This study involves approximately 200 patients designed to evaluate the efficacy and safety of intranasal (IN) morphine 7.5 mg and 15 mg, intravenous morphine (IV) 7.5 mg, immediate release oral (PO) morphine 60 mg or placebo in patients with acute postsurgical pain following third molar extraction.

Diagnosis and Main Criteria for Inclusion: Dental outpatients undergoing the removal of 3 or more third molars (2 of which were required to be mandibular and both must be bony impacted third molars).

Inclusion Criteria:

• Male or female 18-40 years of age
• Surgical extraction of at least three or more third molars (two must be mandibular and both must be bony impacted third molars)
• Moderate or severe pain within 6 hours of completion of surgery

Exclusion Criteria:

• Other oral surgical procedures during the same session except the removal of supernumerary third molars
• Evidence of nasal congestion, nasal polyps, mucosal lesions of the nostrils, postnasal drip of any etiology or any clinically significant nasal pathology that may affect the absorption of study medication or the assessment of safety
• Chronic respiratory insufficiency such that treatment with an opioid analgesic is contraindicated
• Allergy to shellfish

Additional Inclusion/Exclusion Criteria May Apply