Mandibular tori
Palatal torus
Nodular swellings of normal bone in the oral cavity
Also known as tori (torus = singular)
Common sites:
Hard palate (torus palatinus )
Lingual premolar region of the mandible (torus mandibularis )
Buccal alveolar bone of maxilla or mandible
Epidemiology Edit
Incidence varies between different races[1]
More common in Inuit, Native American and Asian populations
Torus palatinus
More common than mandibular tori
Incidence - 9-66%
♀ > ♂
Torus mandibularis
Incidence - 0.5-63.4%
♂ > ♀
Clinical Features Edit
Firm swellings with normal overlying mucosa
Whilst mucosa is normal it is usually thin and can have a blanched appearance (sometimes can ulcerate)
Small-sized lesions → <3mm elevation and <10mm diameter
Medium-sized lesions → 3-5mm elevation and 10-15mm diameter
Large-sized lesions → >5mm elevation and >15mm diameter
Usually only affects one site in an individual
Torus palatinus
Occurs in the midline of the palate (usually in the mid-third)
Usually symmetrical but if large can also become an irregular rounded mass
Torus mandibularis
Found on the lingual surface of the mandible
Usually adjacent to premolars and above the mylohyoid attachment
If very large can interfere with tongue movement
Common presentations:
Bilateral solitary > bilateral multiple > unilateral solitary > unilateral multiple
Other sites
Multiple bone exposes can also affect the buccal aspect of maxilla or mandible
Aetiology and Pathogenesis Edit
Aetiology Edit
Largely unknown
Some suggestions:
Hereditary (autosomal dominant inheritance has been described in some)
Masticatory hyperfunction
Pathogenesis Edit
Also largely unknown
In palatal tori, there is suggestion of continued activity of the embryonic osteoblasts which pile up at the palatal suture after the median palatal suture junction is completed
Investigations Edit
Radiographically tori appear as radiopaque masses
Dense bone ∴ they can obliterate details of the teeth and maxillary sinus in plain film radiographs
In large tori - the spongy layer in the middle appears less dense than the cortical bone
Histology Edit
Torus palatinus
Cross-sectional analysis of tori palatine demonstrate three layers:
Nasal compact layer - same thickness irrespective of size of tori ∴ confirming that development occurs by downward growth (nasal floor always remains flat)
Middle spongy layer - may not be seen in smaller tori
Oral compact layer
Torus mandibularis
Seen as lamellar periosteal outgrowth of the mandible
Management Edit
No active treatment needed
Patient reassurance
Removal is sometimes needed if they interfere with function or to facilitate dental prosthesis
Tori have been described as a source of autogenous bone graft in implant placement[2] [3] [4]
Prognosis and Complications Edit
Benign
Recurrent ulceration can occur due to thin overlying mucosa
Large lesions can interfere with function and dental prosthesis
Follow-up Edit
References Edit