 | Note: Large images and tables on this page may necessitate printing in landscape mode.
Copyright 2007 The McGraw-Hill Companies. All rights reserved.
Current Otolaryngology > VI. Oral Cavity , Oropharynx, & Nasopharynx > Chapter 24. Jaw Cysts >
| Jaw Cysts: Introduction Cysts of the maxilla and mandible are common occurrences. Bone cysts occur more frequently in the jawbones than in any other bone because of the presence of epithelium from odontogenic elements (eg, teeth) and nonodontogenic epithelial remnants of embryonic structures. A cyst is defined as an epithelial-lined pathologic cavity that may contain fluid or a semisolid material. A group of cystic lesions devoid of an epithelial lining is classified as pseudocysts. A jaw cyst is usually located deep within the jawbone, but it may occur on a bony surface, producing a saucerization. Essentials of Diagnosis - Well-defined , totally or predominantly radiolucent, and sometimes expansile lesions.
- Usually slow growing and benign .
- Initially asymptomatic unless long-standing with significant enlargement or secondary infection.
- Usually initially discovered on routine dental x-rays.
- Requires histopathologic examination for diagnosis.
General Considerations Jaw cysts encompass a group of lesions that are variable in their incidence, etiology , location, clinical behavior, and treatment. The most common jaw cyst is the radicular cyst, which is odontogenic and inflammatory in nature. The odontogenic developmental cyst is the second most common jaw cyst. Nonodontogenic cysts, pseudocysts, and ganglionic cysts of the temporomandibular joint (TMJ) are much less common. Cysts occur in both the mandible and the maxilla: inflammatory radicular cysts occur around the roots of nonvital teeth; odontogenic developmental dentigerous cysts and keratocysts occur in the common regions of impacted and unerupted teeth; nonodontogenic developmental cysts are found in regions of epithelial embryonic remnants; pseudocysts usually present in site-specific regions ; and ganglionic cysts develop in the TMJ. Each type of jaw cyst usually has a specific behavior pattern, ranging from small 56 mm osteolytic defects to massive involvement of the jaw and contiguous structures. Classification of Jaw Cysts The classification of jaw cysts includes (1) odontogenic cysts, (2) nonodontogenic cysts, and (3) pseudocysts. The ganglion cyst, which presents in the TMJ, has been added to this conventional classification for completeness; it is significant to clinicians managing the pathology of the head and neck region. Pathogenesis The pathogenesis of jaws cysts varies according to the specific cyst type. Inflammatory cysts derive their epithelial lining from the proliferation of odontogenic epithelium within the periodontal ligament; dentigerous developmental cysts result from the proliferation of reduced enamel epithelium. Figure 241 illustrates the development of dentigerous and radicular cysts. Cystic lesions may also result from cortical bone defects or trauma, they may represent reactive lesions, or they may have an unknown pathogenesis. It has been shown that there is an osmotic pressure gradient that produces fluid accumulation within the cyst lumen and generates pressure, creating cyst expansion. Prevention It may be possible to prevent odontogenic jaw cyst formation through the immediate treatment of nonvital teeth and the removal of impacted or unerupted teeth. Strategies should include preventing the progression of jaw cysts to large, destructive lesions that require aggressive management. Prevention is aided by routine and regular dental and oral examinations with appropriate imaging. Clinical Findings Symptoms and Signs The patient with a small cyst is usually asymptomatic. Symptoms such as pain and swelling occur when the cyst becomes secondarily infected. The patient may report an unpleasant or even foul taste if the cyst has discharged into the mouth through a sinus tract . Teeth contiguous to all cysts, except radicular cysts, have vital pulps, unless coincidental disease of these teeth exists. Tooth vitality can be assessed with electrical pulp testers or ice. Erupted teeth contiguous to a large cyst may maintain their vitality , despite the loss of a significant amount of supporting alveolar bone. Benign jaw cysts rarely produce loosening of adjacent teeth unless the cyst becomes very large. Large cysts can displace the roots of teeth that can be evident clinically, on an x-ray, or both. The clinical absence of one or more teeth, as seen on routine dental x-rays, may suggest the