Epistaxis

Although in the majority of patients this is a relatively easy clinical problem to deal with, this may not always be the case and in certain situations the haemorrhage may be life threatening. The most common site of bleeding is from Kiesselbach’s plexus in Little’s area of the anterior portion of the septum . The usual cause is microtrauma to these blood vessels sandwiched between the mucosa and the underlying cartilage. In young children, heavy bleeding sometimes occurs from an engorged retro-columellar vein. Less often bleeding arises from the lateral nasal wall. Anterior bleeding is common in children and young adults as a result of nose blowing or picking. In the elderly, arteriosclerosis and hypertension are the underlying causes of arterial bleeding from the posterior part of the nose. The degeneration of the muscle layer of small arteries with age and the gradual replacement with collagen and calcification hinder post­traumatic vasoconstriction and prolong bleeding. Less common causes are trauma, foreign bodies within the nose, blood diseases, disorders of coagulation and malignant tumours of the nose or sinuses. Nasopharyngeal angiofibroma is a rare condition that affects boys and may lead to massive life-threatening attacks of bleeding. Hereditary haemorrhagic telangiectasia (Osler’s disease) gives rise to recurrent multifocal bleeding from thin-walled vessels deficient in muscle and elastic tissue .

Management of epistaxis
Bleeding from Kiesselbach’s plexus may be controlled by silver nitrate cautery under local anaesthesia. Bleeding from further back in the nose, as seen in the elderly, may require anterior nasal packing with Vaseline-impregnated ribbon gauze. The packing is inserted in layers starting on the floor of the nasal cavity. Sometimes hypoxia can be induced by nasal packing and may be exacerbated in patients with chronic obstructive airways disease. The packing is usually kept in place for 48 hours and the patient commenced on a broad-spectrum antibiotic. An alternative to anterior packing is the use of an epistaxis balloon catheter (Fig. 39.9). The catheter is inserted in the nose and the distal balloon is inflated first within the choana to secure the catheter and then the proximal balloon, which is sausage shaped, is inflated within the nasal cavity proper. These catheters are usually effective but can be quite uncomfortable.
Sometimes anterior nasal packing alone is not sufficient to control haemorrhage and posterior nasal packing may be required. This is usually carried out under general anaes­thesia inserting a gauze pack into the naso pharynx, which is then secured by tapes passed through each side of the nose and tied together across a protected columella. A third tape is brought out through the mouth and taped to the patient’s cheek. The nasal fossae are then packed with anterior nasal packs. All packs are left in for 48 hours and prophylactic antibiotics are given. The tape attached to the cheek is to facilitate removal of the pack usually without a general anaesthetic.
In uncontrolled life-threatening epistaxis where the above methods have proved ineffective, haemostasis is achieved by vascular ligation. Depending on the origin of bleeding itmay be necessary to ligate the internal maxillary artery in the pterygopalatine fossa and the anterior and posterior eth­moidal arteries within the orbit. An alternative measure is external carotid artery ligation above the origin of the lingual artery.
In Osler’s disease anterior nasal packing is best avoided if at all possible because it is most likely to lead to further mucosal trauma and bleeding. High-dose oestrogen induces squamous metaplasia of the nasal mucosa and has been used effectively in treating this condition. In some cases however, it may be necessary to resort to excision of the diseased nasal mucosa via a lateral rhinotomy and replace it with a split skin graft — a procedure known as septodermoplasty. It is not unknown, however, for the grafted skin to undergo similar abnormal vascular change over time.

Epistaxis — summary
•Young people bleed from the anterior septum —Kiesselbach’s plexus
•Older people bleed from the posterior part of the nose
•Silver nitrate cautery is good for controlling anterior septal bleeding
•Moderate bleeding may require anterior nasal packing
•Severe bleeding may require anterior and posterior nasal packing
•Persistent bleeding will probably require arterial ligation

