Maceration (bone)
Encyclopedia
Maceration is a bone preparation technique whereby a clean skeleton
is obtained from a vertebrate
carcass
by leaving it to decompose
inside a closed container at near-constant temperature. This may be done as part of a forensic investigation, as a recovered body is too badly decomposed for a meaningful autopsy
, but with enough flesh or skin remaining as to obscure macroscopically visible evidence, such as cut-marks. In most cases, maceration is done on the carcass of an animal for educational purposes.
, a stage of decomposition
in which the proteins of the body's cells are broken down and consumed by bacteria
in anaerobic
conditions. The temperature is usually maintained at a constant optimal temperature in an incubator. Maceration generates very strong and distasteful odors, and is therefore usually done in a closed container in a ventilated area.
Maceration is an alternative to the Dermestes
method in which skin beetles are used to clean the flesh off of the corpse, a method which is used with corpses of small mammal
s, bird
s, reptile
s, and amphibian
s, because these animals' bones tend to fall apart in many tiny parts. Maceration is an unsuitable method to clean the bones of a fish
, as they have a poorly articulated, pliable skeleton.
by hand as much as is practical, and all internal organs are removed. In this process, extra care is taken when removing the eyeballs, ears and jugular muscles, because some bones are shallow and brittle, such as the thickened external acoustic opening of many mammals. The tongue is usually left in place, because of its attachment to hyoid bone
s. Severed parts of the carcass are sometimes kept in nylon panty hose. Water is then put in a container and maintained a constant temperature, usually 35°C though not warmer than 50°C. Washing powder with enzyme
s (like Biotex) may be added, as it will soften the tissue. A mild detergent
or emulsifier is sometimes used to remove fatty acids from the bone. When the carcass is put in the container, putrefying bacteria
begin (or continue) to consume the cells of body's cells, and will continue to do so as long as the temperature remains constant. After a few days, the water is replenished to maintain the bacteria, and some additional flesh may be cut away. Most medium sized animals (like dog
s) are macerated within about ten days.
Lipid
s and fatty acid
s in the bone and in the fat tissues tend to stain the bone brown. Biotex can be used to whiten the bone, but if too much is used the perchlorate
can damage the bone, leaving it chalky and brittle.
markers will be noted, and measurements of the bones will provide evidence suggesting the individual's height and race. If the skull is intact, facial reconstruction is another option that may help in identifying the individual. If a crime has been established, an examination of the bones without overlying soft tissue may provide evidence on what weapon (if any) was used or on the nature of the injuries sustained.
In most cases, an animal has been macerated for educational purposes. Once dry, the bones are collected, inventoried, and sometimes labelled or separated into labelled bags, all of which may then be placed in a container for storage. Alternately, steel wire is used to arrange the bones to appear as an articulated skeleton, and posed as the animal may have stood in life.
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
is obtained from a vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
carcass
Carcass
Carcass may refer to:*Cadaver of a human, or carrion of an animal.*Carcass , a death metal/grindcore band*Carcass , a type of incendiary ammunition designed to be fired from a cannon, three ships of the Royal Navy...
by leaving it to decompose
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
inside a closed container at near-constant temperature. This may be done as part of a forensic investigation, as a recovered body is too badly decomposed for a meaningful autopsy
Autopsy
An autopsy—also known as a post-mortem examination, necropsy , autopsia cadaverum, or obduction—is a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present...
, but with enough flesh or skin remaining as to obscure macroscopically visible evidence, such as cut-marks. In most cases, maceration is done on the carcass of an animal for educational purposes.
Description
Maceration is a form of controlled putrefactionPutrefaction
Putrefaction is one of seven stages in the decomposition of the body of a dead animal. It can be viewed, in broad terms, as the decomposition of proteins, in a process that results in the eventual breakdown of cohesion between tissues and the liquefaction of most organs.-Description:In terms of...
