The Journal of Laryngology and Otology July 1991, Vol. 105, pp. 522-524
Anatomy of the temporalis fascia P. J.
WORMALD
M.B.Ch.B., T.
ALUN-JONES
F.R.C.S. (Cape Town, South Africa)
Abstract The anatomy of the different layers of the temporalis fascia is reviewed. The superficial and deep layers of the temporalis fascia have been studied by light microscopy to assess any histological difference between the two. We have also assessed the physical characteristics of the different layers by measuring their Young's modulus in the wet and dry states. Anatomically the superficial layer is part of the epicranial aponeurosis and thus covers nearly the entire lateral aspect of the skull. The deep temporal fascial layer covers exactly the temporalis muscle and measures 10 x 12 cm. The fascial layers have a separate arterial and venous supply enabling them to be used as a homograft, a rotation flap or free microvascular flap. Histologically there is no difference between the two layers. A study of the physical characteristics of the two fascial layers using Young's modulus revealed no significant difference in elasticity between the two. The most significant factor affecting the elasticity was the state of hydration of the fascia.
laryngologists concerning the layers of the temporalis fascia. We also aim to assess any histological, anatomical or physical differences between the fascial layers that may make one or the other layer more suitable for tympanoplasty. No otolaryngology study of the anatomy of the temporal fascial layers has been described in the literature although a great deal has been written about the use of temporalis fascia in tympanoplasty.
Introduction The use of the temporalis fascia was first described in the repair of the tympanic membrane by Ortegren in 1959. Subsequently the use of autologous temporalis fascia for tympanoplasty has become commonplace. This study of the anatomy and microscopy of the temporalis fascia was motivated by the confusion that exists amongst oto-
Anatomical review of the temporal fascial layers There are six layers superficial to the skull. The pericranium is adherent to the calvarium which is covered by a loose layer of connective tissue. Superficial to this in the temporal region lies the temporalis muscle covered by the deep temporal fascia which in turn is covered by the superficial temporal fascia. The outer two layers are the subcutaneous fat and the hair-bearing scalp (Fig. 1) (Brent et al., 1985; Hing et al., 1988). There is some confusion about the nomenclature of the two temporal fascial layers. The superficial temporal layer has many synonyms, for example the temporoparietal layer, epiFrontalis muscle
Scalp Superficial Temporalis Fascia
FlG. 1
FIG. 2 Diagram showing the attachments of the left superficial temporal fascia.
Diagram to show the different layers of the scalp, a = skin; b = subcutaneous fat; c = superficial temporal fascia; d = deep temporal fascia; e = periosteum.
Accepted for publication: 27 February 1991. 522
523
ANATOMY OF THE TEMPORALIS FASCIA
Deep Temporalis Fascia over I Temporalis muscle
above the arch. None of its branches pass into the superficial temporal fascia but some do supply the temporalis muscle. The middle temporal vein accompanies the artery closely in its course through the deep temporal fascia (Abul-Hassan etal., 1986). Histological examination
Reflected superficial Temporalis Fascia FIG. 3 Diagram showing the boundaries of the right deep temporal fascia.
cranial aponeurosis and the galeal extension (Abul-Hassan et al., 1986). The deep temporal fascia has clear anatomical boundries and is thus easier to define. It lies directly over the temporalis muscle and is thus confined by the anatomical limits of the muscle. The superficial temporal fascia
The superficial temporal fascia is found directly below the fatty layer and hair follicles of the scalp. It is a thin, highly vascular layer of moderately dense connective tissue which is attached loosely to the overlying subdermal layer above the zygomatic arch, but increasingly firmly as one approaches the vertex. In contrast, its deep surface is separated from the underlying deep temporal fascia by a loose avascular plane. Its other attachments are the galea above, the frontalis muscle in front, the occipitalis muscle behind and the post-auricular muscles and the subcutaneous musculoaponeurotic system of the face below (Fig. 2). This layer has its own rich blood supply. Its arterial supply comes from the superficial temporal artery lying within its thickness. It is drained by a vein of the same name lying on top of the fascial layer. Arterial branches pass to the subdermal plexus but are not given off to the deep temporal fascia. Approximately two-thirds of the way towards the vertex from the zygomatic arch, the arterial vessels leave the superficial temporal fascia and enter the subdermal layer. The temporal branch of the facial nerve lies just deep to the superficial temporal layer about one finger's breadth behind the zygomatic arch. The auriculo-temporal nerve lies just posterior to the superficial temporal vessels and its branches lie within the superficial temporal fascia. The galea and superficial temporal fascial layers are continuous and no distinction can be made between the two (Abul-Hassan et al, 1986).
