Resorption: part 2. IN BRIEF Provides an overview of the clinical indicators of root resorption. PRACTICE Diagnosis and management Explains the role of modern imaging in classifying resorptive lesions. Discusses the management of resorption J. Darcey*1 and A. Qualtrough2 considering classifcation and aetiology. Provides algorithms for practitioners to follow when considering the diagnosis VERIFIABLE CPD PAPER and management of resorption. In this second paper the clinical indicators of root resorption and their diagnosis and management are considered. While the clinical picture can be similar, pathological processes of resorption vary greatly from site to site and this paper pro- poses appropriate approaches to treatment for teeth that are affected by resorption. INTRODUCTION approaches to treatment for teeth that are Root resorption has been defned as the affected by resorption. loss of dental hard tissue as a result of osteoclastic cell action1 and can occur on DIAGNOSIS both external and internal surfaces. The History process can be self limiting and is often sub-clinical as seen in the case of surface Diagnosis should be based upon a sound resorption.2 It can, however, be more pro- clinical history. Teeth affected by resorp- Fig. 1 Evident discolouration of the crown gressive and potentially destructive.2 The tion lesions are often asymptomatic and with darkening of the cervical portion post resorptive process has been classifed as may present as an incidental fnding upon trauma. This was diagnosed as ERR being internal or external to the tooth with radiographic examination so it is essen- Clinical examination a number of sub-classifcations.3 Internal tial that the clinician should pay particu- resorption is infammatory in nature but lar attention to aspects of the history that Full extra and intra oral clinical exami- the resorptive process may have a replace- may play a role in the development of nations should be performed before more ment component with tissue of mixed resorption. specifc investigations of the relevant teeth origin being deposited within the canal.4 These factors include: are carried out. The colour of the tooth This tissue can be calcifc.4 External root History of trauma3,5 should be noted with specifc reference to resorption can be classifed as being sur- History of crown preparation6 precise site of any discolouration (Fig. 1). face, infammatory, cervical or replace- History of pulpotomy6 In the cervical portion of the teeth pink- ment resorption.2 Although the clinical Orthodontic history7,8 ish colouration is indicative of resorption. picture may be similar and any difference Use of intra-pulpal chemicals such as The presence of all restorations should be appears only to be related to the site of internal bleaching products9–11 recorded and note made of primary dis- resorption, the pathological processes are History of removal of impacted ease, leaking margins and recurrent car- somewhat different and thus demand dif- teeth12,13 ies. The use of percussion is of relevance ferent treatment protocols. Accurate and History of surgical procedures in in resorption cases and thus should be early diagnosis of resorption is critical for proximity to the affected roots noted and compared to adjacent teeth: a successful treatment. This paper consid- History of periodontal disease and its metallic sound may suggest a diagnosis ers diagnosis and proposes appropriate management14,15 of ankylosis. An increase in mobility may In more extensive resorptive indicate attachment loss or pathological conditions involving multiple teeth fracture due to extensive external resorp- 1Speciality Registrar, 2Senior Lecturer/Honorary it may be of interest to discuss if the tion. This should be compared by record- Consultant in Restorative Dentistry, University Dental patient has any contacts with cats (see ing the mobility of the adjacent teeth. A Hospital of Manchester, Higher Cambridge Street, 16 Manchester, M15 6FH below). complete loss of physiological mobility *Correspondence to: James Darcey may also indicate an ankylosed tooth. Email: [email protected] For a more extensive review of possible After a basic periodontal examination Refereed Paper aetiological factors that may be elicited has been recorded, note should be made Accepted 26 February 2013 DOI: 10.1038/sj.bdj.2013.482 from the history the reader should refer to of any pocketing in relation to the teeth © British Dental Journal 2013; 214: 493-509 the frst of these papers.17 under investigation. Subgingival cavities BRITISH DENTAL JOURNAL VOLUME 214 NO. 10 MAY 25 2013 493 © 2013 Macmillan Publishers Limited. All rights reserved. PRACTICE may be noted on pocket charting. These should be probed and the nature of the cavities described. Radiographic examination If resorption is suspected one or more periapical radiographs should be taken. Panorals do not provide suffcient detail for the diagnosis of smaller lesions.18 Parallax radiographs should be considered as this technique will yield further infor- a mation about the