Maxillomandibular fixation (MMF) method is performed in maxillary or
   mandibular fractures , plastic surgeries and congenitally anomaly of
   mandibular. Post operative nausea and vomiting due to anesthesia and
   opioids is one of the most important complications. This study performed for
   determination of metoclopramide and metoclopramid plus dexamethasone
   effects for reduction of nausea and vomiting after maxillomandibular
   fixation surgery in the patients with mandibular fractures.

          In this double-blind clinical trial , 60 patients candidated to
   maxillomandibular fixation surgery were randomized into two treating
   groups(A: Metoclopramide alone, B: Metoclopramide + Dexamethasone )
   and evaluated in nausea and vomiting rates after operation. The patients
   were followed in three stages in the operation room , in recovery room , and
   in the ward upto 24 hours.

          In first stage , 30% of patients in group A and 6% of patients in group B
   encountered post operative nausea and vomiting. During second stage ,
   these rates were 17% in group A and zero for group B. Non of the patients  
   in both groups , encountered post operative nausea and vomiting in third
   stage of following. 

          The findings indicate that combination of metoclopramide and
   dexamethasone can decrease post operative nausea and vomiting
   incidence rates effectively. Suitable tolerance of patients to drug and less
   complications of dexamethasone compared risk of post operative vomiting
   are more factors that account for complication therapy with
   dexamethasone and other antiemetic agents. However , expand use of this
   method needs more studied.