Three main arteries of the face and their tortuosity K. Soikkonen,
J. Wolf,
J. Hietanen,
Depurtment of Dental Radiology, University of I lelsinki, Finlund
K. Mattila
Department
of Orul Puthology. und Institute of l*‘orensic Medicine.
SUMMARY.
The anatomy of the facial, transverse facial and infraorbital arteries and their tortuosity was studied in 69 human cadavers (age range 18-95 years). The types of facial vascularisation were divided into four categories according to the gradually diminishing relative dominance of the facial artery. Type A, in which the facial artery was dominant, comprised 22% of the cases; type B. 49%; type C 20%; and the variant of the hypoplastic facial artery, type D, 9% of the cases. The type of vascularisation was not dependent on age or sex. The tortuosity of all three arteries showed a statistically signilicant increase with age. A weak correlation was found between the relative dominance and the tortuosity of the facial artery.
INTRODUCTION The blood supply to the face is provided mainly by the facial, transverse facial and infraorbital arteries, which are in haemodynamic balance. The facial artery is usually the largest, and the other two play a subordinate role (Adachi, 1928; Lasjaunias, 1981). The position and size of the vessels vary between different individuals and even in the same person from one side to the other. There are also some racial differences concerning their origins and ramification patterns (Adachi, 1928). Senile degenerative changes increase in diameter and elongation of arteries as a result of reduced elasticity and arterial hypertension produce arterial tortuosity. Tortuosity increases in incidence and severity with age. However, agcing of the vascular system does not occur in all vessels simultaneously, and the process also begins in different arteries in different individuals (Buergcr & Hevelke. 1956). In spite of the considerable individual variation in the agcing of different arteries, evidence has been found that the arteries arc affected in a particular sequence. The aorta and carotid arteries are affcctcd by atherosclerosis before the coronary arteries (Dreizen ef al., 1974). Oral arteries in rabbits have been shown to have as high an atherosclerotic potential as the aorta and the coronary vessels (Dreizcn et al., 1978). Although some sources consider the senile arteriosclerosis and the resulting tortuosity to bc of little consequence (Anderson, 198.5), studies concerning the dynamics of blood flow and the formation of atherosclerotic plaques at bifurcations and downstream of bends, kinks, strictures or intimal vcgctations indicate that arterial tortuosity is a major predisposing factor in the formation of these plaques (Clarisse et al., 1979; Motomiya & Karino, 1984; Middleton et uf., 1988). IIowcvcr, the devclopment of atheroma probably also requires the presence
of other predisposing factors, such as high dietary intake of saturated fatty acids and cholesterol, as well as genetic predisposition (Anderson. 1985). The purpose of this study was to investigate the arterial vascular pattern of the facial. transverse facial and infraorbital arteries and their tortuosity, in I-innish autopsy material. MATERIAL
ANI) METHODS
The material consisted of 69 human cadavers. 42 male and 27 female, investigated at the Institute of University of Helsinki. The Forensic Medicine, mean age was 57 years (range I895 years). All the subjects were white Finns. Using panoramic tomography, stereoscopic selective arteriographs of the external carotid artery and its branches were obtained with the method previously described in detail (Mattila et d., 1981; Wolf et al., 1985). The arterial vascularisation types of the face were classified into four categories: A, B, C and D (Fig. the diminishing 1). The categories rcprcscnt dominance of the facial artery in the blood supply to the face from A=dominant, to D=hypoplastic facial artery as described by Lasjaunias (1981). In type A, the facial artery is long, reaching the infraorbital arca and assuming the most posterior course in comparison with the other types. The transverse facial and infraorbital arteries are insignificant when compared with the facial artcry. In type H, a slightly smaller facial artery is accompanied by larger transverse facial and infraorbital arteries than in type A, and the facial artery takes a more anterior course and does not reach the infraorbital area. In type C, all three vcsscls arc of equal or almost equal size, and the facial artcry is still more anterior, supplying mainly the lips and adjacent area. In type D, the facial artery is hypoplastic and dots not rise above the lower lip.
