Estrogen deficiency increases variability of tissue mineral density of alveolar bone surrounding teeth

Ames, Matthew S.; Hong, Semi; Lee, Hye Ri; Fields, Henry W.; Johnston, William M.; Kim, Do-Gyoon

doi:10.1016/j.archoralbio.2010.05.011

« PreviousArchives of Oral Biology
Volume 55, Issue 8 , Pages 599-605, August 2010

Estrogen deficiency increases variability of tissue mineral density of alveolar bone surrounding teeth

Matthew S. Ames
- College of Dentistry, Division of Orthodontics, The Ohio State University, Columbus, OH, USA
Semi Hong
- College of Dentistry, Division of Orthodontics, The Ohio State University, Columbus, OH, USA
Hye Ri Lee
- College of Dentistry, Division of Orthodontics, The Ohio State University, Columbus, OH, USA
Henry W. Fields
- College of Dentistry, Division of Orthodontics, The Ohio State University, Columbus, OH, USA
William M. Johnston
- College of Dentistry, Division of Restorative and Prosthetic Dentistry, The Ohio State University, Columbus, OH, USA
Do-Gyoon Kim
- College of Dentistry, Division of Orthodontics, The Ohio State University, Columbus, OH, USA
- Corresponding author at: Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall, 305 W. 12th Ave, Columbus, OH 43210-1267, USA. Tel.: +1 614 247 8089; fax: +1 614 688 3077.

Accepted 18 May 2010.

Abstract

Objective

Estrogen deficiency increases bone remodeling leading to increased variability of tissue mineral density (TMD). Due to the functional demands of mastication, alveolar bone around teeth is inherently a highly remodeled region of bone tissue with a highly variable distribution of TMD. This study investigated the effect of estrogen deficiency on the TMD distribution of alveolar bone.

Design

Using three-dimensional micro-computed tomography images of sham surgery (Sham) and ovariectomized (OVX) rat mandible sections, alveolar bone region (AB) and control bone region (CB) of interest were isolated. Based on histograms of gray levels equivalent to TMD values, mean (Mean), standard deviation (SD) and coefficient of variation (COV=SD/Mean) were computed. Fifth and 95th percentile gray level values were also obtained (Low₅ and High₅, respectively). Absolute value of percentage (%) differences of the gray level parameters between AB and CB regions were computed.

Results

Both SD and COV were significantly higher in AB region than those in CB region for all specimens of both Sham and OVX groups (p<0.001). The mean values of % differences for SD were moderately higher (p<0.073) and those for COV and Low₅ were significantly higher for the OVX group than for the Sham group (p<0.04).

Conclusions

Higher variability of mineralization observed in AB of OVX group indicates that estrogen deficiency amplifies the active bone remodeling of AB already present due to the mastication. These findings provide an insight that the increased variability of TMD induced by estrogen deficiency may compromise the mechanical stability of the tooth-bearing alveolar bone.

Keywords: Rat, Micro-computed tomography, Estrogen, Bone remodeling, Variability, Mineralization