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an antero-posterior skiagram of the skull, the light shadows formed by the bidal cells are seen to occupy the well-defined area bounded on either side by ill lighter shadow of the orbital cavities and above by the dense horizontal w of the cribriform plate, which occupies the frontier line between these es and the frontal sinuses. Anteriorly the ethmoidal area is overlapped e vertical shadow caused by the frontal processes of the maxillæ and by dges of the lacrimals. Not infrequently the ethmoidal cells will be seen to d into the roof of the orbit, while inferiorly and laterally they come into close on to the superior and medial angle of the shadow formed by the maxillary
The comparative transparency of the area of the ethmoidal cells is nted for by the fact that it is superimposed upon that of the sphenoidal
a profile skiagram the ethmoidal area is seen to extend from the frontal ss of the maxilla backwards across the orbits to the sphenoidal sinuses, with
they are contiguous. This area is crossed about its middle by the vertical w caused by the lateral margin of the orbit. In front of this, and occupying, ore, the light area of the orbital cavity, are the anterior ethmoidal cells; while d it are the posterior ethmoidal cells. In a profile view of the skull, the tior ethmoidal cells, the sphenoidal sinuses, and the hypophyseal fossa all lie before backwards in the axis of those rays which pass through the thinnest n of the cranial box, namely, the anterior part of the temporal fossa ; hence ossibility of being able to identify them even in a skiagram taken from a
subject. ne sphenoidal sinuses are so deeply placed behind the upper half of the rm aperture of the nose that their outlines cannot be identified in an -posterior skiagram. If the sinuses be filled with bismuth before the am is taken, it will be seen that they produce a well-defined and slightly black shadow, about the size of a shilling, situated opposite the superior half e piriform aperture, the superior limit of the shadow reaching just up to the verse curvilinear line already referred to, while laterally the shadow reaches medial to the inferior half of the medial margin of the orbit (Logan Turner). 1 a profile skiagram of the skull the light shadow produced by the sphenoidal is seen immediately inferior to and in front of the characteristic well-defined haped shadow formed by the concave floor of the hypophyseal fossa. Inferiorly nus area is bounded and to some extent overlapped and obliterated by the
shadow which corresponds from latero-medially to the tuberculum articulare he horizontal portion of the great wing of the sphenoid, that is to say, to the of the middle fossa of the base of the skull. This dark shadow is continuous, riorly, with that which is caused by the dense petrous portion of the temporal
Anteriorly is the shadow of the posterior ethmoidal cells (blurred by that ced by the vertical portion of the great wing of the sphenoid), while riorly it is limited by the shadow produced by that portion of the body of the hoid which lies inferior to the dorsum sellæ.
he topography of the sella turcica, which lodges the hypophysis cerebri, E importance now that surgery has succeeded in dealing with certain urs and enlargements of this organ. The fossa hypophyseos lies imately behind the superior part of the sphenoidal sinuses, and, in a median tal section of the skull, the anterior half of the fossa is seen to project into
would correspond to the supero-posterior angle of the sinuses. The more sphenoidal sinuses project backwards, beneath the sella turcica, the thinner e plate of bone which separates the sinus from that part of the posterior
of the base of the skull which supports the pons. When, on the other 1, the sphenoidal sinuses are small and do not extend backwards below the
turcica, the latter may be difficult to identify. In order to reach the physis surgeons have abandoned the intra-cranial route, partly on account of damage produced in the brain, and partly because, when the hypophysis
enlarges, it frequently does so by projecting downwards towards the sphenoidai sinuses rather than upwards into the cranial cavity.
The sphenoidal sinuses constitute the surgeon's guide to the hypophysis To reach them he traverses the upper portions of both nasal cavities, removing from before backwards, the upper portion of the septum nasi, the superior and middle conchæ, and the anterior and posterior ethmoidal cells. The rostrum sphenoidale, situated at the superior and most posterior part of the nasal septum. serves as a guide to the anterior wall of the sphenoidal sinuses; after removing it the sinuses are opened up by removing their anterior walls and the septum. The hypophysis is then exposed by breaking down the anterior portion of the floor of the sella turcica, which forms a bullous-like projection into the superior and posterior part of the sinuses. In making the opening from the sphenoidal sinuses into the hypophyseal fossa, the surgeon must keep strictly to the median plane, so as to avoid opening into the cavernous sinus; if the roof of the sinus be penetrated in front of the fossa the optic chiasma would be injured and the cranial cavity opened, while if the posterior wall of the sinus be penetrated below the level of the fossa hypophyseos the spongy tissue of the body of the sphenoid would be opened into, and if the sinus happened to extend unusually far back, the anterior part of the posterior fossa of the base of the skull would be opened into opposite the basilar artery and the ventral surface of the pons.
