In all cases the tumour tends to infiltrate the surrounding tissues indiscriminately. There is severe pain referred to the distribution of the maxillary division of the trigeminal nerve. Haemorrhage is liable to occur when exposed portions of the tumour ulcerate--for example in the nasal fossae. Sarcoma is to be distinguished from the solid and cystic forms of odontoma, which also may distend the bone, bulging the hard palate and projecting on the face.
_Treatment of Malignant Disease._--Without the help of radiation the results of operative treatment of malignant disease of the maxilla are far from encouraging. Probably the best line to follow is to embed several tubes of radium in different parts of the tumour for several days, and when the resulting shrinkage of the growth appears to have attained its limits, the maxilla should be excised. If on microscopic examination it is found to be a carcinoma, the glands on the same side of the neck should be removed at a second operation on lines similar to those in Butlin"s operation in cancer of the tongue. The aid of the dentist is required to fit a denture which will at least restore the hard palate and alveolar margin. The operation of excising the upper jaw is not a dangerous one, especially if the risk of broncho-pneumonia is minimised by the intra-tracheal administration of ether. The final illness in cases of malignant disease of the upper jaw left to nature, or when it has recurred after operation, is a terrible one; the growth displaces and destroys the globe, blocks the nose and fungating on the face, causes hideous disfigurement.
#Simple tumours# are rare. _Fibroma_ may originate in the periosteum or in the lining membrane of the maxillary sinus. It usually tends to a.s.sume the characters of sarcoma. _Chondroma_ usually begins either on the nasal surface of the bone or in the maxillary sinus. _Osteoma_ occurs in two forms: the exostosis, which may be composed of cancellated or of compact tissue, and the diffuse osteoma or leontiasis ossea (Volume I., p. 485). All intermediate forms are met with, and when confined to the maxilla, the resulting disfigurement may be improved or remedied by operation; the cheek is raised or reflected and the bone shaved away with a strong knife or osteotome.
#Tumours of the Mandible.#--The same varieties are met with as in the maxilla. The non-malignant forms--osteoma, chondroma, and fibroma--are rare.
A _dentigerous cyst_ appears as a smooth, rounded, and painless swelling, usually in the region of the molar teeth. The bone gradually becomes expanded and crackles on pressure. The cyst is filled with a glairy mucoid fluid, and may contain one or more unerupted teeth (Fig.
252). The X-ray appearances are characteristic. The treatment consists in removing the anterior wall of the cyst, sc.r.a.ping the interior, and packing the cavity with iodoform or bis.m.u.th gauze.
[Ill.u.s.tration: FIG. 252.--Dentigerous Cyst of Mandible containing rudimentary tooth.
(From Sir Patrick Heron Watson"s collection.)]
The myeloid tumour or _myeloma_ is comparatively common. It develops in the interior of the bone and expands the affected segment (Fig.
253). It grows slowly, is more or less encapsulated, and therefore does not infiltrate the surrounding tissues. Sometimes it so weakens the bone that pathological fracture occurs. There is no glandular involvement, and the tumour shows little evidence of malignancy.
[Ill.u.s.tration: FIG. 253.--Osseous Sh.e.l.l of Myeloma of Mandible.
(From Professor Annandale"s collection.)]
The _periosteal sarcoma_ is the most malignant form. It grows rapidly, and infiltrates the surrounding tissues. The submaxillary salivary glands and the cervical lymph glands are usually implicated, and the disease tends to spread by metastasis to distant parts.
_Epithelioma_ is the commonest new growth affecting the mandible; it usually involves the central portion of the bone, being a direct spread from the lower lip, tongue, or floor of the mouth. When it originates in the pillars of the fauces it implicates the ascending ramus. In all cases the infection of the cervical lymph glands is a serious factor both in prognosis and treatment.
_Treatment._--_Partial removal_ of the mandible may be undertaken for myeloma, and in cases of sarcoma and epithelioma in which the tumour is limited to a small area of the bone--for example, to the alveolar process, the angle, the horizontal ramus, or the symphysis; in other cases, the whole bone must be removed.