site and type of lesion. Using the ‘same lingual, opposite buccal rule’ (SLOB) the shift of an external lesion can be detected. Internal lesions, however, should remain in a similar position relative to the root canal (Figs 2a-c).19 a The limitations of routine den- tal radiography are widely known.20–22 Superimposition of anatomical features, inadvertent distortion when flm holders are used and the two-dimensional nature of the image may result in a less than ideal image. Furthermore, it has been demon- strated that radiographs may not be suf- fciently sensitive to enable diagnosis of external resorptive lesions.18 The size of b the lesion, its location, local anatomy and b bone density have all been demonstrated to infuence the detection of lesions.23–25 Small resorptive cavities and those pre- sent on buccal and lingual surfaces are more likely to remain undiagnosed.23,25,26 Signifcant differences in inter and intra- rater detection of resorption have been demonstrated.27,28 Thus clinicians should be aware of these limitations, examine radiographs under appropriate conditions and refer for an opinion for further imag- ing if in doubt. Cone beam computed tomography (CBCT) A number of case reports have demon- c c strated that CBCT can enhance the diagno- Figs 2a-c The radiolucency in 44 is Figs 3a-c This patient was referred sis of resorptive lesions.29-31 These have been indicative of resorption. Following parallax for re-RCT of the 46. After initial further supported by clinical studies though radiography the lesion shifts in the opposite investigation there appeared to be direction as the flm indicating the lesion a diffuse connection between the most are in vitro.32–34 The one in vivo study is buccally situated and thus external. Note mesial aspect of the mesial root and 22 had a small sample size. The use of CBCT also the walls of the canal clearly visible the periodontia. CBCT reveals the full enables the precise determination of site, throughout the lesion. The poor prognosis is extent of the pathology. The tooth was type and extent of the lesion. There has confrmed when CBCT was used to quantify considered to be unrestorable and was the extent of the lesion extracted been an increase in the number of publica- tions related to the use of CBCT for diag- nosis of both internal and external lesions the indications are that CBCT is of value in be kept to a minimum, referral for CBCT although many are case reports.30,35-37 Most the diagnosis, and ultimately the manage- should only be made if it will be of sig- clinical studies are related to artifcially ment of resorption (Figs 3a-c and 4a-c).22 nifcant assistance in diagnosis or manage- generated root lesions.34,38,39 Nonetheless As exposure to ionizing radiation must ment. Figure 5 presents a simple algorithm 494 BRITISH DENTAL JOURNAL VOLUME 214 NO. 10 MAY 25 2013 © 2013 Macmillan Publishers Limited. All rights reserved. PRACTICE Radiolucency/alteration of root form: suspected resporption cavity? Parallax radiograph No Lesion shifts with tube? Alteration of Yes canal anatomy? a Cervical 1/3? Mid or coronal 2/3? Ragged margins with bony infltration and no radiolucency? Yes No b External External Internal External cervical replacement infammatory resorption resorption resorption resorption Uncertain about diagnosis, site and/or extent? Consider CBCT Fig. 5 A fow diagram to aid radiographic diagnosis of resorption c publication/172.pdf. This comprehensive bears certain characteristics and it is only Figs 4a-c This lesion presented as an report reviews the current evidence per- following accurate diagnosis that the cor- incidental fnding. A preliminary diagnosis was made of external cervical resorption. taining to the use of CBCT in dental and rect form of treatment can be instigated. The depth of radiolucency of the mid/ maxillofacial imaging and provides evi- In the following section different forms coronal third indicates an extensive lesion. dence-based guidelines for clinicians using of resorption are considered. CBCT reveals the true extent of the lesion or seeking to use CBCT as a diagnostic and treatment planning aid. External surface resorption that may be used to help classify lesions At this point the clinician may have Surface resorption is usually sub-clinical. radiographically and indicates when CBCT come to a reasonably accurate diagnosis, Radiographically it may be seen as cavita- may be of value. although not necessarily the extent of the tion in the cementum and dentine, or an For further information upon the use lesion or the possible management options. alteration of the root contour.40 There is of CBCT in dentistry readers are directed In order that resorption can be accurately no corresponding infammatory response towards the European guidelines on diagnosed and classifed careful examina- in the periodontal ligament and there is dental CBCT at http://ec.europa.eu/ tion and use of any appropriate special no destruction of adjacent alveolar bone.41 energy/nuclear/radiation_protection/doc/ tests are essential.