External Root Resorption associated with Impacted Third Molars: A Case Report

The indications for impacted third molar extraction include the prevention of dental reabsorption on the adjacent tooth. Resorption can be classifi ed as physiological (when deciduous teeth are exfoliated) or pathological (when caused by injury or irritation to the periodontal ligament). Many causes can trigger external root resorption (ERR), the most common cause of which is orthodontic forces. The most common cases of ERR involve impacted third molars which, due to the lack of space for their eruption, generate a greater chance of ERR on the distal portion of the second molar. This pathology is becoming progressively more frequent in clinical dental care. Periapical and panoramic radiographs are used to aid in diagnosis, as is cone beam computed tomography. In cone beam computed tomography scans, radiolucent areas with irregular gaps are detected; these gaps represent a signifi cant loss of dental material. The objectives of this article were to report a case of second molar resorption triggered by an impacted third molar and to perform a review of the literature on the causes of external root resorption. Ideally, this information will aid dental clinicians (and orthodontists in particular) in understanding the features of this pathology so that they may recommend preventive third molar extraction when necessary. Case Report External Root Resorption associated with Impacted Third Molars: A Case Report Gabriela Mayrink, Paula Ramos Ballista, Laisa Kinderlly, Stella Araujo and Renato Marano* Ciências da Cirurgia, Faculdade de Ciências Médicas da Universidade Estadual de Campinas, FCM-UNICAMP, Brazil *Address for Correspondence: Renato Marano, Ph.D. in Ciências da Cirurgia, Faculdade de Ciências Médicas da Universidade Estadual de Campinas, FCM-UNICAMP, Brazil, Tel: 30977712/995747712; Email: [email protected]; [email protected] Submitted: 06 April 2017 Approved: 25 April 2017 Published: 26 April 2017 Copyright: 2017 Renato Marano, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. How to cite this article: Mayrink G, Ballista PR, Kinderlly L, Araujo S, Marano R. External Root Resorption associated with Impacted Third Molars: A Case Report. J Oral Health Craniofac Sci. 2017; 2: 043-048. INTRODUCTION Lower third molars are frequently impacted due to the lack of space between the distal portion of the second molar and the anterior border of the ascending ramus of the mandible. Impacted teeth may be asymptomatic or may be associated with pathologies such as caries, pericoronitis, odontogenic tumors and cysts, and root resorptions of the adjacent tooth [1,2]. External root resorption (ERR) of the second molar is a pathological process which occurs on the surface of the root and which is induced by local in lammation or mechanical stress [2]. According to Consolaro [3], pathological tooth resorptions may occur through one of two mechanisms: in lammation or replacement. In lammation occurs when the mineralized surface of the root is exposed and the cementoblasts are removed from the surface. Thus, the closely located bone cells enable root resorption, albeit temporarily. Resorption resulting from replacement occurs after trauma to the teeth in which dentoalveolar ankylosis is induced. In this case, bone remodeling also involves the mineralized dental tissues, which are gradually and inevitably reabsorbed and replaced by bone [3]. The primary identi ication of ERR relies on radiographic exams; however, periapical or panoramic radiographs are not the most adequate method for determining External Root Resorption associated with Impacted Third Molars: A Case Report Published: April 26, 2017 44/48 abnormalities in the scan. Cone beam computed tomography provides a more precise view of the dental structures, resulting in a more exact diagnosis [1]. The objectives of this article are to report a case of external root resorption of the second molar associated with the presence of an impacted third molar and to provide a review of the literature on the subject. CLINICAL CASE A male patient referred to as YM, 16 years of age, had been diagnosed with four impacted third molars at a routine orthodontic exam. At that time, he was instructed by the orthodontist to seek the preventive extraction of the teeth, as they were in an unfavorable position and there was no space in the patient’s arch for proper eruption. The pacient signed de informed consent form. It was not until 20 years of age, when he began an airline pilot training program, that the patient sought