Course of maxillary cysts
DEFINITION
“Pathological cavities which do not communicate with the external environment dug in the maxillofacial skeleton, which present an airy, liquid, semi-liquid, more rarely solid content.”
ETIOPATHOGENESIS
Jaw cysts can:
-Be the consequence of an embryological disorder (dysembriological cysts);
-Be linked to a bone abnormality;
-Be associated with an included tooth;
-Following an infection of dental origin (inflammatory odontogenic cysts).
CLASSIFICATION
The recent classification of maxillary cysts by the World Health Organization developed in 2017 (ADEL K. EI-NAGGAR et al 2017).
According to this new WHO 2017 classification.
Regarding pseudocysts: the aneurysmal cyst and the simple bone cyst are not included in the new classification and are now part of the benign non-odontogenic tumors of the jaws.
The 2017 WHO classification distinguishes two groups of maxillary cysts:
* Odontogenic cysts of inflammatory origin
Radicular cyst
Collateral inflammatory cyst
*Odontogenic and non-odontogenic developmental cysts
Dentigerous cyst
Odontogenic keratocyst
Lateral periodontal cyst and odontogenic botryoid cyst
Gingival cyst
Odontogenic glandular cyst
Calcifying odontogenic cyst
Orthokeratotic odontogenic cyst
Nasopalatine canal cyst
DIAGNOSIS OF CYSTIC LESIONS
The diagnosis of cysts is based on questioning, clinical examination, radiological examinations and anatomopathological analysis.
5-1- Circumstances of discovery
Accidental discovery;
In the event of dental movements, mobility, eruption anomalies or in the presence of endo-oral or exo-oral swelling.
5-2- Interrogation
Personal and family medical and surgical history;
Characteristics of pain:
General signs: fever, asthenia, weight loss, etc.;
Functional disorders.
5-3- Clinical examination
*At the stages of deformation and/or exteriorization, certain complications may arise:
*Dental movements (root divergences leading to coronal rapprochements).*Mobility of one or more teeth.*Anomalies in dental development.*Dental pain, changes in color, pulp mortifications, hence the importance of tooth vitality tests in relation to the lesion.*Infectious accidents.
*Traumatic complications (rare) resulting in a pathological fracture following minimal trauma.
5-4- Radiological investigations
They usually appear as a rounded or oval image, of variable size, from one to several centimeters in diameter,
- Surrounded by normally trabeculated tissue
- Moving teeth without damaging the roots and ligament
- Presenting a clear, homogeneous radio tone of a geodic or lacunar type
- Pushing back without invading or destroying neighboring anatomical elements such as: the inferior alveolar canal,
- The floor of the maxillary sinus, the floor of the nasal fossae and the nasopalatine canal.
Geode: single cavity resulting from a loss of bone substance, often very:
Clear with regular contours forming a continuous line surrounded by a more or less fine condensation border depending on the age of the lesion.
A more blurred outline indicates repeated inflammatory flare-ups.
Lacuna : hollow appearance, empty space that continues directly with the bone tissue, without border, result of the decrease in radiographic density which results in a more or less limited image, of light tone whose outline is not marked by a dense line.
5-5- Anatomopathological analysis :
*The nature of the examination requested;*The date and place of the sample;*The description of the sample;*Clinical information on the nature of the pathology;*The medications administered before the sample was taken.
When the apex of the tooth has been removed with the lesion, it may be of interest to check the integrity of the cystic membrane at the apex.
The anatomopathological appearance of the cyst is that of a pocket containing a liquid, semi-liquid or gaseous substance, gradually increasing in volume, and which includes:
- A thin and regular connective wall, the internal wall of which is covered with a stratified squamous epithelium (+/-), sometimes ciliated, of the respiratory type and keratinized (+/-) ortho or parakeratotic for true cysts.
In pseudocysts, this internal wall is devoid of any epithelial structure.
- A more or less liquid content, in variable quantity, most often clear, which may contain blood, pus, cholesterol flakes or white keratin flakes (keratocysts).
ANATOMO-CLINICAL STUDY OF MAXILLARY CYSTS
6-1- Odontogenic cysts of inflammatory origin
6-1-1- Radicular cyst
Definition
A radicular cyst is an odontogenic cyst of inflammatory origin associated with a non-vital tooth. A residual cyst is a radicular cyst that remains in the maxilla after extraction of the causative tooth.
Other names : Inflammatory dental cyst, dental cyst, periapical cyst, apical periodontal cyst.
Epidemiology
They represent approximately 55% of all odontogenic cysts. They occur at any age with a peak incidence during the fourth and fifth decades of life.
Etiopathogenesis
The epithelial lining derives from proliferation of remnants of Hertwig’s sheath epithelium (Malassez epithelial cells) in the periodontal ligament resulting from inflammation following pulp necrosis, usually due to dental caries.
