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Ectopic soft-tissue mesiodens
Ectopic soft-tissue mesiodens Scott L. Diekmann,* Lincoln, Neb. UNIVERSITY
OF NEBRASKA
Donald M. Cohen, D.M.D.,**
MEDICAL
CENTER
COLLEGE
and Dennis P. Gutz, D.D.S., M.S.,***
OF DENTISTRY
The mesiodens is the most common supernumerary tooth. It can be found in both the erupted and the impacted states. A case of a developing mesiodens located entirely in soft tissue is described. The lesion presented as a pedunculated palatal mass. No case of soft-tissue mesiodens has been previously reported. A theory of origin for this supernumerary tooth is proposed.
S
upernumerary teeth occur throughout the oral region, with a predilection for certain sites. The most common supernumerary tooth is the mesiodens, being located in the region of the maxillary central incisors. It has a prevalence of 0.15 to 1.90 percent in the white population’ and accounts for 45.4 to 66.8 percent of all supernumerary teeth.2-4Most mesiodens never erupt. When they do erupt, the most common site is behind the central incisors within the premaxilla.5 Reported here is a unique case of a mesiodens which presented as a pedunculated softtissue mass. CASE REPORT A 3-year-old white boy presented with a pedunculated masson the palate just lateral and posterior to the incisive papilla (Fig. 1). The lesion had been present since birth and was asymptomatic. The clinical impression was that it was a fibroma, and the lesion was removed and submitted for microscopic examination. Histologic examination revealed a massof densefibrous connective tissue containing a cone-shaped developing tooth germ. The tooth germ was composed of dental papillae, haphazardly arranged ameloblasts, enamel matrix, an odontoblastic layer, dentin, and some predentin and dentinoid material (Fig. 2). The tooth germ was surrounded by dense fibrous connective tissue containing numerous islands of odontogenic epithelium (Fig. 3). DISCUSSION
A review of the literature revealed numerous reports of teeth in unusual locations. Ectopic teeth have been found in the ramus,6-gcoronoid process,10-‘2
*Senior Dental Student. **Assistant Professorof Oral Pathology. ***AssociateProfessorof Pedodontics. 0030-4220/82/040391
+ 04$00.40/O
@ 1982 The C. V. Mosby Co.
Fig. 1. Pedunculated palatal mass contained developing supernumerary tooth germ. Mass was located behind the right central incisor just lateral and posterior to the incisive papilla.
condylar process,‘2-14 condyle,15inferior border of the mandible,’ chini zygomatic fossa,” posterior-superior surface of the tuberosity,18 nasal cavity,1g*20 maxillary sinus,2’-23eyelid,24l25 orbit,*‘j and frontal sinus.*’ In all of these cases the teeth were at least partially embedded in bone. There have been only three reported casesof teeth completely located in soft tissue. Rion** reported two supernumerary bicuspid crowns near the vermillion border of the upper lip. This lesion may actually have been a compound odontoma, judging from the multiplicity of teeth and the dissimilar appearance of the crowns. Carver2greported a canine erupting through the lower eyelid, and Gans30described a sessilemass on the palate near the deciduous second molar. The palatal mass was found to be a developing tooth surrounded by fibrous connective tissue. Gans 391
392
Diekmann, Cohen, and Gutz
Oral April,
Surg. 1982
Fig. 2. Conical-shaped developing supernumerary tooth germ. Note irregular dentin layer and investing fibrous connective tissue. The tooth lies entirely in soft tissue with no connection to the underlying bone. (Hematoxylin and eosin stain. Magnification, X 10.)