INJURIES OF THE JAWS
#Fracture of the Maxilla.#--Fractures of the maxilla are nearly always due to direct violence, such as a blow on the face, a stab, or a gun-shot wound. They are often rendered compound by opening into the mouth, into the maxillary sinus, or on to the skin of the cheek. The alveolar process, in whole or in part, may be separated from the body of the bone by a severe blow, such as the kick of a horse, and when the whole alveolus is detached, it may carry with it the hard palate.
Limited portions of the alveolus are frequently broken in the extraction of teeth. The main trouble after severe alveolar fractures is that the upper teeth do not accurately oppose the lower ones, and mastication is thereby interfered with.
When the frontal (nasal) portion of the maxilla is broken, the lachrymal sac and nasal duct may be damaged and the flow of the tears obstructed. In such cases emphysema is also liable to develop.
Fractures of the facial portion are frequently complicated by haemorrhage from the infra-orbital vessels, and anaesthesia of the area supplied by the infra-orbital nerve. Suppuration may occur in the maxillary sinus. In some cases the maxilla is driven in as a whole, and in others the fracture radiates to the base of the skull and cerebral symptoms develop.
The _treatment_ consists in reducing any deformity that may be present, ensuring efficient drainage, and keeping the mouth as aseptic as possible. Union takes place rapidly, and owing to the vascularity of the parts necrosis is rare, even when suppuration ensues. When the alveolar portion is comminuted, the fragments may be kept in position by fixing the mandible against the maxilla by means of a four-tailed bandage (Fig. 255), or by adjusting a moulded lead or gutta-percha splint to the alveolus and palate.
The _zygomatic (malar) bone_ is sometimes fractured by direct violence, along with the adjacent portion of the maxilla. It may be possible to manipulate the displaced fragments into position with the fingers introduced between the cheek and the gum; if this fails, a small incision should be made in the mucous membrane anterior to the ma.s.seter, and the bone levered into position with an elevator.
The _zygomatic arch_ is occasionally fractured by a direct blow. As the depressed fragments are liable to interfere with the movement of the mandible, they should be elevated either by manipulation or through an incision.
#Fractures of the Mandible.#--The most common situation for fracture of the mandible is through the _body_ of the bone in the vicinity of the canine tooth (Fig. 254). The depth of the socket of this tooth, and the comparative narrowness of the jaw at this level, render it the weakest part of the arch. The fracture is usually due to direct violence, such as a blow with the fist, the kick of a horse, or a fall from a height. It is sometimes bilateral, the bone giving way at the canine fossa on one side and just in front of the ma.s.seter on the other; or both fractures may be at the canine fossae. The fracture is usually oblique from above downwards and outwards, and is nearly always rendered compound by tearing of the mucous membrane of the mouth.
[Ill.u.s.tration: FIG. 254.--Multiple Fracture of Mandible.
(From Sir Patrick Heron Watson"s collection.)]
When only one side is broken, the smaller fragment is usually displaced outwards and forwards by the ma.s.seter and temporal muscles, so that it overlaps the larger fragment. In bilateral fractures the central loose segment is driven downwards and backwards towards the hyoid bone by the force causing the fracture, and is held in this position by the muscles attached to the chin, while both lateral fragments are tilted outwards and forwards by the ma.s.seters and temporals. The amount of displacement is best recognised by observing the degree of irregularity in the line of the teeth. Abnormal mobility and crepitus are readily elicited, and there is severe pain, particularly if the inferior dental nerve is stretched or crushed. The patient"s att.i.tude is characteristic; he supports the broken jaw with his hands, and keeps it as steady as possible when he attempts to speak or swallow. Saliva dribbles from the open mouth, and the speech is indistinct.
In adults, the bone may be broken at the _symphysis_ as a result of lateral compression of the jaw--for example, pressing together of the angles. The general characters of the fracture are the same as those of fracture of the body, but the displacement is inconsiderable.
Fractures of the _angle_ and through the _ramus_ are less common, and are not attended with deformity, as the fragments are retained in position by the ma.s.seter and internal pterygoid muscles. Fracture of the _coronoid process_ is rare.