, a stage of decomposition
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
in which the proteins of the body's cells are broken down and consumed by bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
in anaerobic
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...
conditions. The temperature is usually maintained at a constant optimal temperature in an incubator. Maceration generates very strong and distasteful odors, and is therefore usually done in a closed container in a ventilated area.
Maceration is an alternative to the Dermestes
Dermestes
Dermestes is a genus of larder beetles in the family Dermestidae. Both the adult beetles and the larvae feed on dry dead animals and vegetable material. Dermestes, especially its larvae, can seriously damage natural animal fibers, foodstuff, furnishing and zoological collections...
method in which skin beetles are used to clean the flesh off of the corpse, a method which is used with corpses of small mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s, reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, and amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, because these animals' bones tend to fall apart in many tiny parts. Maceration is an unsuitable method to clean the bones of a fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, as they have a poorly articulated, pliable skeleton.
Process
In the process of maceration, the carcass is first skinned and defleshedExcarnation
In archaeology and anthropology, the term, excarnation , refers to the burial practice of removing the flesh and organs of the dead, leaving only the bones....
by hand as much as is practical, and all internal organs are removed. In this process, extra care is taken when removing the eyeballs, ears and jugular muscles, because some bones are shallow and brittle, such as the thickened external acoustic opening of many mammals. The tongue is usually left in place, because of its attachment to hyoid bone
Hyoid bone
The hyoid bone is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies at the level of the base of the mandible in the front and the third cervical vertebra behind.Unlike other bones, the hyoid is only distantly...
s. Severed parts of the carcass are sometimes kept in nylon panty hose. Water is then put in a container and maintained a constant temperature, usually 35°C though not warmer than 50°C. Washing powder with enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s (like Biotex) may be added, as it will soften the tissue. A mild detergent
Detergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...
or emulsifier is sometimes used to remove fatty acids from the bone. When the carcass is put in the container, putrefying bacteria
Putrefaction
Putrefaction is one of seven stages in the decomposition of the body of a dead animal. It can be viewed, in broad terms, as the decomposition of proteins, in a process that results in the eventual breakdown of cohesion between tissues and the liquefaction of most organs.-Description:In terms of...
begin (or continue) to consume the cells of body's cells, and will continue to do so as long as the temperature remains constant. After a few days, the water is replenished to maintain the bacteria, and some additional flesh may be cut away. Most medium sized animals (like dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s) are macerated within about ten days.
Lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...
s and fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s in the bone and in the fat tissues tend to stain the bone brown. Biotex can be used to whiten the bone, but if too much is used the perchlorate
Perchlorate
Perchlorates are the salts derived from perchloric acid . They occur both naturally and through manufacturing. They have been used as a medicine for more than 50 years to treat thyroid gland disorders. They are used extensively within the pyrotechnics industry, and ammonium perchlorate is also a...
can damage the bone, leaving it chalky and brittle.
Completion
When the process of maceration is complete, the bones are removed from the solution and left to dry. If the skeleton is human and the subject of an investigation, the forensic anthropologist will then conduct and inventory and analysis of the remains. If the individual is to be identified, occupational and age-related osteologicalOsteology
Osteology is the scientific study of bones. A subdiscipline of anatomy, anthropology, and archeology, osteology is a detailed study of the structure of bones, skeletal elements, teeth, morphology, function, disease, pathology, the process of ossification , the resistance and hardness of bones , etc...
markers will be noted, and measurements of the bones will provide evidence suggesting the individual's height and race. If the skull is intact, facial reconstruction is another option that may help in identifying the individual. If a crime has been established, an examination of the bones without overlying soft tissue may provide evidence on what weapon (if any) was used or on the nature of the injuries sustained.
In most cases, an animal has been macerated for educational purposes. Once dry, the bones are collected, inventoried, and sometimes labelled or separated into labelled bags, all of which may then be placed in a container for storage. Alternately, steel wire is used to arrange the bones to appear as an articulated skeleton, and posed as the animal may have stood in life.