Imaging Sci Dent.  2013 Dec;43(4):219-225. 10.5624/isd.2013.43.4.219.

Prevalence of missing and impacted third molars in adults aged 25 years and above

• Jung YH
• Cho BH

• KMID: 2229603
• DOI: http://doi.org/10.5624/isd.2013.43.4.219

Abstract

PURPOSE
The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above.
MATERIALS AND METHODS
The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars.
RESULTS
A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars.
CONCLUSION
The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health.

Keyword

Radiography, Panoramic; Molar, Third; Tooth, Impacted; Dental Caries

MeSH Terms

Adult*
Alveolar Bone Loss
Dental Caries
Diagnosis, Oral
Female
Humans
Incidence
Male
Molar
Molar, Third*
Prevalence*
Radiography, Panoramic
Tooth, Impacted

Reference

1. McArdle LW, Renton T. The effects of NICE guidelines on the management of third molar teeth. Br Dent J. 2012; 213:E8.

2. Phillips C, Norman J, Jaskolka M, Blakey GH, Haug RH, Offenbacher S, et al. Changes over time in position and periodontal probing status of retained third molars. J Oral Maxillofac Surg. 2007; 65:2011–2017.

3. Technology appraisal guidance. No. 1. Guidance on the extraction of wisdom teeth [Internet]. London: National Institute for Clinical Excellence;2000. cited 2012 September 12. Available from: http://www.nice.org.uk/nicemedia/pdf/wisdomteethguidance.pdf.

4. Stathopoulos P, Mezitis M, Kappatos C, Titsinides S, Stylogianni E. Cysts and tumors associated with impacted third molars: is prophylactic removal justified? J Oral Maxillofac Surg. 2011; 69:405–408.

5. Susarla SM, Blaeser BF, Magalnick D. Third molar surgery and associated complications. Oral Maxillofac Surg Clin North Am. 2003; 15:177–186.

6. Centers for Disease Control and Prevention (CDC). Trends in aging - United States and worldwide. MMWR Morb Mortal Wkly Rep. 2003; 52:101–106.

7. Kaminishi RM, Lam PS, Kaminishi KS, Marshall MW, Hochwald DA. A 10-year comparative study of the incidence of third molar removal in the aging population. J Oral Maxillofac Surg. 2006; 64:173–174.

8. Renton T, Al-Haboubi M, Pau A, Shepherd J, Gallagher JE. What has been the United Kingdom's experience with retention of third molars? J Oral Maxillofac Surg. 2012; 70:S48–S57.

9. Ventä I. How often do asymptomatic, disease-free third molars need to be removed? J Oral Maxillofac Surg. 2012; 70:S41–S47.

10. Hashemipour MA, Tahmasbi-Arashlow M, Fahimi-Hanzaei F. Incidence of impacted mandibular and maxillary third molars: a radiographic study in a Southeast Iran population. Med Oral Patol Oral Cir Bucal. 2013; 18:e140–e145.

11. Almendros-Marqués N, Berini-Aytés L, Gay-Escoda C. Influence of lower third molar position on the incidence of preoperative complications. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006; 102:725–732.

12. Lima CJ, Silva LC, Melo MR, Santos JA, Santos TS. Evaluation of the agreement by examiners according to classifications of third molars. Med Oral Patol Oral Cir Bucal. 2012; 17:e281–e286.

13. Kinard BE, Dodson TB. Most patients with asymptomatic, disease-free third molars elect extraction over retention as their preferred treatment. J Oral Maxillofac Surg. 2010; 68:2935–2942.

14. Carvalho RW, do Egito Vasconcelos BC. Assessment of factors associated with surgical difficulty during removal of impacted lower third molars. J Oral Maxillofac Surg. 2011; 69:2714–2721.

15. Renton T, Smeeton N, McGurk M. Factors predictive of difficulty of mandibular third molar surgery. Br Dent J. 2001; 190:607–610.

16. American Association of Oral and Maxillofacial Surgeons. AAOMS white paper on third molar data [Internet]. Rosemont, IL: AAOMS;2007. cited 2012 September 12. Available from: http://www.aaoms.org/docs/third_molar_white_paper.pdf.

17. McArdle LW, Renton TF. Distal cervical caries in the mandibular second molar: an indication for the prophylactic removal of the third molar? Br J Oral Maxillofac Surg. 2006; 44:42–45.

18. Chang SW, Shin SY, Kum KY, Hong J. 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.

19. Chu FC, Li TK, Lui VK, Newsome PR, Chow RL, Cheung LK. Prevalence of impacted teeth and associated pathologies -a radiographic study of the Hong Kong Chinese population. Hong Kong Med J. 2003; 9:158–163.

20. Polat HB, Ozan F, Kara I, Ozdemir H, Ay S. 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:e41–e47.

21. Punwutikorn J, Waikakul A, Ochareon P. Symptoms of unerupted mandibular third molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999; 87:305–310.

22. Knutsson K, Brehmer B, Lysell L, Rohlin M. Asymptomatic mandibular third molars: oral surgeons' judgment of the need for extraction. J Oral Maxillofac Surg. 1992; 50:329–333.

23. 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.

24. Mercier P, Precious D. Risks and benefits of removal of impacted third molars. A critical review of the literature. Int J Oral Maxillofac Surg. 1992; 21:17–27.

25. Allen RT, Witherow H, Collyer J, Roper-Hall R, Nazir MA, Mathew G. The mesioangular third molar - to extract or not to extract? Analysis of 776 consecutive third molars. Br Dent J. 2009; 206:E23. discussion 586-7.

26. Falci SG, de Castro CR, Santos RC, de Souza Lima LD, Ramos-Jorge ML, Botelho AM, et al. Association between the presence of a partially erupted mandibular third molar and the existence of caries in the distal of the second molars. Int J Oral Maxillofac Surg. 2012; 41:1270–1274.

27. Eliasson S, Heimdahl A, Nordenram A. Pathological changes related to long-term impaction of third molars. A radiographic study. Int J Oral Maxillofac Surg. 1989; 18:210–212.

28. Chuang SK, Perrott DH, Susarla SM, Dodson TB. Age as a risk factor for third molar surgery complications. J Oral Maxillofac Surg. 2007; 65:1685–1692.

29. Phillips C, White RP Jr, Shugars DA, Zhou X. Risk factors associated with prolonged recovery and delayed healing after third molar surgery. J Oral Maxillofac Surg. 2003; 61:1436–1448.

30. Garcia RI, Chauncey HH. The eruption of third molars in adults: a 10-year longitudinal study. Oral Surg Oral Med Oral Pathol. 1989; 68:9–13.

31. Nance PE, White RP Jr, Offenbacher S, Phillips C, Blakey GH, Haug RH. Change in third molar angulation and position in young adults and follow-up periodontal pathology. J Oral Maxillofac Surg. 2006; 64:424–428.

32. Kahl B, Gerlach KL, Hilgers RD. A long-term, follow-up, radiographic evaluation of asymptomatic impacted third molars in orthodontically treated patients. Int J Oral Maxillofac Surg. 1994; 23:279–285.

33. Kandasamy S, Rinchuse DJ, Rinchuse DJ. The wisdom behind third molar extractions. Aust Dent J. 2009; 54:284–292.

34. Marciani RD. Is there pathology associated with asymptomatic third molars? J Oral Maxillofac Surg. 2012; 70:S15–S19.