Palatal necrosis: a rare complication of local anesthetic in dentistry

¹Department of Oral Surgery, Dental Center of Treatment and Diagnosis, Ibn Sina Hospital, Rabat, Morocco, ²Dentistry Medical School , Mohammed V University Rabat ,Morocco.

^&Corresponding author
Ayekinam Kao, Department of Oral Surgery, Dental Center of Treatment and Diagnosis, Ibn Sina Hospital, Rabat, Morocco

To the editors of the PAMJ Clinical Medicine    

A 50-year-old female, with no previous medical history, described pain felt in the middle part of palate for 7 days an extraction of an impacted maxillary canine under local anesthetic in our Oral Surgery Department. Before the extraction, 1.8 ml of lignocaine 2% with epinephrine 1:100,000 was injected for palatal and buccal infiltration. No history of allergies to local anesthetic was reported from previous dental treatments. According to the patient, 2 days after the extraction, he started feeling a pain in the middle of the hard palate. An intraoral examination of the area revealed an ulcer lesion surrounded by a swollen mucosa in the middle of the hard palate which measured approximately 1 cm x 1 cm. The floor of the ulcer was covered with a necrotic lesion (Figure 1). On palpation, the ulcer had no peripheral induration. The patient was prescribed (paracetamol1g) and an antiseptic mouth wash (chlorexidin 12%) and was followed up for 3 consecutive weeks. Complete healing was achieved in about 21 days (Figure 2).

In literature, "local anesthetics" are defined as agents which produce a temporary loss of sensation or pain in one part of the body [1]. The clinical use of local anesthetic agents have been classified as either amino-esters or amino-amides. According to physical and chemical properties, these agents exert their anesthetic effect by acting on the highly lipid nerve membrane [2]. Their main components are a local anesthetic agent, a vasoconstrictor, an antioxidant and a preservative [1,2]. Vasoconstrictors added to a local anesthetic solution are most of time epinephrine in a concentration ranging from 1:50,000 to 1:200,000 and its main purpose is to prolong the duration of anesthesia, decrease the rate of absorption from the local site, reduce systemic toxicity and also to minimize bleeding [1,2]. Various local complications in a dental practice described in literature are mostly due to local anesthetic. According to studies of Daublander et al. in Germany (1997), the overall incidence of complications was 4.5%. It was significantly higher in risk patients (5.7%) than in non risk patients (3.5%). Complications such as dizziness, tachycardia, agitation, nausea, tremor, were the most frequently observed. Severe complications such as seizure and bronchospasm occurred in only two cases (0.07%). It was also reported that Articaine 1: 100,000 caused more sympathomimetic side effects than that of Articaine 1: 200,000 [3]. In the case we presented, the side effects were observed under 1:100,000. In literature, post-anesthetic necrosis is an uncommon complication which occurs in the hard palatal mucosa and is very rare since only few cases have been reported [4].

According to many authors, the etiology of post-anesthetic necrosis could be explained by an increase in pressure during a rapid or forced infiltration into the hard palatal tissues adherent to the underlying bone causing pain and soreness, or poor blood supply causing deprivation of the tissue of its necessary sustenance secondary to vasoconstriction. Tissue necrosis may be a result of a transient ischemia of structures located distally to the infiltration area secondary to a contraction of smooth muscle within the arterial wall causing vasoconstriction [1,4,5,6]. The differential diagnosis of this lesion can be aphthous stomatitis, herpes simplex, neoplastic lesion or mucormycosis [4,5]. The healing of the wound is due to the rich vascularization of palatal arteries by providing oxygen and nutrients [6]. Management of patients with such local complications is conservative and consists of reassurance of the patient and prescription of analgesics and/or topical antiseptics [1,4-7]. Antibiotics are only necessary if the lesion is secondarily infected [1]. Surgical management is only necessary if the ulcer does not heal [4,5]. In order to reduce the incidence of post-anesthetic necrosis, it is recommended to take certain precautions such as proper knowledge of the anatomy of the area before infiltration, limiting infiltration to 1-2 ml to maximize efficacy and the use of an anesthetic solution with a lower epinephrine concentration than that with a higher concentration (i.e. 1:50,000 ; 1:30,000) [4,5,7].

Figures    

Figure 1: intraoral view showing palatal mucosal necrosis

Figure 2: intraoral view after the complete healing

Competing interests     

The authors declare no competing interests.

Authors´ contributions     

Ayekinam Kao: writer. Bouchra Taleb: reviewer and final approval of the paper. All the authors have read and agreed to the final manuscript.

References