: 2016  |  Volume : 28  |  Issue : 2  |  Page : 192--198

Diagnostic and therapeutic approach in dens in dente

Walid Lejri1, Ines Kallel1, Omar Marwen2, Nabiha Douki1,  
1 Department of Dental Medicine, Sahloul Hospital, Sousse, Faculty of Dentistry; Laboratory of Research in Oral Healh and Maxillo Facial Rehabilitation (LR12ES11), Faculty of Dental Medicine, University of Monastir, Monastir, Tunisia
2 Department of Dental Medicine, Sahloul Hospital, Sousse, Faculty of Dentistry, Monastir, Tunisia

Correspondence Address:
Walid Lejri
Department of Dental Medicine, Hospital Sahloul, 4050 Sousse


The dental invagination is an abnormal dental development merely agreed to be a gene-related disorder. There are three types of invaginations, of which Type I is the most common. The diagnosis is based on clinical and above all radiological examinations. An early prophylactic approach is often the most effective mean of treatment. This paper describes the clinical and radiographic features related to the different types of dens invaginatus and the therapeutic approach through several cases.

How to cite this article:
Lejri W, Kallel I, Marwen O, Douki N. Diagnostic and therapeutic approach in dens in dente.Endodontology 2016;28:192-198

How to cite this URL:
Lejri W, Kallel I, Marwen O, Douki N. Diagnostic and therapeutic approach in dens in dente. Endodontology [serial online] 2016 [cited 2021 Oct 24 ];28:192-198
Available from: https://www.endodontologyonweb.org/text.asp?2016/28/2/192/195432

Full Text


The dental invagination (dens in dente) is a tooth dysmorphogenesis resulting from a partial invagination of the enamel organ to variable depths, during its development.

The exact etiology of this malformation remains unknown. An embryonic (Rushton 1937),[1] traumatic (Gustafson and Sundberg 1950),[2] infectious origin (Fischer 1936,[3] Sprawson 1937) and “the external forces exerted on the dental germ,”[4] as many theories suggested to explain this dysmorphogenesis, are involved. However, the genetic theory remains most probable (Grahnen et al. 1959, l'Irlande et al. 1987, Hosey and Bedi 1996, Dassule et al., 2000) regarding the increased prevalence in members of the same family.[5]

Various classifications were proposed to describe dental invagination. Still, the classification of the OEHLERS, which is based on the radiological criteria, continues to be the most commonly used.[6]

The relatively increased prevalence of this pathology may range from 0.3% to as high as 10% (Boyne 1952). This anomaly implies, in 85% of the cases, the second upper incisor (Hülsmann 1997, Hamasha and Al-Omari 2004) including the contralateral incisor in 43% of the cases.[7]

The invagination Type I is most common; in fact, we will present two cases of this kind of invagination. It accounts for 79% of the cases.[8] According to its morphology, the invagination constitutes a privileged zone for plaque formation and prevents an efficient dental hygiene control. Moreover, we should not overlook the fact that the thin and hypomineralized enamel also stands out in causing pulpal and periapical complications.

As this anomaly is generally underdiagnosed, this paper lays out four cases in patients with dens invaginatus aiming therefore to raise more awareness and knowledge among dental professionals to the morphological characteristics, diagnostic assessment, and confirmation of the invagination and mostly to the importance of the clinical examination.[9]

 Case Reports

First Case: Type I

A 24-year-old patient with an overall good health consulted us with a chief complaint being the spontaneous pain associated with the 36.

The clinical examination led to a fortuitous discovery of a deep cervical pit or fissure on the palatal surface of tooth number 12, with a prominent cingulum which can be implemented for further investigations.

A positive response to vitality testing was noted. The tooth examination also showed the presence of a black decayed tissue of hard consistency, with 3 mm of depth; however, we found no immediate communication between the carious lesion and the pulp [Figure 1]. No attack of coronal tooth structure was observed on the buccal side [Figure 2]. The tooth was not tender to percussion.{Figure 1}{Figure 2}

According to the OEHLERS classification, the patient has a Type I standard invagination on which the evolution of decay has stopped that has also been confirmed after radiological examination which shows a tiny invagination, confines within the crown, and does not overextend the cementoenamel junction [Figure 3].{Figure 3}

A prophylactic treatment was adopted for fissure sealing using a fluid resin. A local anesthesia (mepivacaine 2% with epinephrine 1:100,000) was performed. The elimination of this decayed tissue with round bur (Ø 2 mm) gave us access to the invagination [Figure 4]. The infiltration of the fluid resin (Dental Advisor Reflectys Flow ITENA Universel) helped sealing the invagination [Figure 5].{Figure 4}{Figure 5}

