The prevalence of root dilaceration among southern Jordanian population

 The most prevalent theory concerning the development of dilaceration is trauma to the primary teeth that can cause displacement of the calcified portion of the permanent teeth

In relation to the non-calcified portion.^3-6 Another theory for the development of dilacerations in case of no history of trauma is idiopathic developmental disturbance.^7,8 Dilaceration that affects the crown can be observed through visual inspection during clinical examination; however, radiographic assessment is needed to diagnose root dilaceration.⁹ Radiographic evaluation of root dilacerations is performed in two planes, and the dilaceration can be categorised as mesial, distal, or orofacial (i.e. buccal or lingual direction).¹⁰ The last one can be diagnosed once bull’s eye appearance (a round opaque area with radiolucency in its central region) is detected.¹¹ Although dilaceration can manifest in both permanent and deciduous dentition, its prevalence is more in the former.¹² While some studies observed no gender predilection for this anomaly¹³, others reported a male to female ratio of 1:6.^14,15 Diagnosis of dilaceration is vital before performing dental procedures including endodontic treatment³, surgical extraction¹⁶, and orthodontic treatment.¹⁷ In case of overlooked dilaceration, these procedures would be immensely demanding and susceptible to failure. Hence, adequate diagnosis and awareness of dilaceration prevalence are instrumental in providing effectual, high-quality, and safer dental treatment.

The aim of this study was to methodically investigate the prevalence of root dilaceration in a group of Jordanian dental patients and assess the distribution of this anomaly among different types of teeth.

Materials and Methods

A cross-sectional study was conducted at the prince Ali Ben Al Hussein hospital which is part from Jordanian Royal Medical Service (JRMS) hospitals. Prior to the start of the study, the requisite ethical approval was sought from and granted by the Human Research Ethics Committee at the JRMS, and all research steps were undertaken in accordance with the ethical principles of the Helsinki Declaration. Dental digital radiographical records (i.e. digital panoramic X-ray images) were examined for dental patients who were treated at the Dental Department, Prince Ali Ben Al-Hussien Hospital, Al-Karak, Jordan over a three-year period (from 2013-2015). All digital panoramic X-ray images were viewed using the Carestream software®. Other pertinent data such as age and gender were extracted from the patients’ files. Exclusion criteria included dental digital panoramic X-ray images with inadequate quality and dental digital panoramic X-ray images of only primary teeth. In addition, teeth with incomplete root formation were excluded. Supernumerary teeth were not counted as examined teeth as they exceed the normal dentition count. Diagnosing criteria of root dilaceration was the following: a tooth was recognised as having mesial or distal root dilaceration if there was a deviation of 90 degrees or more from the normal long axis of the tooth. Orofacial direction of the dilacerations was determined by evaluating the bull’s eye appearance of the root, which results from the root deviation of 90 degrees or more.

The deviations were assigned to either apical, middle, or the coronal third of the root. In case of multirooted teeth, a tooth was recognised as having the dilacerations of the root if at least one root exhibited dilaceration. Regarding the prevalence of dilaceration, multirooted teeth having one or more dilacerated roots were counted as a single case of root dilaceration. To minimise variability in the analysis of root dilacerations, meticulous examinations were conducted jointly by the first two authors of this study. 

Statistical analysis: All data were amassed, coded, and statistically analysed using the Statistical Package for Social Sciences (SPSS 20; Chicago, IL, USA) Program. Patients’ characteristics and the prevalence rate were reported using descriptive statistics. The distribution of dilacerations was assessed among the jaws and the teeth. The Pearson chi-squared (χ²) test was used to evaluate the effect of gender on the prevalence of dilaceration. A p-value < .05 was considered statistically significant.

Table I: Characteristics of included patients.

Table II: Distribution of examined teeth among arches and excluded teeth with reasons. 

Results

The records of 1,004 patients were included in this cross-sectional study. Characteristics of included patients are succinctly presented in Table 1. The age range of the included patients was (19-52) with a mean of 35.6 ± 16.3 years. Patients were distributed approximately equally based on gender with 497 male patients (mean age 36.9 ± 17 years) and 507 female patients (mean age 35 ± 15.7 years). A total of 27,229 teeth were examined and 1,002 were excluded on the basis of the exclusion criteria of incomplete root formation (Table 2). Moreover, 3,897 teeth were reported as missing as specified in the examined records (Table 2). The findings of this study reveal that the prevalence of dilaceration was 0.8% (225 teeth out of the total 27,229 teeth). In addition, the dilacerations occurred more in the mandibular arch (139 teeth) than the maxillary arch (86 teeth). The distribution of dilaceration among teeth is encapsulated in Table 3. According to the results of this study (Table 3), mandibular third molars (11.1%) were the most frequent dilacerated teeth, followed by maxillary third molars (2.3%), maxillary second premolars (1.3%), mandibular second molars (1.1%), and maxillary second molars (1%). Root dilacerations were not detected in mandibular central incisors and mandibular canines (Table 3). Regarding the location of dilacerations along the root length, the results of this study (Table 4) reveal that dilacerations occurred predominantly in the apical third (51%), followed by the middle third of the root (46%), while the coronal third exhibited the least dilacerations (2.6%). The results of this study (Figure 1, Table 5) show that dilacerations were more common in female patients (76 patients, 56%) than male patients (60 patients, 44%). The difference was, however, not statistically significant based on chi-squared (χ²) test (p = .177) (Table 5).

