Soft Tissue Trauma

before treatment

Last week I received an incident report from my 2 year old daughter’s school: “Diana fell and bit her lower lip.”  By the time she got home, the lip was visibly swollen and red, and she complained about her “boo-boo” hurting during dinner. Over the next couple of days the swelling remained and the traumatized area developed the yellow-white crust that is classic for the healing phase. I am reminded, from this small incident, how alarming the lip swelling and ulceration can appear after trauma, but often there is little to do except to let the area heal on its own.

In dentistry, we often see signs of soft tissue trauma caused by lip or cheek biting after dental anesthesia.  According to a 2000 prospective study, 13% of children ages 2 to 18 experienced soft tissue trauma following a mandibular nerve block anesthesia (College, Feigal, Wandera, and Strange, 2000). The incidence of soft tissue trauma was highest in the youngest age groups – 18% among children less than 4 years of age, 16% in children ages 4 to 7, 13% in 8 to 11 year old children, and 7% in children 12 years of age and older. Sometimes, a pediatric patient bites his or her lower lip out of curiosity because of the unfamiliar sensation of being numb or inadvertently because they do not feel any pain. Accidental lip biting can also happen when eating or during sleep, in the post-operative time frame while the area is still numb. Therefore, it is important to closely monitor younger patients after local anesthesia.
When lip trauma does occur, keep in mind that often the lip swelling and ulcerated area can often look alarming and make you wonder if further medical attention is required.  Management, however, is usually is limited to palliative care such as ice to reduce swelling, warm salt water rinses, and OTC pain medications. No medical or surgical intervention is necessary unless the ulcer becomes secondarily infected, which is very rare, and would typically present with systemic signs such as fever and malaise. Most lesions resolve on its own in 1-2 weeks.


Dr. Sharon Jin
Prosthodontist, Bedford and Needham offices


College C, Feigal R, Wandera A, Strange M. “Bilateral versus unilateral mandibular block anesthesia in a pediatric population.” Pediatr Dent. 2000 Nov-Dec;22(6):453-7.

Chi D, Kanellis M, Himadi E, Asselin ME. “Lip biting in a pediatric dental patient after dental local anesthesia: a case report.” J Pediatr Nurs. 2008 Dec;23(6):490-3. doi: 10.1016/j.pedn.2008.02.035. Epub 2008 Sep 10.

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