believed the tooth to be the missing second premolar and hypothesized that the anlage for the succedaneous tooth failed to be enclosed in the alveolar process. Explanations for the aberrant location of teeth have been numerous. They include migration”l’4’22; displacement due to trauma,16 infection, and cysts; developmental disturbances such as cleft palate; genetic factors; obstruction to eruption secondary to crowding, persistent deciduous teeth, or exceptionally densebonelo;and ectopic location of an extra tooth bud in the case of supernumerary teeth. There have been several theories specifically relating to the pathogenesisof supernumerary teeth. The theory most commonly accepted states that supernumerary teeth are the result of a local hyperactivity of the dental lamina.’ However, it is presently thought that the initiation of tooth formation is actually the result of the programming of the epithelium comprising the dental lamina by the underlying ectomes-
enchyme.3’ If dental epithelium is grafted onto skin mesenchyme the tissue formed is skin, and if skin epithelium is grafted onto dental mesenchyme the result is the formation of a tooth. The misplaced dental lamina was not solely responsible for the development of the soft-tissue mesiodens or the resultant tissue formed would have been palatal mucosa. Johnston and Sulik32stated that neural crest cells that have migrated in the vicinity of the pharyngeal endoderm are preconditioned by the endoderm. The preconditioned crest cells will react with oral ectoderm, differentiating into tooth papilla mesenchyme. Thus, the neural crest cells are ultimately responsible for the induction of the epithelium to form the tooth bud. The soft-tissue mesiodenscan then be explained on the basis of ectopic neural crest cells. This hypothesis would also explain why so many dental lamina rests exist in the gingiva, and yet the incidence of supernumerary teeth is relatively low. The
Volume 53 Number 4
Ectopic soft-tissue mesiodens
393
Fig. 3. Developing tooth germ surrounded by dense fibrous connective tissue containing numerous islands of odontogenic epithelium. (Hematoxylin and eosin stain. Magnification, X50.)
presence of the palatal mass at birth also lends circumstantial evidence supporting the theory of ectopic neural crest cell origin. REFERENCES 1. Primosch, R. E.: Anterior Supernumerary Teeth-Assessment and Surgical Intervention in Children, Pediatr. Dent. 3: 204-215, 1981. 2. Bergstrom, K.: An Orthopantomographic Study of Hypodontia, Supernumeraries and Other Anomalies in School Children Between the Ages of 8-9 Years, Swed. Dent. J. 1: 145, 1911. 3. Bodin, I., Julin, P., and Thomsson, M.: Hyperodontia. I. Frequency and Distribution of Supernumerary Teeth Among 2 1,609 Patients, Dentomaxillofac. Radio]. 7: I S-17, 1978. 4. Stafne, E. C.: Supernumerary Teeth, Dent. Cosmos 74: 653-659, 1932. 5. Bruce, K. W.: Supernumerary Maxillary Central Incisors, Chron. Omaha Dist. Dent. Sot. 23: 178180, 1960. 6. Zernov, M. W., and Paris, M. D.: Misplaced Third Molar in the Region of the Condyle Erupting Through the Cheek, Br. Dent. J. 87: 295, 1949. 7. Stones, H. H.: Oral and Dental Diseases, ed. 5, Edinburgh, 1966, E. & S. Livingstone, Ltd., pp, 144-145, 148149. 8. Gigliotti, R., Baker, R. C., and MacLeod, D. K.: Removal of
an Ectopic Lower Third Molar: Case Report, Dent. Surv. 52: 45-46, 1916. 9, Bey, M. A.: Eruption of a Third Molar Through the Skin, Quintessence Int. 1: 17-18, 1970. 10. Hopson, M. F.: A Mandibular Third Molar Situated in the Coronoid Process, Proc. R. Sot. Med. (Odont. Sect.) 13: 76-77, 1920. 1I. Sutton, P. R. N.: Migrating Nonerupted Mandibular Premolars: A Case of Migration Into the Coronoid Process, ORAL SURG. 25: 87-98, 1968.
I2. Stark, W., and Keim, R. P.: Bilateral Mo!ar impactions in Coronoid Processeswith Unilateral Molar Impaction in Neck of Left Condyle, ORAL SURG. II: 707-709, 1958. 13. Balendra, W.: Unerupted Lower Third Molar in the Region of the Condyle, Br. Dent. J. 86: 229, 1949. 14. Schwimmer, A., Keaveny, J. T., Caponigro, C., and Ragaini. V. E.: Subcondylar Impaction of a Third Molar Resulting in Chronic Preauricular Sinus: Report of Case, J. Oral Surg. 30: 41-44, 1972. 15. McKenzie, C., and Sharpless, D. H.: Surgical Removal of Aberrant Teeth: Report of Two Cases, J. Oral Surg. 5: 231-234, 1947. 16. Ebling, H.. and Lopes, J. V. S.: Ectopic Eruption of a Canine Tooth in the Chin, ORAL SURG. 21: 1.51-153,1966. 17. Geren, T. J.: A Clinical Report of Two Badly Misplaced Upper Third Molars, Dent. Cosmos 71: 1198-1201, 1929. 18. Thoma, K. H.: Clinical Pathology of the Jaws, London, 1934, Baillibre & Company, pp. 285-286.
