Endodontic Retreatment of a Maxillary Central Incisor with Two Root Canals in a Patient with Cleft Lip and Palate

Abstract

The failures in endodontic treatments are often related to anatomical variations. Some anatomical changes in anterior teeth occur in patients with cleft lip and palate. This paper aims to report the endodontic retreatment of a maxillary central incisor with two roots and two canals on a patient who presents cleft lip and palate. A male patient, 11-year-old, reported pain when chewing related to the left maxillary central incisor tooth (tooth 21) which featured a sinus tract after primary endodontic treatment. In periapical radiograph, it was observed an alteration on the anatomy of the root on the tooth 21, which featured a radiolucent area on the dental apex and had been properly endodontically treated. In cone-beam computed tomography (CBCT) images the presence of an accessory root in the palatal region was observed, that had not been prepared, or filled. Thus, the non-treated accessory canal was instrumented with the crown-down technique and filled with gutta-percha and endodontic sealer. After 1 year of follow-up, the patient presented the tooth with a normal masticatory function and no painful symptoms. Therefore, it can be concluded that the additional root canals may be present and the CBCT is an important tool to evaluate the internal root morphology. In cleft lip and palate patients, the root canals morphology should be carefully analyzed due to high prevalence of dental anomalies which may influence the success in endodontic treatment.

Introduction

Variations in the internal morphology of root canals may influence on the success of the endodontic therapy [1, 2]. One of the many associated reasons to the flaws in this therapy is the persistence of infection within the root canals [3-5].

Previous studies show that 100% of the maxillary central incisors presented single root and one root canal [6-8]. However, there are a few reported cases in the literature of maxillary central incisors presenting two [4, 9-11], three [12, 13], four [14-16] and, even, five root canals [17]. Usually, the presence of more than one canal in the maxillary central incisors is related to some rare anomalies in the development of the teeth, such as gemination [18], fusion [11], dens invaginatus [17] or supernumerary roots [19]. Other cases of anatomical changes in the antero-superior teeth occur in patients with cleft lip and palate [20-22].

The cleft lip and palate are the most frequent congenital anomalies in the head and neck region [20, 23] and are a result of a failure in the merging of the nasal and the maxillary processes [24]. Some studies show that the frequency of dental anomalies is directly associated with the severity of the cleft [24, 25] and it occurs in about 70% of the cases [20, 21, 25]. The main anatomical changes are hypodontia, microdontia, root dilaceration and the presence of supernumerary teeth [20-22, 26].

Although periapical radiographies are important for diagnosis, planning and implementation of the endodontic treatment, their use is quite limited in cases of alterations in root canal morphology [7, 27, 28]. In order to overcome the radiograph limitations and to provide higher resolution images, cone-beam computed tomography (CBCT) has been used as an efficient resource to identify and locate roots and additional canals in anomalous teeth [7]. Hence, this work aims to report the endodontic retreatment of a maxillary central incisor with two canals on a patient with cleft lip and palate.

Case Report

An 11-year-old male with cleft lip and palate was referred to the Endodontic Specialization Course of the School of Dentistry of the University of São Paulo (São Paulo, Brazil), reporting sensitivity to chewing related to the left maxillary central incisor (tooth #21). The patient reported a previous endodontic treatment and, after 4 months, he observed the development of a “small bubble on the gum”.

The intraoral examination showed dental absences, alteration on the dental crowns of teeth 11 and 21 (probable imperfect amelogenesis), and cleft palate. The patient was wearing a space maintainer device and a maxillary expander fixed to the maxillary molar teeth (Figures 1A and 1B). The presence of a sinus tract in the palatal groove region of the tooth 21 was also noted (Figure 1C). In the periapical radiographic examination, it was observed a change in the anatomy of the root on the tooth 21 in comparison with its contralateral tooth. This tooth has also presented a periapical radiolucent area which had been endodontically treated (Figure 1D).

Figure 1.

Clinical and radiographic exams. A) Intraoral clinical examination in frontal view, observing the upper arch; B) Evidencing the presence of cleft palate; C) Periapical radiograph, before primary endodontic treatment; D) After primary endodontic treatment

Next, a CBCT exam was requested to improve the assessment of the internal and the external root anatomy, in order to assist the diagnosis as well as the clinical planning. The CBCT scan was performed by an ICAT device (Sorensen, Helsinki, Finland) which confirmed the presence of two roots and two canals (Figure 2). It was noticed that the buccal root canal had been well shaped and sealed. In the face of the recent endodontic treatment of the buccal canal, it was decided to carry out the treatment only on the palatal root canal.

Figure 2.