Trauma to the nose

Injuries to the nose are commonly sustained in fights, sport­ing injuries and road traffic accidents. A blunt injury of moderate force may lead to springing of the nasal septal cartilage with separation of the overlying mucoperichondrium. Bleeding into this potential space will cause a septal haematoma which may be unilateral or bilateral. The haema­toma will give rise to nasal obstruction and can be easily overlooked in the presence of extensive facial injuries. It is, however, an important diagnosis not to miss because untreated, a septal haematoma will progress to abscess forma­tion and ultimately result in necrosis of the septal cartilage. Robbed of this support the tip of the nose will collapse. A septal haematoma should be treated by incision and evacuation of the blood clot. The insertion of a small silicone drain and packing of the nasal fossa will prevent reaccu­mulation and encourage the mucoperichondrium to readhere to the septal cartilage. A broad spectrum prophylactic antibiotic should be prescribed.
A more violent blunt injury to the nose can fracture the nasal bones. This may be a simple crack of the nasal bones without displacement, but greater force may result in deviation of the bony nasal complex laterally (Fig. 39.7) or depression of the bony pyramid if the blow is directly from the front. Greater impacts from this direction may cause a comminuted fracture and widening of the nasal bones or involve the lacrimal bones causing a nasoethmoidal fracture. Lateral injuries with displacement of the nasal bones may also be associated with a C-shaped fracture of the septal cartilage and the anterior portion of the perpendicular plate of the ethmoid (Jarjavay fracture). Nasal bone fractures can extend into the lacrimal bone tearing the anterior ethmoidal artery to produce catastrophic haemorrhage. This may be delayed, occurring only as the soft-tissue swelling subsides and the torn artery opens up.
Violent trauma to the frontal area of the nose can result in a fracture of the frontal and ethmoid sinuses extending into the anterior cranial fossa. Dural tears and brain injuries are then at risk from ascending infection through the fracture line from the nose or sinuses which may progress to meningitis or a brain abscess.
Cerebrospinal fluid (CSF) rhinorrhoea is a certain sign of a dural tear. There may be associated surgical emphysema, proptosis with or without loss of vision or frontal pneumoencephalocele. Anosmia occurs in 75 per cent of patients with these injuries, and cranial nerves II—VI may be injured. A clear discharge from the nose may be confirmed to be CSF by a simple stix test demonstrating the presence of glucose, which is not present in nasal mucus. Such injuries are man­aged by neurosurgical exploration to remove bone fragments, repair the skull base and close the dura. Late complications of this injury include CSF fistula, recurrent late meningitis, brain abscess, osteomyelitis and the formation of mucopyoceles.

Management of fractured nasal bones
Fractured nasal bones are often accompanied by extensive overlying soft-tissue swelling and bruising which may hinder the assessment of the underlying bony deformity. Reviewing the patient 4—5days later will give time for the soft-tissue swelling to subside and make subsequent assessment of any deformity much easier. If a fracture to the nasal bones has caused a significant degree of nasal deformity then this should be corrected by manipulation of the nasal bones under general anaesthesia. This must he carried out within 10 days of the injury while the bony fragments are still mobile. The deviated nasal bones are repositioned to restore the correct alignment of the nose or, in the case of a depressed fracture, the fragments are elevated and supported if necessary with anterior nasal packing. Often a satisfactory result can be obtained by simple manipulation, but should this fail then a rhinoplasty procedure (see later) may be necessary at a later date to obtain further improvement in the appearance of the nose. Any blow to the nose may cause displacement or fracture of the cartilaginous septum giving rise to post-traumatic nasal obstruction. Unlike the nasal bones, the nasal septum cannot be manipulated back into position and requires a formal septoplasty to restore the anatomy and the patency of the nasal airways (see later).

Nasal trauma — summary
•Do not overlook a septal haematoma
•Displaced nasal bone fractures should be reduced within 10 days of injury
•Severe epistaxis suggests lacrimal bone fracture and anterior ethmoid artery injury
•CSF rhinorrhoea indicates fracture involving frontal or ethmoid sinuses with a dural tear

Fractures of the facial skeleton and treatment

Fractures of the facial skeleton may be divided into those in the upper third (above the eyebrows), the middle third (above the mouth) and the lower third (the mandible). Frac­tures tend to occur through points of weakness — the sutures and foramina, and in thin unsupported hone.

The upper third
The patterns of fracture of the skull tend to be random but there are points of weakness, mainly involving the frontal sinuses and the supraorbital ridges.

