Dentigerous Cyst Associated with a Formocresol Pulpotomized

Case Report/Clinical Techniques

Dentigerous Cyst Associated with a Formocresol Pulpotomized Deciduous Molar Eugenia Asián-González, PhD, MD, DDS,* Manuela Pereira-Maestre, MD, DDS,† Dolores Conde-Fernández, PhD, MD, DDS,* Ignacio Vilchez, DDS,‡ Juan José Segura-Egea, PhD, MD, DDS,* and José Luis Gutiérrez-Pérez, PhD, MD, DDS§

Abstract This report presents a case of dentigerous cyst associ- ulpotomy is considered a safe procedure, although side effects such as malposition, ated with a formocresol pulpotomized deciduous molar Pdelay in eruption, enamel defects, discoloration, cyst formation, and damage to the detected during routine examination. Dentigerous cyst permanent dentition have been reported (1–3). A dentigerous cyst can form in the is an epithelial-lined developmental cavity that encloses periradicular region after pulpotomy (4, 5) caused by an alteration of the reduced the crown of an unerupted tooth at the cementoenamel enamel epithelium (after completion of amelogenesis), which results in fluid accumu- junction. The present case describes a 9-year-old girl lation between the epithelium and the tooth crown (6). The persistent and prolonged sent to the dental clinic by her dentist, who had acci- inflammation may cause chronic irritation to the dental sac of the unerupted tooth, dentally discovered in the panoramic radiograph a sin- which in turn leads to the development of a dentigerous cyst (7). Histological evidence gle, unilocular, well-defined, radiolucent area enclosing for this process has been found (8), concluding that inflammatory exudate is induced the second left unerupted mandibular premolar. The by infection that spreads to the dental follicle, causing separation of the reduced enamel second left primary molar had been pulpotomized 2 epithelium from the enamel. This would be true for immature permanent teeth found years before and buccal swelling without redness oc- under necrotic or pulp-treated primary teeth (9). Inflammation and prolonged irrita- curred near the tooth, evidencing bone expansion. Sur- tion are apparent causes of, and the trigger for, proliferation of the epithelial rests (10). gical treatment was carried out, the tooth was ex- This explains why cysts are found in conjunction with necrotic or pulp-treated teeth in tracted, and a cystectomy was performed under local the primary dentition (9–11). Periradicular cysts described in association with pulpo- anesthesia in the dental office. The histological study confirmed the suspected diagnosis of dentigerous cyst. tomized primary molars seem to show specific clinical features: large size, rapid The relation between pulpotomy and dentigerous cysts growth, buccal expansion, and displacement of succedaneous teeth (5, 11). Grundy et is discussed. (J Endod 2007;33:488–492) al. (9) recorded the time lapse between the pulp therapy and the detection of buccal bone expansion; it ranged from 5 months to 3 years, the average being 20 months. Key Words A dentigerous cyst is an epithelial-lined developmental cavity that encloses the Dentigerous cyst, primary molar, pulpotomy, tooth crown of an unerupted tooth at the cementoenamel junction, and thus it is also named impacted “tooth-containing cyst.” The cyst arises from the separation of the follicle from the crown of an unerupted tooth and, although it may involve any tooth, the mandibular third molars are the most commonly affected, followed by maxillary canine, mandibular premolars, supernumerary teeth, and, rarely, the central incisor (12). *Associate Professor, Department of Stomatology, School Dentigerous cysts are the second most commonly occurring odontogenic cysts of Dentistry, University of Seville, C/Avicena s/n, 41009-Seville, after radicular cysts, accounting for roughly 24% of all true cysts in the jaws, represent- Spain; †Associate Professor, Department of Molecular Biology, School of Environmental Sciences, University “Pablo de Olav- ing the most common intrabony lesion of jaws in children. These cysts are frequently ide,” Seville, Spain; ‡Associate Professor, Department of Sto- discovered when radiographs are taken to investigate a failure of tooth eruption, a matology, School of Dentistry, University of Seville, C/Avicena missing tooth, or misalignment (13). § s/n, 41009-Seville, Spain; and Professor, Department of Sto- The cyst usually presents as a single lesion. However, bilateral and multiple cysts matology, School of Dentistry, University of Seville, C/Avicena s/n, 41009-Seville, Spain. can occur in association with syndromes, including delayed dental eruption, such as Address requests for reprints to Prof. Juan José Segura- cleidocraneal dysplasia, nevus basocelular syndrome, and Hunter’s disease, and also in Egea, Department of Stomatology, School of Dentistry, Uni- association with alterations of the PTCH gene (14), the superexpression of the P53 gene versity of Seville, C/Avicena s/n, 41020-Seville, Spain. E-mail address: [email protected]. (15), and treatments with cyclosporins. 0099-2399/$0 - see front matter Epidemiological studies carried out by Mourghed (16) found a total prevalence of Copyright © 2007 by the American Association of 0.8% for a dentigerous cyst and 3.6% in patients with an unerupted tooth. Endodontists. Although cysts related to primary molars are frequent (10), they tend to be over- doi:10.1016/j.joen.2006.10.011 looked because they usually resolve after removal or exfoliation of the primary teeth. For the same reasons, biopsies are seldom taken. The only cases reported have been those in which the cyst became enlarged before detection and in which severe symptoms and side effects were already present (5, 10). The prevalence in the mandible and the relationship of cyst development to the second primary molars have been stressed (7, 10, 17). Two possible explanations are that the mandibular molars are associated with greater susceptibility to caries and more treatment and that a mandibular second primary molar is more closely associated with its successor’s follicle (5); such associ-

