Cysts of the jaws, oral and facial soft tissues. Management.
Commonly cysts has it’s own capsule and grows at the expense of increasing pressure at it’s walls by increasing volume of it’s contents.the main diffirence between cyst and benign tumor,also having its own capsule,consists I the fact that in evacuation of the contents and cessation of the pressure a cyst stops growing. Another difference is that cyst as a rule is a consequence of a particular pathologic process or defect of development cyst of the jaws and soft tissues of the face belong to common pathologic processes depending on character, location and size of the cyst it is treated either in hospital or polyclinic.
1.Concrete aims: A student must familiarize with the problem of realization of treatment cyst for children, among the different age-related groups.
2. A student must know the features of anatomic structure of maxillufacial area for the children of the different age-related groups and feature of physiology processes for children.
3. A student must know classification of cysts.
4. A student must conduct differential diagnostics of the cysts and tumors.
1. To develop professional internalss and feelings of responsibility during realization of for children.
2. Able to carry out and psychological approach in-process treatment cyst with children
3 Base knowledges, abilities, habits which are necessary for study the topic.
The structure of the maxillofacial region, the blood and nerve supply
Histological structure of the oral mucous cavity. The mechanism of development and phase of inflammation
Know the features of a child's body. Know the basic diseases of importance in conducting the diagnosis of major dental diseases
Task for independent work during preparation to employment.
4.1. List of basic terms, parameters, descriptions which a student must master at preparation to employment :
Is a cavernous formation,predominantly of spherical shape,filled with some contents
Complication of tooth eruption of the mandibular third molar,that is why this cyst is sometimes called eruption cyst
Grow slowly asymtomatically,sometimes are diagnosed incidentally or when suppurated
4. Enuclination of the cyst
Complete removal of the cystic formation, treatment of suppurated cysts presents considerable difficulty, because the suppurative process complicates radical excision which leads to possible relapseor forming fistula
4.2. Theoretical questions to employment:
1.what is the etiology of odontogenic cyst formation?
2.what is the diffrential diagnosis of the cystic formation of bones of the jaws?
4.clinical manifestation and methods of diagnostics of the cyst of tissue of the face and neck?
5.types and pathogeneses of development of nonodontogenic cyst of the jaws?
4.3Practical works (tasks)
To conduct the different types of the local anaesthetizing on phantoms.
5. A plan and organizational structure of lesson in discipline.
Stages of employment
Distribution of time
Types of control
Facilities of studies
practical tasks, situatioonal tasks, verbal cross-examination at standart list of questions.
Text-books, methodical recommendations.
OThe organizational questions.
Forming of motivation.
initial level of preparation.
Control of eventual level of preparation.
General estimation of studing activity of student.
Informing of students about the theme of next employment.
Maintenance of theme
Cysts of the jaws
A cyst, by definition, is a pathological cavity that is usually lined with epithelium and which contains fluid or semi-fluid. The vast majority of cysts of the jaws form within bone and grow slowly. They may therefore attain a relatively large size because they are often initially symptom free. Diagnosis of a cyst is not uncommonly made when the cyst becomes acutely infected, or it is found by chance on routine radiography of the dentition.
A radicular cyst is by far the most common cyst of the jaws. Its synonyms are dental cyst, periapical cyst or simply apical cyst. From time-to-time the teeth responsible for the formation of a radicular cyst may be extracted but the cyst remains and may well increase in size subsequent to the extraction. In this circumstance the name residual cyst is commonly used.
A radicular cyst develops when epithelial debris of Mallassez in a granuloma at the apex of a non-vital tooth is stimulated to proliferate. The epithelium forms a ballor mass of cells, which may break down centrally, perhaps due to lack of nutrients, to form a liquefied central area. Alternatively, the epithelium cells may form strands and sheets that encompass part of the granuloma, with a similar resulting breakdown of the enclosed granulomatous content to form the fluid centre of the cyst. Whichever method occurs, the effect is the formation of an epithelial semipermeable lining to the cyst content that allows fluids to enter the lumen by osmosis and leads to its gradual enlargement. This whole process is sometimes known as cystic degeneration.
