Objective The multiple-momentum (MM) based multitarget (MT) approach has been developed through a single surgeon's experience to overcome the limits of the conventional Nuss procedure, which is the single target-single momentum approach that corrects only symmetric pectus excavatum (PE). The new techniques that have been devised on a morphologic basis, according to the Terrain Contour Matching (TERCOM) system, have made this approach a comprehensive one that can cover all types of pectus deformity. The aim of this study was to elucidate the difference between the conventional technique and the new approach. Methods The data of 630 PE patients who received the modified Nuss procedure, based on the MM-MT-TERCOM approach, between 1999 and 2005, were retrospectively studied. The conceptual differences between the new approach and the conventional one were determined. The techniques according to a new paradigm, for treating asymmetry, adults, and complex morphology, as well as the bar fixation technique, were analyzed. The results of the repair were assessed with a new CT index, the Asymmetry Index (AI). Results According to the morphologic classification, 269 patients were asymmetric (42.7%): 138 were eccentric (53 Grand Canyon type), 88 were unbalanced, and 36 were combined. On the basis of the MM-MT-TERCOM concept for repairing complex morphology, multiple targets were selected in 224 patients (35.6%). To correct targets simultaneously, positive momentum (630 patients, 100%) and negative momentum (124 patients, 19.7%) were applied as appropriate. The techniques used were an asymmetric bar (250 patients, 39.7%), a seagull bar (107 patients, 17%), a complex bar via TERCOM (126 patients, 20%), the crest compression technique (59 patients, 9.4%), and a compound bar (84 patients, 13.3%). The postoperative changes of the AI were from 1.03 ± 0.06 to 1.02 ± 0.13 (P = 0.117) in the symmetric group and they were from 1.1 ± 0.05 to 1.02 ± 0.02 (P < 0.001) in the asymmetric group. Conclusions Refinement of techniques in accordance with the morphology and cause-effect basis of the bar action provided reproducible results for achieving postrepair symmetry for treating complex PE. Therefore, the new approach with techniques that use multiple momentums (MM-MT-TERCOM) supports the new paradigm of the Nuss procedure is effective in repair of all morphologic types of PE.