medical care from an oral and maxillofacial surgeon. A panoramic radiograph was obtained. Though the impaction was asymptomatic, tooth 38 was horizontal and exhibited mesial bone loss. A radiolucent image was observed on the distal portion of tooth 37 (Figure 1). Cone beam computed tomography revealed external root resorption of tooth 37 (Figure 2). The patient was evaluated by endodontic specialists who indicated extraction of the second molar due to the impossibility of endodontic treatment (the limited amount of root remaining), as this would generate perforation of the root canal. Mere observation of the tooth was not a viable option: because the patient was studying to be a pilot, the possibility of barodontalgia would be high and frequent. For this reason, teeth 37 and 38 were extracted in a single session under local anesthesia with the aid of a high-speed dental hand piece and refrigeration with 0.9% saline solution. The resorption of tooth 37 was clinically evident after extraction (Figure 3a,b ). The surgery was performed with no intraoperative complications. Three months after the excision, an osseo integrated dental implant was installed in the region of tooth 37. The patient is currently rehabilitated and has reported no complications or complaints. DISCUSSION Impacted teeth are those which cannot reach their normal functional position. This Figure 1: Panoramic radiograph. A radiolucent image was observed on the distal portion of tooth 37. External Root Resorption associated with Impacted Third Molars: A Case Report Published: April 26, 2017 45/48 pathology frequently occurs in the case of the third molar. The etiology of impaction has been theorized to be the gradual evolutionary reduction in the size of the jaw due to the loss of stimulation of bone growth resulting from the modern human diet, which requires relatively little effort in mastication [2]. Third molar extraction may be indicated as a preventive measure due to the Figure 2a: Cone beam computed tomography revealed external root resorption of tooth 37. Figure 2b: Cone beam computed tomography revealed external root resorption of tooth 37. Figure 2c: Cone beam computed tomography revealed external root resorption of tooth 37. External Root Resorption associated with Impacted Third Molars: A Case Report Published: April 26, 2017 46/48 possibility of serious consequences of acute pericoronitis and other pathological conditions such as caries, odontogenic cysts, and root resorption [4-6]. It is believed that the early removal of third molars is necessary to avoid crowding of the lower incisors; however, this indication is uncertain [7]. In a study analyzing radiographs, Nemcovsky et al. (1996) evaluated the incidence of second molar root resorptions caused by third molars. The authors concluded that a higher percentage of ERR cases were associated with third molars with mesial inclination greater than 60 degrees, and the number of cases increased as patient age increased [8]. In 2015, Oenning et al. [9] performed a retrospective study to analyze CT scans from patients with horizontal or mesioangular third molars that were in contact with the second molar. They analyzed the frequency of ERR in the adjacent tooth. The authors concluded that both mesioangular and horizontal molars resulted substantial potential for second molar resorption, particularly in cases of Pell and Gregory Class A and Class B third molars in patients 25 years of age and older. The authors suggested that, under these conditions, preventive extraction of the third molar should be indicated due to the high risk of second molar ERR. In this case report, the patient was 20 years of age, and resorption of the second molar had already begun. Early extraction of the third molar may have prevented the loss of the second. This resorption associated with impacted third molars occurs through the in lammatory root resorption of the second molar due to an obstruction of the blood vessels of the adjacent tooth. After the cause is eliminated, cellular stress in the area and the in lammatory process end. Osteoblasts and osteoclasts migrate to the root surface, and the pH returns to its normal levels. These changes enable the recolonization of new cementoblasts. In cases of bacteria in the pulp cavity, endodontic treatment is adequate for resolving in lammatory process. Another method of treatment is to spread Figure 3a,b: The resorption of tooth 37 was clinically evident after extraction. External Root Resorption associated with Impacted Third Molars: A Case Report Published: April 26, 201747/48the