Initially, the cyst will be contained within the alveolar bone around the apex of the non-vital tooth. At this stage the bone increases its density peripherally around the lesion in an attempt to wall it off. This is possible due to its slow rate of growth and explains why, radiographically, there is a sharp radio-opaque line surrounding the radiolucent shadow of the cyst.
With continued growth, the cyst eventually approaches the surface of the alveolar bone and as the apices of most teeth lie closer to the buccal than the palatal or lingual plates, it is the buccal plate which is usually first affected. Lying on the surface of the bone is the periosteum, and this layer of osteogenic tissue in turn reacts to the encroaching cyst by laying down new bone over its advancing front. The first real evidence of a cyst is therefore a bony swelling, known as bony expansion, in the buccal sulcus. Occasionally, especially with an upper lateral incisor, the expansion may be palatal, reflecting the palatal inclination of the apex. This expansion will feel hard to palpation and its presence may be convincing only on comparison with the contour of the bone on the other side of the jaw. With further growth, this enlargement will continue until the periosteum can no longer lay-down bone sufficiently rapidly and the cyst erodes through an ever-thinning bony buccal covering until it presents as a soft fluctuant (fluid-filled) swelling in the sulcus, which often appears slightly blue in colour. When the overlying expanded bone is very thin, palpation may elicit the characteristic eggshell crackling though this is rarely felt in practice.
Acute infection can supervene at any time during this process of evolution and this will convert the cyst, as far as its clinical features are concerned, into those of an acute apical abscess. If the acutely infected cyst bursts and discharges into the mouth, the continued discharge may lead to formation of a sinus.
Loosening or tilting of adjacent teeth is only encountered in very large cysts, and resorption of roots usually results from repeated infection of the cyst and is relatively uncommon.
As mentioned above, many radicular cysts are found either by chance radiographically or because of acute infection. However, other clinical features may present. Expansion of bone is usually buccal and hard to palpation. Later it is soft, fluctuant, and bluish in colour. The tooth will be non-vital. Radiographic features will show the classic appearance of a round or oval-shaped radiolucency surrounded by a sharply delineated thin white line of increased bone density. The affected tooth will show loss of its apical lamina dura. Very occasionally there may be evidence of resorption of adjacent teeth and this reflects repeated acute episodes of infection within the cyst. Similarly, such infection can cause a haziness in the sharp radio-opaque delineations of the margin of the cyst. In larger mandibular cysts there may be clear evidence of the inferior dental canal having been displaced downwards by the advancing lesion.
Aspiration of the cyst contents may be possible in larger cysts with little or no bony covering. Classically, the fluid appears as straw-coloured in which a shimmer may be seen due to its cholesterol content. However, if the cyst has been infected, this characteristic appearance may be lost and the fluid may well consist of pus or blood-stained pus. Many authorities have alluded to the difference between the higher soluble protein content of the radicular cyst and thedentigerous cyst compared with the lesser amount contained in odontogenickeratocysts. Such analyses are in practice seldom, if ever, carried out because of their cost and due to the fact that the differences between aspirates are visible to the naked eye and the use of a simple cytological smearing of suspected keratocysts makes such expensive tests unnecessary.
With very large cysts, especially in the mandible, it may be prudent to obtain some lining for histopathologicalexamination, as this may allow differentiation between a large radicular (or residual) cyst, a keratocystor a cystic ameloblastoma, especially when considering the differential diagnosis of a radiolucency of the angle of the mandible.
There are two main methods of treatment for cysts: enucleation (removal of the lining in total) and marsupialisation (creation of a permanent opening into the cyst cavity). The vast majority of cysts are treated by enucleation, with marsupialisation tending to be reserved for certain categories of patients, usually with larger cysts.
This is suitable for all small to moderate-sized cysts and the majority of large cysts.
Root-treating and conserving the tooth causing the cyst may be worthwhile and surgery may therefore be preceded by endodontic treatment.
A standard mucoperiosteal flap is raised buccally with the vertical relieving incision placed anteriorly. The thin bone is then removed with bone rongeurs(nibblers) or burs to allow surgical access to the fluid filled sac. The cyst lining is then separated with periosteal elevators or curettes from its bony wall and 'shelled' out. The lining should be sent for histopathologicalinvestigation. After irrigating with sterile saline the flap is sutured back to its anatomical position. If the tooth has been root filled, an apicectomy should be performed at the same time with retrograde sealing of the canal if appropriate.