394
Diekmann, Cohen, and Gutz
19. Thawley, S. E., and LaFerriere, K. A.: Supernumerary Nasal Tooth, Laryngoscope 87: 1770-1773, 1977. 20. Smith, R. A., Gordon, N. C., and DeLuchi, S. F.: Intraoral Teeth, ORAL SURG. 47: 120-122, 1979. 21. Hervery, W.: Removal of a Foreign Body. A Tooth From the Right Antrum, Dent. Cosmos 69: 107, 1927. 22. Edwards, J. L. and Ferguson, J. W.: Ectopic Maxillary Canine, N. 2. Dent. J. 72: 33-34, 1976. 23. Prassanna, N. M., and Vecchio, S. R.: Detigerous Cysts, Can. J. Otolaryngol. 3: 625-629, 1974. 24. Savundranayagam, A.: A Migratory Third Molar Erupting Into the Lower Border of Orbit Causing Blindness in the Left Eye, Aust. Dent. J. 17: 418-420, 1972. 25. Subramaniam, K. S., Prabhakaran, M., and Premalatha, R.: Ectopic Teeth in Eyelid, Arch. Ophthalmol. 75: 810-81 I, 1966. 26. McKenzie, C., and Sharpless, D. H.: Surgical Removal of Aberrant Teeth: Report of Two Cases, J. Oral Surg. 5: 231-234, 1947.
Oral April,
Surg.
1982
27. Berroyer and Laquerriere: A Tooth in the Frontal Sinus, Br. Dent. J. 42: 388, 1921. 28. Rion, C. L.: Tooth in Upper Lip: Report of Case, J. Am. Dent. Assoc. 17: 2295, 1930. 29. Carver, E.: Irregular Eruption, Br. Dent. J. 8: 757, 1887. 30. Gans, B. J.: Ectopic Tooth: Report of a Case, J. Oral Surg. 20: 435-437, 1962. 31. Ten Cate, A. R.: Oral Histology, St. Louis, 1980, The C. V. Mosby Company, pp. 84-86. 32. Johnston, M. C., and Sulik, K. K.: Orban’s Oral Histology and Embryology, ed. 9, St. Louis, 1980, The C. V. Mosby Company, p. 18. Reprint requests to: Dr. Donald M. Cohen UNMC College of Dentistry 40th & Holdrege Lincoln, Neb. 68583
OF NEBRASKA
Donald M. Cohen, D.M.D.,**
MEDICAL
CENTER
COLLEGE
and Dennis P. Gutz, D.D.S., M.S.,***
OF DENTISTRY
The mesiodens is the most common supernumerary tooth. It can be found in both the erupted and the impacted states. A case of a developing mesiodens located entirely in soft tissue is described. The lesion presented as a pedunculated palatal mass. No case of soft-tissue mesiodens has been previously reported. A theory of origin for this supernumerary tooth is proposed.
S
upernumerary teeth occur throughout the oral region, with a predilection for certain sites. The most common supernumerary tooth is the mesiodens, being located in the region of the maxillary central incisors. It has a prevalence of 0.15 to 1.90 percent in the white population’ and accounts for 45.4 to 66.8 percent of all supernumerary teeth.2-4Most mesiodens never erupt. When they do erupt, the most common site is behind the central incisors within the premaxilla.5 Reported here is a unique case of a mesiodens which presented as a pedunculated softtissue mass. CASE REPORT A 3-year-old white boy presented with a pedunculated masson the palate just lateral and posterior to the incisive papilla (Fig. 1). The lesion had been present since birth and was asymptomatic. The clinical impression was that it was a fibroma, and the lesion was removed and submitted for microscopic examination. Histologic examination revealed a massof densefibrous connective tissue containing a cone-shaped developing tooth germ. The tooth germ was composed of dental papillae, haphazardly arranged ameloblasts, enamel matrix, an odontoblastic layer, dentin, and some predentin and dentinoid material (Fig. 2). The tooth germ was surrounded by dense fibrous connective tissue containing numerous islands of odontogenic epithelium (Fig. 3). DISCUSSION
A review of the literature revealed numerous reports of teeth in unusual locations. Ectopic teeth have been found in the ramus,6-gcoronoid process,10-‘2
*Senior Dental Student. **Assistant Professorof Oral Pathology. ***AssociateProfessorof Pedodontics. 0030-4220/82/040391
+ 04$00.40/O
@ 1982 The C. V. Mosby Co.
