Background <p>Mandibular fractures constitute 57% of all maxillofacial trauma cases, particularly in developing countries such as India. The treatment of mandibular fractures involves either open reduction and internal fixation (ORIF), or closed reduction which is intermaxillary fixation (IMF). These fractures diminish the mandible's load-bearing capacity and compromise the functional ability of the patient. Masticatory efficiency, which measures the effectiveness of chewing, is a key indicator of the functionality of a remodeled mandible.</p> Aim <p>This study evaluates the masticatory efficiency and mandibular function as affected by open or closed reduction of mandibular fractures.</p> Materials and methods <p>In this study, 14 cases of mandibular fractures were divided into two groups, Group 1—open reduction; and Group 2—closed reduction. The following outcomes were evaluated; subjective evaluation of masticatory efficiency of chewing function questionnaire, occlusion was assessed clinically, and mandibular function was assessed by maximal interincisal opening, maximal protrusion, maximal lateral excursion, and maximal retrusion.</p> Result <p>Group 1 consisted of nine patients (64.29%), while Group 2 had five patients (35.71%). A significant difference was achieved in masticatory efficiency between Group 1 and Group 2 in Week 3 (0.025) and Week 6 (0.003). Mean values of Maximal Interincisal Opening (MOI) and their comparison at different intervals revealed that in Group 1, MIO values significantly improved from preoperative 19.69±6.60 to postoperative 33.11 ± 5.25 with <i>p</i>-value &lt;.001.</p> Conclusions <p>The study concluded that mandibular function, as measured by mouth opening and occlusion, is similar in ORIF and IMF. Although both groups'masticatory efficiency improved significantly subjectively and objectively as compared to their preoperative efficiency, significant differences were observed. However masticatory efficiency is higher in ORIF patients than in IMF patients after 6 weeks.</p>