Specimens of the two fascial layers were obtained from five routine tympanoplasty patients and fixed in 10 per cent buffered formalin. Representative blocks of tissue were chosen and parraffin-embedded. Sections were obtained after routine processing and examined by light microscopy with the anatomical origin of a particular section being unknown at the time of examination. No significant morphological difference was found between the various specimens, their respective collagen bundles being indistinguishable with Haematoxylin and Eosin or connective tissue stains. Physical examination
Young's modulus was measured on all specimens, using a strain gauge, at 100 and 200 Hertz and the results expressed in Newtons/square meter. Separate measures were made of both fascial layers in the wet and dry states. Fascial samples were taken at routine tympanoplasty operations. They were transferred to the laboratory for measurement on a wooden spatula. All samples were air dried for 45 minutes and the dry state measurements taken. The specimens were then soaked in normal saline until fully hydrated and the wet state measurements recorded. The averaged results are shown in Table I. The thickness of the fascial layers were recorded using a micrometer and revealed no significant difference between the two. Discussion
There are two distinct temporal fascial layers each with a separate blood supply. Many authors (Smyth, 1976; Walby etal., 1982) use the term 'temporalis fascia' without qualification. In view of the anatomical difference between the fascial layers, the origin of the fascial layer should be stated. Routine histology of the two layers revealed no significant differences. Connective tissue stains showed no difference between the collagen of the two layers. The physical characteristics, using Young's modulus, showed no difference in elasticity either between the two layers or between individual patients. The elasticity was, however, directly related to the content of dehydration of the fascia. It has been our clinical impression that the superficial fascia is thinner than the deep, but the results of TABLE I
The deep temporal fascia
The deep temporal fascia closely covers the temporalis muscle and its aponeurosis follows the muscle's anatomical boundaries (Fig. 3). The blood supply of this fascia is from the middle temporal artery which arises from the superficial temporal artery. The middle temporal artery always runs superficial to the zygoma, entering the deep temporal fascia
AVERAGED RESULTS OF YOUNG'S MODULUS MEASUREMENTS
Superficial fascia Dry Wet Young's modulus (x 10n/m2) at 100 Hz 1300 at 200 Hz 1397
372 344
Deep fascia Dry Wet
1200 1100
290 280
524 this study show no significant difference in thickness be ween the two layers. Though individual surgeons may have a preference for one or other fascial layer our results do not suggest a morphological or physical difference between the two. The total area of fascia available on one side of the head is 260 cm2 (Abul-Hassan et al., 1986; Antonyshyn et al., 1986). The importance of this is emphasized because temporal fascia (superficial or deep) should always be available for tympanoplasties even in repeat operations. Access to the fascia is easily obtained by extending a post-auricular incision vertically into the hairline, by utilizing a separate hairline incision or by using the opposite side of the head. There has been much discussion about the use of allograft dura or zenografts in otology. This study indicates that there should be enough temporalis fascia for any otological procedure with 520 cm available if both sides of the head are used. We feel that the risks of disease transmission, in particular the slow viruses i.e. JacobCreutzfelt infection, support the use of homografts. The fact that the fascial layers have separate blood supplies allows both layers to be used as vascularized rotation flaps for mastoid cavity lining or even possibly a vascularized tympanoplasty. These vascularized grafts may also be used for reconstruction of oropharyngeal defects following excisional surgery as vascularized rotation flaps or free microvascular flaps. The blood supply limits the average size that can be used for rotation or free flaps to not more than 10 x 14 cm in length and width (Upton, 1986). It has been shown in animal and cadaver experiments that a parietal bone graft can be lifted on a temporalis muscle (Antonyshyn et al., 1986) or fascial pedicle (McCarthy, 1986) and rotated for use in reconstructing the mandible (Antonyshyn et al., 1986). Acknowledgements We wish to thank Dr R. Bowen from the Department Key words: Temporalis fascia; Myringoplasty
P. J. WORMALD, T. ALUN-JONES
of Anatomical Pathology, University of Cape Town, for performing the histological examination. We would also like to thank Dr W. Kapper and Prof A. Bunn from the Department of Biomedical Engineering, University of Cape Town for their measurements of Young's modulus.