The _condyle_ is usually fractured just below the insertion of the external pterygoid muscle (Fig. 254) by a fall on the chin or by a severe blow on the side of the face. When the fracture is unilateral, the broken condyle is tilted inwards and forwards by the external pterygoid, and can be palpated from the mouth, while the rest of the jaw is displaced _towards_ the affected side, and not away from it, as happens in unilateral dislocation. When the fracture is bilateral, the mandible falls backwards, so that the lower teeth lie behind those of the maxilla.
In a few cases the condyle has been driven through the floor of the glenoid cavity, causing fracture of the base of the skull. The diagnosis may be established by means of the X-rays.
_Complications._--As the majority of these fractures are compound, suppuration is comparatively common during the process of repair, but if means are taken to keep the mouth clean it can usually be kept in check, and seldom leads to necrosis. The teeth adjacent to the fracture are liable to be loosened or displaced. If merely loosened they should be left in place, as they usually become firmly fixed in the course of a few days. Care must be taken that a displaced tooth does not pa.s.s between the fragments, as this has been the cause of difficulty in reducing a fracture and of its failure to unite.
Irregular union, by destroying the alignment of the teeth, leads to interference with mastication. The bone usually unites in from four to six weeks. Want of union is a rare event.
_Treatment._--In the majority of cases of unilateral fracture after reduction, the fragments can be kept in apposition by closing the mouth and keeping the lower jaw fixed against the upper by means of a four-tailed bandage (Fig. 255). Care must be taken that the posterior tails of the bandage do not pull the mandible backward. Additional security may be given by a light poroplastic or gutta-percha splint fitted to the chin, the vertical portion pa.s.sing well up the ramus of the jaw. After a few days the apparatus is removed, the patient is encouraged to move the jaw, and ma.s.sage is employed. The mouth must be regularly cleansed by an antiseptic mouth-wash, or by a spray of hydrogen peroxide.
[Ill.u.s.tration: FIG. 255.--Four-tailed Bandage applied for Fracture of Mandible.]
In certain fractures implicating the body of the jaw, and particularly when bilateral, the co-operation of the dentist is necessary to obtain the best results. After the fragments have been coapted, a plaster impression is taken of the jaw and teeth, and from this a silver frame is cast which surrounds but does not envelop the teeth. This frame is then applied to the fractured jaw, and restrains movement of the fragments without interfering with the action of the jaw (W. Guy).
The use of an intra-oral frame obviates the necessity of wiring the fragments.
Even in badly united fractures the original contour of the bone is eventually restored by the movements of the tongue moulding it into shape.
AFFECTIONS OF THE TEMPORO-MANDIBULAR ARTICULATION
#Dislocation of the Mandible.#--Dislocation of the lower jaw may be unilateral or bilateral. The bilateral form is the more common, and is met with most frequently in middle life, and in females. The liability to dislocation is greatest when the mouth is widely open--for example, in yawning, laughing, or vomiting--as under these conditions the condyle, accompanied by the meniscus, pa.s.ses forwards out of the glenoid cavity and rests on the summit of the articular eminence. If, while the bone is in this position, the external pterygoid muscle is thrown into contraction, it pulls the condyle forward over the eminence into the hollow beneath the root of the zygoma, and the contraction of the ma.s.seter and temporal muscles retains it there.
Muscular contraction is therefore an important factor in its production.
Dislocation may be produced also by a downward blow on the chin, by the unskilful introduction of a mouth gag, particularly while the patient is anaesthetised, or even in the attempt to take a big bite--say, of an apple. The dislocation that results from such causes is usually unilateral.
In some persons the ligaments of the joint are unnaturally lax, and dislocation is liable to occur repeatedly from comparatively slight causes--_recurrent dislocation_.
_Clinical Features._--The appearance of a patient suffering from _bilateral_ dislocation is characteristic. The mouth is open, the jaw fixed, and the chin protruded so that the lower teeth project beyond the upper. The patient has difficulty in swallowing, and the saliva dribbles from the mouth. As the lips cannot be approximated, the speech is indistinct and guttural. Just in front of the auditory meatus a deep hollow can be felt, and in front of this the condyle forms an undue projection. The coronoid process is displaced below and behind the zygomatic (malar) bone, and may be felt through the mouth.
