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Orthodontic therapy in patients with pericoronal hamartoma
CLINICIAN’S CORNER
Orthodontic therapy in patients with pericoronal hamartoma Claudia Quintella,a José Humberto Damante,b Guilherme Janson,c Eliete Guerra,d Marcos Roberto de Freitas,e and Claudia Starlingf Bauru, São Paulo, Brazilia, and Minas Gerais, Brazil Pericoronal lesions are undesirable for dental eruption, and they are always associated with unerupted teeth. Pericoronal lesions are common and are usually treated by extraction of the permanent tooth. Pericoronal hamartoma is a special type of pericoronal lesion, and little information about it is available in the orthodontic literature. This report presents a patient with pericoronal hamartoma on the mandibular left permanent first molar who had orthodontic treatment. Because of the similarity of the radiographic radiolucency of pericoronal hamartoma and other lesions, a differential diagnosis must be made to avoid extraction of permanent teeth. (Am J Orthod Dentofacial Orthop 2008;133:758-61)
T
he term hamartoma refers to tumor-like lesions arising during development of an organ or a tissue; they are not apparently neoplastic. Hamartomatous lesions in the pericoronal areas might induce active tissue remodeling and result in fibrosis in their surroundings; this could prevent tooth eruption.1 In 1980, Cahill and Marks2 stated that the dental follicle is believed to be a primary requirement for tooth eruption, and its role should be important in the local control of alveolar bone formation and resorption. Tooth eruption is the result of bone resorption around the occlusal tooth surface and bone formation around the radicular portion of a tooth. These events are initiated, coordinated, and terminated by the dental follicle. The enlargement of the eruption pathway by bone resorption, formation of new trabecular bone in the bone crypt base, and exfoliation of the overlying deciduous tooth require the presence of the dental follicle. Radiographically, pericoronal hamartoma is characterized by radiolucency that surrounds the crown of an unerupted tooth. Most of these lesions occur in the mandibular a
Master in orthodontics, Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. b Chairman, Department of Stomatology, Bauru Dental School, University of São Paulo, São Paulo, Brazil. c Associate professor, Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. d Associate professor, Department of Stomatology, Brazilia Dental School, Brazilia, Brazil. e Chairman, Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. f Graduate student, Department of Orthodontics, São Leopoldo Mandique Dental School, Minas Gerais, Brazil. Reprint requests to: Claudia Quintella, Gronslandsgade 34 5000, Denmark; e-mail, [email protected]. Submitted, February 2006; revised and accepted, May 2006. 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2006.05.037
758
posterior region and are always associated with unerupted teeth. The lesions can occur at any age, from childhood to late adulthood.3 It is an asymptomatic condition, an abnormal eruption sequence. Recently, 2 cases of hamartoma in the pericoronal follicle of mandibular first molars that were delayed in eruption were described.4 Histopathologic examinations showed that they contained osteodentin, cementum, pulp-like components, mesenchymal multinucleated giant cells, and dysplastic dental matrices.4 Yonemochi et al1 examined pericoronal hamartomas in teeth with delayed eruption using immunohistochemistry for extracellular matrix molecules. They found that the hamartomatous lesions in the pericoronal areas might induce active tissue remodeling and consequent fibrosis in their surroundings; these might obstruct tooth eruption. These lesions have also been associated with some syndromes.5 Damante and Fleury,6 in 2001, suggested that, in most routine pericoronal space enlargements, the first radiographic diagnosis should be inflammation of the follicle. A dentigerous or paradental cyst is suggested as the second diagnosis. CASE REPORT
A girl, age 8 years 9 months, came to the oral medicine clinic at Bauru Dental School (University of São Paulo, Brazil) seeking treatment for an asymptomatic unerupted mandibular permanent first molar on the left side (Fig 1). She was healthy. The eruption sequence of the mixed-dentition stage was normal with the exception of this delayed molar. A pericoronal space enlargement surrounding the crown of the unerupted molar was seen on the panoramic radiograph. Delayed odontogenesis of the mandibular left second
Quintella et al 759
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 5
Fig 1. First molars on the left side were missing.
Fig 3. Microscopic analysis: hyperplastic odontogenic ectomesenchymal tissue.