References Abul-Hassan, H. S., von Draek Ascher, G., Ackland, R. D. (1986) Surgical anatomy and blood supply of the fascial layers of the temporal region. Plastic and Reconstructive Surgery, 77: 17-24. Antonyshyn, O., Colcleugh, R., Hurst, L., Anderson, C. (1986) The temporalis myo-osseousflap:an experimental study. Plastic and Reconstructive Surgery, 77: 406-413. Brent, B., Upton, J., Acland, R., Shaw, W., Finseth, F., Rogers, C , Pearl, R., Hentz, V. (1985) Experience with the temporoparietal fascial free flap. Plastic and Reconstructive Surgery, 76: 177-187. Hing, D. N., Buncke, H.J., Alpert, B. S. (1988) use of the temporoparietal free fascial flap in the upper extremity. Plastic and Reconstructive Surgery, 81: 534—543.
McCarthy, J. (1986) Discussion—The temporalis myo-osseous flap: an experimental study. Plastic and Reconstructive Surgery, 77: 414-415. Ortegren, U. (1959) Tympanic membrane grafts of full thickness skin, fascia and cartilage in its perichondrium. Ada Otolaryngology, Supplement 244. Smyth, G. D. L. (1976) Tympanic reconstruction—a 15-year report on tympanoplasty. Journal of Laryngology and Otology, 85: 1167-1171. Upton, J. (1986) Discussion: Surgical anatomy and blood supply of the fascial layers of the temporal region. Plastic and Reconstructive Surgery, 11: 25-28. Walby, A. P., Kerr, A. G., Nevin, N. C , Woods, G. (1982) Tissue culture of surgically prepared temporalis fascia. Clinical Otolaryngology, 7: 313-317. Address for correspondence: Dr P. J. Wormald, Groote Schuur Hospital, Observatory 7925, Cape Town, South Africa.
Anatomy of the temporalis fascia P. J.
WORMALD
M.B.Ch.B., T.
ALUN-JONES
F.R.C.S. (Cape Town, South Africa)
Abstract The anatomy of the different layers of the temporalis fascia is reviewed. The superficial and deep layers of the temporalis fascia have been studied by light microscopy to assess any histological difference between the two. We have also assessed the physical characteristics of the different layers by measuring their Young's modulus in the wet and dry states. Anatomically the superficial layer is part of the epicranial aponeurosis and thus covers nearly the entire lateral aspect of the skull. The deep temporal fascial layer covers exactly the temporalis muscle and measures 10 x 12 cm. The fascial layers have a separate arterial and venous supply enabling them to be used as a homograft, a rotation flap or free microvascular flap. Histologically there is no difference between the two layers. A study of the physical characteristics of the two fascial layers using Young's modulus revealed no significant difference in elasticity between the two. The most significant factor affecting the elasticity was the state of hydration of the fascia.
laryngologists concerning the layers of the temporalis fascia. We also aim to assess any histological, anatomical or physical differences between the fascial layers that may make one or the other layer more suitable for tympanoplasty. No otolaryngology study of the anatomy of the temporal fascial layers has been described in the literature although a great deal has been written about the use of temporalis fascia in tympanoplasty.
Introduction The use of the temporalis fascia was first described in the repair of the tympanic membrane by Ortegren in 1959. Subsequently the use of autologous temporalis fascia for tympanoplasty has become commonplace. This study of the anatomy and microscopy of the temporalis fascia was motivated by the confusion that exists amongst oto-
Anatomical review of the temporal fascial layers There are six layers superficial to the skull. The pericranium is adherent to the calvarium which is covered by a loose layer of connective tissue. Superficial to this in the temporal region lies the temporalis muscle covered by the deep temporal fascia which in turn is covered by the superficial temporal fascia. The outer two layers are the subcutaneous fat and the hair-bearing scalp (Fig. 1) (Brent et al., 1985; Hing et al., 1988). There is some confusion about the nomenclature of the two temporal fascial layers. The superficial temporal layer has many synonyms, for example the temporoparietal layer, epiFrontalis muscle
Scalp Superficial Temporalis Fascia
FlG. 1
FIG. 2 Diagram showing the attachments of the left superficial temporal fascia.
