This study will assess the efficacy and safety of levobupivacaine for postoperative pain control in patients received orthognathic surgery. In this split-mouth study, each side will be randomized to receive 1) 5ml 0.5% levobupivacine, 2) 2.5ml 0.5% levobupivacaine, or 3) placebo. One shot of these agents will be delivered by nerve block to maxillary and mandibular branches of trigeminal nerve before the incision was made. The degree of postoperative pain will be evaluated daily by visual analog scale for up to 3 days. The anticipated time on study is 1 year, and the target sample size is 40 individuals.

Design of intervention vs. control Intra-operative injective of (chirocaine) before incision Location of injection: inferior alveolar nerve proximal to its entrance to ramus of mandible, maxillary nerve around pterygopalatine ganglion Amount of injection on each injection site: (1) Experimental group 1: 5mg/ml chirocaine 5cc (2)Experimental group 2: 5mg/ml chirocaine 2.5cc (3)Control group: normal saline 5cc. There are totally 4 injection sites for two jaw surgery and 2 injection sites for one jaw surgery. The experimental site and control site will be determined randomly before injection.

Outcome measurement

• Primary: effectiveness of intra-operative nerve block on post-operative pain control

• Secondary:

  1. whether the pain relieve effect is dose-related
  2. how long will this effect last

The intensity of post-operative pain will be measured by VAS, visual analog scale)daily until patients are discharged.

Report adverse outcome:

• Intolerable pain on control group
• Adverse reaction to local anesthetic agent
• Injection-related complications (puncture of major vessels, hematoma on -injection site, etc.)

Inclusion Criteria:

• all patients who will receive orthognathic surgery (one jaw or two jaw, with or without genioplasty) in Chang Gung Memorial Hospital since July 2011

Exclusion Criteria:

• more complex (2- or more piece LeFort I osteotomy, combined gonial resection in BSSO, etc.) or less complex (only Wassmund and/or Kole osteotomies in upper or lower jaw) orthognathic procedures
• unexpected fracture (unilateral)
• intra-operative nerve injuries
• significant facial asymmetry which demands different procedures (location of osteotomy, extension of muscle stripping, etc.)
• cleft patient, post-traumatic patients, patients with craniofacial syndromes or other neurological or systemic problems which might interfere pain evaluation post-operatively