Mandibular trauma are a frequent injury of maxillofacial skeleton due to the mandible's prominence and relative lack of support. Maxillofacial injuries can be complex and can involve the skin and soft-tissues as well as bones resulting in fractures. Although, several cases of severe crush injury of the lower jaw have already been presented but total avulsion of mandible has rarely been reported. As with any facial fracture, consideration must be given for the need of emergency treatment to secure the airway or to obtain hemostasis if necessary before initiating definitive treatment. We presents a case report of completely avulsed mandible along with soft-tissue of midface region in pediatric patient following trauma, which was attempted to manage or repaired by successful microvascular surgical technique. Unfortunately, we lost the patient in next postoperative day due to cardiac complication. Avulsion of the lower jaw may further complicate the obstructive nature of the upper airway. Multi-specialty involvement in their management may be needed for management of such type of avulsion injury.