A cystic cavity is formed, which results from hydrostatic pressure accompanied by bone resorption
Location
50% of cases occurring in the anterior region. Always located at the apex of the tooth, but a lateral radicular cyst may be associated with a lateral root canal.
Clinical expression
Many radicular cysts are asymptomatic and discovered incidentally on an X-ray examination of a decayed or necrotic tooth.
Overall, radicular cyst is probably the most common cause of maxillary expansion.
Radiological aspects
Clear, round or oval, unilocular, well-marbled radiograph at the apex of a tooth, usually about 1 to 2 cm in diameter.
Large lesions may also occur.
Radiology:
The image is that of a rounded or oval geode, hanging from the apex of a mortified tooth and surrounded by an opaque border.
Macroscopy :
*Variable in size (0.5 to several cm in diameter), *Its wall, of variable thickness (a few mm to 0.5 cm) is whitish.
* The contents are a citrine, viscous or hemorrhagic liquid, often dotted with yellowish cholesterol crystals .
Histological aspects
Radicular cysts have a wall composed of fibrous tissue or granulation tissue lined with a stratified, nonkeratinized, squamous epithelium.
Differential diagnosis
It is discussed with periapical granuloma, follicular cyst and keratocyst.
Prognosis and predictive factors
Depending on their clinical specificities and their radiological and therapeutic characteristics;
Although lesions may persist as residual cysts, recurrence is rare.
*Residual cyst :
The residual cyst results from the development of a radicular cyst or a granuloma not removed after avulsion of the causative tooth. The revealing signs are identical to those previously described.
6-1-2- Collateral inflammatory cyst
Other names : Inflammatory periodontal cyst, mandibular bifurcation buccal cyst, infected mandibular buccal cyst, juvenile periodontal cyst.
Definition
Inflammatory collateral cysts occur on the vestibular surface of tooth roots during eruption following inflammation in the pericoronary tissues.
Periodontal cysts appear on the lower third molars.
Epidemiology
Collateral inflammatory cyst accounts for up to 5% of all odontogenic cysts.
The male/female ratio is 2/1.
Etiopathogenesis
The etiopathogenesis of collateral cysts is not clearly elucidated. They are of inflammatory origin, associated with pericoronitis.
Location
More than 60% of collateral inflammatory cysts are periodontal cysts on the mandibular third molars.
Clinical expression
Are usually associated with a long history of pericoronitis, with symptoms of pain, swelling and trismus. The teeth involved are vital.
Radiological aspects
clear, well-demarcated radiograph that may extend to the lower border of the mandible.
Histological aspects
The histology of the collateral inflammatory cyst is not specific and is indistinguishable from that of a radicular cyst.
Prognosis and predictive factors
6-2- Odontogenic and non-odontogenic developmental cysts
6-2-1- Dentigerous cyst
Definition
Attached to the cervical region of an inert tooth envelops the crown. The eruption cyst is a variant of the dentigerous cyst found in the soft tissues covering an erupting tooth.
There are 3 types:
Follicular cyst: When it includes the crown and roots which are still evolving.
Pericoronal cyst: When it symmetrically encloses only the crown of the tooth concerned, the roots remain extra-cystic.
Latero-coronary cyst: When it encompasses the crown asymmetrically
Epidemiology
Represent approximately 20% of all odontogenic cysts and are the second most common cysts of the jaws. With a male to female ratio of 3:2.
Eruption cysts account for less than 2% of cases and occur in children.
Etiopathogenesis
It occurs due to an accumulation of fluid between the reduced enamel epithelium and the crown of the impacted tooth.
Location
Approximately 75% of the mandibular third molar is impacted.
Are the maxillary canines, the maxillary third molars, and the mandibular second premolars.
Clinical expression
The dentigerous cyst is usually asymptomatic.
Radiological aspects
Clear, unilocular, well-demarcated radiograph, often with a cortical margin, surrounding the crown of the impacted tooth, which may be displaced.
Histological aspects
A wall of loose fibrous tissue, often with a slightly myxoid appearance, lined by a thin, regular epithelium 2 to 4 cell layers thick.
Prognosis and predictive factors
Treated by enucleation, with avulsion of the impacted tooth. The eruption cyst can be marsupialized so that the impacted tooth can erupt normally.
Eruption cyst
It is observed in a child in the form of a bluish curvature, of firm or renitent consistency (maxillary temporary teeth).
6-2-2- Odontogenic keratocyst
Definition: This cyst was first described by Philipsen in 1956, it is characterized by significant keratinization of its malpighian border, aggressive growth and a high propensity for recurrence.
We distinguish between epidermoid cyst and primordial cyst:
Isolated keratocysts are most frequently found in males between the ages of 20 and 30. They most often affect the mandible.
Multiple para-keratotic keratocysts that occur at any age with a slight male predominance between 10 and 40 years of age.