488 Asián-González et al. JOE — Volume 33, Number 4, April 2007 Case Report/Clinical Techniques ation can more easily facilitate the spread of inflammation in compari- son with other primary teeth (17). This study reports a case of dentigerous cyst associated with formocresol pulpotomy detected during routine examination in a patient with transitional dentition. Case Reports A 9-year-old girl presented to the dental clinic sent by her dentist, who had accidentally discovered a lesion in the panoramic radiograph. Her medical and dental history was uneventful. She had suffered a dental injury. The four upper incisors were splinted with composite resin and did not show symptoms or signs of pulp involvement. Upper temporary molars have not yet exfoliated. A Chrom-nickel crown (3M, TM) was evident on tooth #75, pulpotomized 2 years before as related by the patient’s mother. Local buccal swelling without redness occurred near the tooth, evidencing bone expansion, although the gingiva and alveolar mucosa appeared normal (Fig. 1). A panoramic radiograph showed a mandibular radiolucent lesion (Fig. 2). A single, unilocular, well-de- Figure 2. Panoramic radiograph showing displacement and retention of suc- fined, radiolucent area enclosed the second left mandibular premolar. cedaneous premolar and mandibular canal. Primary molar has been pulpoto- A dentigerous cyst was initially diagnosed. To better study the radiolu- mized. cent lesion, taking into account its proximity to the mentonian nerve, a mandibular TAC (Dentascan) was requested (13, 18)(Fig. 3). Thus, the great size of the lesion could be appraised not only in the mesiodistal together with the retained tooth (Fig. 4). The histological study con- aspect, but also in the buccolingual one. The swelling, the buccal cor- firmed the suspected diagnosis (Fig. 5). Microscopically, a dense fi- tical break, and the bone expansion were obvious. These features indi- brous connective tissue cyst wall was lined by remnants of dysplastic cated a benign lesion. keratinizing stratified squamous odontogenic epithelium. The lining The patient was informed about the nature of her lesion, a denti- cells demonstrated a degree of nuclear and cellular pleomorphism and gerous cyst, and the low possibility (6% according to WHO) (19)of nuclear hyperchromatism. In focal areas, islands and strands of cells developing an amelobastoma. The patient’s parents and her dentist invaded the cyst wall. These invasive cords were composed of keratin- asked for the total excision of the cyst. Before intervention the following izing squamous cells with occasional mitotic activity. The cords were medication was prescribed and supplied to the patient: (1) hydroxicine separated by collagenous fibrous connective tissue and focal areas dichlorhidrate (Atarax): 25 mg the night before the intervention and showed chronic inflammatory cell infiltrates. No evidence of nuclear other 25 mg dose 1 hour before. (2) Amoxycilin/Clavulamic acid 500/ palisading or reverse polarity of cells was noted within the islands. 125 mg (Augmentin): one dose the night before, continuing for 6 days Healing was uneventful and, 1 week after the operation, the surgical after the intervention every 8 hours. (3) Ibuprofen (Dalsy): a 200 mg sites showed good healing. After 3 months, there had been complete dose the night before and another one 1–2 hours before the interven- healing. There was also no evidence of recurrence of the cysts (Fig. 6). tion, continuing it with the same guideline as that of the recommended antibiotic. With the suspected diagnosis of a dentigerous cyst associated with a retained premolar, surgical treatment was carried out, the tooth was extracted, and a cystectomy was performed under local anesthesia in the dental office. The buccal flaps were raised and the cysts enucleated

Figure 3. Mandibular TAC (Dentascan). The great size of the lesion is appraised Figure 1. Clinical feature of the lesion. not only in the mesiodistal aspect, but also in the buccolingual one.

