Oral tori are slow-growing, localized bony protrusions, classified as exostoses, commonly found during routine dental examinations. These growths are non-pathological overgrowths of normal, dense bone tissue. Their presence is considered a benign anatomical variation of the jawbones.
Defining the Types of Oral Tori
Oral tori are primarily categorized into two distinct types based on their location within the jaw structure. The most common type is the Torus Palatinus, which manifests as a hard, non-moving lump along the midline seam of the hard palate (the roof of the mouth). This growth, observed more frequently in females, can vary significantly in shape and size, ranging from a small elevation to a large, lobulated mass.
The second type is the Torus Mandibularis, which presents as a bony elevation on the tongue-side surface of the lower jaw, typically near the premolar teeth. These mandibular tori are most often bilateral, occurring on both sides of the mouth in approximately 90% of cases. Both Torus Palatinus and Torus Mandibularis are composed of compact cortical bone, sometimes with spongy bone, resulting from hypertrophy.
Primary Factors Influencing Tori Formation
The development of oral tori is considered multifactorial, stemming from a complex interaction between inherited traits and local environmental influences. Genetic predisposition is widely accepted as a highly influential factor in the appearance of these bony masses. Evidence suggests a pattern of inheritance that may be autosomal dominant, meaning a single copy of a specific gene from either parent may be enough to influence their formation.
Studies involving twins have shown a high concordance rate for the presence of tori in identical twins, strongly indicating a hereditary component to the condition. However, genetics alone do not fully account for their growth, as local biomechanical stress plays an equally significant role. The application of functional forces, particularly those exceeding normal chewing loads, stimulates the bone remodeling process.
Masticatory hyperfunction, which includes habits like teeth clenching and bruxism (teeth grinding), contributes substantially to bone overgrowth. The constant, excessive pressure exerted by these activities causes a reactionary hypertrophy, where the bone thickens and expands in response to the strain. This mechanism explains why the size of tori may increase during periods of heightened stress or intense bruxing activity.
While less impactful than genetics and functional stress, certain dietary and systemic factors may also contribute to the etiology. Some research indicates a possible correlation with mineral metabolism, suggesting that diets high in calcium or deficient in Vitamin D may influence bone density. However, these factors are generally viewed as secondary modulators that work in combination with the primary genetic and stress-related mechanisms.
Clinical Relevance and Management
For the majority of individuals, oral tori are asymptomatic and non-tender, posing no health risks, and typically require no active treatment. They are simply observed during regular dental check-ups. Intervention is only considered when the tori begin to interfere with a person’s oral function or necessary dental procedures.
One of the most common reasons for surgical removal is the need to construct or wear a removable dental prosthesis, such as a full or partial denture. Large tori can prevent the denture base from seating properly, compromising its stability and retention.
Another indication for excision is recurrent trauma, where the thin layer of gum tissue covering the dense bone becomes easily scraped or ulcerated by hard foods, leading to chronic irritation. Very large tori may occasionally obstruct normal tongue movement, leading to difficulties with speech, chewing, or swallowing, which would necessitate bone reduction.
The surgical procedure, known as torus excision, involves precisely removing the excess bone using specialized instruments to contour the jaw or palate. While successful, the tori can potentially regrow if the underlying functional factors, like unmanaged bruxism, continue to place excessive stress on the area.