Accidental Intraoral Formalin Injection: A Rare Case Report

Abstract

Formalin is a hazardous chemical that needs cautious handling and special storage.Owing to its disinfectant and fixative (i.e. for preserving pathologic tissue specimens in histopathology) properties, it is widely used in dentistry. Although, the terms formaldehyde and formalin are often confused as being identical, these are different as to the concentrations of the primary component i.e. formaldehyde. In fact, the common fixative available as 10% neutral buffered formalin is actually a 4% solution of formaldehyde (i.e., a 10% solution made from a 37-40% commercially pure formaldehyde solution). This case report describes an unfortunate case of accidental injection instead of local anesthetic, of formalin into the pterygomandibular space in a 35-year old woman during inferior alveolar nerve block for surgical removal of impacted lower right third molar and its successful management by cautious debridement (under both local and general anesthesia) and empirical drug therapy (utilizing analgesics and antibiotics).

Unintended Formalin Injection instead of Local Anesthetic Agent: Its Causes & Management

“…All of them need special storage and handling. 6 In this case report mistake happened because of negligence and use of untagged multiuse vial containing clear liquid formalin. In dentistry formalin are basically used for preserving extracted teeth (use for educational purpose) and to collect biopsy specimen.…”

Chemical Facial Cellulitis due to Inadvertent Injection of Formalin into Oral Tissue Space

“…Lian and Ngeow 8 (1998), Gupta et al 9 (2011), Arakeri and Brennan 5 (2012), Vaka et al 4 (2014), and Dandriyal et al (2014) 6 have reported similar cases of accidental administrations of formalin during dental procedures. 5 , 7 , 8 Though the extra-oral swelling in our case exceeded that described in any of these cases.…”

“…Accidental injury from dental chemicals may occur with a number of substances. 6 Formalin is a chemical commonly used for tissue preservation in dental office. It is also used for preserving extracted teeth, which are for preclinical program, by dental trainees.…”

“…They supported the patient with systemic antibiotic and analgesic therapy, to ease the trauma. Dandriyal R et al 6 performed surgical debridement and excision of necrotized muscle attachment under general anesthesia.…”

“…3 , 4 The accidental administration of formalin in to facial tissue spaces may lead to chemical cellulitis over 24 h. Fatty infiltration with necrosis of the area involved and osteolytic changes have also been reported. 5 , 6 This paper reports adverse effects and management of inadvertent injection of 40 percent formalin in pterygomandibular space in an 8-year old child leading to chemical facial cellulitis.…”