Cysts Of Jaw Question And Answers
Question 1. Classify cyst of oral cavity. Describe in details clinical features, radiographic feature and differential diagnosis of dentigerous cyst.
Or
Classify cysts of orofacial region. Describe clinical features radiographic features and differential diagnosis of dentigerous cyst.
Or
Write short note on dentigerous cyst.
Or
Classify cysts. Write clinical features, radiological features and management of dentigerous cyst.
Answer.
Classification of Cysts of Oral Cavity By Mervin Shear
Cysts of the Jaws
Dentigerous Cyst Epithelial:
Keratocystic Odontogenic Tumors
Cysts of the Jaws Developmental:
- Odontogenic
- Gingival cyst of infants
- Odontogenic keratocyst (neoplasm)
- Dentigerous cyst
- Eruption cyst
- Lateral periodontal cyst
- Gingival cyst of adults
- Botryoid odontogenic cyst
- Glandular odontogenic cyst
- Calcifying odontogenic cyst (neoplasm)
Cysts of the Jaws Non-odontogenic:
- Nasopalatine duct cyst
- Nasolabial cyst
- Midpalatal raphe cyst of infants
- Median palatine, median alveolar
- Median mandibular cyst
- Globulomaxillary cyst
Cysts of the Jaws Inflammatory:
- Radicular cyst, apical and lateral
- Residual cyst
- Paradental cyst and mandibular infected buccal cyst
- Inflammatory collateral cyst
Nonepithelial (pseudocysts):
- Solitary bone cyst
- Aneurysmal bone cyst
Cyst Associated with Maxillary Antrum
- Benign mucosal cyst of the maxillary antrum
- Postoperative maxillary cyst
Cyst of the Soft Tissues of Mouth, Face and Neck
- Dermoid and epidermoid cyst
- Lymphoepithelial cyst (branchial cyst)
- Thyroglossal duct cyst
- Anterior medial lingual cyst (intralingual cyst of foregut origin)
- Oral cyst with gastric or intestinal epithelium
- Cystic hygroma
- Nasopharyngeal cyst
- Thymic cyst
- Cyst of salivary glands: Mucous extravasation cyst, mucous retention cyst, ranula, polycystic disease of the parotid.
- Parasitic Cyst: Hydatid cyst, cysticercus cellulosae, trichinosis
Read And Learn More: Oral Medicine Question And Answers
Dentigerous Cyst
It is also called as follicular or pericoronal cyst. It is most common type of odontogenic cyst which encloses the crown of impacted teeth.
Dentigerous Cyst Clinical Features
- It is found in children and adolescents with incidence in 2nd and 3rd decade.
- Mandibular 3rd molars and maxillary canines are most commonly impacted.
- Teeth adjacent to developing cyst and involved teeth are severely displaced and resorbed.
- Generally, it is painless but may be painful, if it gets infected.
- When dentigerous cyst expands rapidly to compress sensory nerve, then it produces pain which is referred pain.
- Dentigerous cyst has a potential to become an aggressive lesion with expansion of bone and subsequent facial asymmetry.
- Lesion has potential to expand. Cystic involvement of an unerupted third molar resulting in hollowing out of entire ramus extending to coronoid process and condyle.
Keratocystic Odontogenic Tumors
Dentigerous Cyst Radiographic Features
- It is a well-defined radiolucency which is associated with hyperostotic borders unless it is secondarily infected and is seen around an unerupted tooth.
- The cyst is unilocular but, it can be multilocular too. Multilocularity is caused by ridges in the bony wall.
- Bony margins are well-defined and sharp.
- Dentigerous cyst may involve the crown symmetrically but it can expand laterally from the crown. Cyst is attached to cementoenamel junction. Tooth which is associated with the cyst can be displaced in any direction. Mainly direction of displacement is in apical region
- Large cysts are confined to mandible. There may be resorption of roots of the adjacent teeth.
- Floor of maxillary sinus can get displaced, if cyst encroaches on it.
