Replication of ancient Egyptian osteotomies of the facial skeleton: insights into the mummification process

Abstract

A recent radiographic study of an Egyptian mummified head from the Middle Kingdom revealed methodical mutilations of the facial skeleton that were performed after death and prior to wrapping the corpse for burial. These mutilations consisted of removal of the coronoid processes of the mandible and portions of the zygomas presumably via an intraoral approach. They are unique in the archaeological record. The authors hypothesize that the procedures were carried out to facilitate jaw opening and may be related to a ritual known as the ‘Opening of the Mouth’ ceremony. The purpose of this study was to demonstrate the feasibility of performing these remarkable osteotomies on two human cadavers using instruments similar to those available to the ancient embalmer. Bilateral osteotomies of the zygomas and coronoid processes were carried out transorally and the bones removed. Pre- and postoperative maximal incisal opening measured 25 mm and 53 mm, respectively. Postoperative high-resolution computed tomographic (CT) scans were obtained. Comparison of the postoperative cadaver and mummy CT scans demonstrate remarkable similarity between the resections. Results of this study demonstrate that the ancient skeletal mutilations could have been performed transorally during the mummification process and would have enhanced jaw opening.

The mummification process used by ancient Egyptians continues to hold great fascination for Egyptologists, historians, physicians, surgeons and lay people. Recent discoveries regarding a well-known mummy in the Boston Museum of Fine Arts add additional intrigue to the subject.

The tomb of Djehutynakht, a local governor of Middle Egypt circa 2000 BC, was excavated in 1915 by an expedition from Harvard University and the Museum of Fine Arts, Boston. Its contents have been in the museum collection since that time . The burial chamber contained extraordinarily beautiful coffins and funerary equipment belonging to the ruler and his wife. The tomb had been robbed in antiquity and its human remains scattered or destroyed. The plunderers set aside, undisturbed, the head of one of the tomb occupants after they had torn it free from the body. The mummified head fortuitously remained intact, wrapped with moulded linen, with facial features crudely drawn in red and black paint ( Fig. 1 ).

Fig. 1
Mummified head of Djehutynakht. Note the moulded linen wrappings and marking of the left eyebrow.
G upta R, M arkowitz Y, B erman L, C hapman P. High-resolution imaging of an ancient Egyptian mummified head: new insights into the mummification process. Am J Neuroradiol 2008: 29 (4): 705–713 © by American Society of Neuroradiology.

The wrapped head was studied using computed tomography (CT) in the 1980s, revealing bone defects in the ethmoid, sphenoid, and maxillary sinuses . These were thought to be related to excerebration, or brain removal. The limitations of CT technology at the time precluded a more detailed analysis. More recently the head was studied again using high resolution CT scanning . It was confirmed that there were no external incision over the anterior scalp, face and mandible and that the brain had been removed transnasally via the cribriform plate. In addition, the embalmers had created a second skull opening in the basal occiput just to the left of the foramen magnum. This was also presumably to facilitate brain removal. There is only one other example of such an occipital defect in an Egyptian mummy, a young woman dating from approximately the same period .

In the Djehutynakht skull, there were also extensive mutilations of the facial skeleton and mandible unrelated to brain removal. These included multiple osteotomies and removal of the anterior maxillary sinus walls, contiguous inferior orbital rims and zygomatic arches bilaterally, right zygoma and right and left coronoid processes. The left zygomatic complex was incompletely removed and a small portion of the zygomatic body remained displaced inferomedially ( Fig. 2 ).

Fig. 2
Frontal (A), left lateral (B) and right lateral (C) views of 3D reconstructions of the high-resolution CT scan performed on the mummy of Djehutynakht. Note the missing coronoid processes and portions of the zygomaticomaxillary complex.
G upta R, M arkowitz Y, B erman L, C hapman P. High-resolution imaging of an ancient Egyptian mummified head: new insights into the mummification process. Am J Neuroradiol 2008: 29 (4): 705–713 © by American Society of Neuroradiology.

Radiographic findings related to the head of Djehutynakht are of considerable historical interest with regard to Egyptian funerary practises and ritual. It is perhaps the earliest documentation of excerebration in a mummy of precisely known provenance. Of equal, if not greater, importance are the extraordinary mutilations of the facial skeleton, which have never been previously observed. Given the lack of historical precedent, their purpose is obscure, although it can be assumed that, similar to the excerebration procedure, they were performed in the course of preparing the corpse for burial.

