Journal of Indian Academy of Oral Medicine and Radiology

: 2018  |  Volume : 30  |  Issue : 2  |  Page : 132--136

Radiographic assessment of apical root resorption in inflammatory periapical pathologies

Lim Xin Wei, Felicia How Pei Min, Syed Zafri Bin Syed Zaharuddin, Elise Khaw Wei Ling, KV Suresh, Khairiyah Bt Abd Muttalib, Daniel Devaprakash Dicksit 
 Faculty of Dentistry, SEGi University, Kota Damansara, Selangor, Malaysia

Correspondence Address:
Dr. K V Suresh
Faculty of Dentistry, SEGi University, No. 9 Jalan Teknologi, Taman Sains, Petaling Jaya, Kota Damansara, Selangor - 47810


Introduction: Apical root resorption (ARR) is a common condition associated with periapical pathologies which is invariably detected by intraoral periapical radiographs. Although it is common, its distribution in different periapical pathologies has not been assessed so far. The aim of this study was to determine the distribution and severity of ARR in common inflammatory periapical pathologies. Materials and Methods: A cross-sectional radiographic study was conducted on 333 patients who visited SEGi Oral Health Centre in the 6-month period of the study. Digital intraoral periapical radiographs of patients with clinically established periapical pathologies were taken. Data were collected using a structured proforma regarding the type of periapical lesions, presence or absence of ARR. Collected data were analyzed using SPSS version 21 and Chi-square test was applied to check the association between ARR and periapical pathologies. Results: During this study period, 333 patients with inflammatory periapical pathologies were reported. Of which 135 (40.5%) showed definite ARR. Among 135 ARR, 97 (71.9%) were moderate resorption and 38 (28.1%) were severe resorption. ARR was significantly greater in periapical granuloma and cyst (72.8%) followed by periapical abscess (35%) and acute apical periodontitis (18.1%) which was statistically significant (P < 0.001). Young adults (40.7%) and male patients (58.5%) had higher ARR compared to old-aged adults and female patients. Conclusion: The presence of ARR is the concern for the infection control in endodontics, as these conditions provide a favorable environment for bacterial colonization and also exact working length determination is difficult as there is altered apical constriction.

How to cite this article:
Wei LX, Pei Min FH, Syed Zaharuddin SZ, Wei Ling EK, Suresh K V, Abd Muttalib KB, Dicksit DD. Radiographic assessment of apical root resorption in inflammatory periapical pathologies.J Indian Acad Oral Med Radiol 2018;30:132-136

How to cite this URL:
Wei LX, Pei Min FH, Syed Zaharuddin SZ, Wei Ling EK, Suresh K V, Abd Muttalib KB, Dicksit DD. Radiographic assessment of apical root resorption in inflammatory periapical pathologies. J Indian Acad Oral Med Radiol [serial online] 2018 [cited 2022 Jan 29 ];30:132-136
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Apical root resorption (ARR) is a common phenomenon noticed in periapical pathologies arising due to inflammation of pulp and periapical tissues. The persistent encounter between microbes and host defenses at the periapical area results in local inflammation thereby releasing chemical mediators such as cytokines IL-1a, IL-1b, TNFa, prostaglandins and lipopolysaccharides, thus initiating the pathogenesis of periapical lesions.[1] These chemical mediators may stimulate root resorption in the same way how they stimulate bone resorption.[2] The resorbed area at the root apex may provide the suitable environment for numerous microbes, which can lead to delayed healing of periapical pathologies and in some cases failure of endodontic treatment.[3] In addition, resorbed surfaces are frequently associated with technical problems as these sites are not within the reach of root-canal instruments or medication and are difficult in obtaining an ideal apical seal.[1] Intraoral periapical radiographs (IOPAR) provides accurate information required for diagnosis and treatment planning of periapical lesions. Recently, cone beam computed tomography (CBCT) proved to be more accurate; however, due to its high radiation exposure its use becomes impractical for routine endodontic purpose. The resorptive sites on the root apex have great clinical significance in prognosis and success of endodontic treatment. The errors in diagnosis and treatment planning of resorptive roots may lead to failure of endodontic treatment. Although ARR is a common phenomenon observed in periapical pathologies, its prevalence among different periapical pathologies has not been assessed so far. Hence, in this study an attempt was made to assess the distribution and severity of ARR in common inflammatory periapical pathologies.

