How Often Do Odontogenic Infections Progress to Necrotizing Fasciitis and Can Progression be Predicted?

ABSTRACT How often do odontogenic infections progress to necrotizing fasciitis and can progression be predicted? 

Purpose: The progression of odontogenic infections (OI) to necrotizing soft tissue infections (NSTIs) is well-described. The frequency of this progression and predictive factors are unknown. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score has been used in early identification of NSTI. The aims of this study are 1) to estimate the frequency at which OI patients progress to NSTI in an inpatient cohort, 2) to measure the value of the LRINEC score in predicting this progression, and 3) to estimate the inpatient billing charges associated with managing patients with NSTIs. 

 Materials and Methods:  The authors implemented a retrospective cohort study and enrolled a sample derived from the population of all subjects admitted to Harborview Medical Center, a tertiary care center, for the management of OIs from 2001-2013. The primary predictor variable was the LRINEC score. The primary outcome variable was NSTI status. The secondary outcome variable was in-patient billing charges.  Additional study categorical variables were patient demographics, comorbidities (body mass index, dental history, diabetes mellitus, immunosuppression medication or illness related, tobacco, alcohol and drug use), laboratory findings on presentation, imaging frequency, and treatment details. Descriptive and analytical statistical analysis was performed.  Statistical significance was set at a p-value < 0.05.

Results:The sample was composed of 489 subjects having a mean age of 38 years, and composed of 180 (37%) female subjects. Five (1%) subjects presented with OIs that progressed to NSTIs.  The mean LRINEC scores for the NSTI and non NSTI/OI were 5.25 (4-7) and 3.4(0-8), respectively (p= 0.08). Charges for NSTI and non-NSTI/OI was $319,336.51 ($114,841.93 - $660,426.33) and $19,290 ($1,883- $335,953), respectively (p=0.051*). 

Conclusions:The frequency of OIs progression to NSTIs was approximately 1%.  The LRINEC score was not associated with progression. NSTI patients were billed sixteen times more than non-NSTI/OI patients. Early diagnosis and intervention is known to be imperative in NSTIs, however, we were unable to identify any specific predictive factors.  Given the rarity of this condition, patient morbidity and financial burden, a large scale, multi-center study would be beneficial.  

References: 

 1. Christensen B, Han M, Dillon JK. "The Cause of Cost in the Management of Odontogenic Infections 1: A Demographic Survey and Multivariate Analysis." Journal of Oral and Maxillofacial Surgery; 71.12 (2013): 2058-067. 

2. Christensen B, Han M, Dillon J.K: The Cause of Cost in the Management of Odontogenic Infections 2: Multivariate Outcome Analyses. J Oral Maxillofac Surg. 2013 Dec;71(12):2068-76.

3. Wong CH, Khin LW, Heng KS, Tan KC, Low CO. "The LRINEC( Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections". Cri Care Med. Jul 32.7 (2004):1535-41