Fig. 1. Pedunculated palatal mass contained developing supernumerary tooth germ. Mass was located behind the right central incisor just lateral and posterior to the incisive papilla.
condylar process,‘2-14 condyle,15inferior border of the mandible,’ chini zygomatic fossa,” posterior-superior surface of the tuberosity,18 nasal cavity,1g*20 maxillary sinus,2’-23eyelid,24l25 orbit,*‘j and frontal sinus.*’ In all of these cases the teeth were at least partially embedded in bone. There have been only three reported casesof teeth completely located in soft tissue. Rion** reported two supernumerary bicuspid crowns near the vermillion border of the upper lip. This lesion may actually have been a compound odontoma, judging from the multiplicity of teeth and the dissimilar appearance of the crowns. Carver2greported a canine erupting through the lower eyelid, and Gans30described a sessilemass on the palate near the deciduous second molar. The palatal mass was found to be a developing tooth surrounded by fibrous connective tissue. Gans 391
392
Diekmann, Cohen, and Gutz
Oral April,
Surg. 1982
Fig. 2. Conical-shaped developing supernumerary tooth germ. Note irregular dentin layer and investing fibrous connective tissue. The tooth lies entirely in soft tissue with no connection to the underlying bone. (Hematoxylin and eosin stain. Magnification, X 10.)
believed the tooth to be the missing second premolar and hypothesized that the anlage for the succedaneous tooth failed to be enclosed in the alveolar process. Explanations for the aberrant location of teeth have been numerous. They include migration”l’4’22; displacement due to trauma,16 infection, and cysts; developmental disturbances such as cleft palate; genetic factors; obstruction to eruption secondary to crowding, persistent deciduous teeth, or exceptionally densebonelo;and ectopic location of an extra tooth bud in the case of supernumerary teeth. There have been several theories specifically relating to the pathogenesisof supernumerary teeth. The theory most commonly accepted states that supernumerary teeth are the result of a local hyperactivity of the dental lamina.’ However, it is presently thought that the initiation of tooth formation is actually the result of the programming of the epithelium comprising the dental lamina by the underlying ectomes-
enchyme.3’ If dental epithelium is grafted onto skin mesenchyme the tissue formed is skin, and if skin epithelium is grafted onto dental mesenchyme the result is the formation of a tooth. The misplaced dental lamina was not solely responsible for the development of the soft-tissue mesiodens or the resultant tissue formed would have been palatal mucosa. Johnston and Sulik32stated that neural crest cells that have migrated in the vicinity of the pharyngeal endoderm are preconditioned by the endoderm. The preconditioned crest cells will react with oral ectoderm, differentiating into tooth papilla mesenchyme. Thus, the neural crest cells are ultimately responsible for the induction of the epithelium to form the tooth bud. The soft-tissue mesiodenscan then be explained on the basis of ectopic neural crest cells. This hypothesis would also explain why so many dental lamina rests exist in the gingiva, and yet the incidence of supernumerary teeth is relatively low. The
Volume 53 Number 4
Ectopic soft-tissue mesiodens
393
Fig. 3. Developing tooth germ surrounded by dense fibrous connective tissue containing numerous islands of odontogenic epithelium. (Hematoxylin and eosin stain. Magnification, X50.)
presence of the palatal mass at birth also lends circumstantial evidence supporting the theory of ectopic neural crest cell origin. REFERENCES 1. Primosch, R. E.: Anterior Supernumerary Teeth-Assessment and Surgical Intervention in Children, Pediatr. Dent. 3: 204-215, 1981. 2. Bergstrom, K.: An Orthopantomographic Study of Hypodontia, Supernumeraries and Other Anomalies in School Children Between the Ages of 8-9 Years, Swed. Dent. J. 1: 145, 1911. 3. Bodin, I., Julin, P., and Thomsson, M.: Hyperodontia. I. Frequency and Distribution of Supernumerary Teeth Among 2 1,609 Patients, Dentomaxillofac. Radio]. 7: I S-17, 1978. 4. Stafne, E. C.: Supernumerary Teeth, Dent. Cosmos 74: 653-659, 1932. 5. Bruce, K. W.: Supernumerary Maxillary Central Incisors, Chron. Omaha Dist. Dent. Sot. 23: 178180, 1960. 6. Zernov, M. W., and Paris, M. D.: Misplaced Third Molar in the Region of the Condyle Erupting Through the Cheek, Br. Dent. J. 87: 295, 1949. 7. Stones, H. H.: Oral and Dental Diseases, ed. 5, Edinburgh, 1966, E. & S. Livingstone, Ltd., pp, 144-145, 148149. 8. Gigliotti, R., Baker, R. C., and MacLeod, D. K.: Removal of
an Ectopic Lower Third Molar: Case Report, Dent. Surv. 52: 45-46, 1916. 9, Bey, M. A.: Eruption of a Third Molar Through the Skin, Quintessence Int. 1: 17-18, 1970. 10. Hopson, M. F.: A Mandibular Third Molar Situated in the Coronoid Process, Proc. R. Sot. Med. (Odont. Sect.) 13: 76-77, 1920. 1I. Sutton, P. R. N.: Migrating Nonerupted Mandibular Premolars: A Case of Migration Into the Coronoid Process, ORAL SURG. 25: 87-98, 1968.
