Impacted Mandibular Third Molar, Associated Pathoses, and Their Relation to Angulation and Impaction Depth: A Cone Beam CT Study
Statement of problem: prophylactic removal of the impacted lower third molar (ILTM) is controversial and accompanying pathologic conditions play an important role.
Objectives: The aim of the present study is to evaluate the prevalence of commonly found pathoses associated with ILTM in relation to angulation and impaction depth in cone beam computed tomography (CBCT).
Materials and Methods: We evaluated CBCT of 500 ILTMs from 235 females (57%) and 177 males (43%) for the presence of caries on the second and third molars, external root resorption (ERR) of the second molar, and follicular spaces (FS) >5 mmin diameter in relation to angulation and impaction depth according to Pell and Gregory and Winter’s classifications, respectively.
Results: We observed that 55.6% of ILTM had at least one detectible lesion. ERR was the most frequent pathologic condition (31.2%), followed by caries on the second (26%) and third (13.4%) molars, and FS >5 mm (2.4%). ERR was the only pathology influenced by angulation. There was significantly more ERR in mesioangular ILTMs (40.5%, P<0.001). Most ERR occurred in direct contact with the third molar. Class C showed a lower risk for second and third molar caries (P<0.001), but higher risk for ERR (P=0.008) and FS >5 mm(P=0.035). There were more caries on the second molar (P=0.013) and FS >5 mm (P<0.001) in class III.
Conclusions: Prophylactic removal of ILTMs (especially in mesioangular or horizontal impactions) could be suggested considering the potential for pathologic changes in ILTMs and the propensity for these teeth to cause ERR in second molars.
Tamimi D, ElSaid K. Cone beam computed tomography in the assessment of dental impactions. Seminars in Orthodontics 2009; 15:57-62.
Chu FC, Li TK, Lui VK, et al. Prevalence of impacted teeth and associated pathologies-a radiographic study of the Hong Kong Chinese population. Hong Kong Med J. 2003; 9:158-163.
Polat HB, Özan F, Kara Is, et al. Prevalence of commonly found pathoses associated with mandibular impacted third molars based on panoramic radiographs in Turkish population. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008; 105:41-47.
Richards D. Management of unerupted and impacted third molar teeth. A National Clinical Guideline. Evidence-Based Dentistry. 2000; 2:44-46.
Dodson TB. Surveillance as a management strategy for retained third molars: Is it desirable? J Oral Maxillofac Surg. 2012;70:20-24.
Mettes TG, Nienhuijs ME, van der Sanden WJ, et al. Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults. Cochrane Database Syst Rev. 2005; 18:CD003879
Al-Khateeb TH, Bataineh AB. Pathology associated with impacted mandibular third molars in a group of Jordanians. J Oral Maxillofac Surg. 2006; 64:1598-1602.
Oenning AC, Neves FS, Alencar PN, et al. External root resorption of the second molar associated with third molar impaction: comparison of panoramic radiography and cone beam computed tomography. J Oral Maxillofac Surg. 2014; 72:1444-1455.
Haney E, Gansky SA, Lee JS, et al. Comparative analysis of traditional radiographs and cone-beam computed tomography volumetric images in the diagnosis and treatment planning of maxillary impacted canines. Am J Orthod Dentofacial Orthop. 2010;137:590-597.
Pauwels R, Beinsberger J, Collaert B, et al. Effective dose range for dental cone beam computed tomography scanners. Eur J Radiol. 2012; 81:267-271.
Miracle AC, Mukherji SK. Conebeam CT of the head and neck, part 1: physical principles. AJNR Am J Neuroradiol. 2009; 30:1088-1095.
Oenning AC, Melo SL, Groppo FC, et al. Mesial Inclination of Impacted Third Molars and Its Propensity to Stimulate External Root Resorption in Second Molars—A Cone-Beam Computed Tomographic Evaluation. J Oral Maxillofac Surg. 2015;73:379-386.
Akarslan ZZ, Kocabay C. Assessment of the associated symptoms, pathologies, positions and angulations of bilateral occurring mandibular third molars: Is there any similarity? Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;108:26-32.