A–D) Imaginological exams: CBCT scan in sagittal; E and F) Axial sections, evidencing the presence of a root and an additional canal in the palatine region (red arrows)

After explaining the choice of treatment to the patient and getting the consent form of him, the access to the canals was performed with a 1014 drill, removing the dentine until the palatine canal was found (Figure 3A). The new canal was explored with a #10 K-file and the working length was performed with a #15 K-file, using an electronic foramen locator (RomiApex A15; Romidan, Kiryat Ono, Israel). The working length was established 1 mm short of the apical foramen (Figure 3B). The canal instrumentation was done manually by crown-apex technique and the apical preparation was performed with the #40 NiTiflex file (Dentsply Maillefer, Ballaigues, Switzerland). At every file change, the canal was irrigated with 2 mL of 2.5% sodium hypochlorite (Fórmula e Ação Farmácia de Manipulação, São Paulo, São Paulo, Brazil). To remove the smear layer, the canal was rinsed with 1 mL of 17% Ethylene diamine tetraacetic acid (EDTA) solution (Fórmula e Ação Farmácia de Manipulação, São Paulo, Brazil) for 3 min. Afterwards, irrigation was performed with saline solution and the root canal was filled with calcium hydroxide paste, which remained for 15 days. In the second session, the patient was asymptomatic. So, the interappointment medication inside root canal was removed with 2.5% sodium hypochlorite, followed by irrigation with 17% EDTA and saline solution. After drying the root canal, obturation procedure was performed with gutta-percha cones associated with EndoFill sealer (Dentsply Maillefer, Ballaigues, Switzerland) by the lateral condensation technique (Figure 3C). The tooth was restored with A2 Filtek ™ Z250 XT composite resin (ESPE, Rio de Janeiro, Brazil).

Figure 3.

Endodontic retreatment. A) Display of the pulp chamber, being observed the buccal canal filled with shutter and the empty palatal canal; B) Evidencing the presence of an accessory canal with a file in the working length; C) Post-filling of the canal; D) One year after completion of the endodontic treatment, highlighting a decrease in periapical bone rarefaction

After one year follow-up, the patient reported no pain to apical palpation or vertical percussion. Radiographically, there was a decrease in the periapical bone rarefaction (Figure 3D). In the face of signs of repair of the periapical region and the tooth having a regular masticatory function, the patient was referred for surgical treatment of the cleft lip and palate.

Discussion

In the present case report, two root canals in a maxillary central incisor were observed in a patient with cleft lip and palate. There is a consensus in previously published papers regarding the anatomy of the maxillary central incisors presenting single root and single canal in 100% of cases [6-8]. However, there are few case reports in which these teeth present two to five root canals, constituting a rare clinical finding [4, 10, 11, 13, 15-17]. The vast majority of these reports are related to the presence of associated anomalies, such as gemination, [18, 29], fusion [11, 30-33], dens invaginatus [14, 17], macrodontia [34] and enamel hypoplasia [35, 36]. Several cases have been reported where the maxillary central incisors with 2 canals were considered typical anatomy [4, 9, 16, 37].

In this case report, the observed dental alteration was the amelogenesis imperfecta, which is a genetic condition that affects the development of the tooth enamel. As the defective enamel is quite thin or completely absent, the yellowish or brown dentin of the crown is revealed, presenting dentin sensitivity and poor aesthetics [38]. At the moment, even a single study relating the amelogenesis imperfecta to the presence of two roots and two canals in the maxillary central incisor has not been found in the literature.

With regards to patients with cleft lip and palate, anomalies of number, size and shape of teeth, as well as changes in periods of formation and eruption, are frequently observed, causing not only aesthetic problems but also difficulties in chewing, swallowing, breathing and phonation [21]. In a retrospective analysis of 207 panoramic radiographs of patients with cleft lip and palate, the presence of dental anomalies in 75.4% of the cases was observed, being 31.2% of those presenting dental agenesis [20]. In another study, Ajami et al. [1] observed the presence of dental anomalies in 92.5% of the studied cleft patients. The most prevalent ones were hypodontia (71.25%), microdontia (30%), root lacerations (21.25%) and supernumerary teeth (15%), respectively. Usually the most affected teeth are the maxillary lateral incisors [22, 25]. However, in the present case report, the patient presented agenesis of the right lateral incisor and the central incisors with amelogenesis imperfecta. The association between the presence of teeth with amelogenesis imperfecta and cleft lip and palate could not been found in the literature, that shows a rare clinical presentation. It has also been observed that only the maxillary left central incisor presented two roots and two root canals, and there was no prior similar report.

Several papers have already discussed the importance of a complete disinfection of all root canals so that healing of the periapical region happens especially if the canals present independent foramen [4, 16, 17, 39], as shown in this case. Nevertheless, some root canals might be left untreated during treatment, mostly in the teeth with difficult access or visualization of these canals. One possible difficulty in the identification of an additional canal might be due to the arrangement of the roots in buccal and palatal direction. Periapical radiographs present limitations in the diagnosis, showing overlapping structures. The CBCT is a viable option to diagnose calcified and additional canals [40-42]. In the present case, the patient felt persistent pain after the endodontic treatment, which ended only after the preparation and filling of the additional canal in the palatine region. After 1 year of follow-up, absence of the infection and decrease of the periapical bone rarefaction was observed.

Conclusions

Cleft lip and palate patients might have dental anomalies that hinder the endodontic treatment, mainly related to the presence of supernumerary canals. Additional care, such as the use of CBCT should be employed, in order to check with high fidelity the anatomical condition of the teeth of patients with cleft palate.

Conflict of Interest:

‘None declared’.