 Materials and Methods

A cross-sectional radiographic study was conducted on patients visited SEGi Oral Health Centre, SEGi University, Malaysia, from May to October 2016. The ethical clearance was obtained from the institutional ethical committee and written consent was obtained from the patients willing to participate in the study (SEGi UC Ethics committee). Patients with clinically diagnosed periapical pathologies were subjected to intraoral radiographic examination. Digital intraoral periapical radiographs with paralleling technique was taken by keeping the exposure parameters constant (Belmont Phot-X2303-WK intraoral X-ray machine at 70 kVp and 8 mA and Apixia Digirex Photostimulable Phosphor Plates).

Inclusion criteria constituted the patients with clinically diagnosed inflammatory periapical pathologies in permanent teeth.

The following group of patients were excluded from the study:

Patients suffering from endocrine imbalances and systemic diseases such as hyperparathyroidism, hypoparathyroidism, hypophosphatemia and hyperphosphatemiaPatients with advanced periodontitis, cysts and tumorsPatients undergone orthodontic treatmentRoot canal treated teeth, primary teeth and young permanent teeth.

Clinical diagnosis of periapical lesions

Patients reporting with clinical signs and symptoms of periapical pathologies were examined by the experienced oral medicine and radiology specialist. Following signs and symptoms were considered for diagnosis of periapical lesions.[4]

History of pulpal pain or presence of pain at the time of examinationSensitivity to percussionPresence of intraoral and extraoral swellingSensitivity to hot and cold fluidsPresence of fistulaDiscolored tooth/fractured restoration.

Radiographic diagnosis of periapical lesions

Each periapical radiograph was assessed by the experienced oral medicine and radiology specialist to check the morphology of the root surface, width of periodontal ligament space and continuity of the lamina dura. The diagnosis of different periapical lesions were made based on the radiographic findings. Acute apical periodontitis was considered if there was widening of periodontal ligament space. Chronic periapical abscess was considered when there was a loss of continuity of lamina dura and presence of irregular ill-defined radiolucency at the periapex. Periapical granuloma and periapical cyst were considered when there was a well-defined radiolucency with corticated margins. Periapical granuloma was considered if the size of the radiolucency is <1.6 cm and lesions measuring more than this size were considered as periapical cyst

The following variables were considered to measure: the size of the lesion, periodontal ligament space and lamina dura.

Size of lesion: was calculated by measuring the diameter of lesion using the area of lamina dura continuity loss as reference point.

Periodontal ligament space widening: the space was horizontally measured in mm from the root surface up to the lamina dura.

Lamina dura: the radio-opaque continuity was observed, from the bone crest to the apex of the tooth.[4]

Criteria to assess the severity of ARR

The teeth with periapical radiolucencies was examined for the absence or presence of resorption in the apical third of the root and were divided into three categories:

No resorption: intact outline of the root surface with uniform density in root contour.

Moderate resorption: presence of blurred irregularities on the apical root contour, with less radio dense areas than the rest of the root [Figure 1].{Figure 1}

Severe resorption: presence of distinct radiolucent indentations or shortening of root tip [Figure 2].[1]{Figure 2}

Data collection and statistical analysis

The presence and severity of ARR was recorded along with different gender and age groups. Data were collected using a structured proforma consisting of patient's details, type of periapical lesions, presence or absence and severity of ARR. Subjects participated in the study were divided into young-aged adults (18–35 years), middle-aged adults (36–55 years) and old-aged adults (>55 years). Data were analyzed using IBM SPSS Statistics 21.0. Chi-square test was used to find out association between ARR and type of periapical pathologies. P value was set at <0.05 as significant.


[Table 1] shows the distribution of gender and age groups. Out of 333 periapical pathologies, 135 (40.5%) showed ARR. Among 135 ARR, 97 (71.9%) had moderate resorption and 38 (28.1%) had severe resorption [Table 1] and [Table 2].{Table 1}{Table 2}

ARR was higher in periapical granuloma and cyst (72.8%) followed by periapical abscess (35%) and apical periodontitis (18.1%) which was statistically significant (P = 0.000 < 0.05) [Table 3].{Table 3}

Among the 205 male patients with periapical pathologies, 79 (58.5%) showed ARR in which 59 were moderate and 20 were severe ARR. Among 128 female cases, 56 (41.5%) showed ARR in which 38 cases showed moderate and 18 cases were showing severe ARR [Table 4].{Table 4}

ARR was slightly higher in young (40.7%) and middle (34%) aged adults than old adults (25%). Male patients had higher ARR (58.5%) than female patients (58.5%) with periapical pathologies [Table 4].