Dentigerous Cyst Diagnostic Features
Dentigerous Cyst Clinical diagnosis: Presence of expansive swelling over posterior region of mandible provide clinch to the diagnosis.
- Content of cystic lumen is usually thin watery yellow fluid and is occasionally blood tinged.
Dentigerous Cyst Differential Diagnosis
- Ameloblastoma or ameloblastic fibroma: They are multilocular and not associated with crown of an unerupted teeth.
- Adenomatoid odontogenic tumor: They are rare and occur in maxillary anterior region.
- Calcifying odontogenic cyst: It occurs as pericoronal radiolucency and contains evidences of calcification.
- Developmental primordial and follicular primordial cyst: It occurs in the crown of unerupted tooth and superimposition of image which may cause cyst- like radiolucency to appear as dentigerous cyst on radiograph.
- Hyperplastic follicle: Normal size of dental follicle is 2 to 3 mm. If the size of follicular space is more than 5 mm, then dentigerous cyst is most likely the diagnosis.
- Odontogenic keratocyst: OKC does not expand the bone as dentigerous cyst does. OKC is attached more apically as compared to dentigerous cyst.
Dentigerous Cyst Management
- Surgical: Small lesions should be surgically removed. Larger lesion consists of the surgical drainage as well as marsupialization. It causes relief in pressure and gradual shrinking of the cystic lesion by peripheral apposition of the new bone.
- Decompression: Place a small acrylic button or the short section of rubber in preformed surgical opening inside the cyst which keeps opening open and leads to drainage.
- Orthodontic treatment: Patients who want to retain the tooth, orthodontic tooth movement should be done.
Question 2. Write short note on radiographic image of dentigerous cyst.
Or
Write short note on radiographic features of dentigerous cyst.
Answer.
The radiographic image according to Thoma.
Dentigerous Cyst Central Variety
In it, crown is enveloped symmetrically. In this instance, pressure is applied to crown of tooth, and may push it away from direction of eruption. In this way, the mandibular third molar may be found at lower border of mandible and in ascending ramus and maxillary canine in sinus or as far as floor of orbit.
Dentigerous Cyst Lateral Type
Dilaceration of follicle on one aspect of crown. The type is commonly seen when an impacted mandibular molar is partially erupted so that its superior aspect is exposed.
Keratocystic Odontogenic Tumors
Dentigerous Cyst Circumferential
In it, entire tooth appears to be enveloped by cyst. The entire organ around neck of tooth becomes cystic often allowing tooth to erupt through cyst.
Dentigerous Cyst According to Mourshed
Class 1: Dentigerous cyst is associated completely with unerupted teeth.
- Dentigerous cyst is associated with unerupted teeth, who fail to erupt due to lack of space in the dental arch.
- Dentigerous cyst is associated with unerupted teeth, who fail to erupt due to malpositioning of tooth germ
- Dentigerous cyst is associated with unerupted supernumerary teeth
Class 2: Dentigerous cyst is associated with partially erupted teeth.
Question 3. Write short note on primordial cyst.
Answer. It is the type of odontogenic cyst.
Recent concept: The term primordial cyst is not in use now-adays because it is considered to be an odontogenic keratocyst.
Primordial Cyst Clinical Features
- It is found in children and young adult between 10–30 years of age, it may persist in older age group.
- It can arise in any portion of jaw, mostly seen in ascending ramus of mandible in third molar area.
- It enlarges painlessly and slowly replace large portions of cancellous bone before expansion of cortical plates.
- Pain is associated with large cyst caused by infection that may follow perforation of expanded cortical plate.
Primordial Cyst Radiographic Features
- Cyst-like radiolucency that is well-defined and have hyperostotic borders.
- Internal structure is unilocular or have scalloped outline which give multilocular appearance.
- Teeth produces deflection of adjacent tooth root, but seldom cause root resorption.
Primordial Cyst Differential Diagnosis
- Ameloblastoma: Occur in old age. It is multilocular but at times, it can be unilocular. It present with paresthesia.
- Residual cyst: History of tooth extraction is present.