Odontogenic keratocyst (primordial)
Also called epidermoid cyst; First described by Philipsen in 1956; Odontogenic keratocyst is the most common cyst of the jaws after radicular cyst and follicular cyst; Derives from the dental lamina or its vestiges (60% > keratocyst) or from the basal layer of the oral epithelium (40% > primordial); Higher recurrence for the primordial type; More or less high local aggressiveness (true tumor).
Clinical
Common between the 3rd and 4th decades ; preferential locations are the mandible, at the angle and ramus, and the anterior maxilla; Clinical signs are related to the expansion of the cyst and the dental movements it causes.
Radiology
the image is that of a mono- or polyfocal geode, homogeneous, round or oval, with a regular, clear, well-drawn outline,
The keratocyst is sometimes very extensive, invading each bone segment, but always respecting the condyle;
Macroscopically, the cyst, which is often large (4 to 5 cm), contains a creamy, whitish liquid.
Histology:
It has a thin connective tissue shell and a malpighian epithelial border of 5 to 8 cell layers; the basal layer is made of cubic or cylindrical cells;
Keratocysts are found either as a solitary lesion or as multiple lesions as a partial symptom of basal cell nevus syndrome (Gorlin-Goltz syndrome)
Gorlin-Goltz syndrome (basal cell nevus syndrome)
Discovered by Jarisch in 1894, Described by Gorlin and Goltz in 1960 – Clinical signs
*Major criteria; Odontogenic keratocysts; Palmar-plantar porokeratosis; Basal cell carcinomas; Intracranial calcifications.
*Minor criteria: Macrocephaly, frontal bossing, hypertelorism, prognathism, high-arched palate
Epidermal cysts, Bone anomalies: costovertebral, thoracic, Ovarian fibromas, medulloblastoma
Histology:
There are two types:
* Parakeratotic * Orthokeratotic
Positive diagnosis of Gorlin and Goltz :
At least 02 of the 04 major criteria or 01 major criterion and 02 minor criteria.
6-2-1- Lateral periodontal cyst
First described in 1958 by Standish and Shafer.
The lateral periodontal cyst is located next to or between the roots of a living tooth.
Extremely rare (constitutes 0.7% of maxillary cysts).
The lateral periodontal cyst is located preferentially in the mandibular premolar and then anterior maxillary regions.
Radiology:
Usually small in size (less than 1 cm), it produces a round or ovoid single- or multi-locular radiolucency well circumscribed by a thin bony shell;
Excision of the cyst allows healing without recurrence.
6-2-3- Odontogenic gingival cyst
Uncommon (0.08% to 0.5%); Arises from the epithelium of the dental organ, develops on the gingival crest or on its vestibular side or on the interdental papilla;
Whitish nodule of < 1 cm; Located mainly in the canine and premolar region of the mandible, in patients in the 5th decade ;
Etiopathogenesis:
Is poorly understood; dental lamina residues, reduced enamel epithelium or Malassez malpighian remains are thought to be involved.
6-2-4- Odontogenic glandular cyst (sialoodontogenic cyst)
First described in 1988 by Gardner, the lesion is rare and has no specific clinical or radiological signs.
Clinic:
According to the literature review by Patron et al. *this cyst is exceptional (13 cases in the literature),*occurs at any age (5th decade ),*slight predominance in male subjects; *it is mainly located in the mandible (anterior region).
6-2-5- Calcifying odontogenic cyst (Gorlin cyst)
*Very rare entity; *More common in young women; *The remains of the dental lamina are responsible for its appearance; *At first, it is not calcified and presents as a radiolucent image; with maturation it develops calcifications; *Unilocular, it gives the impression of being a solid tumor; *Enucleation of the cyst allows healing without recurrence.
6-2-6- Nasopalatine cyst KNP
the first description is that of Meyer in 1914;* Formerly called incisive canal cyst;* * The cyst would derive from the epithelial remains of the nasopalatine canal (incisive canal);
Located at the anterior end of the median suture line of the palatine processes of the maxillae which fuse between the 8th and 12th week of intrauterine life;
Clinic:
Usually latent, the cyst occurs during the 5th and 6th decades with a slight male predominance. Its frequency varies from 0.08% to 1.5% (KNP is the most frequent of this group, found in 3.6% of maxillary cysts.
Rarely motivated by inflammatory phenomena (pain, median retro-incisive palatal swelling, possible fistulization) or more often by incisor displacements;
The vitality of the incisors is always preserved
X-ray :
Highlights a radiolucency well demarcated by a rim of peripheral osteocondensation (image is round or ovoid, sometimes in the shape of a “playing card heart”) between the roots of the incisors.
Histology:
The KNP is lined with a malpighian epithelium on the buccal side, and a pseudo-stratified ciliated respiratory-type epithelial covering on the nasal side.
