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 Table of Contents  
Year : 2017  |  Volume : 29  |  Issue : 1  |  Page : 69-73

Type III dens invaginatus in a permanent maxillary canine: A rare case report

1 Department of Conservative Dentistry and Endodontics, AMC MET Dental College, Ahmedabad, Gujarat, India
2 Department of Conservative Dentistry and Endodontics, Subharti Dental College, Meerut, Uttar Pradesh, India
3 Department of Oral Medicine and Radiology, H.P. Government Dental College and Hospital, Shimla, Himachal Pradesh, India

Date of Web Publication25-May-2017

Correspondence Address:
Parul Bansal
Department of Conservative Dentistry and Endodontics, Subharti Dental College, Meerut, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0970-7212.207007

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Occurrence of dens invaginatus in maxillary canine is rare. This article reports a case of maxillary left canine with type III dens invaginatus associated with periapical pathology, which was managed successfully by apicocurettage of apical pathology and root canal treatment of both the main canal and invagination separately. Wide open invagination as well as incompletely formed root apex was sealed with mineral trioxide aggregate (MTA) through retrograde approach and tooth was obturated with MTA to fill all the irregularities present in the invagination and the main canal.

Keywords: Dens invaginatus; maxillary canine; mineral trioxide aggregate; open apex.

How to cite this article:
Malik A, Bansal P, Sharma N, Kothari A. Type III dens invaginatus in a permanent maxillary canine: A rare case report. Endodontology 2017;29:69-73

How to cite this URL:
Malik A, Bansal P, Sharma N, Kothari A. Type III dens invaginatus in a permanent maxillary canine: A rare case report. Endodontology [serial online] 2017 [cited 2021 Feb 26];29:69-73. Available from: https://www.endodontologyonweb.org/text.asp?2017/29/1/69/207007

  Introduction Top

Dens invaginatus is a rare developmental anomaly with a broad spectrum of morphological variations. Dens invaginatus results from the deepening or invagination of the enamel organ into the dental papilla, beginning at the crown and often extending to the root, which occurs before the calcification of the dental tissues. The etiology of dens invaginatus is controversial and remains unclear. The possible factors responsible are lateral fusion of two germs, constriction of dental arch in the enamel organ, increased external pressure, focal growth retardation, focal growth stimulation in certain areas of tooth buds, infection and genetic factors.[1] Most commonly affected teeth are maxillary lateral incisor.[1] Though involvement of other teeth have also been reported but dens invaginatus in maxillary canine is rare. Only very few cases of dens invaginatus involving maxillary canine have been reported.[2],[3],[4],[5],[6]

Oehlers [7] have described three forms of dens invaginatus: Type I: An enamel-lined minor form occurring within the confines of the crown not extending beyond the cemento-enamel junction. Type II: An enamel-lined form which invades the root as a blind sac and may communicate with the dental pulp. Type III: a severe form which penetrates through the root perforating and opens in the apical region without communicating with the pulp. Present case was associated with Ohler's type III form of dens inveginatus. Schulze and Brand (1972) proposed a more detailed classification which also included invagination starting at the incisal edge or the top of the crown, as well as dystrophic root configuration.[8]

Clinically tooth may be present with no clinical signs of malformation to unsual form such as deep lingual invagination, greater buccolingual dimensions, peg shaped crown, barrel shaped crown, conical crown. This case was presented with wide dimensions of the crown mesiodistally and deep palatal invagination. Dens invaginatus has clinical significance because of predisposition to early decay, pulp necrosis and development of periapical abscess or cyst.[1] This may be related to the patient inability to keep the defect free of cariogenic plaque and presence of thin dental tissue (i.e., enamel and dentin) between invagination and pulp space.

Radiographically tooth with dens invagination may appear unusual and may be frequently interpreted incorrectly as a double root, a radicular invagination or an odontome, or a tooth twin.[9],[10] Correct radiographic interpretation and proper treatment planning require understanding of the variable and complex internal anatomy of invaginated teeth. Various techniques for treating dens invaginatus have been reported. The present article reports the endodontic management of this particular type III variant of dens invaginatus involving Maxillary left permanent canine.

  Case Report Top

An 18-year-old male patient was referred to the Department of Conservative Dentistry and Endodontics for evaluation and management of maxillary left canine. Clinical examination revealed maxillary left canine with greater mesiodistal dimensions and deep lingual invagination. Intra oral swelling and sinus tract was also present in relation to 23. The tooth was tender on percussion and palpation and nonresponsive to pulp testing.

Radiographic examination revealed malformation of the root with enamel lined tract mesial to and separate from the main root canal [Figure 1]. Large periapical pathology approximately sized 1.5–2 cm was associated with the tract. The tract was communicating to periapical pathology through a wide apical opening.
Figure 1: Preoperative radiograph

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A diagnosis of type III dens invaginatus associated with pulpal necrosis and acute exacerbation of chronic periapical abscess was established. Root canal treatment of main root canal as well as dens tract followed by apicocurrettage was planned. Treatment was explained to the patient and consent was obtained.

