J Periodontol • May 2000 Alveolar Bone Height and Postcranial Bone Mineral Density: Negative Effects of Cigarette Smoking and Parity Charles F. Hildebolt, * Thomas K. Pilgram, * Naoko Yokoyama-Crothers, * Michael W. Vannier, † Mary Dotson, ‡ Jane Muckerman, § Jay Hauser, ‡ Sheldon Cohen, ‡ E. Eugenia Kardaris, ‡ Philip Hanes,  Michael K. Shrout, ¶ and Roberto Civitelli § 683 Background: Our objective was to test the association between cemento-enamel junction, alveolar-crest distance (CEJ-AC, as measured on digitized vertical bite-wing radiographs) and post- cranial bone mineral density (BMD) relative to clinical, dietary, and demographic variables. Methods: Data were collected in a cross-sectional study of 134 postmenopausal women. CEJ-AC distances were determined from digitized vertical bite-wing radiographs. Lumbar spine and proximal femur BMDs were determined from dual-energy x-ray absorptiometric scans. Correlation analysis and Student t tests were used to identify those variables most associated with CEJ- AC distance. The selected variables were modeled with a back- ward stepwise regression analysis, with CEJ-AC distance as the dependent variable. Results: Parity (number of pregnancies to term), cigarette smoking, and the interaction of lateral spine BMD with ciga- rette smoking were independent predictors of CEJ-AC dis- tance (P ≤0.05). Statistical models containing these variables accounted for 19% of the variation in CEJ-AC distances. Conclusions: CEJ-AC distance in postmenopausal women is the result of a complicated interaction of many effects, includ- ing but not limited to, parity, cigarette smoking, and skeletal BMD. J Periodontol 2000;71:683–689. KEY WORDS Alveolar bone; bone density; pregnancy (parity); osteoporosis, postmenopausal; smoking/adverse effects; risk factors. * Department of Radiology, Washington University School of Medicine, St. Louis, MO. † Department of Radiology, University of Iowa, College of Medicine, Iowa City, IA. ‡ Department of Dentistry, Barnes-Jewish Hospital, St. Louis, MO. § Department of Internal Medicine, Washington University School of Medicine.  Department of Periodontology, School of Dentistry, The Medical College of Georgia, Augusta, GA. ¶ Department of Oral Diagnosis & Material Sciences, School of Dentistry, The Medical College of Georgia. S ystemic bone loss that occurs after menopause should affect the alve- olar bone; thus, it is commonly assumed that osteopenia/osteoporosis contribute to oral bone loss and eventual tooth loss. Direct demonstration of this assumption is, however, unconvincing. Although data in the current literature seem to suggest a relationship between osteoporosis and oral bone loss, contro- versy exists on this issue. 1-3 It is also unclear whether other risk factors may affect this potential relationship. We report the analysis of baseline data from a sub- set of postmenopausal women enrolled in a double-blind, placebo-controlled, 3- year study on the effectiveness of estro- gen replacement therapy on dental and postcranial bone health. Alveolar bone height, assessed as the distance between the cemento-enamel junction and the alveolar crest (CEJ-AC), was used as a linear measurement of oral bone loss and compared with postcranial bone density at the spine and proximal femur. The purpose of the cross-sectional study was to determine the relationships between postcranial BMD and CEJ-AC measure- ments in a select population of post- menopausal women without active peri- odontal disease and to assess the impact of clinical, dietary, and demographic vari- ables on such a relationship. We have previously published the results of simi- lar analyses for attachment loss and tooth loss for this same population. 4