The middle third
Fractures of the middle third of the face have been studied extensively and René Le Fort in 191 1 classified fractures according to patterns which he created on cadavers using vari­ous degrees of force. The Le Fort classification is used exten­sively today throughout the world. While Le Fort classified the fractures from superior to inferior, the custom today is that the classification runs inferiorly to superiorly .
The Le Fort I fracture effectively separates the alveolus and palate from the facial skeleton above. The fracture line runs through points of weakness from the pyriform aperture, through the lateral and medial wall of the maxillary sinus running posteriorly to include the lower part of the pterygoid plates.
The Le Fort II fracture is pyramidal in shape. The fracture involves the orbit, running through the bridge of the nose, and the ethmoids whose cribriform plate may be fractured, leading to a dural tear and CSF leak. It continues to the medial part of the infraorbital rim, through the infraorbital foramen and through the infraorbital fissure. The orbital floor is always involved. It continues posteriorly through the lateral wall of the maxillary antrum at a higher level than the Le Fort I to the pterygoid plates at the back. The nasal septum is displaced and lateral walls of the nose are fractured.
The Le Fort III fracture effectively separates the facial skeleton from the base of the skull — the fracture lines run high through the nasal bridge, septum and ethmoids, again with the potential for dural tear and CSF leak, and irreg­ularly through the bones of the orbit to the frontozygomatic suture. The zygomatic arch fractures, and the facial skeleton is separated from the bones above at a high level through the lateral wall of the maxillary sinus and the pterygoid plates. The nasal septum will he fractured and may be displaced.
These fractures are seldom confined exactly to this classification and may be combinations of any of the above.

The zygoma
This is the most common fracture of the middle third of the face apart from the nose, as the patient turns the cheek to approaching danger. The fractures occur though points of weakness — infraorbital margin, the frontozygomatic suture, the zygomatic arch and the anterior and lateral wall of the maxillary sinus. Tears on the mucosa of the antrum lead to bleeding from the nose. The infraorbital plate of bone is always involved to a greater or lesser extent and may cause entrapment of the orbital contents.

Blow-out fractures of the orbit
Direct trauma to the globe of the eye may push it back within the orbit. The globe is a fairly robust structure and as it is thrust backwards, the pressure increases within the orbit and the weaker plates of bone may fracture, without necessarily fracturing the bones of the orbital rim. Such injuries can occur where a pointed object hits the globe of the eye — for example, a bent elbow of a standing man inadvertently being thrust into the orbit of a person sitting. A finger deliberately thrust into the eye may have the same effect. The weakest plate of bone, commonly the infraorbital plate, ruptures and the orbital contents herniate downwards into the maxillary antrum. On rebound, as the pressure within the orbit is reduced, the small fractured pieces of bone may entrap the orbital contents, particularly the inferior oblique and inferior rectus muscles, leading to failure of the eye to rotate up­wards. Enophthalmos and profound diplopia can follow although initially both may he concealed by oedema. Anaes­thesia over the distribution of the infraorbital nerve may be an important clue to the blow-out fracture. Pain is experi­enced on movements of the eye as the entrapped muscle is stretched. There may be enophthalmos although this may be masked in the early stages by oedema. Any fracture that may involve the orbital floor (Le Fort II and zygomatic bone) must be considered a potential for orbital content entrapment too.

Fractures of the mandible
These are usually as a result of blows from the side or from the front to the lower third of the face. The condylar neck is the weakest part of the bone and is the most frequent site of fracture (Fig. 38.6) while other fractures tend to occur through un erupted teeth (the impacted wisdom tooth) or where the roots are long (the canine tooth). Blows from the side may fracture at the point of injury but, as the force is transmitted to the base of the skull via the condylar neck, this may fracture first. Blows from the front may cause fracture in the midline and fractures of both condyles. Individual sharp blows with a blunt instrument may fracture a segment away from the mandible. Blows from below may cause the mandible to be thrust upwards fracturing the alveolus and teeth as they hit their fellows in the maxilla. Fractures of the mandibular body may also fracture the teeth in the fracture line.
Much has been made in the past of the ‘butterfly’ fracture of the mandible. Here a segment of mandible in the midline is detached from the rest of the mandible with fractures in the canine regions. The segment of bone takes on the appear­ance of a butterfly, and this will include the anterior insertion of the tongue (geniohyoid and genioglossus). Conceptually, the tongue may fall back and occlude the airway. First, the fracture is extremely rare, and second, the patient can still control the tongue, if allowed to by a good nursing position (see above).