39h
British
Journal
of Oral
and Maxillofacial
Surger)
2
II
Fig. 1 - I‘he arterial vascularisation
types of the
face--facial (I). transverse
‘The tortuosity of the facial, transverse facial and infraorbital arteries was asscsscd by mutual agrcemcnt between two oral radiologists, and was classified into three categories: 1 straight. 2 slightly tortuous. 3 tortuous I’hc tortuositics were determined from the main trunk of the arteries, and in the infraorbital artery from the segment between its origin and the infraorbital foramcn. The anatomic curve of the facial artery at the lower horder of the mandible was not consider-cd to bc a tortuosity. In the statistical analysis of the findings, the Chisquare test was used.
facial (2) and infraorbital
(3) arteries.
KESULTS The types of facial vascularisation were divided into four categories according to the relative dominance of the facial artery. Type A, in which the facial artcry was dominant, comprised 22% (O/69) of the casts; type B, 49% (34/69); type C. 20% (14/69); and the variant of the hypoplastic facial artery, type D. 9% (6169) of the cases. The type of vascularrsation was not dependent on age or sex. The facial and lingual arteries arose separately from the external carotid artcry in 84% of the cases. They had the same point of origin in 3% of the cases. and a common trunk in 13%. Neither vascularisation type nor sex showed any correlation with the ramification pattern of the facial and lingual arteries. In four cases there was a large vertical anastomosis
Three
main
artcries
of the face and their
tortuositv
397
Fig. 2 - Examples
used in the classification of the tortuosity in the facial (thick arrows), transverse facial (small arrows) and infraorbital (curved arrows) arteries. In (A) all three arteries are straight, in (B) slightly tortuous and in (C) tortuous. In (A) there is an anastomosis (open arrows) between maxillary and facial artzrics.
between the facial and maxillary arteries. Two of these casts were classed as type D, one of which also exhibited a double transverse facial artery. The other two anastomoscs were of type B. Examples of the classification of tortuosity types arc shown in Fig. 2. IJp to the age of 30 years, the transverse facial artery was fairly straight, but the facial and infraorbital arteries in some subjects (four out of seven) showed signs of tortuosity. After the age of 40 years, the tortuosity of all three arteries was greater (Table). Ncarly94% ofthoseover6Oyearscxhibitcda tortuous facial artery. The transverse facial and infraorbital arteries were tortuous in nearly 69% and 81% respectively of the casts over 60 years. The increase in tortuosity in those over 40 years old was statistically significant in all three arteries. No statistically significant differences in the tortuosity of the three vessels were found between the sexes. The facial artery showed a greater tendency to tortuosity than the other two arteries in vascularisation types A, B, and C. This tendency diminished from A to D. In type D, the transverse facial artery
Table - Degree
was most often the most tortuous artery. No statistically significant relationship was demonstrated between the tortuosities of the vessels and the vascularisation types.
DISCUSSION According to Lasjaunias (1981), the transverse facial artery plays a subordinate role in the blood supply to the face, and the facial and infraorbital arteries arc the major vcsscls through which the circulation is reestablished if one of them is occluded for some reason. In a series of 146 Japanese autopsies in which both sides of the face were examined, Adachi (1928) found that when the facial artery was hypoplastic (10.6% of cases), its area was supplied mainly by the transverse facial artery. The infraorbital artery was in these cases somewhat larger than normal, but never the dominant vessel. This is in accordance with our results, in which the variant of the hypoplastic facial artery comprised 9% of the cases;
of tortuosity of the facial. transvcrsc facial and infraorbital
artcrics in three aye groups
Age (yearh) O-40 4 I-M)
Facial artery”’ I 2 3
Total
‘l’ranxvcrsc facial artcry. I 2 3 Total
62
hl t‘l‘otal
o 8
Infraorbital I 2
7 4
6 I2
IY IX
IO 3
8 4
I II
IY IX
0 4
2 I3
30 4X
32 6’)
3 I6
7 IY
22 34
32 69
I I4
Dcgrcc: I -straight. 2=slightly tortuous. .i=tortuous. ;-Not radiologically rlctcctablc in one GM. :Not radiologically detectable in five cases. Statisticalsignificanccofthediffcrcnccin tortuositywith;lec(hetwccn
thoscundcr4O~carsand
thoscovcriloycars):
5 h
artery’ 3 ;-
Total I9 17.: 27;: 63’
‘p
J. Wolf,
J. Hietanen,
Depurtment of Dental Radiology, University of I lelsinki, Finlund
K. Mattila
Department
of Orul Puthology. und Institute of l*‘orensic Medicine.
