Introduction:
Skull reconstruction involves reconstructing the fractured skull bones and soft tissues to restore the original form or near original form. Skull reconstruction is quite a complex process and needs expertise. There are different methods of reconstruction of the skull however the type of reconstruction technique depends on the amount of damage to the skull.
The skull reconstruction process begins with assessing the type of fracture, evaluating the available fracture segments, analysis of missing attachments or parts, and considering the normal anatomical features of an individual. Reconstruction of skull fractures needs a multidisciplinary approach to completely manage the skull fractures.
What Are Different Types of Reconstruction Techniques?
There are two different types of reconstruction techniques:
-
Two-Dimensional Reconstruction Techniques: Two-dimensional (2D) reconstruction technique was first described by Karen Taylor in Austin in 1980. This method involves the estimation of soft tissue structure depth to restore the facial structures along with the skull. This technique involves a team approach of a forensic anthropologist, an artist, and a plastic surgeon to reconstruct and restore the facial structures and fractured skull bones based on photographs. Different software is currently used for quick two-dimensional reconstruction such as forensic anthropology computer enhancement system (FACES) and computer assisted recovery enhancement system (CARES).
-
Three-Dimensional Manual Reconstruction Techniques: In this technique, materials like clay or wax are used on the victim's skull directly or a replica of the skull which needs to be identified. This method also involves the use of tissue depth markers similar to the two-dimensional reconstruction technique. Tissue depth markers are available in different lengths and are inserted into the small holes on the skull cast.
Different Methods of Manual Reconstruction Are:
1. Tissue Depth Method: It was given by Krogman in 1946. This method involves the use of fine needles, X-rays, and ultrasound for fine measurements. However, this technique is currently of no use.
2. Anatomical Russian Method: This method was introduced by Gerasimov in 1971. This technique does not involve soft tissue depth data as a measurement parameter. Facial muscles were used as anatomical landmarks. This technique involves reconstruction in sequential steps by shaping muscles, glands, and cartilage onto the skull.
3. Combination Manchester Method: This technique was introduced by Neave in 1977. It is the most frequently used method and is the most accepted reconstruction technique. This method involves both the soft tissue depth data and facial muscles for reconstructing skull fractures.
Procedure: After the articulation between the cranium and mandible is achieved, it is mounted in the FH plane (Frankfort Horizontal plane- a point connecting the lower margin of orbit to the highest point of external auditory meatus) on an adjustable stand. A 3-millimeter drill bit is then used to drill holes in the cast to place facial tissue markers. Age, gender, and build are the factors that determine facial tissue depth. Plaster eyeballs of 25 mm in diameter are placed into the orbits. The nasal profile, width, shape, and size are determined by the nasal aperture. Ear length is measured by the length of the nose approximately. Facial muscle recreation is done in sequential steps layer by layer using clay.
4. Forensic Three-Dimensional Facial Reconstruction: This technique is quite quick and cost-effective for skull reconstruction. Three-dimensional computerized models and software are used in this method. Few three-dimensional software currently in use are Haptic feedback systems. The haptic feedback system helps to analyze the minute surface details of the skull for the reconstruction procedure.
What Are the Indications of Skull Reconstruction?
The reconstruction of the skull is indicated in the following conditions:
-
TBI (Traumatic Brain Injury): Skull reconstruction is required in case of brain injuries due to road traffic accidents or accidental falls.
-
Hereditary Cranial Defects: Inborn skull defects like cleft lip and palate, and Apert syndrome (genetic abnormalities causing fusion of skull bones) may require skull reconstruction procedures for correcting cosmetic as well as functional abnormalities.
-
Craniofacial Abnormalities: Such as craniosynostosis (premature fusion of cranial sutures in infants during birth). It may require surgical reconstruction of the skull to correct the shape of the skull and for normal development of the brain.
-
Cranial Infections: Infections like osteomyelitis involving the skull bones results in skull bone defects or damage. Skull reconstruction is required in such conditions after the removal of infected bony defects.
-
Cranial Tumors: Skull base tumors such as chondrosarcoma (cancer of the cartilaginous junction of the skull bone) may require surgical removal of the tumor followed by the reconstruction of the skull defects.
-
Decompressive Craniectomy: In a few cases where there is intracranial pressure, a part of the skull may need to be removed temporarily (decompressive craniectomy) followed by reconstruction of the cranium later to protect the brain.
What Are the Complications Associated With Skull Reconstruction Procedures?
A few complications or risks that are associated with skull reconstruction procedure are:
-
Risk of injury to the cranial nerves.
-
Regular and long follow-up is needed after the skull reconstruction procedure (mostly in growing children).
-
Chances of partial or complete loss of bone grafts at the surgical site resulting in dead space.
-
Permanent scarring of the surgical site.
-
Risk of severe bleeding or intracranial hematoma (blood collection formation).
Conclusion:
Skull reconstruction is quite a technique-sensitive procedure and requires artistic skills. Complete reconstruction of the skull for restoring its cosmetic appearance and functions of the skull requires a multidisciplinary team approach. Due to various advancements in technology, different methods have been implemented for the reconstruction of the skull like three-dimensional virtual reconstruction or printing using different software. These newer advancements have contributed greatly to the healthcare field by enhancing fine accuracies and more efficiency in skull reconstruction techniques.