Harmonic analysis of mandibular form and symmetry with computerized tomographic views

Objective. To quantitatively describe the isotropic (ie, orientation indepe ndent) morphologic characteristics of a standardized computed tomographic i mage of the mandible with the use of the elliptic Fourier series. Study design. Spiral CT scans parallel to the mandibular plane and enclosin g both mental foramina were obtained in 17 adults (9 edentulous women, mean age, 75 years; 4 edentulous men, mean age, 68 years; and 4 dentate men, me an age, 30 years). The mandibular outline was traced, digitized, and mathem atically reconstructed with the elliptic Fourier series. Mandibular area, s hape, and individual symmetry were quantified. Results. Mandibular area and symmetry were larger in men than in women (P < .05). In men, no effect of edentulousness was observed in either area or s ymmetry. Mandibular shape seemed to be influenced neither by sex nor by the presence of teeth. Conclusion. Mandibular size and symmetry in the analyzed computed tomograph ic scan (which included only the mandibular basal bone) seemed to be sex re lated but independent of the dental status. Mandibular shape did not seem t o be modified by sex or edentulousness. Different findings may be obtained in the analysis of a section of the alveolar bone.