Can cone beam CT predict the hardness of interradicular cortical bone?

Abstract

ObjectivesOrthodontic mini implants can be inserted at the interradicular site. The bone quality at this site may affect the stability and anchorage of the implant. Bone density is clinically evaluated by Hounsfield units (HU) obtained from cone beam CT (CBCT). The objective of this study was to determine the correlations between HU, microhardness and cortical bone thickness of interradicular site at various segments (anterior/posterior) and aspects (buccal/lingual) of both jaws in a swine model.Materials and methodsEight mandible and maxilla swine bones were scanned by CBCT. The HU and thickness of the above-mentioned sites were determined. Then, a Knoop microhardness test was applied and the Knoop Hardness Number was obtained (KHN).ResultsThe mandible parameters spread over a wider range than the maxilla. The buccal aspect of the maxilla had higher HU and KHN values than the mandible. The lingual aspect of the mandible had higher KHN values than the maxilla. Posterior segments had higher HU and KHN values. The thickness of the alveolar cortical bone was greater in the maxilla than in the mandible. Correlations were found between HU and KHN for 3 of the 4 sites (anterior or posterior, buccal or lingual) of the mandible only. No correlations were found for the maxilla. Upon pooling the HU and KHN data for the whole jaw, correlation was found for the maxilla as well.ConclusionsRelying on HU values as a predictor of cortical bone hardness should be considered with caution.

The Use of Cone‐Beam Computed Tomography in Management of Patients Requiring Dental Implants: An American Academy of Periodontology Best Evidence Review

“…Beyond linear and volumetric measurements, the accuracy of CBCT to evaluate bone mineral density has also been assessed 134‐154 . Evaluation of bone density using CBCT is an area of increasing interest and lingering controversy since Hounsfield units (HU) are not directly applicable for CBCT 149 .…”

The effectiveness of articaine in mandibular facial infiltrations

“…HU depicts a bone density value on CBCT images. 29 The higher cortical HU values were associated with persisting sensation, while higher trabecular HU values were associated with no sensation ( Table 4 ). HU may not be an accurate depiction of the actual bone density, but a broad approximation since anatomical factors may influence the readings.…”

“…HU may not be an accurate depiction of the actual bone density, but a broad approximation since anatomical factors may influence the readings. 29 Thick cortical bone can cause distortions in the measured HU. 29 …”

Predicting primary stability of orthodontic mini‐implants, according to position, screw‐size, and bone quality, in the maxilla of aged patients: a cadaveric study

“…In the context of orthodontic mini‐implant placement, Brosh et al . assessed bone quality at interradicular sites on eight mandible and maxilla swine bones. They reported varying degrees of correlation between gray values and hardness measurements for all sites for each jaw and concluded, within the limits of an animal investigation, that the hardness of the interradicular sites is directly related to the bone density values obtained with computerized tomography, although primarily so for the lower jaw.…”