- Traumatic cyst: Margins of traumatic cyst are scalloped while margins of primordial cyst are hyperostotic.
- Giant cell granuloma: This is commonly present in anterior part of jaw.
- Giant cell lesion of hyperparathyroidism: It is ruled out on basis of serum investigations.
Primordial Cyst Management
- Surgical enucleation.
- Regular check-up due to high recurrence.
Question 4. Write short note on radiographic appearance of periapical cyst.
Answer. It appears as a rounded or pear-shaped radiolucency at the apex of nonsensitive tooth or with nonvital tooth.
- Radiolucency is more than 1.5 cm in diameter but usually less than 3 cm in diameter. It has got well-defined outline with thin hyperostotic borders.
- Margins: In uncomplicated cases, margins are smooth, corticated and cortex is usually well-defined, well-etched and continuous, except in some cases, there may be window formation. There is also thin white line surrounding the margins of bone cavity. This thin layer of cortical bone is almost always present unless suppuration supervenes in the cyst.
- Image of radiopaque borders is continuous with lamina dura around the associated tooth. Infection may cause the borders to become less distinct.
- Radicular cysts of long duration may cause resorption of roots.
- Adjacent teeth are usually displaced and rarely resorbed.
- If maxillary area is involved, there is displacement of maxillary sinus.
Question 5. Classify cysts of jaws. Describe the clinical and radiographic features of radicular cyst.
Answer. For classification refer to Ans 1 of same chapter.
Ameloblastoma
Radicular Cyst Clinical Features
- Incidence: Radicular cyst constitutes about 50 % or more among all types of jaw cysts.
- Age: Mostly third, fourth and fifth decade of life.
- Sex: More common among males.
- Site: The cyst can occur in relation to any tooth of either jaw, but maxilla (60%) is more commonly affected than mandible (40%).
- Origin: The cyst is believed to originate from the cell rests of Malassez.
- The involved tooth is always non-vital and can be easily detected by the presence of caries, fractures or discolorations, etc. Moreover, the affected tooth does not respond to thermal electric pulp testing.
- The cyst becomes more symptomatic as there is acute exacerbation of the periapical inflammation.
- Larger lesions on the other hand, often produce a slow enlarging, bony hard swelling, of the jaw with expansion and distortion of the cortical plates or disturbance in occlusion mostly of the regional teeth; maxillary lesions may cause either buccal or palatal cortical expansion whereas the mandibular lesions often cause buccal or labial expansions and rarely the lingual expansions.
- Severe bone destruction by the cystic lesion results in thinning of the cortical plates, and it may produce a “springiness” of the jawbone when digital pressure is applied.
- There may be presence of fluctuations in case the bone is completely eroded by a large cyst.
- These lesions clinically appear blue as they lie close to the overlying epithelium since the bone has been completely resorbed.
- Pain may be present in the cyst, if it is secondarily infected and it may result in the development of either intraoral or extraoral pus discharging sinuses.
- On rare occasions, there may be occurrence of paresthesia or pathological fractures in the bone, etc.
- Occasionally, radicular cysts can be multiple in numbers, occurring in relation to several teeth or in relation to several roots of a multirooted tooth.
- A radicular cyst may persist in the jaw after the attached tooth has been extracted; such cyst is often called a ’residual cyst’. These cysts frequently cause swelling in the dentulous jaws and they regress slowly and spontaneously.
- In some cases, radicular cysts may develop at the opening of a large accessory pulp canal on the lateral aspect of the tooth root; and these cysts are often termed as ’lateral radicular cysts’.
- If the cyst is secondarily infected, then it leads to the formation of an abscess, which is called “cyst abscess”.
Ameloblastoma
Question 6. Classify odontogenic cysts of oral cavity. Describe clinical features, radiographic features and complications of dentigerous cyst.
Answer.