presence of a developing dentigerous cyst. Extensive cysts in the anterior maxilla may extend under the nasal floor, creating nostril distortion. An infected maxillary cyst may involve the maxillary sinus, producing maxillary sinusitis. Large mandibular cysts may involve the mandibular canal and its contents, the inferior alveolar neurovascular bundle. The mandibular canal and its contents can be deflected inferiorly without producing a neurosensory deficit. However, if an acute infection develops with pus accumulation, a decrease in lower lip sensibility may be observed . Imaging Studies The typical radiographic appearance of a jaw cyst is that of a well-defined, round-to-oval, unilocular or multilocular radiolucent cyst that is circumscribed by a dense periphery of reactive bone. Periapical and panoramic x-rays usually suffice for imaging small- to medium- sized cystic lesions, but computed tomography (CT) scans are indicated for large, expansile lesions. Anatomic structures such as the mental foramen, the incisive foramen, and the maxillary sinus may be misinterpreted as pathologic cystic lesions. Special Tests Needle aspiration of a suspected jaw cyst can reveal valuable diagnostic information. Aspiration of blood from the lesion may indicate the presence of a vascular lesion or an aneurysmal bone cyst. If aspiration of a solid lesion (eg, a tumor) is attempted, no fluid can be aspirated and withdrawing the plunger of the syringe is difficult. Aspiration of a light, straw-colored fluid containing cholesterol crystals (known by their characteristic "shimmering" effect in light) is consistent with a benign odontogenic cyst. Aspiration of a whitish to pale yellow material that appears similar to pus usually reveals an odontogenic keratocyst that contains desquamated cells and keratin. A cyst that has been present for a long time and has become infected may contain a thick yellow or brown material that is difficult to aspirate. A histopathologic examination is essential for establishing a definitive diagnosis. For small lesions, excisional biopsy is appropriate; for large lesions, an incisional biopsy is indicated to establish a diagnosis, develop a treatment plan, and obtain appropriate informed consent . Differential Diagnosis An orderly approach to a differential diagnosis of a jaw lesion can be accomplished by grouping possible lesions into six main categories: (1) cysts, (2) odontogenic tumors, (3) benign nonodontogenic tumors , (4) inflammatory jaw lesions, (5) malignant nonodontogenic neoplasms of the jaw, and (6) metabolic and genetic jaw diseases. An assessment of the radiographic appearance, patient age, and location of the lesion enables the clinician to establish a reasonable differential diagnosis that should ultimately be confirmed by histopathologic examination. A definitive histopathologic diagnosis may rule out more serious lesions (eg, cystic ameloblastoma). Complications Complications related to the destruction caused by a jaw cyst and the surgical treatment required include loss of teeth and bone; infection; cyst recurrence ; neurosensory deficits; oral or facial sinuses; oral, antral, or nasal fistulas, or a combination of these three complications; and pathologic jaw fracture. Carcinoma arising in an odontogenic cyst is a rare occurrence and requires aggressive treatment. Treatment Because contiguous structuresincluding displaced teeth, resorbed roots, bony supports, the maxillary sinus, and the mandibular canalmay be involved or encroached upon, jaw cysts usually require surgical management. However, jaw cysts that demonstrate slow or no progression or growth may be managed by observation in the elderly or severely medically compromised individuals. The exact nature of the surgery depends on the size, location, and clinical behavior of the specific type of cyst. Treatment is necessary because (1) cysts usually increase in size , causing local tissue destruction and usually becoming infected; and (2) extensive involvement of the mandible is capable of creating a potential pathologic fracture. | | Dentigerous (Follicular) Cysts Essentials of Diagnosis - Epithelial-lined, developmental, odontogenic cysts.
- Second most common type of jaw cyst associated with the crown of an impacted, unerupted, or developing tooth.
- Well-defined, radiolucent, sometimes expansile lesion.
- Usually slow growing and benign.
- Initially asymptomatic unless long-standing with significant enlargement or secondary infection.
- Usually discovered on routine dental x-rays.
- Requires histopathologic examination for diagnosis.