Diagram to show the different layers of the scalp, a = skin; b = subcutaneous fat; c = superficial temporal fascia; d = deep temporal fascia; e = periosteum.
Accepted for publication: 27 February 1991. 522
523
ANATOMY OF THE TEMPORALIS FASCIA
Deep Temporalis Fascia over I Temporalis muscle
above the arch. None of its branches pass into the superficial temporal fascia but some do supply the temporalis muscle. The middle temporal vein accompanies the artery closely in its course through the deep temporal fascia (Abul-Hassan etal., 1986). Histological examination
Reflected superficial Temporalis Fascia FIG. 3 Diagram showing the boundaries of the right deep temporal fascia.
cranial aponeurosis and the galeal extension (Abul-Hassan et al., 1986). The deep temporal fascia has clear anatomical boundries and is thus easier to define. It lies directly over the temporalis muscle and is thus confined by the anatomical limits of the muscle. The superficial temporal fascia
The superficial temporal fascia is found directly below the fatty layer and hair follicles of the scalp. It is a thin, highly vascular layer of moderately dense connective tissue which is attached loosely to the overlying subdermal layer above the zygomatic arch, but increasingly firmly as one approaches the vertex. In contrast, its deep surface is separated from the underlying deep temporal fascia by a loose avascular plane. Its other attachments are the galea above, the frontalis muscle in front, the occipitalis muscle behind and the post-auricular muscles and the subcutaneous musculoaponeurotic system of the face below (Fig. 2). This layer has its own rich blood supply. Its arterial supply comes from the superficial temporal artery lying within its thickness. It is drained by a vein of the same name lying on top of the fascial layer. Arterial branches pass to the subdermal plexus but are not given off to the deep temporal fascia. Approximately two-thirds of the way towards the vertex from the zygomatic arch, the arterial vessels leave the superficial temporal fascia and enter the subdermal layer. The temporal branch of the facial nerve lies just deep to the superficial temporal layer about one finger's breadth behind the zygomatic arch. The auriculo-temporal nerve lies just posterior to the superficial temporal vessels and its branches lie within the superficial temporal fascia. The galea and superficial temporal fascial layers are continuous and no distinction can be made between the two (Abul-Hassan et al, 1986).
Specimens of the two fascial layers were obtained from five routine tympanoplasty patients and fixed in 10 per cent buffered formalin. Representative blocks of tissue were chosen and parraffin-embedded. Sections were obtained after routine processing and examined by light microscopy with the anatomical origin of a particular section being unknown at the time of examination. No significant morphological difference was found between the various specimens, their respective collagen bundles being indistinguishable with Haematoxylin and Eosin or connective tissue stains. Physical examination
Young's modulus was measured on all specimens, using a strain gauge, at 100 and 200 Hertz and the results expressed in Newtons/square meter. Separate measures were made of both fascial layers in the wet and dry states. Fascial samples were taken at routine tympanoplasty operations. They were transferred to the laboratory for measurement on a wooden spatula. All samples were air dried for 45 minutes and the dry state measurements taken. The specimens were then soaked in normal saline until fully hydrated and the wet state measurements recorded. The averaged results are shown in Table I. The thickness of the fascial layers were recorded using a micrometer and revealed no significant difference between the two. Discussion
There are two distinct temporal fascial layers each with a separate blood supply. Many authors (Smyth, 1976; Walby etal., 1982) use the term 'temporalis fascia' without qualification. In view of the anatomical difference between the fascial layers, the origin of the fascial layer should be stated. Routine histology of the two layers revealed no significant differences. Connective tissue stains showed no difference between the collagen of the two layers. The physical characteristics, using Young's modulus, showed no difference in elasticity either between the two layers or between individual patients. The elasticity was, however, directly related to the content of dehydration of the fascia. It has been our clinical impression that the superficial fascia is thinner than the deep, but the results of TABLE I