The contracted temporal muscle forms a prominence above the zygoma.
In _unilateral_ dislocation the deformity is the same in character, but is less marked, and in mild cases its cause is liable to be overlooked. In most cases the chin deviates towards the sound side.
_Treatment._--In recent cases, reduction is usually easily effected.
The patient should be seated on a low chair or stool, an a.s.sistant supporting the head from behind. The surgeon, standing in front, places his thumbs, well protected by a roll of lint, far back on the molar teeth, and with his other fingers grasps the body of the jaw.
Pressure is now made downwards and backwards to free the condyles from the articular eminence, and to overcome the tension of the temporal and ma.s.seter muscles, and as this is effected the tip of the chin is carried upward, while the whole jaw is pushed directly backward. The condyle slips into position, sometimes with a distinct snap. When difficulty is experienced in levering the condyle from its abnormal position, a cork may be placed between the molar teeth on each side to act as a fulcrum. After reduction the jaw is fixed by means of a four-tailed bandage for a few days. The patient is warned to avoid for some weeks opening the mouth widely.
_Old-standing Dislocation._--It sometimes happens that, from having been overlooked or neglected, the dislocation remains unreduced. In such cases the movement of the jaw is in time partly restored, and the patient acquires sufficient control of the lips to be able to articulate intelligibly and to prevent dribbling of saliva. The power of masticating the food, however, remains impaired. The hollow behind the condyle and the projection of the chin persist. Reduction by manipulation is seldom possible after the dislocation has existed for more than three months, but it has been effected as long as ten months after the accident. Several attempts at reduction should be made at intervals of two or three days, and if these fail recourse may be had to operation. As the ma.s.seter and internal pterygoid muscles have a.s.sumed a vertical position and become shortened, they form an obstacle to reduction, and to overcome their action it is necessary to separate them from their insertion to the ascending ramus of the bone through an incision carried round the angle. If the adhesions about the dislocated condyle are then separated, reduction can be effected (Samter). In some cases it is necessary to excise the condyle to restore movement.
_Internal Derangements of the Temporo-mandibular Joint._--The intra-articular cartilage is liable to be displaced by excessive traction exerted on it by the external pterygoid muscle during some sudden movement of the joint, particularly in closing the mouth.
There is acute pain in the region of the joint, the teeth on the affected side cannot be brought into apposition, so that mastication is interfered with, and the patient is conscious of something locking inside the joint. The joint is tender to the touch, but there is no external swelling. Replacement is effected by keeping up firm pressure at the back of the condyle with the mouth open, and slowly closing the jaw. If recurrence takes place repeatedly, the disc may be sutured to the periosteum (Annandale), or excised (Hogarth Pringle).
#Arthritis# of the temporo-mandibular joint occurs in two forms, non-suppurative and suppurative.
The _non-suppurative_ form is usually due to gonorrhal infection, and as a rule is bilateral. The patient complains of neuralgic pains shooting towards the ears and temples, and of pain in the joint on movement. The jaw is therefore kept fixed, usually with the mouth slightly open and the chin protruded. Mastication is impossible, and the speech is indistinct. There is effusion into the joint, and a swelling may be detected in front of the ear. The inflammation may subside and movement restored, or fibrous ankylosis may ensue.
The _suppurative_ form may be due either to direct spread of infection from adjacent parts, as, for example, in middle ear disease, suppurative parot.i.tis, or pyogenic affections of the mandible, or it may be part of a general pyaemic infection, as sometimes occurs after exanthematous fevers and in gonorrha. The clinical features are similar to those of the non-suppurative form, but the signs referable to the joint are often masked by those of the primary lesion. When the pus originates in the joint, it may point either towards the skin or into the external auditory meatus through the petro-tympanic (Glaserian) fissure. The joint is usually completely disorganised and ankylosis results.