General Considerations Fifteen to eighteen percent of jaws cysts are dentigerous, surround the crowns, and attach at the cemento-enamel junction of unerupted teeth. The lower third molars and the upper canines are the most commonly involved teeth. Pathogenesis Dentigerous cysts derive their epithelium from the proliferation of the reduced enamel epithelium after the tooth enamel is formed . The cyst develops subsequent to an accumulation of fluid between the remnants of the enamel organ and the contiguous tooth crown. The expansion of this intrabony cyst is associated with an increase in the osmolality of the cyst fluid secondary to the migration of inflammatory cells into the cyst lumen. Epithelial proliferation may also occur simultaneously . Prevention Regular dental and oral examinations with appropriate imaging can identify developing cystic jaw lesions before any significant bony destruction can occur. The removal of impacted teeth, when indicated, serves as a preventive measure. Clinical Findings Symptoms and Signs Small dentigerous cysts rarely produce clinical symptoms. Larger cysts can produce a bony expansion, which creates an intraoral swelling, an extraoral swelling, or both. They also can result in facial asymmetries or can become secondarily infected, which results in pain. Imaging Studies The most common radiographic appearance of a dentigerous cyst is that of a well-delineated round-to-oval mass that is associated with an unerupted tooth, which may possibly be displaced. Figure 242 demonstrates a typical dentigerous cyst as observed on a panoramic x-ray. Periapical and panoramic x-rays can illustrate the extent of the cyst and contiguous anatomic structures. With large lesions, CT scanning is helpful in assessing the degree of expansion perforation and the involvement of adjacent structures. Special Tests Needle aspiration with possible biopsy of the lumen of a suspected cystic lesion can give confirmatory diagnostic information and rule out a vascular lesion. If there has not been significant expansion of the cyst, with thinning of the bony cortex, it will not be possible to penetrate the bone using a needle and syringe technique. In these cases, if aspiration is desired, a small mucosal incision, followed by drilling a small hole through the buccal cortex , enables needle aspiration. Aspiration of a light, straw-colored fluid is characteristic of a dentigerous cyst (Figure 243). Histopathologic examination reveals a thin, nonkeratinized cyst lining. Inflammatory changes may produce epithelial hyperplasia. Mural hemorrhage can result in cholesterol clefts, giant cells, and hemosiderin in the wall of the cyst. Hyaline bodies (eg, Rushton or hyaline bodies) may be present in the epithelium. Differential Diagnosis The differential diagnosis should include odontogenic keratocysts, ameloblastomas, cystic ameloblastomas, ameloblastic fibromas, and nonodontogenic tumors. Complications Complications related to the damage created by an expanding jaw cyst include bony destruction, infection, oral or facial sinuses, weakening of the jaw, displacement of teeth, resorption of adjacent tooth roots, encroachment on the maxillary sinus floor, and deflection of the inferior alveolar canal. The transformation of the epithelial lining of a dentigerous cyst into an ameloblastoma is also possible. Dysplasia or the carcinomatous transformation of the epithelial lining is possible, but rare. Complications related to the surgical management of cysts include devitalization of adjacent teeth, postoperative infection, neurosensory deficits, oral-antral fistulas, jaw fracture, and cyst recurrence. Treatment The treatment of choice consists of enucleation of the cyst and removal of the associated tooth. The surgical exposure is observed in Figure 244. The surgical flap can be repositioned and sutured with primary closure. Even large, bony cavities can regenerate new bone over several months' time. If the tissue breaks down, the cavity can be packed with 1/4 -inch gauze and gradually advanced over 710 days, followed by frequent saline irrigations to allow healing by secondary intention . For extremely large surgical defects, primary bone grafting with autogenous cancellous chips can accelerate the healing process. Marsupialization of the cyst may be considered . Prognosis The prognosis after treatment of the cyst is excellent , with the expectation that the surgical defect will heal. The recurrence rate for the cyst is very low. Rosenstein T, Pogrel MA, Smith RA, Regezi JA. Cystic ameloblastoma: behavior and treatment of 21 cases. J Oral Maxillofacial Surg. 2001;59:1311. (Cystic ameloblastomas have unexpected capacity for bony destruction and recurrence.) [PMID: 11688034]
| Shimoyama T, Ide F, Horie N et al. Primary intraosseous carcinoma associated with impacted third molar of the mandible: review of the literature and report of a new case. J Oral Sci. 2001;43(4):287. (A primary intraosseous carcinoma occurred in a dentigerous cyst associated with an impacted third molarmean patient age 73 years .) [PMID: 11848197]
| | | Eruption Cysts Essentials of Diagnosis - A variant of the dentigerous cyst.
- Presents as a bluish swelling on the alveolar ridge crest at the site of an erupting tooth.
An eruption cyst occurs most commonly in the molar regions of the jaws in children less than 10 years of age. This cyst results from hemorrhage or fluid accumulation in the space between the crown and the reduced enamel epithelium. A dome-shaped, sometimes painful, frequently bluish swelling of the gingiva overlies an erupting tooth. A periapical or panoramic x-ray confirms the presence of an erupting tooth. The clinical presentation is pathognomonic for an eruption cyst. There may be trauma to the cyst, producing hemorrhage, which results in discoloration and pain. Most eruption cysts rupture spontaneously, and no treatment is required. However, excision of the overlying mucosa yields relief and facilitates eruption of the underlying tooth. The prognosis is excellent, and there should not be any detrimental effect to the associated erupting tooth. Bodner L, Goldstein J, Sarnat H. Eruption cysts: a clinical report of 24 new cases. J Clin Pediatr Dent. 2004;28(2):183. (The eruption cyst occurs within the mucosa overlying a tooth that is about to erupt, has a raised, bluish appearance on the alveolar ridge, and should be managed conservatively.) [PMID: 14969381]
| | | Odontogenic Keratocysts Essential of Diagnosis - A developmental odontogenic cyst occurring in the tooth- bearing areas of the jaws or posterior to the mandibular third molar.
- Has a parakeratinized epithelial lining.
- May be a component of basal cell nevus syndrome (ie, Gorlin-Goltz syndrome).
