Incidence of dental caries and pericoronitis associated with impacted mandibular third molar – A radiographic study

 

Ms. Rohini S¹, Dr. V. Jayanth Kumar²

¹Undergraduate Student, Saveetha Dental College, Chennai.

²Senior Lecturer, Department of Oral Medicine and Radiology, Saveetha Dental College, Chennai.

 

ABSTRACT:

Background: Impacted teeth are those which fail to erupt in dental arch within the expected time for a variety of reasons. Any tooth in the dental arch may become impacted but the most common are mandibular third molars followed by the mandibular premolars. Mandibular third molars erupt at 17 to 21 years age. The mandibular third molars when impacted may acquire a range of patterns and positions and can lead to diverse pathologies. One such pathology is pericoronitis and dental caries. Pericoronitis is an acute or chronic inflammatory condition presenting with pain, swelling, limited jaw opening and difficulty in swallowing.

Objective: To assess the incidence of dental caries and pericoronitis associated with impacted mandibular third molars using radiographs and look for associations between the angulation of impaction pericoronitis and dental caries.

Materials and methods:

The study was conducted from the archived images exposed between September 2015 – April 2016. The images were from patients who have taken radiographs for impaction.The images were assessed in Planmeca Romexis viewer, Ver 5.0, Planmeca Oy, Finland in the native format. The image data was stored in Microsoft excel 2016, Redmond, WA, USA.

Results:

The study analyzed 273 radiographs from which 236 were picked up for analysis. 37 radiographs were excluded for poor diagnostic quality. For better analysis, the included subjects were classified into three groups of I (16-20 years), II (21-40 years) and III (41-60 years). The group II (21-40 years) showed higher incidence of pericoronitis and dental caries.

Conclusion:

The study done by us on retrospective radiographs reveals that there is a higher incidence of pericoronitis across the age groups.

 

 

 

INTRODUCTION:

Impacted teeth are those which fail to erupt in dental arch within the expected time for a variety of reasons.^(1,2) Any tooth in the dental arch may become impacted but the most common are the mandibular third molars followed by the mandibular premolars. Lack of space, limited skeletal growth, distal eruption of the dentition, vertical direction of condylar growth, increased crown size of impacted teeth, and the late maturation of third molar are listed among the major causes of third-molar impaction.⁽³⁾ Mandibular third molars erupt at 17 to 21 yrs of age. The mandibular 3 rd molar when impacted may acquire a range of patterns and position and can lead to diverse pathologies.^(4,5) Dental caries, root resorption, cystic processes, periodontitis, periapical infection, benign or malignant tumors of odontogenic origin, and inflammatory processes (pericoronitis) are among the various pathologic conditions that are frequently associated with unerupted or partially erupted third molars^{. (6-9)}

 

Pericoronitis is an acute or chronic inflammatory condition presenting with pain, swelling, limited Jaw opening and difficulty in swallowing. On the basis of the severity of these features pericoronitis is classified into acute, sub-acute and chronic types. If it is not treated, then it may progress to cellulites, osteomyelitis or facial space infections.^(10,11) Position of third molars in jaw and their occlusal anatomy with deep occlusal fissures favours the accumulation of bio film on tooth and leads to dental caries. Impacted mandibular 3rd molars that contact cemento-enamel junction of second molar place this tooth at risk of distal cervical caries.⁽¹²⁾ In such situations, prophylactic removal of impacted tooth can benefit dental health of patients. Impacted mandibular 3rd molar is primarily focused because it is the most common tooth involved in impaction and its association with pericoronitis and dental caries helps in proper diagnosis and treatment planning.

 

MATERIALS AND METHODS:

The study was conducted from the archived images exposed between September 2015 – April 2016. The images are from patients who have taken radiographs for impaction. The images were captured with orthophos XG 3D machine at 65 Kvp and 6 mAs.

 

The images were assessed Planmeca Romexis viewer, Ver 5.0, Planmeca Oy, Finlandin the native format. The image analysis data was stored in Microsoft excel 2016, Redmond, WA, USA.

 

RESULTS:

The study analyzed 273 radiographs from which 236 were picked up for analysis. 37 radiographs were excluded for poor diagnostic quality. For better analysis, the included subjects were classified into three groups of I (16-20 years), II (21-40 years) and III (41-60 years).

 

Fig1: Graphical presentation of the incidence according to gender

 

The radiographs were analyzed if bilaterally mandibular molars were impacted they were recorded as separate observations. Thus in total 439 impacted teeth were taken up for observation from 236 radiographs.