Under rubber dam isolation, a wide mesio-distal oval shaped opening was made to provide adequate access to dens tract as well as to main pulp canal [Figure 2]. Root canal treatment of dens tract and main root canal was planned separately as there was no communication present between them. Working length for both the main canal and the dens tract (which was extending till apex) was established [Figure 3]. Main root canal was prepared till working length by circumferential filing. The dens tract was debrided as well as possible. As the canal was lined with enamel, irrigation was performed using 5.25% sodium hypochlorite and 17% of ethylenediaminetetraacetic acid. Calcium hydroxide (UltraCal, Ultradent) was placed in the dens tract and root canal for 3 weeks for disinfection. The access cavity was sealed with cavit (ESPE ™, Premier) between visits to prevent contamination of the dens and canal system.
Figure 2: Access preparation showing two canal orifices

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Figure 3: Working length radiograph

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At the next appointment, sinus tract was healed. After the administration of local anaesthesia a full thickness periosteal flap was reflected. Buccal cortical plate overlying the pathology was removed with a surgical bur. Pathological tissue was curetted out with the help of a bone currette. Mineral trioxide aggregate (MTA) was placed through retrograde approach to seal the communication of dens tract and wide apical root canal to periapical area [Figure 4] and [Figure 5]. Bony cavity was filled with platelet rich fibrin made up of patients own blood to accelerate healing. Flap was secured in position with suture. Sutures were removed after 7 days and healing was uneventful. Obturation of the root canal and invagination was done with MTA to obturate the dens tract as well as main root canal to fill all the irregularities of canals [Figure 6]. During the follow up period patient was asymptomatic [Figure 7].
Figure 4: Retrograde sealing of dens opening and open apex of the root canal

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Figure 5: Apical sealing with mineral trioxide aggregate

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Figure 6: Postoperative radiograph

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Figure 7: One year follow up radiograph

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  Discussion Top

An early diagnosis and proper management of dens invaginatus is crucial to prevent sequelae like early pupal involvement, abscess formation, retention of neighboring teeth, displacement of teeth, cysts, and internal resorption.[1] An invagination frequently allows the entry of irritants into an area, which is separated from pulpal tissue by only a thin layer of enamel. Even sometimes enamel lining may be incomplete or channels may exist connecting the invagination and the pulp.[1] This may lead to predisposition for early involvement of the pulp soon after the eruption of the tooth even before root completion. In the present case with type III dens invaginatus, pulpal necrosis had occurred before root completion thus open apex with periapical pathology was present at the age of 18 years.

Depending on the extent of malformation and clinical symptoms various treatment modalities have been proposed as preventive, restorative treatment, root canal treatment, surgical treatment, intentional reimplantation or even extraction of teeth with severe anatomical defects that cannot be managed nonsurgically or by apical surgery. Before occurrence of caries, teeth with deep palatal or incisal invagination or foramina coeca should be treated with fissure sealing with composite or other fissure sealing materials and strict periodic review is recommended. Until the 1970s extraction of teeth with invagination was the preferred therapy. Grossman was the first to describe root canal treatment of the invagination only (root invagination treatment).[11] Tagger and Hovland and Block presented cases of invagination treated with conventional root canal therapy.[12],[13]

Dens invaginatus constitutes to be a great challenge for endodontic treatment, since it may present an unpredictable and complicated root canal system and the fact that the invagination is lined with enamel not by the dentin. If there is no communication existing between the invagination and the root canal and no radiographic signs of pulpal involvement present, root canal treatment of the invagination only will be adequate. Pécora et al. report that endodontic treatment is always necessary because the invagination of the enamel favours the penetration of microorganisms into the pulp tissue, due to communication with the oral cavity.[14]

Sometimes changes in the access preparation may be necessary to get adequate access as well as debridement. In the present case access was modified to expose both the dens tract as well as the main root canal. Opening of the dens tract was present mesial to the main canal. The merging of the main canal with the invaginatus space with ultrasonic has also been proposed as an alternative treatment to facilitate endodontic preparation.[15] In types I and types II dens invaginatus, invagination can be removed and transformed into a single canal which can be treated by conventional root canal treatment. In type III dens invaginatus when the dens tract has a separate apical or lateral foramen, root canal treatment of the invagination separately from main root canal is indicated. Mangani and Ruddle and Khabbaz et al. has described the treatment of the dens tract as a separate canal.[16],[17] In present case dens tract was cleaned, shaped and obturated separately from the main root canal in order to prevent further weakening of the tooth.