- Has an aggressive clinical behavior with a high recurrence rate after treatment.
General Considerations Three to ten percent of odontogenic cysts are keratocysts and can occur at any age; however, 60% of patients are between 10 and 40 years of age. Odontogenic keratocysts may be part of Gorlin-Goltz syndrome, which includes multiple odontogenic keratocysts (Figure 245), multiple basal cell carcinomas, cutaneous abnormalities, skeletal anomalies, and cranial calcifications. This syndrome is a genetic disorder with autosomal dominant inheritance (ie, with mutation of the "PATCHED" tumor suppressor gene), high penetration, and variable expression. Pathogenesis The epithelium arises from cell rests of the dental lamina. However, it has been suggested that the cyst originates from extension of the basal cell components of the overlying oral epithelium. It also has been suggested that the growth of a keratocyst may be related to epithelial activity or enzymatic action in the fibrous cyst wall. Prevention Regular dental and oral examinations with appropriate imaging can assist both in identifying cystic lesions early in their course and preventing the development of large, destructive lesions. Clinical Findings Symptoms and Signs The mandible is involved in 6080% of odontogenic keratocysts, with a tendency to involve the posterior mandible and ascending ramus (Figures 246, 247, and 248). These cysts have a locally aggressive clinical behavior. Small odontogenic keratocysts usually are asymptomatic and are identified during routine dental examination and imaging. Larger odontogenic keratocysts may produce pain, drainage, swelling from secondary infection, and asymmetries from bony expansion. The adjacent teeth are vital, but can be displaced.
The features associated with Gorlin-Goltz syndrome include (1) odontogenic keratocysts of the jaws, (2) multiple basal cell carcinomas, (3) an enlarged occipitofrontal circumference, (4) mild ocular hypertelorism, (5) epidermal cysts, (6) palmar or plantar pits, (7) calcified ovarian cysts, (8) calcified falx cerebri, (9) rib abnormalities, (10) spina bifida, (11) short fourth metacarpals, (12) vertebral anomalies, and (13) pectus excavatum. Imaging Studies Panoramic x-rays and CT scans for large, expansile lesions reveal a locally destructive, multilocular lesion that can displace teeth, resorb tooth roots, deflect the mandibular canal inferiorly, and displace the floor of the maxillary sinus superiorly. Special Tests Aspiration of an odontogenic keratocyst produces a whitish or pale yellow, inspissated, cheese-like material that may appear similar to purulent exudates, but is actually liquid-containing masses of desquamated keratinized cells. The combination of fine-needle aspiration biopsy with immunocytochemical testing for cytokeratin-10 in sampled epithelial cells has been shown to be accurate in distinguishing odontogenic keratocysts from nonodontogenic cysts. Histopathologic examination of the cyst reveals an epithelial lining with a wavy or "corrugated" appearance and a thickness of 610 cell layers . The epithelium demonstrates basal palisading and a thin, refractile, parakeratinized lining. Any budding of the basal layer may produce " daughter cysts," which may be related to the high recurrence rate. A protein level > 4 mg/100 mL is highly suggestive of a keratocyst. Differential Diagnosis The differential diagnosis should include dentigerous cysts, ameloblastomas, cystic ameloblastomas, ameloblastic fibromas, and nonodontogenic neoplasms. Complications Complications are related to the aggressive clinical behavior of the keratocyst, which results in bony destruction. They are also related to a high recurrence rate, which may be due to the thin, friable cyst wall that is difficult to enucleate intact from the bone. Squamous cell carcinoma has been reported to occur in maxillary odontogenic keratocysts. Treatment Enucleation (Figure 249), or decompression and marsupialization are the treatments of choice. Pogrel MA. Treatment of keratocysts: the case for decompression and marsupialization. J Oral Maxillofac Surg. 2005;63:1667. (Decompression can be performed by making a small opening in the cyst and maintaining its patency with some type of drain.) [PMID: 16243185]
| Small cysts (approximately 1 cm) may be managed with enucleation, curettage, and peripheral ostectomy. For larger cysts, enucleation followed by cryotherapy with liquid nitrogen may reduce recurrence rates. There have been reports of the effective use of the "Carnoy solution" to eliminate satellite cysts; these cysts are eliminated by the use of a chemical lavage that causes tissue fixation. The potential for keratocysts to involve the overlying soft tissue through cortical perforation may necessitate a supraperiosteal dissection and excision of the overlying mucosa. Prognosis Long- term follow-up is essential because of the high recurrence rate. Most recurrences become evident within 5 years of the initial treatment. Diaz-Fernandez JM, Infante-Cossio P, Belmonte-Caro R, Ruiz-Laza L, Garcia-Perla-Garcia A, Gutierrez-Perez JL. Basal cell nevus syndrome. Presentation of six cases and literature review. Med Oral Patol Oral Cir Buccal. 2005:1;10 (Suppl 1):E57. (Basal cell nevus syndrome may be associated with aggressive basal cell carcinomas and malignant neoplasias, for which early diagnosis and treatment are essential.) [PMID: 15800468]