Treatment

Soft-tissue injuries
Facial soft tissues have an excellent blood supply and heal well. They should be sutured as soon as possible after the injury after careful exploration, débridement and cleaning, particularly where glass or plastic may be embedded. The tissues should be meticulously clean and scrubbed, as retain­ed dirt may cause tattooing and hypertophy of the scar. Many lacerations may be closed using local anaesthesia, injecting into the edges of the wound. If the patient is due to have a general anaesthetic and there is a delay, the wounds should be closed in advance by local anaesthesia. Tissue sufficiently traumatised to have lost its blood supply should be removed with a sharp scalpel, and the edge to which it is to be apposed trimmed to fit as appropriate.
Great care should be taken to replace tissues very accurate­ly, particularly in cosmetically important landmarks such as the vermillion border of the lips, the eyelids and nasal contours. Haemostasis is important. Muscle and underlying layers should be brought together with absorbable sutures so that the edges of the wound lie passively within 2 mm of their final position. Then fine monofilament sutures (5-0 or 6-0) are used to bring the wound edges together (Fig. 38.7). All sutures should be placed so as to avoid compromising the blood supply of the apices of small flaps. Vacuum drains are used where there is concern over dead space beneath the wounds. The lacerations should be covered by antibiotic ointment and this should be replaced two to three times per day. This prevents the sutures causing scarring of the skin. Intravenous dexamethasone 8 mg twice daily for 2 days and broad-spectrum antibiotics should be prescribed. Sutures may be removed from the third day.

Facial nerve injury
The facial nerve may be severed in the depth of a lateral facial wound. If this is suspected, primary repair should be attempted, particularly where clinical signs suggest that a main division is involved. Locating the divided branches in oedematous and damaged tissue may be extremely difficult. Proximal and distal flaps in relatively normal adjacent tissue may have to be raised to identify the nerve on each side of the laceration. The severed nerve may then be traced towards the laceration and the ends approximated using an operating microscope, and the nerve and laceration sutured. Attempt at primary repair is always worthwhile, although extremely difficult, as secondary repair is generally unsatisfactory.

Parotid duct
Lacerations in the same vicinity as those that transect the facial nerve may also transect the parotid duct. The suggested management is to insert a small cannula in the parotid duct from within the mouth and then pass it distally until it appears in the wound. The position of the duct is identified and the proximal end may be found from the site of the distal end as the tissues are approximated and the cannula runs into it. The laceration of the facial tissues may be sutured in the normal way avoiding any tendency to displacement across the ends of the duct. Some advise that the parotid duct is sutured side to side to avoid stricture. Two days of intravenous dexamethasone (8 mg twice a day) should follow the surgery. Antibiotics are recommended.

The lacrimal apparatus
The lacrimal apparatus may be involved in damage to the eyelids and nasal bones in Le Fort II and III injuries. The tissues are generally grossly oedematous and the manipula­tion required to reduce the fractures adds to the difficulties of identifying the cannaliculae. Most surgeons do not attempt repair primarily but refer to an appropriate plastic or ophthalmic surgeon if epiphora become a problem later. Surprisingly, few patients suffer epiphora after a year has elapsed from the injury.

Injuries to the facial bones

The fractured nose
This is the most common fracture of the face. Best results are achieved when oedema has been allowed to settle so that accurate reduction can be achieved. Reduction of oedema may be assisted by intravenous or intramuscular dexametha­sone 8 mg twice daily preoperatively. However, surgery should not be left for longer than a week, as reduction may become difficult or impossible. Accurate reduction always requires a general anaesthetic and an endotracheal tube. A throat pack should always be inserted. Reduction should be directed first to repositioning the nasal bones, disimpacting with Walshams’s forceps with the external blade covered with rubber tubing so as to avoid damage to the skin. The nasal bones are first taken laterally to disimpact them, and then medially to reposition them. It is wise to start on the side opposite to the blow which broke the nose. The septum is then grasped with Asch’s forceps, manipulated until it is straight, and then positioned in the groove of the nasal crest and vomer. Asch’s forceps may be used to pull the disimpacted nasal bones forward to their previous un fractured position. If there is a suggestion that the insertion of inner canthi has been involved, or the nasal bones have been thrust into the ethmoid sinuses, then open reduction may be required (see treatment of Le Fort III). The nasal bones may need supporting by a pack within the nasal bridge. This is best done using ribbon gauze inserted into the finger(s) of a rubber surgical glove previously placed beneath the reduced nasal bones (to reduce the discomfort of pack removal at 3 days). A protective nasal plaster may be placed and removed at 1 week.

