Ij’orensic’Science,
7 (1976) 161--l 70 S.A., Lausanne -Printed
0 Elsevier Sequoia
ASPECTS OF PATHOLOGY*
THE
161 in the Netherlands
HYOID-LARYNX
COMPLEX
IN
FORENSIC
I. GORDON University
of Natal, Durban
(Republic
of S. Africa)
H. A. SHAPIRO IJniuersity
of South
Africa,
Pretoria
(Republic
of S. Africa)
J. J. F. TALJAARD University
of the Witwatersrand,
Johannesburg
(Republic
of S. Africa)
H. E. ENGELBRECHT Department
(Received
of Radiology,
March
University
1, 1976; accepted
of Natal, Durban
(Republic
of S. Africa)
May 13,1976)
SUMMARY Post-mortem radiological studies of the hyoid-larynx complex on excised specimens were undertaken. The post-mortem specimens were fixed to polysterene boards by ratiotranslucent plastic pins. Radiological examinations revealed a fracture of the left greater cornu of the hyoid bone in a case of suicidal hanging; a fracture through the calcified right superior cornu of the thyroid cartilage in a case of blunt trauma to the left side of the head and neck; and a fracture artefact through the middle of the left greater cornu of the hyoid bone through compression of this structure by manipulation during the process of removal of the neck structures. In each instance the fracture sites were exposed and photographed. The use of a technique which permits a radiological examination of free dissected specimens of the hyoid-larynx complex has many advantages in the medicolegal investigations of injuries of the neck.
The procedure generally recommended for the demonstration of fractures of the greater comua of the hyoid bone and fractures of calcified or ossified thyroid and cricoid cartilages is described. The structures are first palpated and then dissected in situ for evidence of haemorrhage at the site of the fracture, after which the fracture itself is defined and, by preference, photographed in situ. Some authors refer to the use of radiography in the diagnosis of fractures of the hyoid bone and the laryngeal cartilages. Kunnen, Thomas and Van de Velde [l] have described a
*This paper was read at the Seventh Zurich 8 - 12 September 1975.
International
Meeting
of Forensic
Sciences
held in
162
Fig. 1.
semi-microradiographic technique for recording anatomical anomalies, dislocations and fractures of the larynx. Pendergrass, Schaeffer and Hodes [2] drew attention to 2 difficulties in the use of radiography in the living - a situation which corresponds to the
163
use of radiography in the dead when the structures of the hyoid-larynx complex remain in situ, with the body in the supine position on a postmortem dissection table. Pendergrass et al. state that “anteroposterior views result in the superimposition of the hyoid bone upon the spine and it is impossible to obtain good detail. If a fracture is suspected, it may be necessary to make a lateral view with the head slightly tilted lateralwards to prevent superimposition of the shadows of the cornua, one upon the other.” We have noted that the denser cervical vertebrae not only tend to obscure the anatomy of the hyoid bone in anteroposterior views but the greater cornua, which are the common sites of fracture, are also greatly foreshortened because of their posterior inclination. Although we have also obtained better visualisation of each of the greater cornua with lateral projections when the neck is slightly tilted obliquely, we find that in these projections the body is foreshortened and the synchondroses are not seen clearly. Bearing these facts in mind we decided to conduct post-mortem radiological studies of the hyoid-larynx complex on excised specimens. The procedure which we adopted for this purpose was as follows. After mobilisation of the tongue, the pharyngeal tissues were dissected from behind forwards and laterally and then carried distally without exerting any traction whatsoever on the structures of the hyoid-larynx complex. The tongue and the hyoid-larynx complex were then cut free by separating the tongue from its attachments to the soft palate and by cutting across the trachea below the cricoid cartilage. With sharp-pointed scissors, the remnants of the pharynx and the oesophagus were dissected off the dorsal wall of the hyoid-larynx complex. The tongue and the epiglottis were then amputated and the specimen of the hyoid bone and the attached larynx-complex laid with their ventral surfaces upwards on a board composed of expanded polysterene, which is ratio-translucent. The structures were fixed to the board by radio-translucent plastic pins (Fig. 1). By securing the structures to the board in this way the radiologist was free to orientate the specimen in a series of planes and directions. As a routine we took the following views:- anteroposterior; right and left lateral views; right and left lateral oblique views; and an axial crania-caudal view. The exposure factors for each view are as follows:
AP Both laterals Both obliques Cranio caudal
Milliamps
Exposure
100 100 100 100
1.0 1.2 1.6 1.6
mA mA mA mA
Second Seconds Seconds Seconds
Kilovolts X X X X
2 2 2 2
40 40 40 40
kV kV kV kV
Film type - Osray R.P.I. (This is a non-screen type film). Two exposures are made for each view because of the cooling time required for the tube. Tridoris 5 S X-ray generator used.
