Mandibular symmetry may be modified by various conditions. A number of studies have attempted to define parameters of "normality" and several techniques have been described using digital orthopantomography (OPG). The aim of this study was to determine mandibular/condylar symmetry indexes in a sample of Chilean patients. A cross sectional descriptive study in digital OPG obtained from the Dental Clinic of Universidad de La Frontera was performed. Inclusion criteria applied were: Patients older than 18 years, complete permanent dentition up to the first molar. Exclusion criteria were also applied: Radiographic signs of bone disease and/or mandibular surgery, not visible condyles, orthodontics. ImageJ soft- ware was used to draw lines and measure the height of the ramus and mandibular condyle on the right and left side with the technique postulated by Kjellberg (1994). With these measurements, the symmetry index between condylar height and ramus (S1) and between condylar and mandibular height (S2) were calculated. The study analyzed 235 digital OPG (95 men, 140 women) with an average age of 24.98 ± 7.32 years. The S1 average was 93.74 % (± 3.85) for men and 93.41 % (± 5.77) for women, and for S2 it was 90.50 % (± 6.51) for men and 90.27 % (± 7.80) for women, without significant differences for either index (p=0.347 and p=0.233, respectively). No significant differences were found in reference to age, for indexes S1 and S2 (p=0.594 and p=0.669, respectively). Therefore, it is concluded that there is presence of condylar/mandibular symmetry in both sexes and in age ranges, when measuring digital OPGs without considering health status or presence of any morphological or functional alteration.
KEY WORDS: Mandibular symmetry; Condylar symmetry; Digital panoramic radiographs; Prevalence.