Odontogenic Cysts of Oral Cavity
Odontogenic Cysts of Oral Cavity Developmental:
- Gingival cyst of infants
- Odontogenic keratocyst (neoplasm)
- Dentigerous cyst
- Eruption cyst
- Lateral periodontal cyst
- Gingival cyst of adults
- Botryoid odontogenic cyst
- Glandular odontogenic cyst
- Calcifying odontogenic cyst (neoplasm).
Keratocystic Odontogenic Tumors
Odontogenic Cysts of Oral Cavity Inflammatory.
Periodontal cyst
- Radicular cyst
- Lateral cyst
- Residual cyst.
Paradental cysts (Inflammatory collateral cyst, mandibular infected buccal cyst).
For clinical features and radiographic features refer to Ans 1 of same chapter.
Complications of Dentigerous Cyst
- Mucoepidermoid carcinoma: This is the malignancy of salivary gland which is associated with dentigerous cyst which mostly consists of mucous-secreting cell.
- Ameloblastoma: It is mainly associated with the lining epithelium of dentigerous cyst or cell rests of odontogenic epithelium present in cyst.
Ameloblastoma
Question 7. Classify cysts of orofacial region. Describe clinical features, radiographic features and radiographic differential diagnosis of dentigerous cyst.
Answer. For classification, clinical features and radiographic features of dentigerous cyst refer to Ans 1 of same chapter.
Radiographic Differential Diagnosis
- Ameloblastic fibroma and ameloblastoma: In their radiographic picture, they generally show multilocular appearance as well as covering of lesion by the crown is not evident.
- Calcifying odontogenic cyst: During radiographic examination, it is seen as pericoronal radiolucency at places it may also show calcification.
- Hyperplastic follicle: On radiographic examination size of normal follicle is 2–3 mm. If it extends beyond 5 mm, then dentigerous cyst can be suspected.
- Odontogenic keratocyst: On radiographic examination, bony expansion is not seen.
- Adenomatoid odontogenic tumor: These are rare and seen in maxillary anterior region.
- Developmental primordial and follicular primordial cyst: It occurs in close proximity to crown of unerupted teeth and superimposition of image may cause cyst like radiolucency to appear as dentigerous cyst on radiograph. In primordial cyst, cystic lining surrounds the crown while in dentigerous cyst, it is attached to the neck of tooth.
Question 8. Define and classify odontogenic cysts of oral cavity. Write in detail the etiopathogenesis, clinical features, investigations and treatment of odontogenic keratocyst (OKC).
Answer. Odontogenic cysts are defined as those which arise from the epithelium associated with the development of teeth.
For classification of odontogenic cyst refer to Ans 6 of same chapter.
Odontogenic Keratocyst (Keratocyst Odontogenic Tumor)
It was given the term keratocyst odontogenic tumor (KCOT) because of its aggressive clinical behaviour depicting increased mitotic rate.
Odontogenic Cysts of Oral Cavity Etiopathogenesis
- Odontogenic cyst is derived from cell rests of dental lamina or its remnants.
- It is derived from extensions of basal cells from the overlying oral epithelium.
Odontogenic Cysts of Oral Cavity Clinical Features
- It occurs between 2nd and 3rd decades of life.
- Its predilection is more in males as compared to females.
- Mandible is affected more commonly than maxilla.
- In the mandible the majority of cysts occur in ramus third molar area, followed by first and second molar area and then the anterior mandible.
- It is asymptomatic unless they become secondarily infected in which case patient complains of pain, soft tissue swelling and drainage.
- Occasionally, patient experience paresthesia of lower lip and teeth.
- There is often one tooth missing from the dental arch.
- Expansion and thinning of bone may result in pathological fracture.
- Maxillary odontogenic keratocyst tends to be secondarily infected with greater frequency than the mandibular ones, due to its vicinity to maxillary sinus.
Odontogenic Cysts of Oral Cavity Investigations
Fine Needle Aspiration Cytology (FNAC)
- Appearance: Keratocystic odontogenic tumor (KCOT) contain a very characteristic thick, creamy, dirty white, viscoid suspension of keratin which has an appearance of pus but it is odorless.
- Smear: Smear of the aspirate should be prepared and stained and is examined under microscope for keratin cells.