The deep temporal fascia
The deep temporal fascia closely covers the temporalis muscle and its aponeurosis follows the muscle's anatomical boundaries (Fig. 3). The blood supply of this fascia is from the middle temporal artery which arises from the superficial temporal artery. The middle temporal artery always runs superficial to the zygoma, entering the deep temporal fascia
AVERAGED RESULTS OF YOUNG'S MODULUS MEASUREMENTS
Superficial fascia Dry Wet Young's modulus (x 10n/m2) at 100 Hz 1300 at 200 Hz 1397
372 344
Deep fascia Dry Wet
1200 1100
290 280
524 this study show no significant difference in thickness be ween the two layers. Though individual surgeons may have a preference for one or other fascial layer our results do not suggest a morphological or physical difference between the two. The total area of fascia available on one side of the head is 260 cm2 (Abul-Hassan et al., 1986; Antonyshyn et al., 1986). The importance of this is emphasized because temporal fascia (superficial or deep) should always be available for tympanoplasties even in repeat operations. Access to the fascia is easily obtained by extending a post-auricular incision vertically into the hairline, by utilizing a separate hairline incision or by using the opposite side of the head. There has been much discussion about the use of allograft dura or zenografts in otology. This study indicates that there should be enough temporalis fascia for any otological procedure with 520 cm available if both sides of the head are used. We feel that the risks of disease transmission, in particular the slow viruses i.e. JacobCreutzfelt infection, support the use of homografts. The fact that the fascial layers have separate blood supplies allows both layers to be used as vascularized rotation flaps for mastoid cavity lining or even possibly a vascularized tympanoplasty. These vascularized grafts may also be used for reconstruction of oropharyngeal defects following excisional surgery as vascularized rotation flaps or free microvascular flaps. The blood supply limits the average size that can be used for rotation or free flaps to not more than 10 x 14 cm in length and width (Upton, 1986). It has been shown in animal and cadaver experiments that a parietal bone graft can be lifted on a temporalis muscle (Antonyshyn et al., 1986) or fascial pedicle (McCarthy, 1986) and rotated for use in reconstructing the mandible (Antonyshyn et al., 1986). Acknowledgements We wish to thank Dr R. Bowen from the Department Key words: Temporalis fascia; Myringoplasty
P. J. WORMALD, T. ALUN-JONES
of Anatomical Pathology, University of Cape Town, for performing the histological examination. We would also like to thank Dr W. Kapper and Prof A. Bunn from the Department of Biomedical Engineering, University of Cape Town for their measurements of Young's modulus.
References Abul-Hassan, H. S., von Draek Ascher, G., Ackland, R. D. (1986) Surgical anatomy and blood supply of the fascial layers of the temporal region. Plastic and Reconstructive Surgery, 77: 17-24. Antonyshyn, O., Colcleugh, R., Hurst, L., Anderson, C. (1986) The temporalis myo-osseousflap:an experimental study. Plastic and Reconstructive Surgery, 77: 406-413. Brent, B., Upton, J., Acland, R., Shaw, W., Finseth, F., Rogers, C , Pearl, R., Hentz, V. (1985) Experience with the temporoparietal fascial free flap. Plastic and Reconstructive Surgery, 76: 177-187. Hing, D. N., Buncke, H.J., Alpert, B. S. (1988) use of the temporoparietal free fascial flap in the upper extremity. Plastic and Reconstructive Surgery, 81: 534—543.
McCarthy, J. (1986) Discussion—The temporalis myo-osseous flap: an experimental study. Plastic and Reconstructive Surgery, 77: 414-415. Ortegren, U. (1959) Tympanic membrane grafts of full thickness skin, fascia and cartilage in its perichondrium. Ada Otolaryngology, Supplement 244. Smyth, G. D. L. (1976) Tympanic reconstruction—a 15-year report on tympanoplasty. Journal of Laryngology and Otology, 85: 1167-1171. Upton, J. (1986) Discussion: Surgical anatomy and blood supply of the fascial layers of the temporal region. Plastic and Reconstructive Surgery, 11: 25-28. Walby, A. P., Kerr, A. G., Nevin, N. C , Woods, G. (1982) Tissue culture of surgically prepared temporalis fascia. Clinical Otolaryngology, 7: 313-317. Address for correspondence: Dr P. J. Wormald, Groote Schuur Hospital, Observatory 7925, Cape Town, South Africa.