Fractures of the maxilla
Treatment of fractures of the maxilla should be undertaken in a maxillofacial unit. They always require a general anaes­thetic given through a cuffed nasotracheal tube. Careful intubation is required ensuring that the tube is directed post­eriorly, not superiorly, on insertion. Correctly placed tubes are of no risk to the cranial base however extensive the frac­ture. Occasionally it may be necessary to begin the operation with an oral tube, and then transfer to a nasal tube once the maxillas reduced and held. Final positioning of a concomitant fractured nose may be left until the end of the operation, just after the nasal tube has been removed. Conversely, if it is necessary to leave in a nasopharangeal airway, a second airway should be inserted in the other nostril, so as to keep the nares equally distended. A tracheostomy may be required occasionally.
The principle of reducing and stabilising fractures of the frontal and facial bones is that the surgeon starts at the top and works down. Where there are extensive lacerations,these may be used, perhaps with small extensions, to approach the fracture lines. Where there are no convenient lacerations, fractures of the frontal bone and supraorbital ridges and fractures of the nasal root may be approached through a coronal incision at the vault of the skull, high in the hair line. The incision is taken from just in front of each ear across the vault of the skull and reflected forwards until the supraorbital ridges are exposed. The supraorbital nerve is identified and freed and the flap extended as required. The nasal root, the lateral orbital rim and zygomatic arch may be exposed through this route. All of the fractured bones may be reduced and held by stainless steel or titanium miniplates or microplates and wires, under direct vision. Bone deficiencies in this area or in the infraorbital plate may be made up with free cranial cortical bone grafts, with the donor sites available through the coronal incision. Where the nasal bones are spread, leading to an orbital hyperteleorism, the root of the medial canthal ligaments may be identified and sutured to the opposite side to restore canthal width.
When the stabilisation of the upper part of the face is complete, attention may be given to the midface. Incisions in the lower eyelid (blephoroplasty incisions) or lower con­junctival sac are used to explore fractures of the infraorbital margin. These also give access to the orbital floor and are used to treat blow-out fractures. The rim may be fixed using miniplates or microplates or wires as above, and the floor of the orbit reconstituted with bone, titanium or alloplastic material according to choice, held by wires or screws.
The lower part of the maxilla is approach through a gingival sulcus incision above the maxillary teeth as far back as the second molar. Fractures may be identified with ease through this route and fixed with plates or wires. The dental arch is restored to its original shape as far as possible so that it matches the previous occlusion with the lower teeth. To achieve accurate location, dental arch wires or eyelet wires (see below) may need to be inserted. Where this is anti­cipated, the necessary wiring is done before the main part of the operation is commenced.
The principle of treatment is to restore the fragments to their original position. To achieve this, usually it is necessary to reduce the maxilla first with Rowe’s disimpaction forceps which grasp the palate between the nasal and palatal mucosa. Considerable force is sometimes required in a series of downward, forward and sideways movement to free it, particularly where the operation has been delayed. After 3 weeks, full disimpaction is often impossible.
With the advent of miniplates and microplates, indirect fixation with pins and halo frame is seldom used. If the fragments are multiple and the whole restored maxilla remains unstable, external fixation may be the only answer. Then the principle is that the mandible is fixed to the cranium, with the maxilla as a sandwich between the two. Cranial fixation is by a halo or supraorbital pins, and mandibular fixation is by pins inserted in the body on each side. All of the pins are con­nected together with connecting bars secured by universal joints. When the teeth of each jaw are fixed together with intermaxillary fixation (see below) the anteroposterior position of the face is likely to be correct. The vertical dimension is adjusted through the connecting bars fixed by universal joints on to the pins. This means that the jaws are fixed together during recovery, and careful attention should be given to advising the recovery staff on how to release the apparatus in an emergency.