| Makowski GJ. Squamous cell carcinoma in a maxillary odontogenic keratocyst. J Oral Maxillofac Surg. 2001;59(1):76. (Description of a case of a malignant growth that developed in an odontogenic keratocyst.) [PMID: 11152194]
| Myoung H, Hong SP, Hong SD et al. Odontogenic keratocyst: review of 256 cases for recurrence and clinicopathologic parameters. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001;91(3):328. (Report of a large series of case reviewing the age at diagnosis, gender of the patient, cyst location, radiographic findings, histopathologic findings, and recurrence rates.) [PMID: 11458242]
| Schmidt BL. The use of enucleation and liquid nitrogen cryotherapy in the management of odontogenic keratocysts. J Oral Maxillofac Surg. 2001:59(7):720. (The combination of enucleation and liquid nitrogen therapy may offer patients improved treatment in the management of odontogenic keratocysts.) [PMID: 11429726]
| Stoelinga PJ. Long-term follow-up on keratocysts treated according to a defined protocol. Int J Oral Maxillofac Surg. 2001;30(1):14. (Brief discussion of the etiology and pathogenesis of odontogenic keratocysts and a treatment protocol for effective management.) [PMID: 11289615]
| Stoll C, Stollenwerk C, Riediger D, Mittermayer C, Alfer J. Cytokeratin expression patterns for distinction of odontogenic keratocysts from dentigerous and radicular cysts. J Oral Pathol Med. 2005;34(9):558. (Immunochemical detection of cytokeratin 17 and 19 seems to be a valuable additional parameter differentiating odontogenic keratocysts from other odontogenic cysts.) [PMID: 16138895]
| | | Gingival (Alveolar) Cysts of Newborns Essentials of Diagnosis - Superficial, keratin-filled cyst found on the alveolar mucosa of infants.
- Present at birth.
Gingival cysts are fairly common in newborns but are rarely identified because they have a tendency to rupture and disappear. Similar inclusion cysts, such as Epstein pearls and Bohn nodules, are found on the palates of newborns. These cysts form from remnants of the dental lamina. They are asymptomatic, small (usually 12 mm in diameter), whitish papules on the mucosa of the alveolar process of neonates. The appearance of these lesions is pathognomonic. No treatment is required since these lesions spontaneously involute as a result of cyst rupture. The prognosis is excellent and there is usually no recurrence. | | Lateral Periodontal Cysts and Variant, the Botyroid Odontogenic Cyst Essentials of Diagnosis - A rare type of odontogenic developmental cyst.
- Occurs lateral to a tooth root, most commonly in the premolar region of the mandible (a common location of supernumerary teeth).
Lateral periodontal cysts are uncommon and are usually discovered on routine dental x-rays. The origin of this cyst may be related epithelial rests in the periodontal membrane . These lesions are usually asymptomatic, with possible expansion of the buccal plate of bone. The adjacent teeth are usually vital and there may be evidence of root divergence caused by expansion of the cyst. Lateral periodontal cysts are characterized by a round to ovoid radiolucency that is lateral to or between the roots of teeth. These cysts are lined by nonkeratinized epithelium and, unless secondarily infected, do not have an inflammatory component. The differential diagnosis includes odontogenic keratocysts and lateral radicular cysts. Complications include local bone destruction, divergence of adjacent tooth roots, and recurrence. Cyst enucleation is the treatment of choice. The prognosis is very good, although cyst recurrence is possible. A more aggressive variant of the lateral periodontal cyst is the botryoid odontogenic cyst. Ucok O, Yaman Z, Gunhan O, Ucok C, Dogan N, Baykul T. Botryoid odontogenic cyst: report of a case with extensive epithelial proliferation. Int J Oral Maxillofac Surg. 2005;34(6):693. (Botryoid odontogenic cyst is considered a rare multilocular variant of the lateral periodontal cyst, can be aggressive, and can extend beyond the typical inter-radicular location.) [PMID: 16053898]
| | | Calcifying Odontogenic Cysts (Gorlin Cysts) Essentials of Diagnosis - A rare odontogenic, developmental cyst with occasionally aggressive behavior.
- Occurs equally frequently in the maxilla and the mandible; most cases are reported in the incisor or canine regions.