orthodontic force established in the region, which eliminates the in lammatoryprocess [3]. The patient in question was an aspiring pilot. In this case, extraction of only thethird molar would remove the mechanical stress on the second molar. However,mere observation was not a viable option in this case due to the moderate to severedegree of resorption. Endodontic treatment was impeded by the lack of viable spacefor endodontic instruments. Furthermore, the risk of barodontalgia is high in patientswho frequently experience changes in air pressure, such as pilots.Barodontalgia is de ined as dental pain associated with changes in pressure. Itaffects 11.9% of divers and 11% of pilots, the latter of which experience barodontalgiaat an average rate of 5 episodes with every 1,000 hours of light. The most prevalentpathologies associated with pain during light are dental restorations, caries withoutpulp involvement, pulp necrosis or periapical in lammation, vital pulp pathology,recent dental treatment, and barosinusitis. The intensity of pain in cases of has beenfound to vary from moderate (25%) to intense (75%) [10].Though uncommon, this condition must be taken seriously, as it can put divers, pilots,and airline passengers’ lives at risk. The World Dental Federation (FDI) recommendsannual dental screenings for these professionals, as well as regular hygiene instructionfrom dentists familiar with each patient. In addition, patients should not dive or ly inunpressurized cabins for 24 hours after dental treatments involving anesthesia and for7 days after surgical dental treatments [10,11].Higher education programs in the ield of aeronautical sciences often requireperiodic dental consults of their students, as well as adequate oral hygiene and adentist’s report on their oral health. In light of these factors and in an attempt to avoidbarodontalgia, the conduct chosen herein (at the patient’s consent) was the extractionof the impacted tooth and the adjacent tooth with external root resorption.CONCLUSIONExternal root resorption of the second molar may be avoided with preventiveextraction of impacted third molars, particularly those in mesioangular or horizontalpositions. Treatment varies according to the degree of resorption and the speci icconditions of each patient.REFERENCES1. Lee YJ, Lee TY. External root resorption during orthodontic treatment in rootfi lled teeth andcontralateral teeth with vital pulp: A clinical study of contributing factors. Am J Orthod DentofacialOrthop. 2016; 149 84-91. Ref.: https://goo.gl/qb8uAd 2. Santosh P. Impacted Mandibular Third Molars: Review of Literature and a Proposal of a CombinedClinical and Radiological Classifi cation. Ann Med Health Sci Res. 2015; 4: 229-234. Ref.:https://goo.gl/FTcJ8O 3. Consolaro A. O conceito de reabsorções dentárias ou As reabsorções dentárias não sãomultifatoriais, nem complexas, controvertidas ou polêmicas! Dental Press J Orthod. 2011; 16: 19-24. Ref.: https://goo.gl/IVhWH9 4. Lysell L, Rohlin M. A study of indications used for removal of the mandibular third molar. Int J OralMaxillofac Surg. 1988; 17: 161-164. Ref.: https://goo.gl/jocsXr 5. Yamalık K, Bozkaya S. The predictivity of mandibular third molar position as a risk indicator forpericoronitis. Clin Oral Investig. 2008; 12: 9-14. Ref.: https://goo.gl/l7AtbH 6. Camargo IB, Sobrinho JB, Andrade ESSA, Van Sickels JE. Correlational Study of Impacted and Non-Functional Lower Third Molar Position with Occurrence of Pathologies. Prog Orthod. 2016; 17: 1-9.Ref.: https://goo.gl/xqNwup 7. Bishara SE, Andreasen G. Third molars: A review. Am J Orthod. 1983; 83: 131-137. Ref.:https://goo.gl/mB0f7S External Root Resorption associated with Impacted Third Molars: A Case Report Published: April 26, 201748/488. Nemcovsky CE, Libfeld H, Zubery Y. Effect of non-erupted third molars on distal roots and supportingstructures of approximal teeth. A radiographic survey of 202 cases. J Clin Periodontol. 1996; 23:810-815. Ref.: https://goo.gl/YAF37c 9. Oenning AC, Melo SL, Groppo FC, Haiter-Neto F. Mesial inclination of impacted third molars andits propensity to stimulate external root resorption in second molars-a cone-beam computedtomographic evaluation. J Oral Maxillofac Surg. 2015; 73: 379-386. Ref.: https://goo.gl/xWzVbg 10. Zadik Y. Barodontalgia: what have we learned in the past decade? Oral Surg Oral Med Oral PatholOral Radiol Endod. 2010; 109: 65-69. Ref.: https://goo.gl/FivRxf 11. Robichaud, R., McNally, M.E. Barodontalgia as a Differential Diagnosis: Symptoms and Findings. JCan Dent Assoc. 2005; 71: 39-42. Ref.: https://goo.gl/1lTgk0