SUMMARY.
The anatomy of the facial, transverse facial and infraorbital arteries and their tortuosity was studied in 69 human cadavers (age range 18-95 years). The types of facial vascularisation were divided into four categories according to the gradually diminishing relative dominance of the facial artery. Type A, in which the facial artery was dominant, comprised 22% of the cases; type B. 49%; type C 20%; and the variant of the hypoplastic facial artery, type D, 9% of the cases. The type of vascularisation was not dependent on age or sex. The tortuosity of all three arteries showed a statistically signilicant increase with age. A weak correlation was found between the relative dominance and the tortuosity of the facial artery.
INTRODUCTION The blood supply to the face is provided mainly by the facial, transverse facial and infraorbital arteries, which are in haemodynamic balance. The facial artery is usually the largest, and the other two play a subordinate role (Adachi, 1928; Lasjaunias, 1981). The position and size of the vessels vary between different individuals and even in the same person from one side to the other. There are also some racial differences concerning their origins and ramification patterns (Adachi, 1928). Senile degenerative changes increase in diameter and elongation of arteries as a result of reduced elasticity and arterial hypertension produce arterial tortuosity. Tortuosity increases in incidence and severity with age. However, agcing of the vascular system does not occur in all vessels simultaneously, and the process also begins in different arteries in different individuals (Buergcr & Hevelke. 1956). In spite of the considerable individual variation in the agcing of different arteries, evidence has been found that the arteries arc affected in a particular sequence. The aorta and carotid arteries are affcctcd by atherosclerosis before the coronary arteries (Dreizen ef al., 1974). Oral arteries in rabbits have been shown to have as high an atherosclerotic potential as the aorta and the coronary vessels (Dreizcn et al., 1978). Although some sources consider the senile arteriosclerosis and the resulting tortuosity to bc of little consequence (Anderson, 198.5), studies concerning the dynamics of blood flow and the formation of atherosclerotic plaques at bifurcations and downstream of bends, kinks, strictures or intimal vcgctations indicate that arterial tortuosity is a major predisposing factor in the formation of these plaques (Clarisse et al., 1979; Motomiya & Karino, 1984; Middleton et uf., 1988). IIowcvcr, the devclopment of atheroma probably also requires the presence
of other predisposing factors, such as high dietary intake of saturated fatty acids and cholesterol, as well as genetic predisposition (Anderson. 1985). The purpose of this study was to investigate the arterial vascular pattern of the facial. transverse facial and infraorbital arteries and their tortuosity, in I-innish autopsy material. MATERIAL
ANI) METHODS
The material consisted of 69 human cadavers. 42 male and 27 female, investigated at the Institute of University of Helsinki. The Forensic Medicine, mean age was 57 years (range I895 years). All the subjects were white Finns. Using panoramic tomography, stereoscopic selective arteriographs of the external carotid artery and its branches were obtained with the method previously described in detail (Mattila et d., 1981; Wolf et al., 1985). The arterial vascularisation types of the face were classified into four categories: A, B, C and D (Fig. the diminishing 1). The categories rcprcscnt dominance of the facial artery in the blood supply to the face from A=dominant, to D=hypoplastic facial artery as described by Lasjaunias (1981). In type A, the facial artery is long, reaching the infraorbital arca and assuming the most posterior course in comparison with the other types. The transverse facial and infraorbital arteries are insignificant when compared with the facial artcry. In type H, a slightly smaller facial artery is accompanied by larger transverse facial and infraorbital arteries than in type A, and the facial artery takes a more anterior course and does not reach the infraorbital area. In type C, all three vcsscls arc of equal or almost equal size, and the facial artcry is still more anterior, supplying mainly the lips and adjacent area. In type D, the facial artery is hypoplastic and dots not rise above the lower lip.
