Reversibilidad mandibular de la rigidez cadavérica por medios químicos en un modelo de rata

Abstract

Mandibular reversibility of the cadaverous stiffness by chemical means in a rat model. The main problem that a dentist faces when collectingpostmortem evidence is the buccal opening, which is limited by the cadaverous stiffness phenomenon that begins 3 hours after death. Thisphenomenon persists until it is destroyed by the late autolytic processes of decomposition, after 36 hours postmortem. Objective. To analyzethe feasibility of accelerating the reversion of the mandibular cadaverous stiffness by means of chemical substances to facilitate the buccalopening. Materials and methods. We assessed substances capable of altering the pH, chelating intramuscular calcium or inducing proteolysisof the actin-myosin complex of the masticatory muscles with cadaverous stiffness in Wistar rats. Results. We found that mandibularcadaverous stiffness in Wistar rats appears after 2.5 hours of death. After 3.5 hours, once the rigidity was established, we carried outinfiltrations with EDTA (20 mM), NaHCO3 (50 μM), Na2CO3 (50 μM) and papain (10 μM). NaHCO3 and Na2CO3 solutions significantlyincreased (p<0.05) the reversion speed (mm/h) from hour 5, in 108% and 100%, respectively. Based on the results of this assay, we doubledthe concentration of NaHCO3 and assessed a 1:1 mixture of NaHCO3 and Na2CO3 without finding significant differences with theNaHCO3 and Na2CO3 prior assays. Conclusion. NaHCO3 solution (50 μM) allows a reversal of buccal opening enough to collect evidencebetween 5 and 5.5 hours.

Keywords

• buccal opening
• cadaverous stiffness reversibility
• masticatory muscles
• rigor mortis