According to Stanley Gibson, the average distance from the nasion to the anterior superior margin of the sphenoidal sinus is 11 inches, while the distance from the anterior superior boundary of the sinus to the anterior superior margin of the sella turcica is a little more than 4 inch, so that the total distance from the nasion to the hypophysis is from 24 to 24 inches. The average distance from the anterior nasal spine to the hypophysis is 7.8 cm. (practically 3 in.). The floor of the hypophyseal fossa is on a level with a plane projected backwards from the nasion to the inion. The fossa measures } inch in its antero- posterior diameter.
In a profile skiagram of the skull, the outline of the cup-shaped sella turcica is marked out by a crescentic linear shadow, the anterior and posterior horns of the crescent being represented by the shadows of the anterior and posterior clinoid processes,
Below and in front of the fossa the outlines of the sphenoidal sinuses may be distinctly traced. (Plate I.)
Enlargements of the hypophysis cerebri can often be clearly demonstrated by an increase in the depth and antero-posterior diameter of the skiagraphic outline of the sella turcica, and by the unusual extent to which the fossa encroaches upon the sphenoidal sinus.
The skin of the face is thin, vascular, and rich in sebaceous and sweat glands it is intimately connected with the subcutaneous tissue, in which are imbedded the facial muscles as well as the main blood vessels. Owing to its elasticity and to the presence of the main blood-vessels in the lax subcutaneous tissue, the face is an admirable site for plastic operations, as the flaps do not necrose in spite of considerable tension. The laxity of the tissues accounts for the marked swelling which attends cedematous and inflammatory conditions about the face. sible, incisions should be made along the line of the natural furrows and creases of the skin, so as to render the resulting cicatrix less noticeable.
The bony landmarks of the face which may be readily palpated are: the superciliary ridges and the glabella, the nasion (fronto-nasal junction), the bridge of the nose, the osseous piriform opening and the anterior nasal spine, the supra- and infraorbital margins, the zygomatic process of the frontal bone, the medial angular process the anterior part of the temporal crest, the zygomatic bone, the zygomatic arch, ard the region of the canine fossa of the maxilla.
Immediately inferior to the root of the zygoma, and in front of the superior part of the tragus, is the condyle of the mandible. By pressing with the point of the finger upon the condyle while the mouth is being widely opened, the bone will be
glide forwards, while the finger sinks deeply into the hollow corresponding nandibular fossa. The close relation of the first part of the internal maxillary to the medial aspect of the neck of the mandible must be kept in mind in ons calling for disarticulation or excision of the condyle. The ramus of the le is sandwiched between the masseter and the pterygoid muscles, and
removed without opening into the mouth. Passing downwards from the 3, one can palpate the anterior and posterior borders of the ramus and the nd body of the mandible. The anterior border of the coronoid process is felt t of the upper part of the anterior border of the masseter, immediately below erior part of the zygomatic arch. · pulsation of the external maxillary artery may be felt as the vessel crosses erior margin of the mandible at the anterior border of the masseter, 14 in. in of the angle of the mandible. To map out the course of the artery upon the raw a line from this point to a point | in. lateral to the angle of the mouth, ence to a point a little behind the ala nasi and along the side of the nose to dial angle of the orbit. The anterior facial vein lies posterior to the external ary artery, and takes a straighter course from the medial palpebral commissure anterior inferior angle of the masseter. The vessel is devoid of valves, hence ve phlebitis and thrombosis are liable to spread along it to the cavernous oy way of the ophthalmic and pterygoid veins. line projected downwards from the supra-orbital notch (junction of medial termediate thirds of the supra-orbital margin) to the inferior border of the ble opposite the interval between the two lower premolar teeth, will cross fra-orbital and mental foramina, the former 1 in. below the infra-orbital 1, the latter midway between the superior and inferior borders of the ble. In performing the operation of neurectomy for the relief of trigeminal gia, these foramina furnish the guides to the correspondingly-named branches
fifth nerve. It should be remembered that the nerves in question, after ing from their respective foramina, lie, in the first instance, beneath the