164
After completion of the radiological examination, the hyoid bone and the larynx-complex were dissected free of their attached muscles, membranes and ligaments. The presence of the fracture, in the site revealed by the radiological examination, was confirmed and the fracture was photographed. The hyoid bone and the thyroid cartilage were then excised and the whole specimen was fixed in 10% form01 saline. After fixation the specimen was decalcified in a 10% nitric acid or 10% formic acid type of decalcifying solution. Thereafter, the normal technique for the preparation of histopathological sections was followed - the tissue was dehydrated and then embedded in paraffin wax. Sections were cut at 5 microns and stained by the haematoxylin and eosin technique. A complete fracture through the posterior third of the left greater cornu of the hyoid bone is shown in Fig. 2 (Case 1870/75). A low-power magnification of the region of the fracture is shown in Fig, 3. The radiological reports on the hyoid bone and the thyroid cartilage using the technique described above, were recorded in 3 of our cases. Case 1870/75 A case of suicidal hanging Figure 4 illustrates the radiological appearance of a geniculate fracture (arrow) at the junction of the posterior one-third and the anterior two-thirds of the left greater cornu of the hyoid bone. Note the acute inferior angulation of the posterior fragment.? Case 1841/75 Blunt trauma to the left side of the of assault There is a complete fracture (arrow) through the comu of the thyroid cartilage (Fig. 5). The cephalad displaced medially and anteriorly. This unequivocal the possibility of fragmented calcification resembling
head and neck in a case calcified right superior or superior fragment is displacement rules out a fracture.
Case 1794/75 Artefact produced after death This was caused by compression of the greater cornua of the hyoid bone by manipulation during the process of removal of the neck structures. There is a fracture (arrow) through the middle of the left greater comu of the hyoid bone (Fig. 6). Apart from demonstrating the presence and the site of fractures of the greater comua of the hyoid bone and fractures of calcified or ossified thyroid cartilages, a radiological examination, using the technique described in this paper, will reveal any displacement of the fractured
‘Since the presentation of this paper in Zurich, one of us (I. G.) has seen another geniculate fracture of the left greater cornu of the hyoid bone in a case of suicidal hanging. The ligature knot was on the right side of the neck. There was an acute inferior angulation of the posterior fragment similar to that described in Case 1870/75. This geniculate type of fracture has apparently not been described before in cases of suicidal hanging.
Fig. 4.
segments. It is a distinct advantage to be able to demonstrate such displacements radiologically before a possible disturbance of the position of the fragments occurs during the dissection procedure. However careful the dissection of a neck may be in cases of suspected fractures, a distinct possibility exists that the position of fracture fragments may be disturbed by the manipulation of the parts.
167
Fig. 5.
Radiological examination may reveal an asymmetric ossification of the synchondroses between the greater comua and the body of the hyoid bone. There is a great deficiency of data in the literature on how sex and ethnic differences may influence the time of ossification of the synchondroses. The ossification is not only asymmetric but sometimes proceeds by the formation of several bridges of bone across the synchondrosis. In unilateral
Fig. 6.
ossification of one synchondrosis, the opposite synchondrosis must not be mistaken for a fracture. In assessing the X-ray appearances, it is important to note that the superior cornua of the thyroid cartilage may undergo fragmented calcifica-
169
tion and such fragments may be mistaken for fractures. It is also important to note that a small cartilaginous nodule termed the cartilage triticea frequently occurs in each of the lateral thyrohyoid ligaments which form the posterior borders of the thyrohyoid membrane, and connect the tips of the superior comua of the thyroid cartilage to the posterior ends of the greater comua of the hyoid bone. These cartilages may undergo calcification and ossification and may simulate fractures of the upper ends of the superior cornua of the thyroid cartilage.