Fig 2. Radiopaque structures show enlarged pericoronal space of the left first molar.
molar was also observed (Fig 1). Some small, round, radiopaque structures were poorly observed in the enlarged pericoronal space of the first molar. Periapical and occlusal radiographs with a periapical film were obtained so that the radiopaque structures could be better observed. These radiographs were digitized, and image tools (Digora-Soredex Orion, Tuusula, Finland) of inversion and the third dimension were used, but they did not improve the radiographic interpretation (Fig 2). A biopsy of the follicle was performed under local anesthesia. A mucoperiosteal flap was detached, and the thin bone cortex was removed. The pericoronal tissues of the unerupted molar were not damaged. No bone cavitation or luminal cyst contents were found in the pericoronal space. The follicle was thick, and the microscopic analysis showed hyperplastic odontogenic
Fig 4. Microscopic analysis: hyperplastic odontogenic ectomesenchymal tissue with pulp-like components and calcified masses similar to dental matrix. Odontogenic epithelial islands are scattered in myxofibrous ectomesenchymal stroma.
Fig 5. Leveling and alignment of the left first molar with Twist-flex archwires.
ectomesenchymal tissue with and calcified masses similar to Odontogenic epithelial islands myxofibrous ectomesenchymal
pulp-like components dental matrix (Fig 3). were scattered in the stroma (Fig 4). The
760 Quintella et al
American Journal of Orthodontics and Dentofacial Orthopedics May 2008
Fig 6. Occlusion of the lower first and second left molars after the orthodontic treatment.
microscopic diagnosis of odontogenic hamartoma was established. In the postoperative period, the patient was examined periodically. Six months after the biopsy, the molar was slowly moving coronally without evidence of recurrent lesion. Because the patient also had an associated malocclusion, orthodontic treatment was undertaken at this stage. The patient initially had a Class I molar relationship on the right side, with a one quarter Class II canine relationship on the left side, poor tooth alignment, 5 mm overbite, and 1 mm overjet. The maxillary dental midline was deviated 2.5 mm to the left. The patient had a good facial profile, slight facial asymmetry to the left side and consequent to the crossbite of the maxillary left canine, and no mandibular left first permanent molar. During orthodontic treatment, leveling and alignment were conducted with Twist-flex archwires (Dental Morelli, Sorocaba, Brazil) (Fig 5), and a removable plate was used to correct the crossbite of the maxillary left canine. Leveling of the mandibular left permanent molar was possible with simple orthodontic mechanics. Facial asymmetry improved, and the maxillary-to-mandibular dental midline deviation was corrected. Orthodontic treatment took 14 months. The patient was followed as the permanent dentition erupted. However, at age 17 years 10 months, the mandibular left second molar still had not erupted. Therefore, a new orthodontic procedure was necessary. A banded fixed lingual arch from the left premolar to the right first molar, with an uprighting spring for the mandibular left first molar was used. The second stage of treatment aimed to align the left second molar with pericoronal hamartoma (Fig 6, A). Edgewise brackets were used with an uprighting spring that was removed when the second molar reached occlusion; this was followed by the usual orthodontic leveling and alignment (Fig 6, B). DISCUSSION
Pericoronal lesions are associated with unerupted teeth. Odontogenic cyst, odontogenic tumor, normal
follicular space, hamartoma, and association with some syndromes have been reported in pericoronal follicles.5,6 It is not unusual to find nests of odontogenic epithelium and calcified material in pericoronal tissues of unerupted teeth in normal follicles.6 They have been occasionally misdiagnosed as odontogenic fibroma, odontogenic myxoma, or myxofibroma. The diagnosis of a pathologic condition depends on the number or the amount of these structures. When they are high, diagnosis of an odontogenic hamartoma is easier. The term hamartoma refers to tumor-like lesions that arise during the development of the organ or the tissue in question; they are apparently not neoplastic. Hamartomas are composed of an abnormal mixture of tissues.7 Based on this description, our diagnosis for this patient was pericoronal hamartoma.7-9 The pericoronal follicle must be thoroughly examined microscopically. Biopsy of the follicle must be always performed. The pathologist, when interpreting clinical, surgical, radiographic, and histopathologic information, will confirm the diagnosis. Only the pathologist can rule out the existence of keratocysts, hamartomas, incipient ameloblastomas, and other lesions associated with pericoronal follicles. The cause of hamartoma is obscure, although there are several hypotheses regarding its etiopathogenesis, including tooth impaction, supernumerary teeth, chronic inflammation, and general factors in patients with multiple lesions. In spite of the cause, hamartomas are not neoplasia. Therefore, they can be surgically and conservatively treated with crown exposure and receive an orthodontic appliance if spontaneous eruption does not occur. CONCLUSIONS
Pericoronal hamartoma is a pericoronal follicle lesion that can be surgically and conservatively treated without extraction. The success of treatment depends on the cooperation of the surgeon, the pathologist, and the orthodontist.
