Presentation

odontogenic cysts

1. Odontogenic Cysts Dr. Mohamed El Sayed Omfs consultant KFMC , Taif , ksa 2018

2. Definition An epithelium-lined sac filled with fluid or soft material. Cysts of the jaws may be divided into two types: (1) those arising from Odontogenic epithelium (i.e., odontogenic cysts) and (2) those from oral epithelium that is trapped between fusing processes during embryogenesis (i.e., fissural cysts ). Enlargement of cysts is sed by-gradual expansion, and most are discovered on routine dental radiographs. Cysts are usually Asymptomatic unless they are secondarily infected. overlying mucosa is normal in color and consistency , and no sensory deficits from encroachment nerves are found. Cysts do not usually cause resorption of the roots of teeth; The radiographic appearance of cysts is characteristic and exhibits a distinct, dense periphery of reactive bone (i.e., condensing osteitis) with a radiolucent center

3. Classification of Odontogenic Cysts Developmental . 2) Inflammatory Dentigerous cyst 1. Periapical ( radicular) cyst Eruption cyst. 2. Buccal bifurcation cyst Odontogenic keratocyst . 3. Residual cyst Gingival (alveolar cyst of the newborn ) Gingival cyst of the adult Lateral periodontal cyst Calcifying odontogenic cyst Glandular odontogenic cyst

4. periapical (i.e., radicular) cyst The most common of all cystic lesions of the jaws and results from inflammation or necrosis of the dental pulp. Because it is impossible to determine whether a periapical radiolucency is a cyst or a granuloma, removal at the time of the tooth extraction is recommended. If, the tooth is restorable, endodontic treatment followed by periodic radiographic follow-up will allow assessment of the amount of bone fill. If none occurs or the lesion expands in size, the lesion probably represents a cyst and should be removed by periapical surgery. When extracting teeth with periapical radiolucencies, enucleation via the tooth socket can be readily accomplished using curettes when the cyst is small In large cysts or cysts proximal to neurovascular structures, nerves and vessels are usually found pushed to one side of the cavity by the slowly expanding cyst and should be avoided or handled as atraumatically and as little as possible.

5. Dentigerous Cyst Occurs in association with an unerupted tooth, most commonly mandibular third molars. Other common associations are with maxillary third molars, maxillary canines, and mandibular second premolars. They may also occur around supernumerary teeth and in association with odontomas Most commonly seen in 10- to 30-year olds. There is a slight male predilection, and their prevalence appears to be higher in Whites than in Blacks. Radiographically, the dentigerous cyst presents as a well-defined unilocular radiolucency, often with a sclerotic border, this radiolucency typically and preferentially surrounds the crown of the tooth

6. types of dentigerous cyst radiographically Central : in which the radiolucency surrounds just the crown of the tooth, with the crown projecting into the cyst lumen. Lateral : the cyst develops laterally along the tooth root and partially surrounds the crown. Circumferential : exists when the cyst surrounds the crown but also extends down along the root surface, as if the entire tooth were located within the cyst.

7. distinguishing between a dentigerous cyst and an enlarged dental follicle. Any pericoronal radiolucency that is > 4 or 5 mm is considered suggestive of cyst formation and should be submitted for microscopic examination.

8. Treatment and Prognosis Enucleation of the cyst and removal of the associated tooth, often without a preceding incisional biopsy Curettage of the cyst cavity Large dentigerous cysts may be treated with marsupialization when enucleation and curettage might otherwise result in neurosensory dysfunction or predispose the patient to an increased chance of pathologic fracture. Some patients who are not candidates for general anesthesia may also be treated with a marsupialization procedure in an office setting under local anesthesia. The prognosis for most histopathologically diagnosed dentigerous cysts is excellent, with recurrence being a rare findings

9. Odontogenic Keratocyst Aggressive clinical behavior. Two variants of this cyst are well known; the sporadic cyst and the cyst associated with the nevoid basal cell carcinoma syndrome. keratocyst is important for three reasons: (1) this cyst is recognized as being more aggressive than other odontogenic cysts,(2) the odontogenic keratocyst has a higher rate of recurrence than other odontogenic cysts,and (3) the association with nevoid basal cell carcinoma syndrome requires that the clinician examine a patient with multiple cysts of the jaws for physical findings that might diagnose this syndrome.

10. Okc 60% of cases are seen in people between 10 and 40 years old. A slight male predilection is usually seen, and 60 to 80% of cases involve the mandible, particularly in the posterior body and ascending ramus . When multiple multilocular radiolucencies are noted on a panoramic radiograph, the clinician must perform an incisional biopsy and investigate the possibility of nevoid basal cell carcinoma syndrome The wall is usually thin and friable, which can pose problems for removal in one piece intraoperatively . Epithelial budding and the presence of daughter cysts may be noted in the connective tissue wall. It is generally advisable to ask the pathologist to examine the sections carefully for these two features as they generally impart a more aggressive character to the cyst.

11. Clinical Features of the Basal Cell Nevus Syndrome ≥ 50% frequency: Multiple basal cell carcinomas Odontogenic keratocysts , Epidermal cysts of the skin, Palmar/plantar pits ,Calcified falx cerebri , Enlarged head circumference ,Rib anomalies (splayed, fused, partially missing, bifid), Mild ocular hypertelorism ,Spina bifida, occulta of cervical or thoracic vertebrae 15–49% frequency: Calcified ovarian fibromas, Short fourth metacarpals, Kyphoscoliosis or other vertebral anomalies, Pectus excavatum or carinatum , Strabismus ( exotropia ) < 15% frequency: (but not random) Medulloblastoma , Meningioma, Lymphomesenteric cysts, Cardiac fibroma, Fetal rhabdomyoma , Marfanoid build ,Cleft lip and/or palate, Hypogonadism in males, Mental retardation

12. Glandular Odontogenic Cyst ( sialoodontogenic cyst) Rare and recently described cyst of the jaws that is capable of aggressive behavior and recurrence. Glandular odontogenic cysts occur most commonly in middle-aged adults, with a mean age of 49 years. Eighty percent of cases occur in the mandible and a strong predilection for the anterior region of the jaws with many mandibular lesions crossing the midline These cysts may appear either unilocular or multilocular radiographically There is a histologic similarity between the glandular odontogenic cyst and the predominantly cystic intraosseous mucoepidermoid carcinoma. Recurrence rate approximately 30% and therefore resection is recommend

13. Calcifying Odontogenic Cyst (COC ) Gorlin’s cyst The COC may be associated with other recognized odontogenic tumors, most commonly the odontoma . Adenomatoid odontogenic tumors and ameloblastomas Ghost cell keratinization, the characteristic microscopic feature of this cyst, is also a defining feature of the cutaneous lesion known as the calcifying epithelioma of Malherbe or pilomatrixoma The World Health Organization’s classification groups the COC with all its variants as an odontogenic tumor The COC is predominantly an intraosseous lesion, although 13 to 30% occur as peripheral lesions. Both the peripheral and central lesions occur with about equal frequency in the maxilla and mandible. There appears to be a predilection for the incisor and canine areas. Mean age of occurrence of about 30 years. COCs that are associated with odontomas tend to occur in younger patients, with a mean age of 17 years. COCs appear radiographically as unilocular well-defined lesions with radiopaque structures within the lesions

14. SURGICAL MANAGEMENT OF CYSTS Cysts of the jaws are treated in one of the following four basic methods: (1) enucleation, (2) marsupialization , (3) a staged combination of the two procedures, (4) enucleation with curettage.

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