I2. Stark, W., and Keim, R. P.: Bilateral Mo!ar impactions in Coronoid Processeswith Unilateral Molar Impaction in Neck of Left Condyle, ORAL SURG. II: 707-709, 1958. 13. Balendra, W.: Unerupted Lower Third Molar in the Region of the Condyle, Br. Dent. J. 86: 229, 1949. 14. Schwimmer, A., Keaveny, J. T., Caponigro, C., and Ragaini. V. E.: Subcondylar Impaction of a Third Molar Resulting in Chronic Preauricular Sinus: Report of Case, J. Oral Surg. 30: 41-44, 1972. 15. McKenzie, C., and Sharpless, D. H.: Surgical Removal of Aberrant Teeth: Report of Two Cases, J. Oral Surg. 5: 231-234, 1947. 16. Ebling, H.. and Lopes, J. V. S.: Ectopic Eruption of a Canine Tooth in the Chin, ORAL SURG. 21: 1.51-153,1966. 17. Geren, T. J.: A Clinical Report of Two Badly Misplaced Upper Third Molars, Dent. Cosmos 71: 1198-1201, 1929. 18. Thoma, K. H.: Clinical Pathology of the Jaws, London, 1934, Baillibre & Company, pp. 285-286.
394
Diekmann, Cohen, and Gutz
19. Thawley, S. E., and LaFerriere, K. A.: Supernumerary Nasal Tooth, Laryngoscope 87: 1770-1773, 1977. 20. Smith, R. A., Gordon, N. C., and DeLuchi, S. F.: Intraoral Teeth, ORAL SURG. 47: 120-122, 1979. 21. Hervery, W.: Removal of a Foreign Body. A Tooth From the Right Antrum, Dent. Cosmos 69: 107, 1927. 22. Edwards, J. L. and Ferguson, J. W.: Ectopic Maxillary Canine, N. 2. Dent. J. 72: 33-34, 1976. 23. Prassanna, N. M., and Vecchio, S. R.: Detigerous Cysts, Can. J. Otolaryngol. 3: 625-629, 1974. 24. Savundranayagam, A.: A Migratory Third Molar Erupting Into the Lower Border of Orbit Causing Blindness in the Left Eye, Aust. Dent. J. 17: 418-420, 1972. 25. Subramaniam, K. S., Prabhakaran, M., and Premalatha, R.: Ectopic Teeth in Eyelid, Arch. Ophthalmol. 75: 810-81 I, 1966. 26. McKenzie, C., and Sharpless, D. H.: Surgical Removal of Aberrant Teeth: Report of Two Cases, J. Oral Surg. 5: 231-234, 1947.
Oral April,
Surg.
1982
27. Berroyer and Laquerriere: A Tooth in the Frontal Sinus, Br. Dent. J. 42: 388, 1921. 28. Rion, C. L.: Tooth in Upper Lip: Report of Case, J. Am. Dent. Assoc. 17: 2295, 1930. 29. Carver, E.: Irregular Eruption, Br. Dent. J. 8: 757, 1887. 30. Gans, B. J.: Ectopic Tooth: Report of a Case, J. Oral Surg. 20: 435-437, 1962. 31. Ten Cate, A. R.: Oral Histology, St. Louis, 1980, The C. V. Mosby Company, pp. 84-86. 32. Johnston, M. C., and Sulik, K. K.: Orban’s Oral Histology and Embryology, ed. 9, St. Louis, 1980, The C. V. Mosby Company, p. 18. Reprint requests to: Dr. Donald M. Cohen UNMC College of Dentistry 40th & Holdrege Lincoln, Neb. 68583