Quintella et al 761
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 5
REFERENCES 1. Yonemochi H, Noda T, Saku T. Pericoronal hamartomatous lesions in the opercula of teeth delayed in eruption: an immunohistochemical study of the extracellular matrix. J Oral Pathol Med 1998;27:441-52. 2. Cahill DR, Marks SC Jr. Tooth eruption: evidence for the central role of the dental follicle. J Oral Pathol 1980;9:189-200. 3. Thunthy KH. Differential diagnosis of pericoronal radiolucencies with and without radiopacities. Gen Dent 1999;47:182-6. 4. Onishi T, Sakashita S, Ogawa T, Ooshima T. Histhopatological characteristics of eruption mesenchymal calcified hamartoma: two case reports. J Oral Pathol Med 2003;32:246-9. 5. Paula LM, Melo NS, Silva Guerra EM, Mestrinho Hd, Acevedo AC. Case report of a rare syndrome associating amelogenesis
6.
7.
8.
9.
imperfecta and nephrocalcinosis in a consanguineous family. Arch Oral Biol 2005;59:237-42. Damante JH, Fleury RN. A contribution to the diagnosis of the small dentigerous cyst or the paradental cyst. Pesqui Odontol Bras 2001;15:238-46. Gardner DG. The concept of hamartomas: its relevance to the pathogenesis of odontogenic lesions. Oral Surg Oral Med Oral Pathol 1978;45:884-6. Fukuta Y, Totsuka M, Takeda Y, Yamamoto H. Pathological study of the hyperplastic dental follicle. J Nihon Univ Sch Dent 1991;33:166-73. Gardner DG, Radden B. Multiple calcifying hyperplastic dental follicles. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:603-6.
Orthodontic therapy in patients with pericoronal hamartoma Claudia Quintella,a José Humberto Damante,b Guilherme Janson,c Eliete Guerra,d Marcos Roberto de Freitas,e and Claudia Starlingf Bauru, São Paulo, Brazilia, and Minas Gerais, Brazil Pericoronal lesions are undesirable for dental eruption, and they are always associated with unerupted teeth. Pericoronal lesions are common and are usually treated by extraction of the permanent tooth. Pericoronal hamartoma is a special type of pericoronal lesion, and little information about it is available in the orthodontic literature. This report presents a patient with pericoronal hamartoma on the mandibular left permanent first molar who had orthodontic treatment. Because of the similarity of the radiographic radiolucency of pericoronal hamartoma and other lesions, a differential diagnosis must be made to avoid extraction of permanent teeth. (Am J Orthod Dentofacial Orthop 2008;133:758-61)
T
he term hamartoma refers to tumor-like lesions arising during development of an organ or a tissue; they are not apparently neoplastic. Hamartomatous lesions in the pericoronal areas might induce active tissue remodeling and result in fibrosis in their surroundings; this could prevent tooth eruption.1 In 1980, Cahill and Marks2 stated that the dental follicle is believed to be a primary requirement for tooth eruption, and its role should be important in the local control of alveolar bone formation and resorption. Tooth eruption is the result of bone resorption around the occlusal tooth surface and bone formation around the radicular portion of a tooth. These events are initiated, coordinated, and terminated by the dental follicle. The enlargement of the eruption pathway by bone resorption, formation of new trabecular bone in the bone crypt base, and exfoliation of the overlying deciduous tooth require the presence of the dental follicle. Radiographically, pericoronal hamartoma is characterized by radiolucency that surrounds the crown of an unerupted tooth. Most of these lesions occur in the mandibular a
