[ Home ]
[ Home ]
From: Dr. Getter
Date: 31 May 2001
Time: 10:03 AM
HOWARD UNIVERSITY, COLLEGE OF DENTISTRY DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY
Dr. Barry Maharaj Summer 2001
THE DIAGNOSIS AND SURGICAL TREATMENT OF CYSTS OF THE JAWS
Definition A Cyst is a pathologic lesion characterized by a cavity filled with fluid, cellular products, air or a combination of these. True cysts usually have an epithelial lining and a connective tissue capsule. Some entities designated as cysts do not contain an epithelial lining and are generally referred to as pseudocysts.
Cysts cause tissue destruction by the displacement of normal functional structures, the weakening of bone or the effects of secondary infection. Displacement, resorption or delayed eruption of teeth may be an initial clinical finding.
In rare cases pathologic fractures may be a presenting clinical sign, with odontogenic Cysts only rarely producing alterations in the function of peripheral sensory nerves. Secondary infections may result in cellulitis and / or osteomyelitis.
Although benign, these lesions may cause considerable local destruction and patient suffering. The goal of treatment is to remove the pathology and prevent further destruction of the tissues while restoring form and function.
Treatment
Use a stepwise approach (a) physical examination,i.e. inspect ( expansile and asymmetry palpation ( bony texture thick Vs thin, thrill : vascular auscultation R/O vascular lesion (b) clinical examination , location, tooth related, tooth vitality, caries, Hx. of surgery (c) radiographic examination ; X-ray must show margins of the lesion May consider CT scan or MRI studies
(d) aspiration (e) biopsy; the surgical procedure for the biopsy must not compromise a subsequent surgical approach for a definitive surgical procedure. (f) treatment MUST HAVE DIFERENTIAL DIAGNOSIS may consider a frozen section at the time of surgery.
-1-
DIAGNOSIS
A. History incidental finding Vs previous history ( trauma, surgery, family Symptoms; pain, swelling, enlargement, caries/infection
B. Clinical examination inspection; asymmetry / enlargement, caries palpation crepitus / fluctuation bone density, thick Vs. thin auscultation ; thrill tooth vitality, displacement( radiographically, roots)
C. Radiographic Examination - 7 May appear as radiolucent or a mixed radiolucent-radioopaque lesion Uniloculated or multilucated Margins must be appreciated, or another study may be necessary, at least two views, preferably at right angles ( PA, panorex / Occlusal ). May need to change technique ( SLOB Rule ) to rule out tooth/root related. CT Scan is preferable to MRI in evaluating bony lesions Sometimes radioopaque contrast may be injected into the cyst, after removing some of the fluid content, this may enhance the margins radiographically. ( eg. To rule out sinus involvement)
D. Aspiration use large lumen needle (14-18g) with 5-10cc syringe Used (1) to rule out vascular lesions ( aspirate is blood) (2) to collect speciment for culture / sensitivity , cytology studies (3) insite into possible diagnosis ; eg. straw colored; cystic blood ( bright red) vascular: Air; traumatic bone cyst; Vacuum; tumor.
D. Biopsy differential diagonosis , may consider frozen section at the time of surgery
E. Treatment Options shoud use the standard of care, therefore must be current. Depend on the age, medical status, anatomical site, histological and pathological behavior of lesion and overall prognosis. Patient must be informed , and aware of possible need for further Treatment / surgery.
-2-
SURGICAL TREATMENT OPTIONS.
1. Enucleation -, the total removal of the cystic lining without removal of associated structures ( bone ). Main advantage is a single surgical procedure and offers a reliable microscopic diagonosis. Used when such a procedure would not result in (a) significant deformity (b) trauma to vital structures -, nerve/sinus (c) fracture to the 'aw (d) loss to tooth Uses a Molt curette with its concave surface facing outwards.
2. Decompression ; Indicated when cyst is very large or in close proximity to vital structures and where there is significant risk of injury with enucleation.
Access site is selected that allows normal function while aflowing ease of drainage and irrigation. Here a small opening is made, the cystic cavity irrigated, auctioned and a tube placed for drainage. Daily irrigation and antibiotics follow. Decompression allows a reduction in intra-cystic pressure, thereby allowing bone regeneration, and a decrease in cystic size. Eventually enucleation is performed to complete surgical care. Main disadvantage; length of treatment, need for daily care, hygiene considerations and does not allow proper histologic study, as such is seldom used.
3. Marsupialization ( exterorization, deroofing) Same indication as decompression. Differs from decompression in that, the entire roof of the cyst is removed and the cystic lining made continuous with the tissue of the surrounding structures. A decrease in size results, this would allow for DEFINITIVE ENUCLEATION or the adjacent tissues would become confluent with what, would have been the cystic lining. Here an acrylic button is used to cover opening to allow for better hygene, but procedure is still time consuming.
4. Enucleation with open packing ; Used for large cysts and when there is a likelyhood of dehiscence of the soft tissue margins. Iodoforrn gauze impregnated with antibiotics may be used as packing. Progressively smaller packings are placed.
Disadvantage in the longer post operative care entailing multiple visits.
-3- 5. Enucleation with Peripherial Ostectomy Better in areas with direct vision Used in lesions with high recurrence potential ( OKC) The ostectomy Involves removing about 2mm of the bony walls This may be achieved with (a) curettes (b) rotary instruments (Acrylic bur) (c) caustic solutions ( phenol, Carnoy's solution; a mixture of absolute alcohol, chloroform, glacial acetic acid and ferric chloride (d) hyperthermia and (e) cryosurgery Sometimes methylene blue dye is used to stain the bone to a 2-3mm depth
6. Peripheral Resection ( Segmental Resection ) Removal of lesion with a bony margin of 5mm. Here bony continuity is maintained and periosteum MAY be involved.