ARR is a pathological process which involves complex interactions between inflammatory cells, resorbing cells, cytokines and various enzymes. The changes in the host cellular immune system may be implicated in altering the resorption process and producing clinically significant external root resorption. The most common etiologies of ARR are pulpal and periapical infections, orthodontic treatment, traumatic injury, cysts, neoplasia, systemic diseases or chemical injury.[5],[6]

In ARR, the outer surface of the root is resorbed by odontoclasts. Radiographically, it appears as radiolucency on the external surface of the dentin with or without shortening of roots.[7]

The common inflammatory periapical lesions include acute apical periodontitis, periapical abscesses, periapical granuloma and periapical cysts. IOPAR is considered as the preferred diagnostic tool for evaluation, diagnosis and treatment planning of periapical pathologies.[3] No previous radiographic studies are available to discuss the prevalence of ARR in periapical pathologies. However, there are few studies done to assess prevalence of ARR in relation to different periapical lesions on extracted teeth using scanning electron microscopy (SEM), CBCT and histopathological method.[8],[9]

Patel et al.[10] compared the accuracy of digital intraoral radiographs with CBCT for the detection of resorption lesions in patients with internal resorption, external cervical resorption and no resorption. They found that the CBCT was effective and gives best results in diagnosing resorption among the other imaging modalities available. Also CBCT gives the true nature of the lesions in three dimensions. However, they concluded that the intraoral digital radiography resulted in an acceptable level of accuracy in diagnosis of resorption. Studies by Estrela et al.[11] and Durack et al.[12] found CBCT has a reliable and valid method of detecting resorption than periapical radiographs. Though CBCT has better detection ability due to its higher radiation dose compared to intraoral radiograph limits its use for routine periapical lesions.[13]

The overall prevalence of ARR in this study was 40.5% of periapical pathologies. Similar results were observed by Vier and Figueiredo.[9] They noticed 42.2% root apices had periforaminal resorption and 28.7% of root apices had foraminal resorption in SEM. Study by Estrela et al.[8] recorded a higher prevalence of ARR using SEM, 61.4% on extracted teeth with periapical lesion. This prevalence rate was reduced to 23.9% when examined using CBCT.

Literature search showed results of previous studies in which very high percentage ARR were reported. However, the results of these reports cannot be compared with the present study because many of these authors investigated resorptions developing after orthodontic treatment or after tooth replantations.

Histopathological evaluation of ARR by Vier and Figueiredo [9] showed periforaminal resorption in 87.3% of the cases, and foraminal resorption in 83.2% of periapical pathologies. Another study by Laux et al.[1] revealed 81% ARR in extracted teeth. These prevalence rates are much higher than the previous radiological studies. The authors concluded that the microscopic analysis of ARR remains a gold standard against the imaging methods. The comparison of the radiographic and histological findings of ARR showed the poor reliability of radiographs in the diagnosis of ARR.[1]

The lower prevalence of 19% ARR was recorded by Laux et al.[1] and 28.8% by Tsesis et al.[14] in a Middle East community. This could be due to use of panoramic radiographs which do not give the fine details as compared to IOPAR [15],[16] and the different study design used by the authors.

Among the various periapical pathologies, periapical cyst and granuloma showed 72.8% ARR which is significantly higher when compared to periapical abscess and apical periodontitis. Study by Vier and Figueiredo [9] showed no association between root resorption and the nature of the periapical lesion. The severity of ARR was higher in periapical granuloma and cyst compared to other lesions. This finding was in accordance with the study by Vier and Figueiredo.[9]

The extent of ARR may affect the outcome of endodontic treatment, severe ARR may lead to open apex increasing the chances of obturating materials extruding into the periapical region. This may in turn sustain periapical irritation, initiate a foreign body reaction and possibly induce furtherroot resorption.[8] Moreover, resorbed roots may pose difficulty in limiting the instrumentation due to the loss of cementum-dentine junction and to achieve the correct apical seal.[7]

The best way of evaluating ARR is by histopathological method, since intraoral radiographs are unable to detect the resorption in early stages, hence there is a tendency of under estimation of exact prevalence of ARR.[15] Therefore, while treating long-standing periapical pathologies, clinicians should be aware thatARR may be present even though it may not be evident on the radiographs.[8]

Conclusion and clinical significance

Present study was aimed to determine the relation between periapical pathologies and root resorption, and to correlate the different types of periapical pathologies with the extent of root resorption. The results showed that the higher prevalence of ARR in periapical pathologies such as periapical granuloma and cyst (71.9%) than the periapical abscess and apical periodontitis. The prevalence recorded in this study could be lesser than the actual resorption rate, as IOPAR may not detect the changes in early stages. Therefore, chronic long-standing periapical pathologies could possibly have resorption which cannot be noticed in IOPAR. Hence, the dental clinician should consider the possibility of having resorption in long-standing inflammatory periapical pathologies.


The authors would like to thank Dr. Priyadarshini H R, Associate Professor, Faculty of Dentistry, SEGI University, for her kind support and cooperation during the study period.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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