|Year : 2009 | Volume
| Issue : 3 | Page : 28-35
Use of computed tomography in diagnosis and management of type III dens invaginatus
Jayshree Hegde, Kusum Bashetty, C Champa
Department of Conservative Dentistry & Endodontics, The Oxford Dental College & Hospital, Bommanahalli, Hosur Road, Bangalore 560 068, Karnataka, India
|Date of Web Publication||23-Feb-2011|
Department of Conservative Dentistry & Endodontics, The Oxford Dental College & Hospital, Bommanahalli, Hosur Road, Bangalore 560 068, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Dens invaginatus is a developmental malformation, which concerns the non-typical arrangement of dental hard tissues. Conventional diagnostic aids like radiographs play an important role in assessment of complex root canal morphologies. These modalities, however, do not provide detailed information of the complexity as a result of their inherent limitations. This calls for use of more advanced imaging modalities such as computed tomography, which can help the clinician in making a more accurate diagnosis.
Report: Type III Dens invaginatus was detected in a 20 year old male patient corresponding to the maxillary lateral incisor and showing extensive periradicular radiolucency and a vestibular sinus. The radiographic and tomographic examination revealed 2 apices: one wide open in the distal part of the root and the other normally formed in the mesial.
Treatment plan: Combined non-surgical and surgical endodontic therapy with MTA as a retrograde filling material was planned in this case.
Outcome: At follow-up examination after 6 months, the tooth was asymptomatic and radiographically showed repair of the lesion.
|How to cite this article:|
Hegde J, Bashetty K, Champa C. Use of computed tomography in diagnosis and management of type III dens invaginatus. J Int Clin Dent Res Organ 2009;1:28-35
|How to cite this URL:|
Hegde J, Bashetty K, Champa C. Use of computed tomography in diagnosis and management of type III dens invaginatus. J Int Clin Dent Res Organ [serial online] 2009 [cited 2019 Aug 26];1:28-35. Available from: http://www.jicdro.org/text.asp?2009/1/3/28/77017
| Introduction|| |
Developmental tooth disturbances pose a challenge to the clinician in diagnosis as well as treatment because of its complex crown and root morphology. One such rare developmental anomaly of teeth is dens invaginatus (DI), which results from the invagination of the enamel organ into the dental papilla before calcification has occurred  . Several theories have been proposed for this phenomenon, but the etiology of DI remains unclear. Its prevalence ranges from 0.04% to 10%  with the maxillary lateral incisor being the most commonly affected and less frequently the central incisors  . A dentist by name Socrates in 1856 was the first to report DI in human teeth  .
Oeheler's  classified DI into 3 types on the basis of severity: Type 1, an enamel-lined minor form occurring within the confines of the crown not extending beyond the CEJ; Type II, an enamel lined form that invades the root but remains confined as a blind sac and might not communicate with the pulp; and Type III, a form that penetrates through the root perforating at the apical area, showing a second foramen in the apical or in the periodontal area. Type II and Type III poses a challenge because of complex root canal anatomy, therefore, early diagnosis and treatment of such cases are important in preventing pulp infection via the invagination. Though, such complex root canal anatomies have been conventionally diagnosed by radiographs, they do not provide detailed information concerning the 3-dimensional image, which would help the clinician to undertake actual treatment plan. 
With the advances in software imaging, the resolution of computed tomography (CT) has been improved; a 3 dimensional model can be reconstructed, allowing qualitative and quantitative examination of complex root canal anatomy  . In these areas computed tomography scan is very useful in confirming the detailed anatomic information and thus rendering more immediate treatment plan.
Non surgical root canal treatment has been considered impractical with Type II and Type III DI because of the challenge in adequately cleaning the root canal without removal of dens  . In severest form of Type III, with the presence of wide apical foramen associated with cyst, surgery is the most commonly used treatment because of anatomic variations, where cleansing and shaping can be particularly difficult.
The following case report presents a case of Type III dens invaginatus with periapical lesion, diagnosed with CT scan and treated surgically with mineral trioxide aggregate (MTA) as a root end filling material.
| Case Report|| |
A 20-year old male patient reported to the Department of Conservative dentistry and Endodontics of The Oxford Dental College & Hospital, Bangalore, with the chief complaint of pain and swelling in relation with upper anterior teeth 1 month earlier, but at the time of examination there were no symptoms. The patient's medical history was non contributory. At the intraoral clinical examination, the right upper lateral incisor 12 appeared to be intact but with a prominent cingulum [Figure 1]. Periodontal probing was within normal limits. There was no decay or discoloration in relation to maxillary central or lateral incisor but a sinus tract was present in the labial vestibule [Figure 2]. Right upper central incisor 11 gave a delayed response, canine 13 gave a normal response and lateral incisor 12 did not respond to a cold test or electric pulp tester and the history of a previous trauma was negative. Gutta percha tracing showed involvement of right upper lateral incisor 12 [Figure 3].The palatal mucosa in relation to 12 was tender to palpation and was soft without any bony resistance suggesting of palatal perforation.
|Figure 1: The intraoral palatal view of lateral incisor (12) showing prominent cingulum|
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|Figure 2: Clinical photograph showing presence of sinus tract in labial vestibule|
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The periapical radiograph revealed the presence of radiolucency in the periapical area ranging from 15 mm X 10 mm with well defined borders. Radicular canal ended with two apices; one wide open in the distal part of the root and the other normally formed in the mesial. The contralateral incisor was also checked for clinical and radiographic sign of same abnormality, but none was detected.
| Diagnosis and Treatment Planning|| |
A clinical diagnosis of dens invaginatus (Oehler's Type III); necrotic pulp with periapical cyst was made. For further accurate diagnosis, CT scans were taken to confirm the details of type of dens and also to know the dimension of periapical lesion and proximity of the lesion to the maxillary sinus [Figure 4]i.