JOE — Volume 33, Number 4, April 2007 Link between Pulpotomy and Dentigerous Cysts 489 Case Report/Clinical Techniques

Figure 4. Operated specimen of dentigerous cyst with the tooth. Figure 6. Radiological image after 12 months.

Discussion With respect to the neoplastic transformation, most of the odontogenic cysts show hyperplastic changes in the squamous epithelium, The maxillofacial territory is the location of a great variety of cysts but they are caused by the chronic inflammation. The epithelial prolif- and neoplasias—whose identification can be very difficult. The most erations observed in the cyst can adopt different forms because they important of these lesions are maxillary cysts (12, 16). Cysts are patho- grow inside the separated connective wall of the cyst epithelial layer or logical cavities with a defined wall of connective tissue and an epithelial grow by invading the connective wall of the cyst (24, 25). The presence carpet. Cysts, which are filled with a liquid, semiliquid, or gaseous of blood vessels in the stroma close to the epithelial proliferations aid in content, grow centrifugally, spread out slowly, and are infiltrative (20). identifying the hyperplastic epithelial growth in the cyst’s wall arising The exact dentigerous cyst histological origin is unknown. Classi- from inflammatory changes from that of ameloblastoma, in which these cally they have been defined as cysts of development of the dental folli- blood vessels are not observed (26). Piatelli et al. (27) carried out an cle. Authors relate them to traumatic pathology or inflammatory pro- immunohistochemical evaluation of Ki-67 in dentigerous cysts, unicys- cesses. Thus, Shetty and Sandler (21) propose “having the eye in the tic ameloblastomas, and ameloblastomas arising in dentigerous cysts grain,” when talking about pulpotomized deciduous teeth. The histology and did not find statistically significant differences between the unicystic of the dentigerous cyst consists of dense fibrous connective tissue cyst ameloblastoma and ameloblastoma arising from the dentigerous cyst. wall lined by keratinizing, stratified squamous odontogenic epithelium. The authors concluded that these immunohistochemical data support Among the complications, secondary local infections, such as os- the concept that an ameloblastoma arising from a dentigerous cyst has teitis and osteomielitis, disturb the inferior alveolar nerve and/or lingual a biological behavior similar to that of the unicystic ameloblastoma and nerve (22), although remote infections such as mediastinitis (23) are should be considered as merely a histologic variant. possible. These circumstances, together with the possibility of amelo- The relationship of cyst development to the mandibular second blastic transformation, support the surgical decision adopted in this primary molars cariously affected or pulpotomized has been stressed case. (5, 7, 10). There are two possible explanations: (1) that the mandibular molars have a greater susceptibility to caries and, consequently, are more frequently treated; and (2) that a mandibular second primary molar is more closely associated with its successor’s follicle; such association can more easily facilitate the spread of inflammation in com- parison with other primary teeth (17). In the periradicular region of pulpotomized deciduous molars, besides the dentigerous cyst, a glandular odontogenic cyst (28)or a periradicular cyst (4) can develop. Periradicular cysts in the primary dentition are located around the roots and in the interra- dicular area; this is in contrast to the periapical location seen in permanent teeth (5). Inflammation and prolonged irritation are apparent causes of, and the trigger for, proliferation of the epithelial rests. This explains why cysts are found in conjunction with necrotic or pulp-treated teeth in the primary dentition (5). Periradicular cysts that have been described in association with pulpotomized primary molars seem to show specific clinical features: large size, rapid growth, buccal expansion, and displacement of succedaneous teeth (9). Symptoms are similar for both periradicular and dentigerous cysts, but they differ by stage of inflammation (chronic or Figure 5. Histological image (hematoxylin–eosin, original magnification acute). Some features of chronic inflammation are buccal bone 400ϫ). expansion, facial swelling, and sinus tract formation.

