Mandibular tori are benign, slow-growing bony growths typically found on the inner surface of the lower jaw. These growths are not a disease but rather a common anatomical variation. Understanding their nature helps clarify why they appear and what their presence means.
What Are Mandibular Tori?
Mandibular tori are smooth, hard bumps on the tongue side of the lower jaw, often near the premolars and molars. Composed of dense, normal bone, they are an excess of existing jawbone. They are typically asymptomatic, causing no pain or discomfort, and are not cancerous.
Their size varies, from small, barely noticeable nodules to larger, lobulated masses. While they can occur on one side, they commonly appear symmetrically on both sides of the jaw.
How Often Do They Occur?
The occurrence of mandibular tori varies significantly among populations, with reported prevalence rates from 5% to over 50%. For instance, lower rates are seen in Caucasian populations, while higher rates are observed in certain Asian and Inuit populations. In the United States, prevalence is reported between 7% and 10%.
Prevalence tends to increase with advancing age, particularly in individuals over 30. While some studies suggest a slightly higher prevalence in males, others show no significant sex difference. This highlights the complex interplay of factors in their development.
Genetic background plays a role, as these growths often run in families. Environmental and functional factors also contribute to their varied presence across individuals and groups.
Why Do They Form?
Mandibular tori form from a combination of genetic and environmental factors. A strong genetic predisposition is evident, as these growths often appear in multiple family members, indicating inherited traits influence their development.
Environmental factors, such as prolonged stress from chewing or bruxism (clenching and grinding teeth), also contribute. The jawbone responds to these increased forces by depositing more bone, forming tori to better withstand the pressure.
The constant mechanical stress on the jawbone can stimulate bone growth in susceptible individuals. Their development is often a combination of inherited tendencies and functional demands.
When Do They Matter?
While mandibular tori are generally harmless, they can sometimes present clinical challenges. One common issue arises when individuals need dentures, as large tori can interfere with the proper fit and stability of prosthetic devices. In such cases, surgical removal might be necessary to ensure comfortable and functional denture placement.
They can also affect oral hygiene, as their irregular surfaces might trap food particles, increasing the risk of plaque buildup and gum irritation. These bony growths are also susceptible to trauma from hard foods, leading to painful ulcers if the overlying gum tissue is injured. Such injuries usually heal on their own but can be a recurring nuisance.
Rarely, extremely large tori might interfere with normal speech or tongue movement, or make it difficult to fully close the mouth. For most people, however, mandibular tori require no treatment and are simply observed during routine dental examinations. Surgical removal is considered only when they cause persistent symptoms or interfere with dental procedures.