Fractures of the mandible
Fractures of the mandible frequently are reduced and then fixed with intermaxillary fixation (IMF). IMF is a means of splinting the upper and lower arches of teeth together. First, eyelet wires or arch bars are fixed to the upper and lower teeth. Eyelet wires consist of a small loop about 4 mm in diameter twisted in the centre of a length of 0.35-mm stain­less steel wire. Each loop is threaded between and around pairs of teeth, and twisted together on the buccal side, with one of the ends going through its own loop. This makes very secure fixation. Four or five eyelets are required for each dental arch. These are most suitable where there is a full, or near full, arch of teeth in each jaw. Where there has been tooth loss with irregular gaps around the mouth, then arch bars may have to be used. These are prefabricated lengths of stainless steel tape or wire, with hooks coming off at 8—10-mm intervals. These are wired to individual teeth so that there are two arch bars opposing one another in each jaw. IMF is applied between the loops of the eyelet wires or the hooks of the arch bars. In the past, custom-made silver cap splints were used, cemented to the opposing jaws. These are rarely used now.
For future comfort of the patient, it is very important to restore the dental occlusion to its original position. With simple minimally displaced fractures, eyelet wiring is all that is required (Fig. 38.8). This may be achieved without general anaesthetic. Undisplaced fractures and fractures of the mandibular condyle may require no active treatment.
Displaced fractures, or fractures which have markedly dis­turbed the occlusion, will require a general anaesthetic. A cuffed nasotracheal tube is required without a throat pack (a throat pack may make it difficult to achieve the correct occlusion). Fractures of the body of the mandible may be explored through intra oral or extra oral incisions according to the access required, and the fractures reduced and fixed with miniplates and/or wires. Any fractured teeth should be removed and also those previously compromised by exten­sive caries or infection. It is unnecessary to remove healthy teeth in the fracture line. To be sure of achieving a correct occlusion it is wise to use temporary intraoperative IMF. There are occasions when the best results can be achieved with IMF alone. In this event, it is necessary to remove the IMF during recovery, so as not to risk complications involving the airway. IMF may be inserted after 12 hours when the patient has recovered from the general anaesthetic. It is retained for 3—4 weeks.
Fractures of the edentulous mandible generally are plated using miniplates. In the atrophic mandible, the raising of periosteum should be kept to a minimum as the blood supply to the jaw may be compromised. Where there is fear that the blood supply may be seriously disadvantaged by the insertion of plates, Gunning’s splints may be constructed. These require dental impressions and are then constructed in the laboratory. In effect, these are like upper and lower dentures, but with the teeth replaced with plastic in which hooks are placed (the patient’s dentures may be used). Each splint is wired to the respective jaw the mandible, with wires going around the mandible (circumferential wires) and the maxilla, with wires going around the zygomatic arches. The circumferential wires around the mandible are sited to stabilise the fracture line. The hooks placed on the buccal surfaces of the plastic arch are used to apply IMF when the patient has recovered from the anaesthetic. The IMF is released after 4—6 weeks.
Fractures of the mandibular condyle may cause disturbance to the occlusion with deviation of the mandible to the side of the fracture. In unilateral fractures, this disturbance may correct spontaneously in a few days. If it is still present at 10 days, or where both condyles are fractured, open surgery may be required to one of the condyles to prevent an anterior open bite developing. The open bite occurs due to the vertical pull of the muscles of mastication shortening the ramus. The posterior teeth contact first and the anterior teeth remain apart. Functionally and cosmetically, this is very undesirable and is almost impossible to counteract by sec­ondary procedures. Simply to fix the mandible in IMF, with or without posterior block to overcome the tendency to open bite, is insufficient. Direct surgical approaches to the condylar neck are difficult owing to the parotid gland and facial nerve lying in close proximity. Preauricular incisions combined with incisions at the lower border of the mandible do give access but reduction of the bones is difficult through these approaches. A simple and effective approach is via a tangential incision at the angle of the mandible that gives access to the bone beneath, between the facial and cervical branches of the facial nerve. The angle of the mandible is identified and the periosteum raised up both sides of the ramus as far as the fracture line. Access to the displaced condyle is achieved by removing the posterior border of the mandible with a vertical subsigmoid cut, running from the sigmoid notch of the mandible down to the angle of the jaw. The condyle may then be removed and offered up to the excised segment of mandible. The two bone fragments are located and fixed together with miniplates outside the body. The restored bone is then returned to the patient and secured to the distal mandible with a miniplate.