Master in orthodontics, Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. b Chairman, Department of Stomatology, Bauru Dental School, University of São Paulo, São Paulo, Brazil. c Associate professor, Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. d Associate professor, Department of Stomatology, Brazilia Dental School, Brazilia, Brazil. e Chairman, Department of Orthodontics, Bauru Dental School, University of São Paulo, São Paulo, Brazil. f Graduate student, Department of Orthodontics, São Leopoldo Mandique Dental School, Minas Gerais, Brazil. Reprint requests to: Claudia Quintella, Gronslandsgade 34 5000, Denmark; e-mail, [email protected]. Submitted, February 2006; revised and accepted, May 2006. 0889-5406/$34.00 Copyright © 2008 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2006.05.037
758
posterior region and are always associated with unerupted teeth. The lesions can occur at any age, from childhood to late adulthood.3 It is an asymptomatic condition, an abnormal eruption sequence. Recently, 2 cases of hamartoma in the pericoronal follicle of mandibular first molars that were delayed in eruption were described.4 Histopathologic examinations showed that they contained osteodentin, cementum, pulp-like components, mesenchymal multinucleated giant cells, and dysplastic dental matrices.4 Yonemochi et al1 examined pericoronal hamartomas in teeth with delayed eruption using immunohistochemistry for extracellular matrix molecules. They found that the hamartomatous lesions in the pericoronal areas might induce active tissue remodeling and consequent fibrosis in their surroundings; these might obstruct tooth eruption. These lesions have also been associated with some syndromes.5 Damante and Fleury,6 in 2001, suggested that, in most routine pericoronal space enlargements, the first radiographic diagnosis should be inflammation of the follicle. A dentigerous or paradental cyst is suggested as the second diagnosis. CASE REPORT
A girl, age 8 years 9 months, came to the oral medicine clinic at Bauru Dental School (University of São Paulo, Brazil) seeking treatment for an asymptomatic unerupted mandibular permanent first molar on the left side (Fig 1). She was healthy. The eruption sequence of the mixed-dentition stage was normal with the exception of this delayed molar. A pericoronal space enlargement surrounding the crown of the unerupted molar was seen on the panoramic radiograph. Delayed odontogenesis of the mandibular left second
Quintella et al 759
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 5
Fig 1. First molars on the left side were missing.
Fig 3. Microscopic analysis: hyperplastic odontogenic ectomesenchymal tissue.
Fig 2. Radiopaque structures show enlarged pericoronal space of the left first molar.
molar was also observed (Fig 1). Some small, round, radiopaque structures were poorly observed in the enlarged pericoronal space of the first molar. Periapical and occlusal radiographs with a periapical film were obtained so that the radiopaque structures could be better observed. These radiographs were digitized, and image tools (Digora-Soredex Orion, Tuusula, Finland) of inversion and the third dimension were used, but they did not improve the radiographic interpretation (Fig 2). A biopsy of the follicle was performed under local anesthesia. A mucoperiosteal flap was detached, and the thin bone cortex was removed. The pericoronal tissues of the unerupted molar were not damaged. No bone cavitation or luminal cyst contents were found in the pericoronal space. The follicle was thick, and the microscopic analysis showed hyperplastic odontogenic
Fig 4. Microscopic analysis: hyperplastic odontogenic ectomesenchymal tissue with pulp-like components and calcified masses similar to dental matrix. Odontogenic epithelial islands are scattered in myxofibrous ectomesenchymal stroma.
Fig 5. Leveling and alignment of the left first molar with Twist-flex archwires.
ectomesenchymal tissue with and calcified masses similar to Odontogenic epithelial islands myxofibrous ectomesenchymal
pulp-like components dental matrix (Fig 3). were scattered in the stroma (Fig 4). The
760 Quintella et al
American Journal of Orthodontics and Dentofacial Orthopedics May 2008
Fig 6. Occlusion of the lower first and second left molars after the orthodontic treatment.