Table III: Distribution of the prevalence of root dilaceration amongst different tooth types.

Table IV: Distribution of the prevalence of root dilaceration according to the location in the tooth root (coronal, middle, and apical).

Table V: Distribution of dilacerations based on gender.

*P-value based on chi-squared (χ²) test.

Figure 1: Distribution of dilacerations based on gender.

Discussion

Dilaceration is an unusual anomaly that can potentially affect the dental root and crown. Root dilaceration is diagnosed usually through radiographical examination.^3,9 Hence, proper radiographic evaluation of dental patients is vital before performing any dental procedure, especially root canal treatment, extractions, and orthodontic treatment, as these dental treatments could be adversely impacted with any overlooked dilaceration. This study focused on evaluating the prevalence of root dilaceration among Jordanian patients who had been treated at a JRMS hospital. Hamasha et al.⁹ considered dilaceration as a deviation of 90 degrees or more of the root from the normal axis of the tooth while Chohayeb¹⁸ considered a tooth or a root to have Dilaceration if there was a deviation of 20 degrees or more from the normal axis of the tooth. In this cross-sectional study, the diagnosis of dilacerations was predicated on the definition posited by Hamasha et al. ⁹ due to its higher accuracy. It is a challenge to explore and negotiate root canal system in dilacerated teeth because of high degree of root curvature which can lead to many endodontic errors as ledging, transportation and zipping. ³ The rate of endodontic errors such as ledging, transportation, and zipping can be higher in these teeth.³ In addition, a dilacerated root may be easily fractured during the surgical tooth extraction.^8,17 The presence of the dilacerations during orthodontic tooth movement can make it complicated.¹⁹

With this study, we found that the prevalence of root dilaceration among Jordanian patients was 0.8%. Our result was fairly lower with the results of Ledesma-Montes et al. (1.6%)²⁰ and Thongudomporn et al. (1.8%) ¹⁷, while it was higher than those reported by Malcić’s et al. (0.32%)¹⁰ and Nabavizadeh et al. (0.3%)¹¹. Furthermore, the prevalence of dilaceration reported in this study was lower than that reported by Udoye et al. (3%)²¹, Hamasha et al. (3.8%)⁹ Miloglu et al. (9.5%)²², and Ezoddiny et al. (15% of patient)²³. The variability in dilaceration’ prevalence between the studies may plausibly be related to ethnic variations and variability in the diagnostic criteria and the radiographic evaluation methods that were used to diagnose dilaceration. Regarding the relationship between the presence of dilacerations and gender, the findings of this study reveal that there was no gender predilection for the presence of dilacerations. This is congruent with previous studies^9,13,17,22. In contrast, other studies^21,24 reported that dilacerations occurred more commonly in females. The etiology of dilaceration is still disputable. If we regarded trauma to the primary teeth as the primary cause for the development of dilaceration, then we should detect more dilacerations in the anterior teeth. However, the results of this study were consistent with previous studies^9,21,22,24 in that dilacerations were more common in the posterior area which is less affected by trauma. This finding can be explained by the proposal of development of dilacerations due to idiopathic developmental disturbances in tooth tissue calcification. We observed that dilacerations were more common in mandible. This result is congruous with the result reported by Hamasha et al.¹, while it is against the result reported by Udoye et al. ²¹ and Malcic et al.⁹, who found that dilacerations were more common in maxilla. Similar to the results of previous studies^10,25, this study showed that dilacerations occur more commonly in the apical third of the teeth which agrees with with the result showed in the study of Miloglu O et al ²². Panoramic radiographs, used to diagnose dilacerations in many previous studies^20,24,25, were used to diagnose dilacerations in this study. The limitations of this study include the authors’ inability to assess the trauma history of the included patients and the inability to investigate the associated syndromes and developmental anomalies. In this study diagnosis of dilaceration depends on panoramic view, while periapical is superior in diagnosis²¹. According to Jafarzadeh et al.³, certain syndromes and developmental anomalies have been associated with dilaceration, which include Smith-Magenis syndrome, the hypermobility type of Ehlers-Danlos syndrome, Axenfeld-Rieger syndrome, and congenital ichthyosis.

 Conclusions