two front teeth. While its presence is relatively uncommon, it is seen more often in males than in females. This extra tooth can disrupt the proper alignment and growth of the surrounding teeth.
A mesiodens may block the normal eruption of permanent incisors, causing them to be delayed or emerge in the wrong position. In some instances, a cyst can develop around the crown of the unerupted mesiodens, or it may cause resorption, which is damage to the roots of neighboring teeth.
The Role of Radiographs in Diagnosis
Diagnosing a mesiodens requires dental radiographs, or X-rays, because the majority of these teeth do not erupt and remain impacted within the jawbone. Dentists often first suspect a mesiodens when they notice that a child’s permanent front teeth are not erupting symmetrically or on time.
An X-ray allows dental professionals to see through the gum and bone, confirming the tooth’s presence while also providing information about its location and general shape. Discovering and diagnosing a mesiodens early, often during a routine radiographic check-up, is beneficial for preventing more complex orthodontic or pathological issues from developing later on.
Types of Dental X-Rays Used
Dentists use several types of radiographs to evaluate a mesiodens, each providing a different perspective. A common initial X-ray is the periapical radiograph, a small image showing the entire tooth from crown to root and its supporting bone. This X-ray is effective for detecting a mesiodens located between the roots of the central incisors.
To get a wider view, an occlusal radiograph of the upper arch is often taken. For this image, the patient bites down on a sensor, which captures a broad view of the roof of the mouth and helps pinpoint the mesiodens’s position. A panoramic radiograph, which shows the entire upper and lower jaws in a single image, can also identify a mesiodens but sometimes lacks fine detail.
For a comprehensive assessment, a dentist may order a cone beam computed tomography (CBCT) scan, which generates a 3D model of the jaw. A CBCT scan provides detailed information about the mesiodens, including its exact size, shape, and orientation—for example, showing if it is inverted or tilted. This detail is valuable when planning for surgical removal, as it shows the tooth’s proximity to structures like the roots of other teeth and the nasal cavity.
Interpreting a Mesiodens on an X-Ray
On a dental X-ray, a mesiodens appears as a radiopaque, or light-colored, object, indicating it is a hard, dense structure like a normal tooth. Its specific appearance can vary, which helps the dentist classify it. The most common form is conical, appearing as a small, peg-shaped tooth. Other forms include the tuberculate type, which is more barrel-shaped, or the supplemental type, which closely resembles the shape of a normal incisor.
A dentist will examine its orientation; a mesiodens can be vertical, horizontal, or even completely inverted with its crown pointing upward. The developmental stage of the tooth is also assessed, such as whether its root is fully formed, which helps predict its potential for movement or eruption.
The X-ray is also used to identify any resulting complications. This includes looking for a dark halo, or radiolucency, around the crown of the tooth, which could signify the formation of a dentigerous cyst. The dentist will also inspect the roots of the adjacent permanent incisors for any signs of resorption, which would appear as a blunting of the root structure. These findings help determine the urgency and type of treatment needed.
Next Steps After X-Ray Confirmation
Once a mesiodens is confirmed with radiographs, the dental team determines the best course of action based on the tooth’s size, position, and its effect on adjacent structures. The two primary management options are surgical extraction or continued monitoring.
Surgical removal is frequently recommended if the X-rays show the mesiodens is causing problems, such as blocking the eruption of permanent incisors, causing crowding, or if there is evidence of cyst formation or root damage to other teeth.
In some cases, if the mesiodens is small, deeply impacted, and not causing any apparent harm, a dentist might recommend monitoring the situation. This approach involves taking periodic X-rays to ensure the tooth is not moving or causing new problems. The decision to monitor is made when the risks of surgery are thought to outweigh the benefits, but this requires regular follow-up to ensure the situation remains stable.