The ancient Egyptians were very practical, so the answer to the mystery undoubtedly relates to the functional importance of the anatomic structures involved. The common denominator is that the portions of the skeleton removed all play an essential role in jaw closure by virtue of their muscular attachments. Their removal and resultant muscular detachment would be expected to result in increased mobility of the mandible. This suggests a relationship to the ‘Opening of the Mouth’ ceremony, which had a central role in funerary ritual.

Throughout the recorded history of ancient Egypt elaborate burial rites were performed to assure the continued existence of the deceased and his or her soul in the afterlife. An essential component of these ceremonies was to open the mouth of the deceased symbolically so that they might speak and take nourishment. Over several thousand years there were changes in many aspects of the funerary cult, but the opening of the mouth maintained its central importance in assuring the deceased’s safe passage into the afterlife.

The present investigation concerns the technical aspects of performing the skeletal mutilations. Given the lack of evidence of external incisions over the scalp, face, and jaw, the authors’ hypothesis is that the entire procedure was performed transorally. The purpose of the current study was to test this hypothesis and to demonstrate that the procedure is feasible and could have been done by the ancient embalmer using simple tools that would have been available at that time.

Materials and methods

Craniofacial CT data from the mummified head of Djehutynakht were used to construct a stereolithographic skeletal model . Two human cadaver heads were obtained to assess the feasibility of performing the osteotomies with limited instruments via an intraoral approach (Science Care ® , Phoenix, AZ). The first head was used to practice the osteotomies and to assess the order in which they were likely performed. The second head was used to carry out the procedure and to document the results.

The instrumentation was limited to a number 15 scalpel blade on a standard handle, mallet, straight 8 mm chisel, and two right angle retractors. An incision was made through mucosa in the depth of the maxillary vestibule extending from the second molar to the second molar. The incision was then extended inferiorly along the mandibular ramus medial to the parotid duct and then anteriorly along the external oblique ridge ( Fig. 3 ). The midfacial skeleton was exposed using the chisel as an elevator.

Fig. 3
Incision to perform the procedure extending from along the maxillary vestibule and passing inferiorly along the anterior mandibular ramus and external oblique ridge.

The mallet and chisel were used to create an osteotomy starting at the anterior wall of the maxillary sinus, which fragmented easily. The osteotomies were extended through the zygomaticomaxillary buttress and inferior orbital rim, respectively. The chisel was driven posteriorly at the inferior orbital rim to the zygomaticosphenoid suture. The chisel was directed in a posterolateral direction through the frontal process of the zygoma just inferior to the zygomaticofrontal suture as this was the position of the osteotomy in the mummy. The chisel was directed through the zygomatic process of the temporal bone posteriorly at the level of the articular eminence. The zygoma and zygomatic arch were reflected laterally to allow stripping of the masseter at its origin with the chisel. The zygomatic bone and arch were removed entirely.

Removal of the zygoma and arch allowed for remarkable access to the coronoid process and the robust insertion of the temporalis muscle ( Fig. 4 ). The entire external oblique ridge and coronoid process were exposed. The chisel was driven through the external oblique ridge beginning in the second molar region and extending in a posterosuperior direction to the posterior aspect of the sigmoid notch. The coronoid process and its temporalis insertion were removed.

Fig. 4
Access to the coronoid and temporalis muscle after removal of the zygoma. The circumferential attachment of the temporalis tendon is seen (arrow).

Postoperative CT scans using a Definition Flash (Siemens Medical Solutions, Erlangen, Germany) at 120 kV, 300 mA, 0.5 s rotation time, slice thickness of 0.6 mm and pitch of 1 were obtained of both heads to assess the osteotomies and ostectomies and for comparison with the mummy CT. The maximal incisal opening was measured before and after the procedures for the second cadaver.

Results

The facial osteotomies were performed without difficulty using limited instrumentation and the intraoral incision and dissection described in this paper. Removal of the zygoma and zygomatic arch first allowed for easy access to the coronoid process and temporalis muscle even with the jaw in a closed position. The procedure was accomplished on the second side of cadaveric head number 1 by a single surgeon (Z.P.) without assistance. Maximal incisal opening of cadaver head number 2 increased from 25 mm preoperatively to 53 mm postoperatively. The jaw passively remained open to 34 mm after release of the muscles of mastication.

High resolution CT scans confirmed removal of the zygomas, zygomatic arches and coronoid processes bilaterally. The three-dimensional (3D) anatomy of the cadaver heads closely resembled that of the mummified head ( Figs. 5 and 6 ). Both zygomas of cadaver number 1 and the right zygoma of cadaver number 2 were fractured and removed at the zygomaticofrontal suture despite attempts to create the osteotomies below the suture as seen in the mummy.

Jan 27, 2018 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Replication of ancient Egyptian osteotomies of the facial skeleton: insights into the mummification process
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