From these scans and 3D reconstruction, diagnosis was confirmed as Oehler's Type III dens invaginatus with apical pathosis ranging 18.1 X 12.8 X 11.5 mm [Figure 4]ii. The lesion was close to the maxillary sinus but was not involving it. CT scan showed presence of 3 root canal orifices, one on both side of the central canal on the pulpal floor. The patient was informed of the long-term prognosis of the tooth, and a decision was made to perform root canal treatment followed by periapical surgery if symptoms persisted.
| Treatment Procedure|| |
At the Ist appointment, after anesthesia and rubber dam isolation, an access cavity was opened and 3 canal orifices were located [Figure 5]. A radiograph was obtained with files inserted in the root canals to establish working lengths [Figure 6]. In working length radiograph, the central and distal canals appeared to be merging at the apex. There did not appear to be any connection between these two canals and the mesial canal. Canals were shaped to size 35 and copious irrigation was done using 2.5% sodium hypochlorite during cleaning and shaping procedure. Calcium hydroxide intracanal medicament was given for 15 days. The access cavity was temporarily sealed with cavit.
After 15 days, patient returned without any symptoms. After rubber dam placement, the canals were irrigated with 1% sodium hypochlorite and dried with paper points. Canals were obturated with lateral condensation of gutta percha and AH-26 sealer. Immediately following treatment of the lateral incisor, the central incisor was treated with conventional orthograde (nonsurgical) endodontic therapy [Figure 7].
After 15 days, the patient returned and apical surgery was performed to remove a portion of the root with undebrided space and to retro seal the canal. The surgical intervention consisted of apical curettage [Figure 8], root-end resection, root-end preparation and retro filling. A vestibular flap was raised and the rough borders of the root were smoothed, granulation tissue was removed, mechanical retention provided and retrograde ProRoot-MTA (DENTSPLY) inserted. Sutures were placed and tissue was sent for histological evaluation for diagnosis of the periapical lesion and was diagnosed as radicular cyst [Figure 9]. At 3-month and 6-month follow-up examinations, the patient was asymptomatic and radiographic evidence of satisfactory healing was confirmed by a decrease in the size of the apical radiolucency [Figure 10] & [Figure 11].
| Discussion|| |
Developmental disturbances of the permanent dentition are most frequently encountered in the lateral incisor  . It is a rare malformation of teeth showing a broad spectrum of morphological variations  .
Dens invaginatus (DI) is undoubtedly an endodontic challenge, especially because of the complex root canal morphology and because of the difficulty accessing the regular and invaginated canals , . Such cases always pose a challenge to the clinician in diagnosis as well as in treatment. Inability to locate, debride and obturate complex root canal spaces will lead to failure in some cases  . Due to the inherent limitations of the radiographs they could not reveal the details of the type and extent of the DI; CT was used for diagnosis in the present case. The benefits of CT scans were that they gave a sharp, focused and 3-D view of the invaginatus; the type and extent of invaginatus as well as lesion were also clearly evident from the scans.
Non surgical endodontic treatment in teeth with DI should be the first treatment alternative before resorting to endodontic surgery, intentional replantation or extraction of the tooth. However, endodontic treatment of DI Type II and III can become complicated because of an unpredictable internal anatomy  . They present a complex root canal configuration that is often not possible to instrument completely. As a result, these teeth should be selected for combined orthograde and surgical treatment , . Endodontic surgery is indicated for cases of severe forms of DI where periapical lesions are prominent  . In other cases, combined treatment may be necessary because of the complexity of the root canal morphology. The surgery will provide an additional retrograde seal to the root canals, which may remain a source of irritation.
In the present study, MTA was used as retrograde filling material. It has been demonstrated that MTA induces the formation of a calcified matrix in the periapical tissue and regeneration of new cement, possibly associated with its high sealing capacity, sets in presence of moisture, biocompatibility, alkaline pH and liberation of substances activating the cementoblasts, which in turn will deposit a matrix for the cementogenesis , . Root end filling with MTA was performed to achieve a better apical seal of root canals. Utilization of AH plus sealer along with gutta-percha has been shown to have better apical sealing ability and adaptation to dentin  . This type of treatment has provided satisfactory clinical and radiographic outcomes.
| Conclusion|| |
Because of the complications presented by dens invaginatus Type III and chronic periapical pathology, combined nonsurgical and surgical endodontic therapy was indicated in this case. Follow-up radiography over 6 months showed evidence of complete healing.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11]