ASPECTS OF FORENSIC
ANATOMY
Warwick and Williams [3] state “The hyoid bone is developed from the cartilages of the second and third visceral arches - the lesser comua from the second, the greater comua from the third, and the body from the fused ventral ends of both. It is ossified from 6 centres: a pair for the body, and one for each cornu. Ossification commences in the greater comua towards the end of intrauterine life, in the body before or shortly after birth, and in the lesser cornua around puberty.” Romanes [4] states “The greater horn and most of the body of the hyoid bone are derived from the cartilage of the third arch. The lesser horn and probably the upper part of the body are from the cartilage of the second, or hyoid, arch which continues up as the stylohyoid ligament. Ossification of the hyoid bone begins shortly before birth as a pair of centres for the body (which soon unite) and one for each greater horn. During the first year, or considerably later, centres appear for the lesser horn. The greater horn and body unite in middle age; the lesser horn is united with them by a synovial joint which only disappears in old age.” Anson [5] states “The thyroid, cricoid, and greater part of the arytenoid are composed of hyaline cartilage; the epiglottic, comiculate, and cuneiform cartilages as well as the apex and vocal processes of the arytenoid are of elastic cartilage. Certain parts of the laryngeal skeleton normally undergo calcification and ossification. Calcification begins at about 20 years of age in thyroid and cricoid cartilages, and later in the arytenoid. The process begins a little later in the female than in the male, and does not extend so rapidly. The extent to which the cartilages are ossified and the time occupied in the process vary considerably. The elastic elements usually are not involved in the process. Calcification of the smaller cartilages, especially, is important clinically because such calcific areas may be mistaken for foreign bodies in roentgen examinations.” Keen and Wainwright [6] , dealing with the ossification of the thyroid, cricoid and arytenoid cartilages, state that “it is possible to demonstrate a gradually increasing ossification related to advancing age. Nevertheless, the immediate correlation between age and degree of ossification is poor, and is of practically no guide, if individual cases are considered.” In their series they examined 133 larynges and found 3 instances of advanced ossification
in the thyroid cartilage in the third decade group (21-30 years) and 2 with advanced bony changes in the cricoid. On the other hand, in the fifth decade (41-50 years) there was one case with no ossification in the thyroid cartilage at all, several with no ossification in the cricoid and even in the last age group (61 years +) there was one specimen of a thyroid cartilage from a female subject showing no changes at all. They quote Woming [7] who pointed out that there can be a difference of 40 or 50 years between individuals in whom the same degree of ossification is found. Keen and Wainwright state that it is impossible to judge a patient’s age from the extent of the ossification in the laryngeal cartilages. Accordingly, they conclude “that there are other factors, apart from advancing age, which influence the time of commencement and the rate of the extension of the bony changes in the laryngeal cartilages.” They also state that the pattern of ossification in the cartilages which they studied “always showed right and left-sided symmetry.”
ACKNOWLEDGEMENT
We are grateful for the assistance of Miss M. Waugh, Principal Radiographer in charge of the XRay Department of King Edward VIII Hospital, Durban.
REFERENCES 1 M. Kunnen, F. Thomas and E. Van de Velde, Semi-microradiography of the larynx on post-mortem material, Med. Sci. Law, 6 (1966) 218-219. 2 E. P. Pendergrass, J. P. Schaefer and P. J. Hodes, The Head and Neck in Roentgen Diagnosis, 2nd edn., Charles C. Thomas, Springfield, 1956, Vol. 2, p. 1663. 3 R. Warwick and P. L. Williams, Gray’s Anatomy, 35th edn., Longman, London, 1973, p. 285. 4 G. J. Romanes, Cunningham’s Textbook of Anatomy, 11th edn., Oxford University Press, London, 1972, pp. 127-128. 5 B. J. Anson, Morris’ Human Anatomy, 12th edn., McGraw-Hill, New York, 1966, p. 1414. 6 J. A. Keen and J. Wainwright, Ossification of the thyroid, cricoid and arytenoid cartilages, S. Afr. J. Lab. Clin. Med., 4 (1958) 83-108. 7 B. Worning, Roentgen examination of laryngeal and hypopharyngeal tumors, Acta Radiol., 15 (1934) 8-23.