The operation is for all but very large cysts usually carried out under local anaesthesia with or without sedation according to the patient's preference. Postoperative complications are rare, although breakdown of the wound in large mandibular cysts can occur. The patient is normally recalled about 4-6 months postoperatively, when a radiograph should show evidence of bony infilling of the cyst cavity.
As the name implies, marsupialisation means creating a pouch. The rationale of this treatment is the permanent destruction of the integrity (wholeness) of the cyst. This, in effect, depressurises the cyst cavity, stops its continued expansion and encourages a shrinkage of the lining by new bone formation around its periphery. It is more suitable for large cysts where enucleation may endanger vital structures such as the inferior dental nerve or there is a risk of fracture during enucleation. The limited surgery involved is very suitable for outpatient care under local anaesthesia and it can therefore be particularly appropriate for elderly or medically compromised patients who would be at risk from a general anaesthetic. Any decision to marsupialise a cyst cavity should be preceded by histological evidence that confirms the lesion as a cyst and this involves a small incisional biopsy or retrieving tissue from the cyst cavity at the time of the procedure.
Marsupialisation may be achieved most simply by extraction of the tooth responsible for the cyst, aspirating the contents through the socket, then irrigating the cyst lumen before packing the opening with a surgical pack. Sterile ribbon gauze soaked in Whitehead's varnish is excellent for this purpose, as the antiseptic content will protect the cyst cavity from infection. The pack is later substituted for a partial denture with a root-shaped acrylic bung extending into the cyst cavity from the socket. The patient is then given syringes with which to irrigate the cyst cavity with warm saline on a twice-daily basis. With the lining no longer complete, the bone heals inwards around the cyst, reducing it progressively in size. Some doctors remove the cyst by enucleation when it has reduced to a more manageable size.
If no tooth is involved - as in a large residual dental cyst - then a small semilunar flap is raised over the most expanded part of the cyst to allow part of the lining to be excised, and the cyst contents to be aspirated and washed out. The flap is then turned into the cyst and sutured to its lining, and the opening maintained initially with a surgical pack and later by a denture or prosthesis with an acrylic bung.
Marsupialisation of a large cyst may take many months for healing to occur and the onus is therefore on the patient to maintain cleanliness by frequent irrigations of the cyst cavity, as described above.
These cysts are developmental odontogenic cysts, which arise when cystic degeneration occurs in the
reducedenamel epithelium (dental follicle). They are seen around unerupted teeth and are therefore most frequently found in the third molar areas, both upper and lower, the upper canine region and, less frequently, around lower second premolars. They may also arise in relation to supernumerary or supplemental unerupted teeth.
These cysts grow slowly and have the same effect as radicular cysts on surrounding bone. A bony expansion occurs initially and at a later stage a soft fluctuant swelling over the area of the unerupted tooth will develop. As with radicular cysts, dentigerous cysts are usually asymptomatic until infected.
Radiographic imaging and aspiration are often fairly conclusive. A very large dentigerous cyst in the lower third molar area can displace the wisdom tooth and may require to be differentiated from other lesions such as a keratocystor ameloblastoma. Although both these lesions are classically described as being multilocularradiolucencies on radiograph, it must be remembered that unilocular lesions do exist. Aspiration may not be sufficient to differentiate a dentigerous cyst from a keratocyst, particularly if there has been infection. Similarly, an ameloblastoma may have within it areas of cystic degeneration, even in the more solid tumours, and a variant of the ameloblastoma – known as the cystic ameloblastoma – can be very similar to the dentigerouscyst in its clinical appearance, radiographic image and aspirated fluid content. If any doubt exists, then biopsy of a small portion of the lining will be diagnostic in most cases, although in the cystic ameloblastoma the tumourmay only be evident histologically in a small area of the cyst lining and the sample taken may therefore be misleading.