muscles. The supra-orbital and infra-orbital nerves are not infrequently ented each by two branches, one of which passes through an accessory en situated lateral to the normal opening. Neurectomy of the inferior ar nerve is performed by trephining the ramus of the mandible midway en its anterior and posterior borders, on a level with the crown of the holar tooth, the nerve being reached as it enters the inferior alveolar canal: ingual nerve, which lies a little anterior to the inferior alveolar, can be ed through the same opening. ne relations of the maxillary and mandibular divisions of the trigeminal nerve become of increased importance to the surgeon since the introduction of the nent of trifacial neuralgia by the injection of alcohol into these nerves diately after their exit from the cranial cavity. According to Symington, Her to reach the maxillary nerve as it lies in the pterygo-palatine fossa, in should be punctured immediately below the zygomatic arch, about 4 cm. nt of the anterior wall of the external acoustic meatus. The needle should rected medially with a slight inclination upwards and backwards. rating the masseter and temporal muscles, the instrument enters the fatty
of the infra-temporal fossa, embedded in which is the internal maxillary y and some veins. By passing the needle still more deeply, it is made to rate between the two heads of the external pterygoid muscle through the go-maxillary fissure into the pterygo-palatine fossa. If the instrument be d too far forwards it will strike the maxillary tuberosity; if too far backs, the lateral pterygoid lamina. The cedema of the eyelids which not inently follows the operation is due to some of the fluid passing upwards into orbit through the inferior orbital fissure. The distance from the skin to the e, as it lies in the pterygo-palatine fossa, is practically 2 in. Should the le, after perforating the masseter, strike the coronoid process of the mandible, atter may be depressed by opening the mouth. The mandibular nerve is injected immediately beyond its exit from the nen ovale, which lies 4 cm. from the skin in the same vertical frontal plane
as the tuberculum articulare. When the mouth is opened widely the condyle of the mandible travels forwards and can be distinctly felt immediately below the tubercle. To avoid entering the mandibular joint the needle is introduced through the skin immediately below the zygoma, a little in front of the eminence. It is pushed medially and slightly backwards through the siginoid notch of the mandible, and thence through, or immediately above, the external pterygoid muscle, into the nerve. Symington points out that “the chief dangers connected with this operation are dependent upon the needle being passed in too far. Thus, if it be directed straight inwards beyond the depth of the nerve (4 cm.) it would penetrate the tensor veli palatini and the auditory tube and open on the lateral wall of the naso-pharynx; or, if directed somewhat upwards, it might pass through the foramen ovale, and even reach the cavernous sinus and the internal carotid artery, as the medial boundary of the foramen slopes upwards and inwards."
The facial nerve, after emerging from the stylo-mastoid foramen, is embedded i in the parotid gland, where it is superficial to the external carotid artery; the nerve can be rolled under the finger as it crosses the posterior border of the ramus of the jaw at the level of the lower margin of the tragus; incisions continued along the ramus above this point should be only skin deep if the nerve is to be avoided. To expose the trunk of the nerve an incision is made from the anterior border of the mastoid process to the angle of the mandible. Incisions upon the cheek should, whenever possible, be planned so as to run parallel with the branches of the nerve; these radiate from the inferior end of the tragus. The nerve may be paralysed by wounds of the cheek and by malignant tumours of the parotid, as also by intra-cranial and middle-ear lesions.
The parotid gland is surrounded by a fascial envelope, the strongest portion of which is continued from the deep cervical fascia over its superficial aspect to become attached to the zygoma (Fig. 1085); hence abscesses in the parotid tend to burrow deeply towards the pterygo-palatine fossa and the superior part of the pharynx (Fig. 1085); the pus should therefore be evacuated by Hilton's method, through an early incision over the angle of the mandible. A study of the relations of the gland explains the surgical difficulties which attend its complete removal
The parotid duct can be rolled beneath the finger as it crosses the masseter, rather less than a finger's breadth below the zygoma. After winding round the anterior border of the muscle it soon pierces the buccinator, and opens into the mouth opposite to the second molar tooth of the maxilla. The duct corresponds to the intermediate third of a line drawn from the inferior margin of the concha to a point midway between the ala nasi and the margin of the upper lip.
Superficial to the parotid and a little in front of the tragus is the pre-auricular lymph gland, which is frequently found to be inflamed in children suffering from eczematous conditions of the eyelids, face, scalp, and external ear. an abscess connected with this gland care must be taken to make the incision as low down as possible, so as to avoid the parotid duct.
