|Year : 2016 | Volume
| Issue : 2 | Page : 176-178
Pressure-induced mesial root resorption of mandibular second molar consequential to an impacted third molar
Priya Mittal, Ajay Logani
Department of Conservative Dentistry and Endodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India
|Date of Web Publication||9-Dec-2016|
Department of Conservative Dentistry and Endodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi
Source of Support: None, Conflict of Interest: None
Resorption is a physiologic or pathologic process which results in mineralized tissue loss. Permanent teeth are resistant to physiologic resorption. Root resorption in such teeth is usually pathological. The aetiology is multi-factorial and encompasses pressure generated from an impacted tooth. Mandibular third molars are the most commonly impacted teeth. Owing to its proximity, distal root resorption of mandibular second molar may occur due to mechanical forces generated during the eruptive phase of impacted tooth. This article documents a case of pressure induced mesial root resorption of mandibular second molar consequential to an impacted third molar. To conclude with, it is prudent to consider all remotely related possibilities for any pathological process. This aids in establishing a correct diagnosis and prevent unnecessary iatrogenic complications
Keywords: Impacted third molar; mesial root resorption; pressure-induced resorption.
|How to cite this article:|
Mittal P, Logani A. Pressure-induced mesial root resorption of mandibular second molar consequential to an impacted third molar. Endodontology 2016;28:176-8
| Introduction|| |
Resorption is a physiologic or pathologic process which results in loss of dentin, cementum, or bone. Deciduous tooth root resorption is a physiologic process that occurs due to the pressure of erupting successor tooth. Permanent teeth are resistant to physiologic resorption due to the existence of hypercalcified intermediate cementum and anti-invasion factor present in the periodontal tissues. Root resorption in such teeth is pathological. It occurs after an injury to the precementum or predentin. Andreasen (1944) broadly classified it as internal or external. The latter originates in the periodontal ligament and is associated with the loss of cementum and/or dentin. It can occur either in a vital or nonvital tooth, is usually asymptomatic and identified during radiographic or clinical examination. The etiology is multifactorial and encompasses pressure generated from an impacted tooth. Failure of tooth eruption at its appropriate site in the dental arch within the normal period of growth is recognized as impaction. Mandibular third molar is the most affected tooth. Insufficient development of the retromolar space is a cause for their inability to erupt. Owing to its proximity, distal root resorption of the second molar may occur due to mechanical forces generated during the eruptive phase of impacted third molar. This article documents a case of pressure-induced mesial root resorption of mandibular second molar consequential to an impacted third molar.
| Case Report|| |
A 26-year-old male reported with a chief complaint of pain in the left lower jaw region. Clinical examination revealed a grossly carious left mandibular first molar that was sensitive to percussion and palpation. Mobility was within physiologic limits. Pulp sensibility tests were negative. Periapical radiograph of tooth #36 revealed a radiolucency in relation to the mesial root (periapical index  score 3) [Figure 1]. A diagnosis of symptomatic apical periodontitis was established. Single sitting endodontic therapy was accomplished [Figure 2]. On the same intraoral periapical radiograph (IOPA), substantial blunting of the mesial root of tooth #37 and an impacted tooth #38 were evident [Figure 1]. Clinically, tooth #37 was healthy. Pulp sensibility tests were positive. On scanning the occlusal surface with DIAGNOdent (Kavo, Biberach, Germany), a reading of 22 was noted. This indicated enamel caries and was restored with glass ionomer cement (Photac-Fill; 3M ESPE, St Paul, MN) [Figure 2]. The patient was informed regarding the incidental radiological finding. Consent was taken to further investigate. An orthopantomograph [Figure 3] revealed a fully mature horizontally impacted third molar impinging on tooth #37. Since no other contributing factor for the unusual radiographic picture of tooth #37 could be ascertained, a provisional diagnosis of pressure-induced mesial root resorption due to impacted molar was established. The impacted tooth was atraumatically surgically removed under local anesthesia (LOX 2%, Neon Lab Limited, Mumbai, India). The patient was followed up clinically and radiographically (6 and 12 months) [Figure 4]a and [Figure 4]b. At 18-month follow-up, IOPA revealed arrest and subsequent repair of the mesial root resorption [Figure 4]c, thus confirming the diagnosis.