Treatment will either be enucleation along with extraction of the unerupted tooth or marsupialisation. Marsupialisation is the method of choice if it is hoped to encourage eruption of the buried tooth, but it is remarkable how seldom the involved tooth is in a satisfactory position in terms of its angulation and depth to make this the preferred choice. The vast majority, therefore, are enucleated with the unerupted tooth.
Keratocysts are believed to be derived from remnants of the dental lamina. They can be found anywhere in the jaws but the most common site is at the angle of the mandible. Unlike other cysts of the jaws, their epithelium is a keratinising stratified squamous epithelium and their contents are therefore filled with desquamated squamesand keratin, which form a semisolid material that has been likened to cottage cheese. Their mode of growth is also different from the other cysts in that the lining appears to be more active, with passive fluid ingress of little significance. Keratocysts are also characterised by the formation of microcysts or satellite cysts which protrude into the surrounding fibrous tissue and tend to be left behind during enucleation. This increases the risk of recurrence and dictates a different managementapproach.
The active growth of keratocysts appears not to be evenly distributed, so the cyst does not expand uniformly as a sphere or oval-shaped lesion. Different rates of activity within areas of the lining probably account for the formation of locules, which, once the cyst has achieved a moderate size, will give rise radiographically to the typical multilocular appearance. They appear to grow selectively within the looser medulla of the jaw initially and although eventually the outer cortical plates do show expansion, the cyst may be by that time a considerable size. Lingual as well as buccal expansion is often noted.
Infection often only occurs when the cyst is quite large and where soft tissue trauma allows ingress of bacteria. It is not infrequent to find that with expansion the cyst communicates with the surface through the periodontal space of an adjacent tooth. It is important to realise that, unless infected, these sometimes very large lesions are painless and do not exert sufficient pressure on vital structures such as the inferior dental nerve to cause anaesthesia of the lip and chin. When infected, however, they can become very painful, cause anaesthesiaand may discharge into the mouth, with consequent bad taste and bad breath as additional clinical features.
As with other cysts, the diagnosis is based on clinical features, radiographic findings and the results of aspiration and biopsy. Two extraoral radiographic views at right angles to each other, such as an orthopantomogram and posteroanterior mandibular view, may be required with large keratocysts. Classically, the appearance is of a multilocular radiolucency with marked expansion of both buccal and lingual plates. Unerupted wisdom teeth may well be pushed into bizarre ectopic positions such as inverted high into the ramus of the mandible. The inferior dental canal may be difficult to see and may reflect the more active growth of these cysts around the canal with less evidence of significant repositioning as is seen with radicular cysts. Displacement or tilting of the teeth can be a feature, as can resorption of roots, although this is again probably a result of infection. Infection within a cyst also accounts for many becoming symptomatic.
As previously indicated, the soluble protein content of the aspirate obtained from a keratocyst is lower than that of other cysts and this is due to the fact that keratin is an insoluble protein. Aspiration will yield a 'dirty' creamcolouredsemisolid material composed of keratinized squames. These can be confirmed histologically and provide good evidence that the lesion is a keratocyst.
As the differential diagnosis may well include odontogenictumours such as ameloblastoma, many surgeons prefer to make a small flap incision and remove some lining of the cyst to confirm the diagnosis.
Keratocysts have a higher recurrence rate than other cysts and especially when they are large and multilocular.
Enucleation is suitable for most keratocysts but may be difficult in large ones where, for example, they extend upwards into the vertical ramus of the mandible. Surgical access may be difficult and with the multilocular pattern of growth it may be impossible to ensure that the whole lining is removed. It is known that small clusters of epithelium known as microcysts, or satellite cysts can lie outside the epithelial lining and within the fibrous wall,and leaving even a small amount of this fibrous wall maywell account for eventual recurrence. For this reason,some doctors have in the past used chemicals such as mercuric salts or, more recently, cryotherapy techniques (particularly liquid nitrogen sprayed around the bony cavity) to try to ensure that no viable soft tissue remnants remain.
Marsupialisation can be used particularly with large keratocysts where it can be very effective. It has the same advantages as mentioned previously with radicular cysts and probably reduces the chance of recurrence. Again, it may be appropriate in some cases to use the technique to reduce the size of the lesion before enucleating it. Whatever method is used, follow-up is required for years to ensure that there is no recurrence, and this is mainly radiographic.