Irregular and complex internal anatomy of the root canal system makes proper cleaning and shaping difficult. To disinfect the root canals with all its irregularities, sodium hypochlorite as an irregant and calcium hydroxide as an intracanal medicament is recommended to eliminate bacteria. In the present case disinfection of the canal was achieved with 5.25% NaOCl irrigation and Ca(OH)2 intracanal medicament for 3 weeks.

Presence of type III invaginatus causes greater difficulty in management of the tooth. Wein report that the endodontic treatment of dens invaginatus is difficult, preferring surgical intervention with retrofilling. When pulp necrosis occurs before completion of root apex, apexification procedures may be necessary.[18] In the present case surgical intervention was done to remove all the periapical pathology as well as apexification of main root canal and apical sealing of invaginatus opening with MTA through retrograde approach.

Due to abnormal anatomical configuration, root canal space obturation with warm Gutta-percha technique or thermoplastisized technique or MTA may have better sealing ability over conventional lateral condensation or single canal obturation. In the present case all the irregularities of canal and dens tract were sealed with MTA to provide three dimensional sealing and demonstrated uneventful healing.

  Conclusion Top

Dens invaginatus associated with maxillary canine is a rare dental anomaly. Type III invagination is commonly associated with early pulpal involvement, open apex and periapical pathosis, requiring combination of surgical and nonsurgical management. Invagination which is opened at the apex or laterally can be treated as a separate canal from main canal system. MTA can be used to fill the dens tract as well as irregular canals with large communication to the periodontal tissues.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Hülsmann M. Dens invaginatus: Aetiology, classification, prevalence, diagnosis, and treatment considerations. Int Endod J 1997;30:79-90.  Back to cited text no. 1
Holtzman L, Lezion R. Endodontic treatment of maxillary canine with dens invaginatus and immature root. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;82:452-5.  Back to cited text no. 2
Sousa-Neto MD, Zuccolotto WG, Saquy PC, Gradini SA, Pecora JD. Treatment of dens invaginatus in a maxillary canine case report. Braz Dent J 1991;2:147-50.  Back to cited text no. 3
Birla BB, Shivakumar. B. A Variant form of dens invaginatus in permanent maxillary canine. Int J Dent Sci Res 2014;2:1-3.  Back to cited text no. 4
Lichota D, Lipski M, Wozniak K, Buczkowska-Radlinska J. Endodontic treatment of a maxillary canine with type 3 dens invaginatus and large periradicular lesion: A case report. J Endod 2008;34:756-8.  Back to cited text no. 5
Stamfelj I, Kansky AA, Gaspersic D. Unusual variant of type 3 dens invaginatus in a maxillary canine: A rare case report. J Endod 2007;33:64-8.  Back to cited text no. 6
Oehlers FA. Dens invaginatus (dilated composite odontome). I. Variations of the invagination process and associated anterior crown forms. Oral Surg Oral Med Oral Pathol 1957;10:1204-18.  Back to cited text no. 7
Schulze C, Brand E. Über den dens invaginatus (Dens in dente). Zahnärztl Welt Reform 1972;81:569-73, 613-20, 653-60, 699-703.  Back to cited text no. 8
Fujiki Y, Tamaki N, Kawahara K, Nabae M. Clinical and radiographic observations of dens invaginatus. J Dentomaxillofac Radiol 1974;3:343-8.  Back to cited text no. 9
Gotoh T, Kawahara K, Imai K, Kishi K, Fujiki Y. Clinical and radiographic study of dens invaginatus. Oral Surg Oral Med Oral Pathol 1979;48:88-91.  Back to cited text no. 10
Grossman LI. Endodontic case reports. Dent Clin North Am 1974;18:509-27.  Back to cited text no. 11
Tagger M. Nonsurgical endodontic therapy of tooth invagination. Report of a case. Oral Surg Oral Med Oral Pathol 1977;43:124-9.  Back to cited text no. 12
Hovland EJ, Block RM. Nonrecognition and subsequent endodontic treatment of dens invaginatus. J Endod 1977;3:360-2.  Back to cited text no. 13
Pécora JD, Conrado CA, Zuccolotto WG, Sousa Neto MD, Saquy PC. Root canal therapy of an anomalous maxillary central incisor: A case report. Endod Dent Traumatol 1993;9:260-2.  Back to cited text no. 14
Girsch WJ, McClammy TV. Microscopic removal of dens invaginatus. J Endod 2002;28:336-9.  Back to cited text no. 15
Mangani F, Ruddle CJ. Endodontic treatment of a “very particular” maxillary central incisor. J Endod 1994;20:560-1.  Back to cited text no. 16
Khabbaz MG, Konstantaki MN, Sykaras SN. Dens invaginatus in a mandibular lateral incisor. Int Endod J 1995;28:303-5.  Back to cited text no. 17
Wein FS. Endodontic Therapy. St. Louis: Mosby; 1982.  Back to cited text no. 18


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]


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