7. En Bloc Resection Removal of lesion together with bony margins of 1 cm (10mm) Here bony continuity is disrupted AND periosteum is involved.
BONY MARGINS ARE BASED ON ARBITRARY GUIDELINES BEYOND THE RADIOGRAPHIC MARGINS. 8. Osseous Sculpture ( used more in tumors) Bony surface is reshaped to remove bulk, without regards to margins. 9. Curettagedebrides and stimulates bleeding Tx. Pseudocyst.
ALL SAMPLES SHOULD BE SUBMITTED FOR HISTOLOGIC EXAMINATION AND DEFINITIVE DIAGNOSIS. DEVITALIZED TEETH SHOULD BE TREATED WITH ROOT CANAL THERAPY OR EXTRACTIONS.
-4-
CLASSIFICATION OF CYSTS THE JAWS
A. ODONTOGENIC CYSTS
1. Primordial Cyst ( rare ) Associated with a missing tooth or originates from a supermumary tooth follicle. Treatment : Enuleation
2. Eruption Cyst Located on the alveolar ridge above an erupting tooth, fluid filled follicular space,compressible,sometimes blue. Tx. Incision
3. Dentigerous Cyst ( Follicular cyst ) 14% rate of occurence, more frequent in males associated with an impacted or unerupted teeth, or with composite odontomas source reduced enamel epithelium may evolve into an ameloblastoma, and implicated in the development of squamous cell carcinoma and mucoepidermold carcinoma. In the Ist decade most commonly associated with the mandibular Ist premolar In adults,, mandibular 3rd molars, then maxillary canines. DDx. Unicystic ameloblastoma, adenomatoid odontogenic tumor (AOT) Odontogenic Keratocyst (OKC), ameloblastic fibroma Tx. (a) enucleation (b) marsupialization
3. Radicular Cyst a. periapical ; most common odontogenic cyst inflammatory origin Tx. enucleation and root canal therapy or extraction b. lateral periodontal cyst developmental in origin, lateral to the root of an erupted tooth mandibular premolar area characterised by ' clear cell ' in the lining DDx. Primordial cyst, odontogenic tumor Radicular cyst Tx. Enucleation
c. Botryoid cyst Polystic, multiloculated variant of the lateral periodontal cyst Potential for reoccurence . Intraepithelial buds containing Glycogen Tx. enucleation
-5- 4. Gingival Cyst Soft tissue cyst ( not radiographically evident Mandibular premolar Cyst of the newborn, Epstein's pearls, Bohn's Nodules are variants Tx. Excision
5. Residual Cyst Cyst that develops or remains following surgery in that area. Tx. excision
6. Odontogenic Keratocyst (OKC) 3%-13% of all jaw cysts, twice as frequent in males mandible more common, angle is more frequent. High incidence of recurrence, as such, following treatment patient should be followed for at least 5 yrs. Unilocular or multilocular, remnants of the dental lamina Histology ; wall is thin 6-8 cell thick, very uniform with no rete pegs. Keratinized (80% parakeratin ), basophilic nuclei, polarized to the basement membrane. Because of its thin tenacious walls and infolding of the lining and budding into the surrounding tissue, complete removal is difficult, hence its high recurrence. Most common in mandibular 3d molar area then maxillary 3rd molar Radiographically ; swiss cheese with multiple hole in the bone Tx. Enucleation with peripheral ostectomy
Associated with Basal Cell Nevus Syndrome / Gorlin's Syndrome Here may have multiple basal cell carcinomas and benign dermal cyst Also have palmar and plantar pits, bifid ribs, calcified falx cerebri and a flat nasal bridge. May also be associated with Hypergonadism in males and ovarian tumors.
7. Calcifying Odontogenic Cyst ( COC, Gorlin's cyst, Odontogenic Ghost Cell Tumor) Very rare ; less than 1%, Lining cells contain 'Ghost Cells' hyalinized, eosinophilic cytoplasm with faint nucleus May be considered an odontogenic tumor. 3 types (a) type I A; unicystic , occurs at any age (b)Type II B ; odontoma producing type 10-30 years, mixed RO / RL lesion DDx. ; Adenomatoid Odontogenic tumor (AOT) Calcifying Epithelial Odontogenic tumor Calcifying odontoma
-6-
(c) type I C ; ameloblastomatous proliferating type
type 11 -, neoplastic like lesion
Tx. ; Enucleation with curettage
NONODONTOGENIC CYSTS
AKA Fissual Cysts. Trapped epithelium
A. Incisal canal cyst ( Nasopalatine canal cyst) Behind maxillary incisors, heart shaped, vital teeth Tx. Enucleation
B. Median Palatal cyst Tx. Enucleation
C. Globumaxillary Cyst Between the lateral incisor and the canine, pear shaped with divergence of the roots. Vital teeth. Tx. Enucleation
D. Nasoalveolar cyst ( nasolabial cyst) Base of nose, rare, little radiographic changes Tx. Excision
E. Median mandibular cyst Similar to a primodial cyst. Tx. enucleation
-7-
REFERENCES
I . Assael, Leon A., et al. , Oral and Maxillofacial Surgery Clinics of North America, Benign Lesions of the Jaws, Volume 3, No. 1. Feb. 1991. 2. Petersen, Larry J. et al. ; Contemporary Oral and Maxillofacial Surgery. St. Louis C.V. Mosby Company pp 503-556, 1993 3. Bhaskar, S. N., Synopsis of Oral Pathology, seventh edition, C. V. Mosby Company pp 226-259. 4. Mygil Karen., The Diagnosis and Surgical Treatment of Cysts Of the Jaws. Lecture Outline 1998.
YOU ARE RESPONSIBLE FOR READING REFERENCE #2 PETERSON, PAGES 503-556.
-8-