Gorlin-Goltz syndrome, or multiple basal-cell naevisyndrome, is an inherited (autosomal dominant) condition in which multiple keratocysts of the jaws form part of the overall syndrome. Other aspects in these patients are the presence of many skin lesions in the form of basal-cell naevi or carcinomas, and skeletal abnormalities affecting the vertebral column and the ribs. Calcification of the falxcerebri is also a noteworthy feature.
These cysts arise from epithelial remnants within or near to the nasopalatine foramen. They are not odontogenicbut are classified as fissural cysts, and they represent by far the most common example of fissural cysts of the jaws.
These cysts cause swelling of the anterior aspect of the midline of the hard palate. They may become infected and cause pain and overlying tenderness and can, on occasion, discharge forming a sinus. However, as with most cysts, they are painless unless infected and may grow to a considerable size.
Presence of a midline anterior palatine swelling is the only usual clinical finding. However, many are again diagnosed through chance by radiographs of the teeth in this region. It can be difficult when such radiolucenciesare found on routine radiographic assessment of the central incisors, to know if the image seen is within normal anatomical limits of the nasopalatine foramen. A radiolucency of approximately greater than 8 mm in diameter is more likely to represent cystic degeneration but, where doubt exists, a further radiograph 6 months to 1 year later may be more conclusive. The normal radiographic image is a round or inverted pear-shaped radiolucency with sharp radio-opaque margins. When they are large, they can cause separation of the central incisor roots, but the laminaedura of the teeth remain intact. If there is doubt whether the cyst is a radicular cyst related to one or other incisor, pulp testing can be carried out and close examination of the apices radiographically should show an intact lamina dura.
These cysts should be enucleated - never marsupialisedbecause marsupialisation in this area can lead to a permanent cavity that will show no evidence of restoration of the normal contour. Normally, enucleationis carried out with a palatal flap taken around the gingival margins of the premolars on one side to the premolars of the other. After enucleation, interdental interrupted sutures are used to replace the flap and in larger cysts. It is sometimes useful to have constructed a palatal plate from preoperative impressions to support the flap and prevent the formation of a painful haematoma.
This is a fissural cyst that is thought to form by cystic degeneration of epithelium from the lower part of the nasolacrimal duct during embryological development. Clinically, they may present as painless swellings in the nasolabial fold, where they may be palpated either externally on the skin surface or intraorally high in the buccal sulcus anteriorly. Radiographically, although they are not intrabony cysts they may, if they attain a reasonable size, cause a depression of the radio-opaque margin of the floor and lateral wall of the nose, which is best viewed by an oblique anterior occlusal radiograph.
This bony surface is normally very gently convex in appearance but may show concavity where the cyst has caused saucerisation of the bone in this region. Confirmation may be obtained by aspiration and the normal treatment would be surgical enucleation.
Solitary bone cyst
This used to be known as a traumatic bone cyst or a haemorrhagic bone cyst. It is usually found in the mandibular body and appears radiographically as a radiolucency that not infrequently shows scalloping around the roots of the lower molar and premolar teeth. It causes no expansion of the bone and even on radiographic examination the outline of the radiolucency is less well defined than would be obtained from other cysts. This cyst is not a true cyst in so far as it has no epithelial lining and, in fact, the majority have apparently no content whatsoever. When surgically explored, they tend to heal spontaneously after the surgery.
Staphne's idiopathic bone cyst
Although usually discussed with cysts of the jaws, this is not in fact cystic at all. It consists of submandibular salivary gland tissue that occupies a recess on the lingual aspect of the mandibular body. These cavities are usually found by chance on routine radiography of the lower jaw where they appear as round or oval-shaped radiolucencieslying below the image of the inferior dental canal. Surgical exploration is not advised and most clinicians would take a further radiograph 6 months to 1 year later to confirm that the shadow of this cavity remains unchanged.
This cyst was originally thought to be a separate clinical entity. It was believed to be a fissural cyst formed between the upper lateral and canine teeth, but many now consider it to be a radicular cyst derived from the lateral incisor.
1.Lectures which are read on the department of pediatric dentistry.