Evaluating Mandibular Cortical Index Quantitatively Fusun Yasara Faruk Akgunlub AbstRAct Objectives: The aim was to assess whether Fractal Dimension and Lacunarity analysis can discriminate patients having different mandibular cortical shape. Methods: Panoramic radiographs of 52 patients were evaluated for mandibular cortical index. Weighted Kappa between the observations were varying between 0.718-0.805. These radiographs were scanned and converted to binary images. Fractal Dimension and Lacunarity were calculated from the regions where best represents the cortical morphology. Results: It was found that there were statistically significant difference between the Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 1 and Cl 2 (Fractal Dimension P:0.000; Lacunarity P:0.003); and Cl 1 and Cl 3 cortical morphology (Fractal Dimension P:0.008; Lacunarity P:0.001); but there was no statistically significant difference between Fractal Dimension and Lacunarity of radiographs which were classified as having Cl 2 and Cl 3 cortical morphology (Fractal Dimension P:1.000; Lacunarity P:0.758). Conclusions: FD and L can differentiate Cl 1 mandibular cortical shape from both Cl 2 and Cl 3 mandibular cortical shape but cannot differentiate Cl 2 from Cl 3 mandibular cortical shape on panoramic radiographs. (Eur J Dent 2008;2:283-290) Key words: Mandibular cortical index; Panoramic radiography; Fractal Dimension; Lacunarity; Digital image analysis. IntRoductIno Osteoporosis is a condition characterized by a loss in bone mineral density and there is micro-architectural deterioration in bone tissue leading to fractures.1 The patient is defined as a Assistant Professor, Selcuk University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Konya, Turkey. b Professor, Selcuk University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Konya, Turkey. Corresponding author: Fusun Yasar Selcuk University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, 42079, Konya, Turkey. Phone: + 90 332 2231228 Fax: + 90 332 2231225 E-mail: drfyasar@hotmail.com October 2008 - Vol.2 osteoporotic when t-score of skeletal BMD is 2.5 standard deviations below the average peak bone density achieved in young adults matched by gender and race.1,2 As osteoporosis and fractures are more difficult and costly to treat than to prevent, several health care interventions have been proposed to identify those people who may be at risk and who could benefit from preventive interventions.3 Bone densitometry is used in the diagnosis of osteoporotic patients.4 however currently available scientific evidence does not justify the use of bone densitometry as a screening tool in the asymptomatic population because of both its poor discriminatory power to detect those who will fracture from those who 283 European Journal of Dentistry