The mean reported age of onset is 33 years, with most cases presenting in the second and third decades. The epithelium is derived from odontogenic sources within the jaw or gingiva. This lesion is considered by some clinicians to be a neoplasm rather than a cyst. It is usually painless and occurs in the tooth-bearing areas of the jaws, but it may be peripheral to the bone in about 25% of cases. Lesions that are extraosseous appear as localized sessile or pedunculated gingival masses. The calcifying odontogenic cyst usually appears as a unilocular or multilocular and well-delineated radiolucency. Radiopacities may appear in the lesion as irregular calcifications or toothlike structures in approximately 50% of cases. The distinctive histopathologic feature of this lesion is "ghost cell" keratinization of the epithelial lining. The keratin may undergo dystrophic calcification. A differential diagnosis should include adenomatoid odontogenic tumors, cystic odontomas, calcifying epithelial odontogenic tumors, and ameloblastic fibroodontomas. Complications include local bony destruction and the potential for loss of contiguous teeth in aggressive cases. The cyst should be removed by enucleation. The prognosis is good, and only a few cases of recurrences have been reported. | | Glandular Odontogenic Cysts Essentials of Diagnosis - This recently described odontogenic developmental lesion is uncommon.
- Occurs in the tooth-bearing areas of the jaws.
This lesion can occur in any jaw site in adults but is more common in the anterior regions. Most cases of glandular odontogenic cysts reported have been in the adult mandible, and they can be locally aggressive. This cyst usually presents as a multilocular radiolucency of the jaw. Glandular odontogenic cysts are lined by a nonkeratinized epithelium, with localized areas of mucus and clear cells in a pseudoglandular pattern. The differential diagnosis should include odontogenic keratocysts. Local bone destruction can result from the growth of this lesion. Surgical management should be based on the extent and aggressiveness of the lesion. The prognosis is good based on relatively few reported cases, but the potential for recurrence exists. | | Radicular Cysts (Periapical Cysts) Essentials of Diagnosis - The most common type of jaw cyst.
- Associated with a nonvital tooth subsequent to dental caries entering the tooth pulp, trauma, or surgical devitalization.
- Usually presents as a radiolucent lesion around the apex of a tooth root.
General Considerations This odontogenic inflammatory cyst represents 6570% of all jaw cysts and can occur around the apex of any tooth (Figure 2410). If a tooth associated with a radicular cyst is extracted and the cyst is not removed, it may remain and continue to expand, producing a residual cyst. Pathogenesis The radicular cyst is the result of dental pulp inflammation that progresses to the periapical area through the apical foramen of the tooth or through a lateral root canal. The epithelium is derived from the epithelial rest of Malassez. This cyst develops within a periapical granuloma at the tooth apex. Prevention The prevention of radicular cyst formation can be accomplished by regular dental examination and imaging to identify nonvital teeth. Once these nonvital teeth are identified, they are treated with endodontics (eg, root canal therapy) or extraction to prevent potential cyst development. Clinical Findings Symptoms and Signs Small radicular cysts do not usually become acutely infected, are frequently asymptomatic, and can be identified on routine dental x-rays. Larger cysts may produce expansion of the bone, displacement of tooth roots, and crepitus when palpating the expanded alveolar plate. The discoloration of nonvital teeth and a negative response of the affected tooth to electric pulp testing or ice are the presenting signs. In addition, infected radicular cysts are painful, the involved tooth is sensitive to percussion, and there may be swelling of the overlying soft tissues and lymphadenopathy. Imaging Studies Dental x-rays (periapical, occlusal, and panoramic) show a cyst around the end of the root (most commonly, the maxillary anterior teeth) that can extend beyond the boundaries of the involved tooth (Figure 2411). Special Examinations Histopathologic examination reveals a cystic lesion with a nonkeratinized epithelial lining. Remnants of cellular debris and fluid containing proteins predominantly derived from the plasma are usually found within the lumen of the cyst. Differential Diagnosis The differential diagnosis should include periapical granulomas, periapical scars (ie, fibrous healing defect), the early stage of periapical cemental dysplasia, giant cell lesions, bone neoplasms, traumatic bone cysts, and metastatic disease. Complications Complications include the loss of supportive alveolar bone and the loss of teeth. Treatment & Prognosis Treatment of radicular cysts involves endodontic therapy for small cysts (ie, < 5 mm), endodontic therapy plus periapical surgery and cyst enucleation for larger lesions, or, if the tooth is not restorable, tooth extraction combined with cyst enucleation. The prognosis is excellent following the appropriate treatment and recurrences are rare unless the cyst is left in situ. Caliskan MK. Prognosis of large cyst-like periapical lesions following nonsurgical root canal treatment: a clinical review. Int Endod J. 2004;37(6):408. (Root canal treatment using calcium hydroxide as an antibacterial dressing in healing large, cyst-like periapical lesions.) [PMID: 15186249]
| | | Nasolabial Cysts (Nasoalveolar Cysts) Essentials of Diagnosis - Rare nonodontogenic developmental cyst.