Fractures of the zygoma
Second to the fractured nasal bone, this is the most common fracture of the maxilla. Displacement is usually posteriorly, but it is important to assess the actual displacement by study­ing the occipitomental radiographs. Most fractures may be reduced by the Gillies approach. This entails an incision in the hairline superficial to the temporal fossa about 15 mm long, at 45degree to the vertical. It is deepened down to and through the temporal fascia. A channel is prepared behind the fascia and down to the body of the zygoma and arch. A Bristow’s or Rowe’s elevator is then inserted beneath the body of the zygoma or arch, according to the site of fracture. Considerable force is applied in the opposite direction to that calculated to have been delivered by the blow which caused the fracture. After reduction, the position of the zygoma can be checked by palpating the bony prominences of the arch, and the lateral and inferior orbital rims. As all fractures of the zygoma involve the orbital floor, it is essential to apply a forced duction test to the globe to ensure that the inferior oblique or inferior rectus muscle is not trapped. For this to be done properly, the lower eyelid should be retracted and the inferior rectus muscle grasped in the lower fornix. The globe can then be rotated upwards and should move freely. Any restriction in movement suggests entrapment of intra orbital tissues and the floor of orbit should be explored as for a blow-out fracture (see below). It is essential to warn the anaesthetist that this manoeuvre is being done, as it can lead to a severe bradycardia.
Should the fracture seem unstable, direct wiring or plating may be necessary. The frontozygomatic suture should be exposed by a small incision just behind the lateral part of the eyebrow and visualised. Displacements may be reduced and generally the fracture becomes stable once this fracture is fixed. Occasionally it is necessary to explore and fix fractures of the infraorbital rim (see above).
If the fragments are very unstable owing to comminution, packing the antrum via a Caldwell—Luc incision in the mouth may be necessary. The antrum should be first examined using a fibre-optic light source, with particular attention given to the orbital floor. Then, with the orbital floor reduced and protected, and the body of the zygoma supported by an assistant, the antrum may be packed from above down with a 2-inch ribbon gauze soaked in Whitehead’s varnish. Great care must be exercised not to overpack the antrum and displace the orbital contents. The incision is closed with a tail of ribbon gauze sutured into the wound to allow drainage. The pack is removed at 3 weeks.
All patients who have had operations around the orbit should be observed formally at 15-minute intervals for 9—12 hours. The condition of the eye, the pupil size and the appre­ciation of light should be recorded. Occasional complications arise, the most serious of which is a developing haematoma in the peri orbital tissues or the cone between the ocular mus­cles. Increasing exophthalmous and loss of vision constitute a postoperative emergency requiring immediate action to reduce the pressure of the haematoma.

Blow-out fractures
The mechanism has been explained above. The floor of the orbit is approached either through a blephoroplasty incision in the lower eyelid or through the inferior fornix. Keeping superficial to the tarsal plate of the lower lid, the infraorbital margin is identified and the periosteum raised, being careful not to displace the delicate fragments of bone constituting the fracture. The peri orbital tissues are gently separated from the bones of the fracture and freed so that no trapping remains. The apex of the orbit should not be explored for fear of damage to the optic nerve or spasm of the retinal artery. Defects of the orbital floor may be made up with bone from the cranium (see above) or the opposite antral wall, titanium mesh, or other suitably rigid materials. Reinforced silastic sheet is no longer thought adequate. The materials are fixed with wires, screws or plates and the wound is closed.

General
Fractures of the facial skeleton are almost always compound and prophylactic antibiotics are important. Penicillin and metronidazole singly or in combination are ideal for those patients who are not allergic. The cephalosporins are an alternative. Where there is the possibility of a CSF leak from a dural tear above a fractured cribriform plate of the ethmoidbone (Le Fort II and III), suitable antibiotics which cross the blood—brain barrier (chloramphenicol, for example) should be given to avoid the risk of meningitis or later intracranial abcess. All patients with fractures of the facial skeleton bene­fit from intraoperative and postoperative dexamethasone, to reduce swelling.
Intermaxillary fixation makes it impossible to chew It is important that the patient receives the advice of a dietician so that high calorific value food may be taken through the IMF. It is surprising how patients find a way to take fluid and semi-solids through clenched teeth. In the badly injured, parenteral feeding may be required. It is wise to leave a nasogastric tube in place, inserted at the time of operation, for as long as food cannot be taken normally.

Dislocation of the mandibular condyles
Dislocation of the mandibular condyles is a relatively uncommon condition and occurs usually after a wide opening of the mouth. Occasionally it may accompany a blow to the face, particularly a blow to the jaw with the mouth already open. The patient is unable to close the mouth as thecondyles have translated in front of the articular eminence and spasm of the closing muscles traps them there. It may be very painful. An attempt should be made to reduce the dislocation by manual manipulation. This is achieved by standing in front of and above the seated patient and grasp­ing the mandible with gloved hands with the thumbs on the occlusal surfaces of the teeth, and the index and middle fingers below the lower border of the mandible. It is wise to wrap the thumbs each in a gauze square. Sudden downward and backward movement is applied bilaterally with an assistant supporting the head. If this fails, one repeat attempt concentrating on one side at a time may then succeed. Reduction may be assisted by injecting local anaesthetic around both joints. Occasionally it may be necessary to sedate the patient with intravenous midazolam or even resort to a general anaesthetic.