Second Case: Type I

Further to our request, with the aim of verifying the genetic component, the mother of the patient of the first case had consulted our department for a clinical examination which as well revealed a conoid crown with deep cervical pits on both the second incisors [Figure 6]. Probing revealed the presence of a decayed tissue and the absence of a communication with the pulp. The vitality test was positive and the tooth was not tender to percussion.{Figure 6}

Eventually, the diagnosis of a typical Type I invagination was suggested. The decayed tissue was eliminated by the same way that the first case. Fluid resin (Dental Advisor Reflectys Flow ITENA Universel) followed by a nanohybrid resin (Universal seen Dental Advisor Reflectys ITENA) was used to seal this invagination [Figure 7].{Figure 7}

Third Case: Type II

A 23-year-old girl consulted our department for a productive fistula on the buccal tissue apical to the second incisor [Figure 8]; the patient was otherwise in good health.{Figure 8}

The percussion test on this intact tooth showed no sensitivity, and the absence of all carious lesions, accordingly, prompted us to deepen our clinical observation. After a thorough examination of the tooth, we noticed the presence of an unusual morphology on the palatal side with three cingulum cervically-located to the incisal edge which suggests a possible invagination [Figure 9].{Figure 9}

An X-ray with a gutta cone inserted into the fistula showed its close relationship to the apex of the tooth as well as the presence of an invagination invading the pulp chamber and exceeding the cementoenamel junction without reaching the periodontal ligament [Figure 10]. Anesthesia was not necessary. Access cavity was performed using round bur (Ø 2 mm) and an Endo-Z giving us access to the root canal. The treatment was based on removing the invagination to finally end up with one broad canal using Gates-Glidden drill first, then F3 file (ProTaper Universal), of which we removed 2 mm of the tips to enhance its resistance alternately and abundantly irrigated with a 2.5% sodium hypochlorite solution. The whole procedure was controlled radiologically to avoid any possible complication while shaping [Figure 11].{Figure 10}{Figure 11}

We finally placed a calcium hydroxide as an intracanal medication for 15 days to have a better disinfection of the root canal system, which eventually led to the resolution of the fistula on the 10th day [Figure 12].{Figure 12}

80/100 and 70/100-mellimeters-in-diameter master coneswere fitted to a gauged apex followed by a radiological control. Gutta-percha cones were sectioned at the apical third of the root. Then, the rest was sealed by flowable gutta-percha (E and Q Master from Meta Biomed) [Figure 13].{Figure 13}

Fourth Case: Type III

A 35-year-old patient showed up in our department with a fistula that has been draining for few months at the level of the anterior upper teeth. No. 11 and 21 were restored with prosthetic crowns including, however, a poor esthetic outcome. Added to an untreated canal in No 21, a nontightly sealed root canal obturation was seen in both teeth on the panoramic radio [Figure 14].{Figure 14}

The morphologically aberrant tooth, evoking dens in dente, showed a direct relation with the fistula after taking an X-ray with a gutta cone threaded through the fistulous tract [Figure 15].{Figure 15}

The diagnosis of a chronic apical periodontitis was made and an endodontic retreatment was then essential. The disposal of the crowns, and removal of the underneath composite restoration on No. 21 along with the intraradicular screw post, exhibited an atypically wide pulp chamber.

The configuration of dens in dente Type “IIIB” was detected on the radiograph with endodontic files in place, which also revealed a fractured instrument within the main root canal [Figure 16]a, making it more prone to the developing periapical lesion and the external radicular resorption as well seen on the X-ray. The invagination extends through the root and communicates with the periodontal ligament in the apical region. Progressive shaping was made with the ProTaper system accompanied by copious irrigation using a 2.5% sodium hypochlorite solution, consecutively followed by a 15-day intracanal-calcium hydroxide-based medication.{Figure 16}

The fistula disappeared within 10 days after root canal calcium hydroxide dressing. Subsequently, an apical plug of Biodentine™ (septodont) was placed to seal the wide open apex of the principal canal. The second one was sealed by gutta-percha, followed by a provisional coronal restoration [Figure 16]b.

The fractured instrument was not removed, yet, bypassed, and lodged in the mass of Biodentine™ (septodont).

Unfortunately, the patient did not return for clinical and radiological follow-up.