In the connective tissue shell, large nerve trunks and numerous vessels are frequent, to which mucous glands and adipose tissue are sometimes added. The possibility of a small cartilaginous island has also been mentioned.
Treatment :
Surgery allows healing without recurrence.
Recurrence is rare, between 0 and 11%. Its time to onset is extremely variable, from a few months to more than 5 years.
It is due to incomplete excision of the cyst wall due to unsuitable surgery.
Nasolabial cyst (nasoalveolar or nasal threshold cyst)
This cyst is located on the surface of the alveolar bone near the base of one of the nostrils.
- Clinic and radiology:
Appears as a nodule opposite the upper incisor-canine region.
Very common in the forties and fifties, of extra-osseous location, it has no radiological expression.
- Evolution and treatment:
Simple enucleation is followed by healing.
Cysts common to the rest of the skeleton:
1. Aneurysmal cyst:
- Modest clinical signs : affects young people ( < 30 years). It is located in more than half of the cases in the mandible: posterior part of the body, angle, BM. Revealed by a painless swelling which blows the cortex.
- Radiology:
Multilocular images of osteolysis separated by thin septa.
- Histopathology:
Within the connective tissue, there are numerous cavities of varying size devoid of endothelium, anastomosing with each other and filled with blood.
- Evolution and treatment:
Simple excision or curettage is followed by reossification.
2. Solitary bone cyst (traumatic, essential, hemorrhagic):
This cyst, more common in long bones than in the jaws, occurs in children or adolescents. It is sometimes preceded by trauma.
It manifests itself as a painless swelling or is discovered incidentally by an X-ray.
- Radiology:
appearance of a well-limited unilocular osteolysis whose contours invaginate between the roots of the teeth located opposite.
- Evolution and treatment:
After evacuation of the cystic contents and curettage, the cyst heals by the formation of newly formed bone.
Treatment of maxillary cysts
This is carried out when there is a superinfection or a clear increase in the volume of the cyst causing functional repercussions (dental displacement, chewing disorders), filling of natural cavities, morphological disfigurement and fracture risks.
Therapeutic means
The best therapeutic procedure is enucleation of the lesion with anatomopathological examination of the entire excision specimen. However, taking into account the volume of the cyst, the risk of surgery and the general condition of the patient, other types of treatment may be recommended.
1- Conservative means
They allow to preserve the teeth and the maximum amount of bone tissue as well as the vascular-nervous pedicles, while limiting the aesthetic inconveniences. They are:
Simple enucleation :
It is the separation of a lesion from the surrounding bone by following the connective tissue envelope which circumscribes the lesion.
Strong curettage :
Either because the lesion is too friable; or because there is no intact capsule or connective tissue envelope surrounding the lesion.
Marsupialization / decompression
Marsupialization :
Removal of the covering tissue (bone or mucosa), excision of the superficial part of the cyst and suturing of the oral mucosa to the cyst wall.
Decompression :
It is based on the principle of marsupialization but proposes drainage of the cavity from a smaller opening in order to be more conservative and to limit postoperative complications.
2-Radical means
When the bone lesion is very extensive, multi-focal or recurrent, the possibilities of conservative treatment become very questionable (particularly at the posterior level) and interruptive resection with immediate or deferred reconstruction then turns out to be the only effective alternative over time.
- Non-interruptive (marginal) resection
It consists of the removal of the lesion in its entirety as well as a margin of healthy tissue all around, without interruption of the bone continuity. It then spares the posterior mandibular border and the lower basilar border.
- Interruptive resection
Consists of the excision of a lesion beyond its limits with interruption of bone continuity and sometimes, resection of adjacent soft tissues.
It can consist of:
– Segmental (partial) mandibular resection : this is the excision of a lesion beyond its limits with interruption of bone continuity, and sometimes resection of adjacent soft tissues, thus sparing the posterior mandibular border.
– Hemimandibulectomy (terminal resection): Performed in cases of large lesions that have blown out at least two bony walls and invaded the surrounding soft tissues.
CONCLUSION
The role of the practitioner is to treat the numerous lesions that he discovers in his patients, lesions that differ in terms of their pathogenesis and their prognosis.
The most precise examination remains the anatomopathological analysis , which can only be done after the surgical intervention.
The interest of this post-surgical anatomopathological diagnosis is to allow the therapist to re-intervene, if necessary, in the event of a diagnostic error and/or to only provide post-operative monitoring given the benign nature of the majority of cysts.
Course of maxillary cysts
Cracked teeth can be healed with modern techniques.
Gum disease can be prevented with proper brushing.
Dental implants integrate with the bone for a long-lasting solution.
Yellowed teeth can be brightened with professional whitening.
Dental X-rays reveal problems that are invisible to the naked eye.
Sensitive teeth benefit from specific toothpastes.
A diet low in sugar protects against cavities.