The deep parotid lymph glands which lie partly in the substance of, and partly deep to, the inferior part of the parotid, form the highest group of the medial superior deep cervical lymph glands. They are especially liable to become infected secondary to tuberculous disease of the middle ear and to malignant affections about the root of the tongue, the fauces, and the naso-pharynx. In removing them it is generally impossible to avoid dividing the cervical branch of the facial nerve, which pierces the cervical fascia immediately below and behind the angle of the mandible. This nerve supplies the platysma and the depressor labii inferioris muscles, so that its division gives rise to inability to depress the lower lip on the affected side At the same operation some trouble may be caused by bleeding from the posterior facial vein and its divisions, which traverse the substance of the gland.
Eyelids.—The skin of the eyelids, more especially of the upper, is very thin and connected with the orbicularis oculi muscle by delicate and lax subcutaneous tissue destitute of fat; hence the marked swelling which occurs in a "black eye" and in cedema of the lids. Along the anterior edge of the free margins of the lids are the eyelashes and the orifices of the sebaceous glands, suppurative inflammation of which gives rise to a “stye”; along the sharp posterior edge of the free margins
minute orifices of the tarsal glands. These glands, embedded in the deep of the tarsi, are seen through the palpebral conjunctiva as a row of parallel, sh, granular-looking streaks. From the deep position of the glands it follows e skin over a Meibomian cyst is freely movable, and that to reach the cyst sion should be made through the conjunctival surface of the lid. - palpebral conjunctiva is closely adherent to the ocular surface of the tarsi; fornix it is loose and contains small lymph follicles, which become hyperd in the condition known as granular conjunctivitis. The ocular conjunctiva , transparent, and loosely attached to the sclera, so that in operating upon e a fold of the membrane can be picked up with forceps to steady the
nflammatory affections of the eye the state of those vessels which are visible gives unt information as to the seat of the mischief. For example, in inflammation of junctiva the posterior conjunctival vessels (derived from the palpebral arteries),
visible normally, appear as a close network which fades away towards the corneal ; these vessels move freely with the conjunctiva, and do not disappear under presIn superficial inflammations of the cornea the anterior conjunctival vessels (the uperficial of the terminal branches of the anterior ciliary arteries) are seen to in a freely branching manner into its superficial layers. In iritis and deep inflams of the cornea there is a pink circumcorneal zone of vascular dilatation consisting ate straight vessels which disappear under pressure and do not move with the cona; they are the subconjunctival (episcleral) terminations of the anterior ciliary 5; in health they are invisible. crimal Apparatus.---The lacrimal gland, situated behind the lateral part
supra-orbital margin, cannot be felt unless enlarged. By everting and the upper eyelid, the accessory (palpebral) portion of the gland is seen to t beneath the lateral third of the fornix, in which situation also the minute s of the lacrimal ducts may be detected. By gently drawing downwards wer lid, the small punctum lacrimale is seen situated upon a slight papillary ion of its margin about 4 min. from the medial palpebral commissure; the ponding orifice of the upper lid is placed a little nearer the commissure. ally the puncta are directed towards, and accurately applied to, the ocular activa immediately lateral to the lacrimal caruncle. By drawing the lids lly the medial palpebral ligament is put upon the stretch, and can be felt as row tense band passing transversely medially to be attached to the frontal ss of the maxilla. The ligament is a guide to the position of the lacrimal which it crosses a little above its centre. Continuous with the inferior end e lacrimal sac is the naso-lacrimal duct, which passes downwards and slightly wards and laterally, to open into the inferior meatus of the nose, under cover e anterior end of the inferior concha. The lacrimal sac and naso-lacrimal each measure about 1 in. in length; the latter is slightly contracted at its nencement and termination, and it is in these situations that pathological tures of the duct are commonest. Spontaneous rupture of an abscess of the mal sac almost invariably occurs just below the medial palpebral ligament; in this situation that the abscess should be opened, the incision being made tle lateral to the angular termination of the external maxillary artery. she canaliculi lacrimales, which convey the tears from the puncta to the lac1 sac, run for the first 1-2 mm. almost vertically to the free margins of the and thence parallel to them. Between the canaliculi is the lacrimal caruncle. the various morbid conditions which give rise either to misdirection of the cta or to stricture at any part of the lacrimal drainage apparatus, overflow the tears (epiphora) is the chief symptom. In passing a probe along a aliculus the instrument, in consequence of the bend upon the duct, is sed at first vertically to the margin of the lid, and afterwards parallel to it, il the point is felt to strike against the medial wall of the lacrimal sac; to s the instrument onwards along the naso-lacrimal duct the handle is rotated vards and upwards through a quarter of a circle, and then pushed gently downrds and slightly backwards and laterally into the inferior meatus of the nose.