- Occurs as a unilateral swelling (10% incidence of bilateral occurrence) of the upper lip lateral to the midline, superficial to the maxilla.
The nasolabial cyst is observed most often in adults in the fourth to sixth decades of life with a 3:1 female -to-male predilection. It is believed that the epithelium is derived from remnants of the nasolacrimal duct. A swelling appears in the lateral aspect of the upper lip and is generally painless unless secondarily infected (Figure 2412). The swelling may elevate the nasal vestibule mucosa and cause obliteration of the nasolabial fold. It may cause nasal obstruction or interfere with the flange of an upper denture. There are no radiographic signs, except for a possible saucerization of the underlying labial surface of the maxilla. The nasolabial cyst is lined by pseudostratified columnar epithelium, which frequently demonstrates cilia and goblet cells. The differential diagnosis should include odontogenic developmental cysts, salivary gland neoplasms, inclusion cysts, and sebaceous cysts. Secondary infection is a potential complicating factor. Transoral surgical excision is the treatment of choice, as observed in Figure 2413. The prognosis is excellent and recurrence is rare.
| | Nasopalatine Cysts (Incisive Canal Cysts) Essentials of Diagnosis - Relatively common nonodontogenic, developmental cyst.
- Occurs in the palatal midline behind the maxillary central incisors in the region of the incisive canal.
Nasopalatine cysts occur in 25% of jaw cysts. This cyst derives its epithelium from the embryonic remnants of the nasopalatine duct. The lesion is usually asymptomatic unless secondarily infected. The maxillary central incisors are vital. There may be palatal bone expansion or palatal mucosal swelling. The patient may complain of a salty taste, which results from drainage. This cyst presents as a well-defined, oval- or heart-shaped mass that is created by the anterior nasal spine; it occurs between and apical to the maxillary central incisors. Periapical and occlusal radiographs demonstrate the lesion very clearly (Figure 2414). It is difficult to determine at times whether the mass is a large incisive foramen or whether it represents a nasopalatine cyst. If the affected area is asymptomatic, if the cyst is less than approximately 7 mm, and if there is a question of the existence of pathology, it is reasonable to follow up the patient clinically and radiographically. The epithelial lining varies from stratified squamous presentation to one that is pseudostratified and ciliated. A differential diagnosis should include periapical cysts, granulomas, and keratocysts. Complications include the loss of bony support for the adjacent incisor teeth, root divergence, root resorption, as well as neurosensory deficit of the anterior palatal mucosa after cyst excision. Surgical enucleation via a palatal flap is the treatment of choice. The prognosis is excellent and recurrence is rare. Elliott KA, Franzese CB, Pitman KT. Diagnosis and surgical management of nasopalatine cysts. Laryngoscope. 2004;114(8):1336. (Nasopalatine duct cysts are the most common cystic lesion of nonodontogenic origin of the maxilla with enucleation as the preferred treatment and low recurrence rates.) [PMID: 15280704]
| | | Aneurysmal Bone Cysts Essentials of Diagnosis - Rare intraosseous jaw lesion characterized by blood-filled spaces associated with a fibroblastic tissue containing multinucleated giant cells and osteoid and woven bone.
- Appears more frequently in the mandible than in the maxilla.
This lesion is typically observed in patients under 30 years of age. Aneurysmal bone cysts are considered reactive rather than neoplastic or cystic lesions. The pathogenesis is unknown, but it is believed that a vascular malformation occurs, producing an alteration of hemodynamic forces that create the cyst. Smaller lesions may be asymptomatic and are identified on routine x-rays; larger lesions present as occasionally painful, nonpulsatile swellings over the jaw. A multilocular jaw mass with cortical expansion is characteristic, as illustrated in Figure 2415. Histopathologic examination reveals a fibrous connective tissue stroma containing variable numbers of multinucleated cells in relation to sinusoidal blood spaces. The differential diagnosis should include ameloblastomas, developmental odontogenic cysts, central giant cell granulomas, and central vascular lesions. Complications include a destructive osteolytic process of the involved jaw. Complete excision is the treatment of choice. The prognosis is generally good, provided the lesion is completely removed. Curettage procedures yield high recurrence rates. Sanchez AP, Diaz-Lopez EO, Rojas SK et al. Aneurysmal bone cyst of the maxilla. J Craniofac Surg. 2004;15(6):1029. (An aneurysmal bone cyst is a nonneoplastic, uncommon solitary bone lesion recognized by distinct radiographic and histopathologic characteristics that can reach a considerable size and is treated by surgical excision.) [PMID: 15547399]
| | | Traumatic Bone Cysts Essentials of Diagnosis - An empty or possibly fluid-filled bone cavity that appears to scallop the roots of vital teeth.