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Several differences can been found between the radiological fea- Conclusions tures of periradicular cysts and dentigerous cysts: (1) periradicular A dentigerous cyst can occur in conjunction with necrotic or pulp- cysts are frequently unilocular (2, 9), although occasionally they are treated teeth in the primary dentition. The time lapse between the pulp multilocular (29); (2) they are well-defined radiolucencies, located therapy and the detection of buccal bone expansion ranged from 5 both periradicularly and interradicularly; and (3) the pericoronal months to 3 years. Taking into account that ameloblastic transformation space of the underlining permanent tooth appears normal, usually with can occur, practitioners should investigate cases of delayed exfoliation an intervening total or partially distinct cortical layer of bone (30). On and expansion of cortical bone in the vicinity of primary molars, par- the contrary, dentigerous cysts: (1) generally have no distinct bound- aries between the roots of the primary tooth and the crown of the ticularly if they are pulpotomized. underlying succedaneous tooth; (2) a single, unilocular, well-defined, radiolucent area encloses each kind of cyst (8, 17); and (3) a radiolucent area that embraces the permanent tooth bud, ill-defined lesion References borders, and arrest of the root development are pathognomonic signs of 1. Pruhs RI, Olen GA, Sharma PS. Relationship between formocresol pulpotomies damaged tooth germs (6, 7). As shown in occlusal radiographs, there on primary teeth and enamel defects on their permanent successors. JADA are no differences between the two types of cysts with respect to size, 1977;94:698–700. 2. Rølling I, Poulsen S. Formocresol pulpotomy of primary teeth and occurrence of buccal bone expansion, or displacement of adjacent permanent teeth enamel defects on the permanent successors. Acta Odontol Scand (17). Shaw et al. (17) noted that distinguishing between dentigerous 1978;36:243–7. and radicular cysts on histologic grounds is difficult but that a histologic 3. Alacam A. Long term effects of primary teeth pulpotomies with formocresol, glutar- examination may determine whether the lesion is chronic or acute in aldehyde-calcium hydroxide, and glutaraldehyde-zinc oxide eugenol on succedane- nature. ous teeth. J Pedod 1989;13:307–13. Because dentigerous cysts can attain considerable size with mini- 4. Shear M. Cysts of the oral region, 3rd ed. Oxford, UK: Wright; 1992:75–89. 5. Lustig JP, Schwartz-Arad D, Shapira A. Odontogenic cysts related to pulpotomized mal or no symptoms, early detection and removal of the cysts is impor- deciduous molars. Clinical features and treatment outcome. Oral Surg Oral Med Oral tant to reduce morbidity. Moreover, frequently they presented without Pathol Oral Radiol Endod 1999;87:499–503. pain and are discovered during investigation of asymptomatic slow- 6. Brook AH, Winter GB. Developmental arrest of permanent tooth germs following growing swellings (31). It is therefore important to perform radio- pulpal infection of deciduous teeth. Br Dent J 1975;139:9–11. graphic examination of all unerupted teeth. Moreover, an alteration in 7. Azaz B, Shteyer A. Dentigerous cysts associated with second mandibular bicuspids in the pattern of permanent tooth eruption under pulpotomized teeth (1, children: report of five cases. J Dent Child 1973;40:29–31. 8. Benn A, Altini M. Dentigerous cysts of inflammatory origin. Oral Surg Oral Med Oral 32) was previously reported. Whereas bitewing and periapical radiog- Pathol Oral Radiol Endod 1996;81:203–9. raphies are typically performed in the routine examination of patients 9. Grundy GE, Adkins KF, Savage MW. Cysts associated with deciduous molars following with a healthy dentition, this series of radiographs may occasionally fail pulp therapy. Aust Dent J 1984;29:249–56. to delineate the full extent of a lesion, if present. A panoramic radio- 10. Mass E, Kaplan I, Hirshberg A. A clinical and histopathological study of radicular cysts graph supplemented with skull series or more advanced imaging such associated with primary molars. J Oral Pathol Med 1995;24:458–61. as tomography may permit a better delineation of the extent of the lesion 11. Savage MW, Adkins KF, Weir AV, Grundy GE. An histological study of cystic lesions and its relationship to adjacent anatomical structures. following pulp therapy in deciduous molars. J Oral Pathol 1986;15:209–12. 