This kind of tooth malformation was first described by Ploquet in 1794, who discovered this anomaly in a Whales' tooth. Dens invaginatus in a human tooth was first described by a dentist named Socrates in 1856.[12]

The complexity of the root canal system architecture within such teeth ultimately leads to the sacrifice of the tooth. Tooth extraction was the most preferred therapy until the 1991s as the introduction of the operating microscopes to endodontics (by Garry Carr) has provided the optimal visual magnification aid.[13]

Clinically, an unusual crown morphology (peg-shaped, barrel-shaped, dilated), a deep foramen cecum, or conoid crown may be important hints, but affected teeth also may show no clinical signs of the malformation, that is why the dental practitioners need to deploy their attention, mainly to the palatal surface and chiefly that of the upper laterals as being the most affected teeth during the physical examination.[14] With this knowledge, the diagnosis of dens in dente is easier; however, only radiographic examination will aid and guide succinct diagnosis.

According to the classification of the OEHLERS [Figure 17], each invagination type requires a different therapeutic approach [Table 1].{Figure 17}{Table 1}

Type I does not present particular difficulties considering that the invagination is confined to the crown. A cone beam computed tomography (CBCT) is not necessary, and the treatment is generally prophylactic as long as the invagination is precociously diagnosed. Nevertheless, an endodontic treatment is mandatory in cases where the tooth exhibits necrosis. A conventional radiography is sufficient to assess the relationship between the cementoenamel junction and the invagination to eventually confirm the diagnosis of dens in dente.[10]

Clinically, the invagination can be suspected whenever a dysmorphic anatomy of the tooth crown is pointed out, whereas a fortuitous discovery of the invagination can be made despite the grossly normal morphology of the tooth. Hence, it goes without saying that further clinical examination should be put forth aiming, thus to spread more awareness among dental professionals, which significantly reduces the chances of all possible pulp complications through early detection and optimal prophylactic treatment.

The only problem that can be encountered in cases of Type I invagination is the choice of the filling materials, mainly depending on the depth of the invagination.

For Type II, many authors advocated procedures to seal minimal invaginations after coronal instrumentation with amalgam glass-ionomer cement, composite, or amalgam as a prophylactic treatment. Unfortunately, most of the teeth with invagination developed irreversible pulpal complications such as irreversible pulpitis or necrosis and root canal treatment is unavoidable. This last represents a huge challenge to endodontist due to the aberrant anatomy present within the invagination.

Tagger (1977) and Holtzman and Lezion (1996) emphasizes the problems associated with achieving adequate chemomechanical debridement of the root canal system and invagination, predictable length control, and consistent filling.

Successful treatment using hand file and gutta-percha was described, but the use of passive ultrasonic energy was still more comfortable.

A CBCT examination is essential in this kind of invagination; unfortunately, we could not carry out a preoperative CBCT for our case due to the lack of means. Generally, these teeth evolve into necrosis before the closure of the apex, leading to either a delayed root formation or an arrested tooth development constricting our treatment options between an apexification with mineral trioxide aggregate/biodentine or a conventional root canal obturation using gutta-percha. Fortunately, in our case, apexification was not necessary and a traditional shaping and gutta-percha obturation was performed.[11]

For Type III, invaginations, while perforating the apical area through the root canal, show the second apical foramen (Type III A/B) and the presence of two distinct root canals or more, and only one of which is a false canal or a pseudocanal bordered by enamel buildup. The major challenge for this kind of invagination is to highlight the pulp vitality given that it will guide our therapeutic approach toward two choices: Either a prophylactic treatment which consists of treating the false canal as a separate entity without damaging the vitality of the tooth, or treating both root canals (or more) in cases of pulp necrosis. Hovland and Block (1977) were the first to describe the use of conventional endodontic methods to treat both the infected invagination and a necrotic pulp separately, and we opt for this method to treat our fourth case using ProTaper universal system for shaping. In contrast, Girsch and McClammy (2002) and Silberman et al. (2006), both of them, describe complete removal of an invagination to create one large canal space in Type III invaginations. Extraction, endodontic treatment in combination with intentional reimplantation has also been described by Lindner et al. (1995) and Nedley and Powers (1997). Finally, some authors describe a surgical approach with apical resection.

A CBCT examination is paramount to yield further assumption of responsibilities in cases of invaginations, especially that a canal can be missed during the treatment.[15]


There is a wide variation in the possible clinical and radiographic presentations of tooth invagination. In addition, there are a number of approaches concerning the management of this anomaly; however, the overriding objective must aim to preserve the health of the pulp if at all possible. This objective can be obtained by achieving early diagnosis and adopting a prophylactic treatment, regardless of the invagination severity. Indeed, when prophylactic treatment is applied on time before the onset of any pulp complication, the prognosis of these invaginations turns out to be very interesting with a success rate of 90%.

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Conflicts of interest

There are no conflicts of interest.


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