Zamiri B, Shahidi SH, Shoeleh S. Assessment of Anatomical Relationship between Impacted Lower Third Molar Tooth and Mandibular Canal in Panoramic View of Men and Women between Ages 20-70 Years Old. J Dent (Shiraz). 2003;4:29-38.
Pell GJ, Gregory B. Impacted mandibular third molars: classification and modified techniques for removal. Dent Digest 1933; 39:330-338.
Winter GB. Principles of exodontia as applied to the impacted mandibular third molar: a complete treatise on the operative technic with clinical diagnoses and radiographic interpretations. American medical book company; 1926.
Wang D, He X, Wang Y, et al. External root resorption of the second molar associated with mesially and horizontally impacted mandibular third molar: evidence from cone beam computed tomography. Clin Oral Investig. 2017;21:1335-1342.
The Management of Impacted Third Molar Teeth [Internet]. Illinois: American Association of Oral and Maxillofacial Surgeons. c 2017. Available from: https://www.aaoms.org/docs/practice_resources/clinical_resources/impacted_third_molars.pdf
Charuakkra A, Prapayasatok S, Janhom A, et al. Diagnostic performance of cone-beam computed tomography on detection of mechanically-created artificial secondary caries. Imaging Sci Dent. 2011;41 :143-150.
Kayipmaz S, Sezgin ÖS, Saricaoğlu ST, et al. An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries. Eur J Radiol. 2011; 80:478-482.
Shahidi S, Zamiri B, Bronoosh P. Comparison of panoramic radiography with cone beam CT in predicting the relationship of the mandibular third molar roots to the alveolar canal. Imaging Sci Dent. 2013; 43:105-109.
Alqerban A, Jacobs R, Souza PC, et al. In-vitro comparison of 2 cone-beam computed tomography systems and panoramic imaging for detecting simulated canine impaction-induced external root resorption in maxillary lateral incisors. Am J Orthod Dentofacial Orthop. 2009;136:764. e1-11.
Alqerban A, Jacobs R, Fieuws S, et al. Comparison of two cone beam computed tomographic systems versus panoramic imaging for localization of impacted maxillary canines and detection of root resorption. Eur J Orthod. 2011; 33:93-102.
Kang F, Huang C, Sah MK, et al. Effect of Eruption Status of the Mandibular Third Molar on Distal Caries in the Adjacent Second Molar. J Oral Maxillofac Surg. 2016; 74:684-692.
Tyndall DA, Rathore S. Cone-beam CT diagnostic applications: caries, periodontal bone assessment, and endodontic applications. Dent Clin North Am. 2008; 52 :825-841.
Chang SW, Shin SY, Kum KY, et al. Correlation study between distal caries in the mandibular second molar and the eruption status of the mandibular third molar in the Korean population. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009; 108:838-843.
Ozeç I, Hergüner Siso S, Taşdemir U, et al. Prevalence and factors affecting the formation of second molar distal caries in a Turkish population. Int J Oral Maxillofac Surg. 2009; 38:1279-1282.
Allen RT, Witherow H, Collyer J, et al. The mesioangular third molar–to extract or not to extract? Analysis of 776 consecutive third molars. Br Dent J . 2009; 206:E23.
Güven O, KeskIn A, Akal ÜK. The incidence of cysts and tumors around impacted third molars. Int J Oral Maxillofac Surg. 2000; 29:131-135.
Patil S, Halgatti V, Khandelwal S, et al. Prevalence of cysts and tumors around the retained and unerupted third molars in the Indian population. J Oral Biol Craniofac Res. 2014; 4:82-87.
Lysell L, Rohlin M. A study of indications used for removal of the mandibular third molar. Int J Oral Maxillofac Surg. 1988; 17:161-164.
White SC, Pharoah MJ. Oral radiology: principles and interpretation(7nd edn): Elsevier Health Sciences 2014:696.
Ericson S, Bjerklin K, Falahat B. Does the canine dental follicle cause resorption of permanent incisor roots? A computed tomographic study of erupting maxillary canines. Angle orthod. 2002; 72:95-104.
- There are currently no refbacks.
This work is licensed under a Creative Commons Attribution 3.0 License.
pISSN :2383-3971 eISSN :2383-398X