microscopic diagnosis of odontogenic hamartoma was established. In the postoperative period, the patient was examined periodically. Six months after the biopsy, the molar was slowly moving coronally without evidence of recurrent lesion. Because the patient also had an associated malocclusion, orthodontic treatment was undertaken at this stage. The patient initially had a Class I molar relationship on the right side, with a one quarter Class II canine relationship on the left side, poor tooth alignment, 5 mm overbite, and 1 mm overjet. The maxillary dental midline was deviated 2.5 mm to the left. The patient had a good facial profile, slight facial asymmetry to the left side and consequent to the crossbite of the maxillary left canine, and no mandibular left first permanent molar. During orthodontic treatment, leveling and alignment were conducted with Twist-flex archwires (Dental Morelli, Sorocaba, Brazil) (Fig 5), and a removable plate was used to correct the crossbite of the maxillary left canine. Leveling of the mandibular left permanent molar was possible with simple orthodontic mechanics. Facial asymmetry improved, and the maxillary-to-mandibular dental midline deviation was corrected. Orthodontic treatment took 14 months. The patient was followed as the permanent dentition erupted. However, at age 17 years 10 months, the mandibular left second molar still had not erupted. Therefore, a new orthodontic procedure was necessary. A banded fixed lingual arch from the left premolar to the right first molar, with an uprighting spring for the mandibular left first molar was used. The second stage of treatment aimed to align the left second molar with pericoronal hamartoma (Fig 6, A). Edgewise brackets were used with an uprighting spring that was removed when the second molar reached occlusion; this was followed by the usual orthodontic leveling and alignment (Fig 6, B). DISCUSSION
Pericoronal lesions are associated with unerupted teeth. Odontogenic cyst, odontogenic tumor, normal
follicular space, hamartoma, and association with some syndromes have been reported in pericoronal follicles.5,6 It is not unusual to find nests of odontogenic epithelium and calcified material in pericoronal tissues of unerupted teeth in normal follicles.6 They have been occasionally misdiagnosed as odontogenic fibroma, odontogenic myxoma, or myxofibroma. The diagnosis of a pathologic condition depends on the number or the amount of these structures. When they are high, diagnosis of an odontogenic hamartoma is easier. The term hamartoma refers to tumor-like lesions that arise during the development of the organ or the tissue in question; they are apparently not neoplastic. Hamartomas are composed of an abnormal mixture of tissues.7 Based on this description, our diagnosis for this patient was pericoronal hamartoma.7-9 The pericoronal follicle must be thoroughly examined microscopically. Biopsy of the follicle must be always performed. The pathologist, when interpreting clinical, surgical, radiographic, and histopathologic information, will confirm the diagnosis. Only the pathologist can rule out the existence of keratocysts, hamartomas, incipient ameloblastomas, and other lesions associated with pericoronal follicles. The cause of hamartoma is obscure, although there are several hypotheses regarding its etiopathogenesis, including tooth impaction, supernumerary teeth, chronic inflammation, and general factors in patients with multiple lesions. In spite of the cause, hamartomas are not neoplasia. Therefore, they can be surgically and conservatively treated with crown exposure and receive an orthodontic appliance if spontaneous eruption does not occur. CONCLUSIONS
Pericoronal hamartoma is a pericoronal follicle lesion that can be surgically and conservatively treated without extraction. The success of treatment depends on the cooperation of the surgeon, the pathologist, and the orthodontist.
Quintella et al 761
American Journal of Orthodontics and Dentofacial Orthopedics Volume 133, Number 5
REFERENCES 1. Yonemochi H, Noda T, Saku T. Pericoronal hamartomatous lesions in the opercula of teeth delayed in eruption: an immunohistochemical study of the extracellular matrix. J Oral Pathol Med 1998;27:441-52. 2. Cahill DR, Marks SC Jr. Tooth eruption: evidence for the central role of the dental follicle. J Oral Pathol 1980;9:189-200. 3. Thunthy KH. Differential diagnosis of pericoronal radiolucencies with and without radiopacities. Gen Dent 1999;47:182-6. 4. Onishi T, Sakashita S, Ogawa T, Ooshima T. Histhopatological characteristics of eruption mesenchymal calcified hamartoma: two case reports. J Oral Pathol Med 2003;32:246-9. 5. Paula LM, Melo NS, Silva Guerra EM, Mestrinho Hd, Acevedo AC. Case report of a rare syndrome associating amelogenesis
6.
7.
8.
9.
imperfecta and nephrocalcinosis in a consanguineous family. Arch Oral Biol 2005;59:237-42. Damante JH, Fleury RN. A contribution to the diagnosis of the small dentigerous cyst or the paradental cyst. Pesqui Odontol Bras 2001;15:238-46. Gardner DG. The concept of hamartomas: its relevance to the pathogenesis of odontogenic lesions. Oral Surg Oral Med Oral Pathol 1978;45:884-6. Fukuta Y, Totsuka M, Takeda Y, Yamamoto H. Pathological study of the hyperplastic dental follicle. J Nihon Univ Sch Dent 1991;33:166-73. Gardner DG, Radden B. Multiple calcifying hyperplastic dental follicles. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:603-6.