7 (1976) 161--l 70 S.A., Lausanne -Printed
0 Elsevier Sequoia
ASPECTS OF PATHOLOGY*
THE
161 in the Netherlands
HYOID-LARYNX
COMPLEX
IN
FORENSIC
I. GORDON University
of Natal, Durban
(Republic
of S. Africa)
H. A. SHAPIRO IJniuersity
of South
Africa,
Pretoria
(Republic
of S. Africa)
J. J. F. TALJAARD University
of the Witwatersrand,
Johannesburg
(Republic
of S. Africa)
H. E. ENGELBRECHT Department
(Received
of Radiology,
March
University
1, 1976; accepted
of Natal, Durban
(Republic
of S. Africa)
May 13,1976)
SUMMARY Post-mortem radiological studies of the hyoid-larynx complex on excised specimens were undertaken. The post-mortem specimens were fixed to polysterene boards by ratiotranslucent plastic pins. Radiological examinations revealed a fracture of the left greater cornu of the hyoid bone in a case of suicidal hanging; a fracture through the calcified right superior cornu of the thyroid cartilage in a case of blunt trauma to the left side of the head and neck; and a fracture artefact through the middle of the left greater cornu of the hyoid bone through compression of this structure by manipulation during the process of removal of the neck structures. In each instance the fracture sites were exposed and photographed. The use of a technique which permits a radiological examination of free dissected specimens of the hyoid-larynx complex has many advantages in the medicolegal investigations of injuries of the neck.
The procedure generally recommended for the demonstration of fractures of the greater comua of the hyoid bone and fractures of calcified or ossified thyroid and cricoid cartilages is described. The structures are first palpated and then dissected in situ for evidence of haemorrhage at the site of the fracture, after which the fracture itself is defined and, by preference, photographed in situ. Some authors refer to the use of radiography in the diagnosis of fractures of the hyoid bone and the laryngeal cartilages. Kunnen, Thomas and Van de Velde [l] have described a
*This paper was read at the Seventh Zurich 8 - 12 September 1975.
International
Meeting
of Forensic
Sciences
held in
162
Fig. 1.
semi-microradiographic technique for recording anatomical anomalies, dislocations and fractures of the larynx. Pendergrass, Schaeffer and Hodes [2] drew attention to 2 difficulties in the use of radiography in the living - a situation which corresponds to the
163
use of radiography in the dead when the structures of the hyoid-larynx complex remain in situ, with the body in the supine position on a postmortem dissection table. Pendergrass et al. state that “anteroposterior views result in the superimposition of the hyoid bone upon the spine and it is impossible to obtain good detail. If a fracture is suspected, it may be necessary to make a lateral view with the head slightly tilted lateralwards to prevent superimposition of the shadows of the cornua, one upon the other.” We have noted that the denser cervical vertebrae not only tend to obscure the anatomy of the hyoid bone in anteroposterior views but the greater cornua, which are the common sites of fracture, are also greatly foreshortened because of their posterior inclination. Although we have also obtained better visualisation of each of the greater cornua with lateral projections when the neck is slightly tilted obliquely, we find that in these projections the body is foreshortened and the synchondroses are not seen clearly. Bearing these facts in mind we decided to conduct post-mortem radiological studies of the hyoid-larynx complex on excised specimens. The procedure which we adopted for this purpose was as follows. After mobilisation of the tongue, the pharyngeal tissues were dissected from behind forwards and laterally and then carried distally without exerting any traction whatsoever on the structures of the hyoid-larynx complex. The tongue and the hyoid-larynx complex were then cut free by separating the tongue from its attachments to the soft palate and by cutting across the trachea below the cricoid cartilage. With sharp-pointed scissors, the remnants of the pharynx and the oesophagus were dissected off the dorsal wall of the hyoid-larynx complex. The tongue and the epiglottis were then amputated and the specimen of the hyoid bone and the attached larynx-complex laid with their ventral surfaces upwards on a board composed of expanded polysterene, which is ratio-translucent. The structures were fixed to the board by radio-translucent plastic pins (Fig. 1). By securing the structures to the board in this way the radiologist was free to orientate the specimen in a series of planes and directions. As a routine we took the following views:- anteroposterior; right and left lateral views; right and left lateral oblique views; and an axial crania-caudal view. The exposure factors for each view are as follows:
AP Both laterals Both obliques Cranio caudal
Milliamps
Exposure
100 100 100 100
1.0 1.2 1.6 1.6
mA mA mA mA
Second Seconds Seconds Seconds
Kilovolts X X X X
2 2 2 2
40 40 40 40
kV kV kV kV
Film type - Osray R.P.I. (This is a non-screen type film). Two exposures are made for each view because of the cooling time required for the tube. Tridoris 5 S X-ray generator used.