|Figure 1: Periapical radiograph revealed a radiolucency in relation to the mesial root (periapical index score 3) of tooth #36. Substantial blunting of the mesial root of tooth #37 and an impacted tooth #38 evident|
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|Figure 2: Nonsurgical endodontic therapy performed in tooth #36. Caries confined to enamel restored with glass ionomer cement in tooth #37. Note: Bulbous crown of impacted #38 in proximity to distal root|
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|Figure 3: Orthopantomograph revealed a fully mature horizontally impacted third molar|
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|Figure 4: (a and b) 6 and 12 months postimpaction, arrest of resorption in mesial root of tooth 37 evident. (c) At 18-month follow-up, subsequent repair of the mesial root resorption|
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| Discussion|| |
Resorption involves interaction between inflammatory, resorbing cells, and hard tissue structures. Injury to dentin or cementum leads to chemical changes within these tissues; the result is the formation of multinucleated giant cells (clasts). These in addition to macrophages and monocytes participate in resorption. Collectively, these cells organize a complex interaction of molecular biologic events which controls the progression of resorption. Unique structural arrangement of the odontoclasts to hard tissues allows the cell to establish a microenvironment between the ruffled border and the tooth in which resorption takes place. The resorptive process is described as being bimodal, involving the degradation of the inorganic crystal structure of hydroxyapatite and the organic structure of collagen, principally type I. The activated odontoclasts produce an acidic pH (3.0–4.5) in their microenvironment. This acidic environment is principally accomplished through the action of a highly active polarized proton pump enclosed within the ruffled border. Degradation of the organic matrix is accomplished by collagenases, matrix metalloproteinase, and cysteine proteinase family.
Root resorption of the second molars is very common due to impacted molar. Nemcovsky et al. in a radiographic survey of 202 cases documented the effect of nonerupted third molars on distal roots and supporting structures of proximal teeth and concluded that the nonerupted tooth's apical position and mesial inclination of 60° or more relative to distal root of second molar were factors significantly associated with root resorption. However, mesial root of the second mandibular molar are usually not resorbed due to impacted third molar. In the present case, tooth was clinically asymptomatic. Carious lesion was limited to enamel and no periodontal pocket was evident. Medical history was noncontributory. No orthodontic treatment was done. No trauma from occlusion was evident. Indirect pressure from impacted tooth was considered to be the cause for resorption. As tooth was horizontally impacted, center of resistance [Figure 5] might have resulted in tipping of crown in distal direction [Figure 5]a and mesial root in mesial direction [Figure 5]b. This could have resulted in excessive stresses on mesial root resulting in damage to pericementum layer which is the primary factor for resorption. Provisional diagnosis was based on this hypothesis and this was proved as the resorption got arrested on surgical removal of the impacted molar. The take home message is that it is prudent to consider all remotely related possibilities for any pathological process. This aids in establishing a correct diagnosis and prevent unnecessary iatrogenic complications.
|Figure 5: Force exerted by horizontally impacted #38 may have resulted in tipping of crown in distal direction (A) and mesial root in mesial direction (B) creating excessive stresses on the later (pressure-induced resorption)|
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| References|| |
Ne RF, Witherspoon DE, Gutmann JL. Tooth resorption. Quintessence Int 1999;30:9-25.
Tronstad L. Root resorption – Etiology, terminology and clinical manifestations. Endod Dent Traumatol 1988;4:241-52.
Andreasen, JO, Hjbrting-Hansen E. Replantation of teeth. II- Histological study of 22 replanted anterior teeth in humans. Acta Odontologica Scandinavica 1966;24:287-306.
Fuss Z, Tsesis I, Lin S. Root resorption – Diagnosis, classification and treatment choices based on stimulation factors. Dent Traumatol 2003;19:175-82.
Archer WH. Oral Surgery: A Step-by-step Atlas of Operative Techniques. 4th
ed. Philadelphia: W.B. Saunders Company; 1966. p. 507-10.
Bishara SE, Andreasen G. Third molars: A review. Am J Orthod 1983;83:131-7.
Nemcovsky CE, Libfeld H, Zubery Y. Effect of non-erupted 3rd
molars on distal roots and supporting structures of approximal teeth. A radiographic survey of 202 cases. J Clin Periodontol 1996;23:810-5.
Orstavik D, Kerekes K, Eriksen HM. The periapical index: A scoring system for radiographic assessment of apical periodontitis. Endod Dent Traumatol 1986;2:20-34.
Fernandes M, de Ataide I, Wagle R. Tooth resorption part I – Pathogenesis and case series of internal resorption. J Conserv Dent 2013;16:4-8.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]