Dense Bone Islands (DBI's) are also known as
enostoses or idiopathic osteosclerosis, bone
scar, focal osteosclerosis and peri-apical
What are Dense Bone Islands (DBI's)?
Dense Bone Islands are synonymous with enostoses or idiopathic osteosclerosis,
bone scar, focal osteo-sclerosis and peri-apical osteo-petrosis.
Dense Bone Islands (DBI’s) present as areas of increased osseous (bone)
density or radio-opacities in the maxilla (upper jaw) or mandible (lower jaw) with
defined borders, located at or around the apical regions (root tips) of teeth, inter-
radicular area or with no apparent connection to the teeth.
DBI’s typically manifest as an incidentally discovered, well-defined homogenous
radio-opacity that is of unknown cause and cannot be attributed to any
inflammatory, dysplastic, neoplasia or systemic disorder. Focal internal growth of
bone commonly seen in the premolar-molar region of the mandible.
They are the internal counterparts of exostoses. These are localised growth of
compact bone that extends from the inner surface of cortical bone into cancellous
bone. It represents a focus of mature compact (cortical) bone within the
cancellous bone (spongiosa).
It is also called a “whorl”. A rare condition in which thousands of DBI’s scattered
through the skeleton is known as osteopoikile or osteopoikilosis.
What are the signs & symptoms (+ demographics)?
DBI’s can arise at any age. The number of DBI’s is found to be significantly higher
in the 2nd decades and 3rd decades in life (10 - 19 and 20 - 29 years) than in
The effect on adjacent teeth may include indistinct lamina dura and periodontal
ligament space and root resorption. The associated teeth are usually
asymptomatic. DBI’s do not cause osseous expansion; hence, these do not affect
the fit of dentures.
In some cases, it inhibits the eruption of normal teeth. Tooth is vital in affected
In rare cases, it may cause external resorption (due to pressure) when it is
located peri-apical to the tooth.
No change in size or any malignant potential.
What are the causes of Dense Bone Islands (DBI's)?
Unknown ætiology but may be considered a normal developmental anatomic bone
How are they diagnosed?
DBI’s are usually found on routine radiographic investigations.
These lesions are ‘cold’ on scintigraphy scans.
Single isolated radio-opacities that may be well defined or diffuse so that the
trabeculæ blend with the trabecular pattern of adjacent normal jaw bone. It is
more or less rounded with size varying from a few millimetres up to a centimetre
The shape of the DBI is classified as either round or irregular.
The location of the lesion is classified as mandibular or maxillary firstly, then
further by region of the jaw: Incisive, canine, canine-premolar, pre-molar, pre-
molar-molar or molar.
How are they treated?
Once, the condition is diagnosed, treatment is neither indicated nor necessary.
Benign cemento-osseous lesions and inflammatory lesions such as apical
sclerosing or condensing osteitis.
• Peri-Apical Idiopathic Osteo-Sclerosis (periodontal ligament widening)
• Peri-Apical Cemental Dysplasia (radio-lucent margin; vital teeth; separated
from surrounding bone by a radio-lucent border or rim of varying thickness)
• Hyper-cementosis (integral part of formed root; within intact lamina dura &
periodontal space; vital tooth)
• Cemento-blastoma (associated with root of teeth; vital & painful)
• Metastatic osteo-blastic carcinoma
• Chondro-sarcoma (radio-lucent component present)
Dr G's Toothpix
Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005. Radiologic Diagnosis of
Enostosis in the Mandible
Oral & Implantology 2008. Dense Bone Island of the Jaw - A Case Report
J Massachusetts Dent Soc 2010. Incidental Dental Radiographic Findings - Dense
J Oral Sci 2011. Asymptomatic Radiopaque Lesions of the Jaws - A
Radiographic Study using Cone-Beam Computed Tomography
J Cranio-Maxillary Dis 2013. Bone Islands of the Craniomaxillofacial Region
|Last Updated 7th September 2016
|Radiographs of Enostoses / Dense Bone Islands