Congenital and developmental anomalies of the teeth and gums

Congenital and developmental anomalies of the teeth

Dental lamina

Teeth develop from the dental lamina, a strand of epithelium originating from the oral mucosa, which migrates backwards from the incisor region of both mandible and maxilla beginning in the sixth week of intrauterine life. As it migrates backwards tooth buds are formed which eventually develop into the teeth and roots, each with its characteristic shape, according to the position in the jaw. Abnormalities in its migration may lead to abnormalities that are laid out below. The concept of the dental lamina, however, has changed in recent years, as it would seem that the epithelium responsible for developing the teeth is not the dental lamina as such but modifications of the oral mucosa. This invaginates beneath the alveolus progressively posteriorly from the incisor region under the influence of genes and activators, which are specific for each part of the mouth, in a time-window of 2—3 days.
The total number of the secondary dentition is 32. The third molar or wisdom tooth may fail to develop in any of the four quadrants. Lack of space may cause them to impact into the second molars or backwards into the ramus. These may lead to pericoronal infection later in life and the third molars may require removal. The upper lateral incisors may fail to develop or develop as small, peg shaped teeth. This is normally associated with an impaction of the canines and is thought to be associated with faults in the dental lamina or gene deficiencies during development.
Failure to develop a large number of primary and sec­ondary teeth is known as hypodontia. It may be associated with other forms of ectodermal dysplasia where there is a lack of sebaceous and sweat glands. Considerable problems are encountered in providing a functional dentition, particularly during the growth period.

Supernumerary teeth and odontomes
Supernumerary teeth tend to occur in the same areas where teeth may be absent — the lateral incisor, second premolar and the third molar areas. Generally they are smaller than the normal teeth in the same area and seldom develop little more than a crown and a vestigial root. They may be multiple. In the incisor region they may be responsible for the failure of eruption of adjacent permanent teeth, particularly the central and lateral incisors and canine. They generally lie palatal to their normal counterparts. They have to be removed to allow eruption of the permanent teeth to occur. Rarely, in the third molar region, dentigerous cysts may develop around the crown. These are characterised by a radiographic appearance of a cyst enveloping the crown of the tooth that is displaced.
Odontomes are aggregations of tooth-like material and may take the form of multiple small teeth (denticles, a com­pound complex odontome) or irregular masses of dentine, cementum and enamel (complex composite odontome). They lie within the alveolus, frequently inhibiting the eruption of the adjacent teeth and are encapsulated. The most common site is the premolar region of the mandible. Odontomes are, in effect, hamartomas. Once formed they do not increase in size. Occasionally they become infected.

Developmental disturbances in the structure of theteeth
The enamel of primary and secondary dentition may be affected by a number of genetic or congenital conditions. There may be effects due to local problems such as trauma during birth or infection. The most notable change affecting all teeth is the result of amelogenesis imperfecta which is genetic and may be dominant or recessive. It is an ectodermal disturbance and the anomalies can range from pits in the teeth to failure of enamel development. It may be associated with osteogenesis imperfecta. By contrast, dentinogenesis imperfecta affects the mesodermal portion of the odontogenic apparatus. The appearance of the teeth is variable with the poorly supported enamel taking on a opalescent tinge. The enamel is readily damaged. Both amelogenesis and dentinogenesis imperfecta result in rapid early tooth loss.

Odontogenic cysts and tumours
Abnormalities in the dental lamina may form benign cysts and odontogenic rumours (keratocyst, odontogenic myxoma). A malignant form, ameloblastoma, is variable between cystic and solid, and is locally invasive. The most common site for these to occur is in the third molar region and ramus of the mandible.


Congenital and developmental abnormalities of the gums

Congenital epulis of the newborn
This uncommon tumour is seen in the anterior mandible and can reach a relatively large size. It is pedunculated and mobile, and can cause extreme concern to parents. It is simple to remove and has no long-term consequences.
Predeciduous teeth
At birth, or shortly afterwards, hard tooth-like structures may be detected in the lower alveolus and can cause the mother considerable discomfort during breastfeeding. These do not represent primary dentition or ‘a third set of teeth’ as. the structures, although calcified, do not take the form of normal teeth. Simple removal is advised where breastfeeding is undertaken.