164
After completion of the radiological examination, the hyoid bone and the larynx-complex were dissected free of their attached muscles, membranes and ligaments. The presence of the fracture, in the site revealed by the radiological examination, was confirmed and the fracture was photographed. The hyoid bone and the thyroid cartilage were then excised and the whole specimen was fixed in 10% form01 saline. After fixation the specimen was decalcified in a 10% nitric acid or 10% formic acid type of decalcifying solution. Thereafter, the normal technique for the preparation of histopathological sections was followed - the tissue was dehydrated and then embedded in paraffin wax. Sections were cut at 5 microns and stained by the haematoxylin and eosin technique. A complete fracture through the posterior third of the left greater cornu of the hyoid bone is shown in Fig. 2 (Case 1870/75). A low-power magnification of the region of the fracture is shown in Fig, 3. The radiological reports on the hyoid bone and the thyroid cartilage using the technique described above, were recorded in 3 of our cases. Case 1870/75 A case of suicidal hanging Figure 4 illustrates the radiological appearance of a geniculate fracture (arrow) at the junction of the posterior one-third and the anterior two-thirds of the left greater cornu of the hyoid bone. Note the acute inferior angulation of the posterior fragment.? Case 1841/75 Blunt trauma to the left side of the of assault There is a complete fracture (arrow) through the comu of the thyroid cartilage (Fig. 5). The cephalad displaced medially and anteriorly. This unequivocal the possibility of fragmented calcification resembling
head and neck in a case calcified right superior or superior fragment is displacement rules out a fracture.
Case 1794/75 Artefact produced after death This was caused by compression of the greater cornua of the hyoid bone by manipulation during the process of removal of the neck structures. There is a fracture (arrow) through the middle of the left greater comu of the hyoid bone (Fig. 6). Apart from demonstrating the presence and the site of fractures of the greater comua of the hyoid bone and fractures of calcified or ossified thyroid cartilages, a radiological examination, using the technique described in this paper, will reveal any displacement of the fractured
‘Since the presentation of this paper in Zurich, one of us (I. G.) has seen another geniculate fracture of the left greater cornu of the hyoid bone in a case of suicidal hanging. The ligature knot was on the right side of the neck. There was an acute inferior angulation of the posterior fragment similar to that described in Case 1870/75. This geniculate type of fracture has apparently not been described before in cases of suicidal hanging.
Fig. 4.
segments. It is a distinct advantage to be able to demonstrate such displacements radiologically before a possible disturbance of the position of the fragments occurs during the dissection procedure. However careful the dissection of a neck may be in cases of suspected fractures, a distinct possibility exists that the position of fracture fragments may be disturbed by the manipulation of the parts.
167
Fig. 5.
Radiological examination may reveal an asymmetric ossification of the synchondroses between the greater comua and the body of the hyoid bone. There is a great deficiency of data in the literature on how sex and ethnic differences may influence the time of ossification of the synchondroses. The ossification is not only asymmetric but sometimes proceeds by the formation of several bridges of bone across the synchondrosis. In unilateral
Fig. 6.
ossification of one synchondrosis, the opposite synchondrosis must not be mistaken for a fracture. In assessing the X-ray appearances, it is important to note that the superior cornua of the thyroid cartilage may undergo fragmented calcifica-
169
tion and such fragments may be mistaken for fractures. It is also important to note that a small cartilaginous nodule termed the cartilage triticea frequently occurs in each of the lateral thyrohyoid ligaments which form the posterior borders of the thyrohyoid membrane, and connect the tips of the superior comua of the thyroid cartilage to the posterior ends of the greater comua of the hyoid bone. These cartilages may undergo calcification and ossification and may simulate fractures of the upper ends of the superior cornua of the thyroid cartilage.