- Electrophoresis: Aspirate will reveal low-protein content and high albumin to globulin ratio.
- Total protein estimation: Estimation of total protein will be found to be below 4 g/100 mL, which differentiates the lesion from other cystic contents.
- Cholesterol crystals, keratin squames, hyaluronic acid, Rushton bodies and heparin as well as chondroitin sulphate are found in aspirate
- Immunofluorescence: It demonstrates an antigen in the cystic fluid which is not present in other cystic lesions, nor in plasma or saliva and is known as keratocyst antigen.
Odontogenic Cysts of Oral Cavity Radiography cysts
An orthopantomogram (OPG) of the patient should be taken, which reveal following findings, i.e.
- Odontogenic keratocyst is oval in shape and it extends to the body of mandible with mediolateral expansion.
- It is very small in size or it can exceed the diameter of 5 cm.
- Margins of the cyst are hyperostotic.
- Mostly odontogenic keratocyst is unilocular and have smooth borders while some of the cysts show irregular borders too.
- Radiolucency is seen in the cystic part which appears to be hazy, if keratin is present in the cavity.
- Radiolucency is surrounded by thin sclerotic rim.
- In some of the cases, perforation of lingual and buccal cortical plates is seen.
- Displacement of inferior alveolar canal is seen downwards.
Odontogenic Cysts of Oral Cavity Biopsy cysts
Biopsy should reveal following histological features for odontogenic keratocyst:
- A parakeratin surface which is usually corrugated rippled or wrinkled.
- Uniformity of thickness of epithelium and is generally between 6 and 10 cells in depth.
- Prominent palisaded, polarized basal cell layer often described as having a “picket fence” or “tomb-stone” appearance.
- Occasionally, orthokeratin is found but if present, parakeratin is evident.
- Connective tissue shows “Daughter cells” or “Satellite cysts”, which are responsible for recurrence of OKC..
- The luman of keratocyst may be filled with thin straw colored fluid or with thick creamy material.
- Sometimes a lumen contains a great deal of keratin while at other times, it has little cholesterol as well as hyaline bodies at the site of inflammation.
Odontogenic Cysts of Oral Cavity Treatment cysts
- Treatment for odontogenic keratocyst is surgical, i.e.
- Enucleation: In this removal of cyst is done along with removal of cystic wall.
- Peripheral osteotomy: This procedure is carried out for reducing the chances of recurrence.
- Chemical cauterization: This is carried out along with enucleation. In this case carnoy’s solution is injected which leads to easy removal of cyst.
Question 9. Define and classify odontogenic cysts of the oral cavity. Write in detail about etiopathogenesis, clinical features, investigations and management of dentigerous cyst.
Answer. Cyst which is derived from odontogenic epithelium, i.e. epithelium associated with development of dental apparatus is known as odontogenic cyst.
For classification of odontogenic cysts of oral cavity refer to Ans 6 of same chapter.
Dentigerous Cysts Etiopathogenesis
- Intrafollicular theory: Dentigerous cyst is caused by fluid accumulation between reduced enamel epithelium and enamel surface which result in a cyst in which crown is located within the lumen.
- Extrafollicular theory: Dentigerous cyst may arise by proliferation and cystic transformation of islands by odontogenic epithelium in connective tissue wall of dental follicle or even outside dental follicle and this transformed epithelium then unite with lining follicular epithelium forming cystic cavity around tooth crown.
Dentigerous Cysts Investigations
- Radiography: There is presence of well defined radiolucency which has association with the impacted teeth. The radiolucency have hyperostotic border with well-defined margins.
- Biopsy: Histologically, there is presence of a thin connective tissue wall with a thin layer of stratified squamous epithelium lining the lumen. Rete peg formation is absent except in case of secondarily infected cyst. It also shows Rushton bodies within the lining epithelium which are peculiar linear and often curved hyaline bodies.
- FNAC: Content of cystic lumen is usually thin watery yellow fluid and is occasionally blood tinged.
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