- Rather than an epithelial lining, there is a fibrous or granulation tissue component, or no identifiable lining.
- Usually identified on routine dental radiographic examination.
General Considerations A traumatic bone cyst is usually observed during the second decade of life and is seen in the mandibular body and symphysis. It is a relatively uncommon lesion that can occur in the humerus and other long bones. This cyst is sometimes referred to as a solitary, simple, hemorrhagic cyst. Pathogenesis The pathogenesis of this lesion is unknown; theories suggest that its pathology results from a traumatic episode that causes a hematoma to form within the intramedullary bone. Rather than forming a blood clot, it breaks down, producing osteolysis and an empty bone cavity. Prevention There are no known preventive measures. Regular dental visits with appropriate imaging are recommended. Clinical Findings Symptoms and Signs The traumatic bone cyst is usually asymptomatic and rarely presents with pain or bony expansion. Although the lesion is around the root apices, tooth vitality is maintained . Traumatic bone cysts that occur in association with florid osseous dysplasia have been reported. Percussion of the teeth contiguous to this cyst may produce a dull percussion sound compared with the more high-pitched sound that is heard when percussing teeth not involved with a hollow bone cavity. Imaging Studies Radiographically, the traumatic bone cyst appears as a well-defined lesion around the roots of contiguous teeth, usually in the mandible (Figure 2416). Adjacent tooth roots may be displaced. Special Examinations Histopathologic examination of surgical specimens usually reveals fragments of fibrous or granulation tissue and bone fragments . Differential Diagnosis The differential diagnosis includes odontogenic keratocysts, central giant cell granulomas, or odontogenic tumors. Complications Complications include local bone destruction and the displacement of tooth roots. Treatment Surgical exploration is the treatment modality most commonly used to rule out the existence of other more aggressive and significant lesions. The aspiration or surgical curettage of the cavity frequently induces hemorrhage, with subsequent healing of the bony cavity. Prognosis Traumatic bone cysts may heal spontaneously without surgical intervention, but with surgical exploration, the healing may be accelerated, with bone fill expected in 612 months. The prognosis is excellent and recurrence is not expected. | | Static Bone Cysts Essentials of Diagnosis - A mandibular anatomic defect that has a cyst-like appearance on x-ray.
- May occur in the incisor or in the cuspid or premolar regions of the lingual aspect of the mandible.
- Usually a unilateral phenomenon but may occur bilaterally.
A static bone cyst is an anatomic defect in the mandible (Figures 2417, 2418, and 2419). These cysts are also known as Stafne bone cysts, lingual mandibular salivary gland depressions, latent bone cysts, and lingual cortical mandibular defects. It is believed to be developmental in nature but does not appear at birth and is not seen in children. Most cases are seen in middle-aged or older adults. Eighty to ninety percent of these defects are seen in males. They are stable in size (ie, static) and have been reported to occur in 0.3% of panoramic x-rays. This entity is asymptomatic and nonpalpable and is discovered during routine radiographic examination. A static bone cyst appears as a well-circumscribed, round to oval mass that is located near the angle of the mandible and below the level of the mandibular canal, with no involvement of the tooth roots (Figure 2420).
Surgical exploration is not indicated, but these defects contain salivary gland or adipose tissue from the floor of the mouth. The radiographic and clinical findings are pathognomonic for this entity. There has been a report of a salivary gland neoplasm developing in the lingual mandibular salivary gland depression. A static bone cyst does not require biopsy or excision unless a mass can be identified or imaged or there are clinical findings. The prognosis is excellent and no treatment is required. Katz J, Chaushu G, Rotstein I. Stafne's bone cavity in the anterior mandible: a possible diagnostic challenge. J Endod. 2001;27(4):304. (Most Stafne bone cavities occur in the angle of the mandible in the area between the mandibular first molar and the mandibular angle, but some may appear in the anterior mandible, which> may be more difficult to diagnose.) [PMID: 11485274]
| | | Ganglion Cysts Ganglions are cystic lesions that develop near joints, including the TMJ. These cystic lesions are not classically described in discussions of cystic lesions of the jaw, but, because of their presentation, they may be confused with parotid tumors. There are two types of ganglion cysts: (1) those with walls that consist of fibrous connective tissue and (2) those with walls that are lined by synovial cells. Ganglions should be considered when evaluating preauricular swellings. The surgical removal with histopathologic examination of the excised tissue is the treatment of choice for jaw cysts in most cases. Kim SG, Cho BO, Lee YC et al. Ganglion cyst in the temporomandibular joint. J Oral Pathol Med. 2003;32(5):310. (The ganglion cyst of the temporomandibular joint should be considered in the differential diagnosis of preauricular masses.) [PMID: 12694356]
| | | | |
Print Close Window 