ASPECTS OF FORENSIC
ANATOMY
Warwick and Williams [3] state “The hyoid bone is developed from the cartilages of the second and third visceral arches - the lesser comua from the second, the greater comua from the third, and the body from the fused ventral ends of both. It is ossified from 6 centres: a pair for the body, and one for each cornu. Ossification commences in the greater comua towards the end of intrauterine life, in the body before or shortly after birth, and in the lesser cornua around puberty.” Romanes [4] states “The greater horn and most of the body of the hyoid bone are derived from the cartilage of the third arch. The lesser horn and probably the upper part of the body are from the cartilage of the second, or hyoid, arch which continues up as the stylohyoid ligament. Ossification of the hyoid bone begins shortly before birth as a pair of centres for the body (which soon unite) and one for each greater horn. During the first year, or considerably later, centres appear for the lesser horn. The greater horn and body unite in middle age; the lesser horn is united with them by a synovial joint which only disappears in old age.” Anson [5] states “The thyroid, cricoid, and greater part of the arytenoid are composed of hyaline cartilage; the epiglottic, comiculate, and cuneiform cartilages as well as the apex and vocal processes of the arytenoid are of elastic cartilage. Certain parts of the laryngeal skeleton normally undergo calcification and ossification. Calcification begins at about 20 years of age in thyroid and cricoid cartilages, and later in the arytenoid. The process begins a little later in the female than in the male, and does not extend so rapidly. The extent to which the cartilages are ossified and the time occupied in the process vary considerably. The elastic elements usually are not involved in the process. Calcification of the smaller cartilages, especially, is important clinically because such calcific areas may be mistaken for foreign bodies in roentgen examinations.” Keen and Wainwright [6] , dealing with the ossification of the thyroid, cricoid and arytenoid cartilages, state that “it is possible to demonstrate a gradually increasing ossification related to advancing age. Nevertheless, the immediate correlation between age and degree of ossification is poor, and is of practically no guide, if individual cases are considered.” In their series they examined 133 larynges and found 3 instances of advanced ossification
in the thyroid cartilage in the third decade group (21-30 years) and 2 with advanced bony changes in the cricoid. On the other hand, in the fifth decade (41-50 years) there was one case with no ossification in the thyroid cartilage at all, several with no ossification in the cricoid and even in the last age group (61 years +) there was one specimen of a thyroid cartilage from a female subject showing no changes at all. They quote Woming [7] who pointed out that there can be a difference of 40 or 50 years between individuals in whom the same degree of ossification is found. Keen and Wainwright state that it is impossible to judge a patient’s age from the extent of the ossification in the laryngeal cartilages. Accordingly, they conclude “that there are other factors, apart from advancing age, which influence the time of commencement and the rate of the extension of the bony changes in the laryngeal cartilages.” They also state that the pattern of ossification in the cartilages which they studied “always showed right and left-sided symmetry.”
ACKNOWLEDGEMENT
We are grateful for the assistance of Miss M. Waugh, Principal Radiographer in charge of the XRay Department of King Edward VIII Hospital, Durban.
REFERENCES 1 M. Kunnen, F. Thomas and E. Van de Velde, Semi-microradiography of the larynx on post-mortem material, Med. Sci. Law, 6 (1966) 218-219. 2 E. P. Pendergrass, J. P. Schaefer and P. J. Hodes, The Head and Neck in Roentgen Diagnosis, 2nd edn., Charles C. Thomas, Springfield, 1956, Vol. 2, p. 1663. 3 R. Warwick and P. L. Williams, Gray’s Anatomy, 35th edn., Longman, London, 1973, p. 285. 4 G. J. Romanes, Cunningham’s Textbook of Anatomy, 11th edn., Oxford University Press, London, 1972, pp. 127-128. 5 B. J. Anson, Morris’ Human Anatomy, 12th edn., McGraw-Hill, New York, 1966, p. 1414. 6 J. A. Keen and J. Wainwright, Ossification of the thyroid, cricoid and arytenoid cartilages, S. Afr. J. Lab. Clin. Med., 4 (1958) 83-108. 7 B. Worning, Roentgen examination of laryngeal and hypopharyngeal tumors, Acta Radiol., 15 (1934) 8-23.