39h
British
Journal
of Oral
and Maxillofacial
Surger)
2
II
Fig. 1 - I‘he arterial vascularisation
types of the
face--facial (I). transverse
‘The tortuosity of the facial, transverse facial and infraorbital arteries was asscsscd by mutual agrcemcnt between two oral radiologists, and was classified into three categories: 1 straight. 2 slightly tortuous. 3 tortuous I’hc tortuositics were determined from the main trunk of the arteries, and in the infraorbital artery from the segment between its origin and the infraorbital foramcn. The anatomic curve of the facial artery at the lower horder of the mandible was not consider-cd to bc a tortuosity. In the statistical analysis of the findings, the Chisquare test was used.
facial (2) and infraorbital
(3) arteries.
KESULTS The types of facial vascularisation were divided into four categories according to the relative dominance of the facial artery. Type A, in which the facial artcry was dominant, comprised 22% (O/69) of the casts; type B, 49% (34/69); type C. 20% (14/69); and the variant of the hypoplastic facial artery, type D. 9% (6169) of the cases. The type of vascularrsation was not dependent on age or sex. The facial and lingual arteries arose separately from the external carotid artcry in 84% of the cases. They had the same point of origin in 3% of the cases. and a common trunk in 13%. Neither vascularisation type nor sex showed any correlation with the ramification pattern of the facial and lingual arteries. In four cases there was a large vertical anastomosis
Three
main
artcries
of the face and their
tortuositv
397
Fig. 2 - Examples
used in the classification of the tortuosity in the facial (thick arrows), transverse facial (small arrows) and infraorbital (curved arrows) arteries. In (A) all three arteries are straight, in (B) slightly tortuous and in (C) tortuous. In (A) there is an anastomosis (open arrows) between maxillary and facial artzrics.
between the facial and maxillary arteries. Two of these casts were classed as type D, one of which also exhibited a double transverse facial artery. The other two anastomoscs were of type B. Examples of the classification of tortuosity types arc shown in Fig. 2. IJp to the age of 30 years, the transverse facial artery was fairly straight, but the facial and infraorbital arteries in some subjects (four out of seven) showed signs of tortuosity. After the age of 40 years, the tortuosity of all three arteries was greater (Table). Ncarly94% ofthoseover6Oyearscxhibitcda tortuous facial artery. The transverse facial and infraorbital arteries were tortuous in nearly 69% and 81% respectively of the casts over 60 years. The increase in tortuosity in those over 40 years old was statistically significant in all three arteries. No statistically significant differences in the tortuosity of the three vessels were found between the sexes. The facial artery showed a greater tendency to tortuosity than the other two arteries in vascularisation types A, B, and C. This tendency diminished from A to D. In type D, the transverse facial artery
Table - Degree
was most often the most tortuous artery. No statistically significant relationship was demonstrated between the tortuosities of the vessels and the vascularisation types.
DISCUSSION According to Lasjaunias (1981), the transverse facial artery plays a subordinate role in the blood supply to the face, and the facial and infraorbital arteries arc the major vcsscls through which the circulation is reestablished if one of them is occluded for some reason. In a series of 146 Japanese autopsies in which both sides of the face were examined, Adachi (1928) found that when the facial artery was hypoplastic (10.6% of cases), its area was supplied mainly by the transverse facial artery. The infraorbital artery was in these cases somewhat larger than normal, but never the dominant vessel. This is in accordance with our results, in which the variant of the hypoplastic facial artery comprised 9% of the cases;
of tortuosity of the facial. transvcrsc facial and infraorbital
artcrics in three aye groups
Age (yearh) O-40 4 I-M)
Facial artery”’ I 2 3
Total
‘l’ranxvcrsc facial artcry. I 2 3 Total
62
hl t‘l‘otal
o 8
Infraorbital I 2
7 4
6 I2
IY IX
IO 3
8 4
I II
IY IX
0 4
2 I3
30 4X
32 6’)
3 I6
7 IY
22 34
32 69
I I4
Dcgrcc: I -straight. 2=slightly tortuous. .i=tortuous. ;-Not radiologically rlctcctablc in one GM. :Not radiologically detectable in five cases. Statisticalsignificanccofthediffcrcnccin tortuositywith;lec(hetwccn
thoscundcr4O~carsand
thoscovcriloycars):
5 h
artery’ 3 ;-
Total I9 17.: 27;: 63’
‘p