12. Donado Rodríguez M, Donado Azcárate A. Quistes odontógenos de los maxilares. In: Treatment choices include extraction of the primary tooth and Bermudo Añido L, ed. Atlas de cirugía oral. Barcelona: Lacer, 2001. preservation of the underlying permanent tooth (5). Some practitioners 13. Shibata Y, Asaumi J, Yanagi Y, et al. Radiographic examination of dentigerous cysts in prefer marsupialization only (8, 9, 17), whereas others perform mar- the transitional dentition. Dentomaxillofac Radiol 2004;33:17–20. supialization and also pack the space with medicated gauze to prevent 14. Pavelic B, Levanat S, Crnic I, et al. PTCH gene altered in dentigerous cysts. J Oral early wound closure (5, 17). Neither treatment modality requires com- Pathol Med 2001;30:569–76. plete removal of the cyst wall. When there is no threat of damage to the 15. Piattelli A, Fioroni M, Santinelli A, Rubini C. P53 protein expression in odontogenic cysts. J Endod 2001;27:459–61. permanent tooth bud, complete curettage of periradicular cyst has been 16. Mourghed FA. Roentgenographic study of dentigerous cyst. Oral Surg Oral Med Oral performed (9, 17). In cases in which the permanent tooth is severely Pathol 1994;18:54–61. damaged, complete enucleation of the cyst to include the permanent 17. Shaw W, Smith M, Hill F. Inflammatory follicular cysts. J Dent Child 1980;47:288–90. tooth bud has been recommended (6, 7, 33). Enucleation was the goal 18. Litonjua LA, Aguirre A, Estrada MC. Radiolucency in the mandible. Oral Surg Oral if it did not jeopardize the permanent tooth germ; otherwise, marsupi- Med Oral Pathol Oral Radiol Endod 2004;28:511–5. alization was elected. Additional packing of the cystic cavity was unnec- 19. Tay AB. A 5-year survey of oral biopsies in an oral surgical unit of Singapore: 1993– 1997. Ann Acad Med Singapore 1999;28:665–71. essary (5). In the case presented, because the premolar was unlikely to 20. Cavalcanti Mde G, Antunes JL. 3D-CT imaging processing for qualitative and quanti- erupt on its own, enucleation with removal of the displaced tooth was tative analysis of maxillofacial cysts and tumors. Pesqui Odontol Bras 2002; favored. 16:189–94. The present case shows the spontaneous evolution of a follicle 21. Shetty R, Sandler PJ. Keeping your eye on the ball. Dent Updat 2004;31:398–402. of a retained premolar associated with a pulpotomized deciduous 22. Hamada Y, Yamada H, Hamada A, et al. Simultaneous paresthesia of the lingual nerve tooth into a dentigerous cyst. The presumed diagnosis was made and inferior alveolar nerve caused by a radicular cyst. J Endod 2005;31:764–6. 23. Basa S, Arslan A, Metin M, Sayar A, Sayan MA. Mediastinitis caused by an infected because of a radiolucent lesion in the orthopantomography. The mandibular cyst. Int J Oral Maxillofac Surg 2004;33:618–20. posterior histological study confirmed the diagnosis. This case, to- 24. Stanley HR, Diehl DL. Ameloblastomas potential of follicular cysts. Oral Surg Oral gether with other published cyst cases related to a pulpotomized Med Oral Pathol 1965;20:260. root–treated deciduous tooth, allow us to recommend that failures 25. Stanley HR, Krogh H, Pannuk E. Age changes in the epithelial components F of pulp therapy, such as periradicular rarefaction, root resorption, follicles (dental sacs) associated with impacted third molars. Oral Surg and enlarged follicular space, should be treated by extraction; fol- 1965;19:128. low-up should be maintained until normal eruption of the succeda- 26. Churchill HR. Histologic differentiation between certain dentígerous cysts and amelo- blastomata. Dental Cosmos 1934;76:1173. neous tooth. Parents should receive more information regarding 27. Piattelli A, Lezzi G, Fioroni M, Santinelli A, Rubini C. Ki-67 expression in dentigerous adverse side effects of pulpotomy and be instructed on how to rec- cysts, unicystic ameloblastomas, and ameloblastomas arising from dental cysts. ognize significant signs and symptoms. J Endod 2002;28:55–8.

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28. Tran PT, Cunningham CJ, Baughman RA. Glandular odontogenic cyst. J Endod 31. Ko KS-C, Dover DG, Jordan RCK. Bilateral dentigerous cysts—report of an unusual 2004;30:182–4. case and review of the literature. J Can Dent Assoc 1999;65:49–51. 29. Lustmann J, Shear M. Radicular cysts arising from deciduous teeth. Int J Oral Surg 32. Hill FJ. Cystic lesions associated with deciduous teeth. Proc Br Paedod Soc 1985;14:153–61. 1978;8:9–12. 30. Wood RE, Nortje CJ, Padayachee A, Grotepass F. Radicular cysts of primary teeth 33. Wood RE, Nortje CJ, Padayachee A, Grotepass F. Radicular cysts of primary teeth mimicking premolar dentigerous cysts: report of three cases. J Dent Child mimicking premolar dentigerous cysts: report of three cases. J Dent Child 1988;55: 1988;55:288–300. 288–300.

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