 

On analysis of the results using Microsoft excel, it was found that 15 teeth out of the 66 impacted teeth (22.73%) in group I had dental caries. In group II 98 teeth out of the 334 impacted teeth (29.34%) had dental caries. In group III 10 out of 39 impacted teeth (25.64%) had dental caries. (Table 1)

 

Table: 1 Results according to groups

	DENTAL CARIES	PERICORONITIS
I (16-20 years)	15/66 (22.73%)	36/66 (54.55%)
II (21-40 years)	98/334 (29.34%)	180/334 (58.38%)
III (41-60 years)	10/39 (25.64%)	20/39 (51.28%)

 

On analysis of the results in group I there were 54.55% of impacted teeth (36/66) had pericoronitis. In group II the prevalence of pericoronitis was 53.89% (180/334) impacted teeth. In group III (20/39) 51.28%had pericoronitis.

 

The mean of prevalence of dental caries was 25.90% and the mean prevalence of periodontal disease was 53.24%.

 

DISCUSSION:

Impacted teeth are those which fail to erupt in dental arch within expected time. Dental practitioners are generally concerned with the development and eruption patterns of third molars and their impact on dental arch.^(1,2)Although third molars with a proper positioning normally emerge between the ages of 18 and 24 years, approximately 40% fail to erupt and thus become partially or completely impacted in the bone^{. (9)} Retained, unerupted third molar teeth have been associated with various pathological conditions. These include cystic lesions, neoplasms, pericorontitis, periodontitis, dental caries, root resorption, and periapical infections.^(13,14)

 

Lack of space, limited skeletal growth, distal eruption of the dentition, vertical direction of condylar growth, increased crown size of impacted teeth, and the late maturation of third molars are listed among the major causes of third molar impaction.⁽³⁾Pericoronitis is the most common problem associated with impacted third molar followed by dental caries of third molar itself or adjacent second molar.^(15,16) Pericoronitis is an acute inflammatory condition associated mostly with partially erupted mandibular third molars. Clinical features include pain, swelling, limited jaw opening, and difficulty in swallowing, fever, malaise and lymphadenopathy. If untreated pericoronitis may progress to cellulites, osteomyelitis, or facial space infections.^(10,11)

 

In literature there are many studies conducted on impaction of third molars and associated problems. Obiechina and others showed that 42.9% of impacted teeth were associated with pericoronitis and 13.9% with caries. Pericoronitis has widely been reported as the main reason for extraction of lower third molars.⁽¹⁷⁾Jamelih and Pedlar also found that pericoronitis was the most common indication for removal of impacted mandibular third molars. But in other study, pericoronitis was seen to be the second common and not the most common reason for extraction of third molars.⁽¹⁸⁾

 

In our study we had higher incidence of pericoronitis than dental caries across the age groups which was consistent with the studies reported in the literature.

 

Many studies have been conducted on prevalence of impaction of third molars in maxilla and mandible. Mead found an equal prevalence of impactions in both jaws,⁽¹⁹⁾ while Bjork et al noted preponderance in the maxilla.⁽²⁰⁾ Shah etal⁽²¹⁾ and Van der Linden ⁽²²⁾et al reported a higher prevalence in the mandible.

This study had only accounted for the lower molar impactions and there was no distinction made between the right and left sides of the mandible

 

The correlation between pericoronitis and angulation of the mandibular third molar has also been previously reported.^(23-25).The majorities of pericoronitis cases were demonstrated to be associated with the vertically oriented mandibular third molars (81%); of the 20.9% were at or below the height of the occlusal plane of the arch.⁽²⁶⁾Our study did not compare the angulation of impaction and the presence of pericoronitis or dental caries.

 

CONCLUSION:

The study done by us on retrospective radiographs reveals that there is a higher incidence of pericoronitis across the age groups. However the study had accounted for only mandibular impactions. The shortcoming of the study was that the sample size was limited and no distinction was made for the left and right sides.

 

REFERENCES:

1.        Nazir A, Asif S, Akram MA. Surgical removal of trans-alveolar mandibular 2nd premolar impactions by lingual approach. Pakistan Oral  and Dent J. 2013; 33: 35-37.

2.         Hupp JR, Ellis III E, Tucker MR. Contemporary Oral and Maxillofacial Surgery. Principles of management of impacted teeth. 6th Ed. Philadelphia: Elsevier Publishers; 2014: 143-67.

3.        HattabFN.Positional changes and eruption of impacted mandibular third molars in young adults. A Radiographic 4 year follow up study. Oral Surg Oral Med Oral Pathol Oral Radiol Endo1997; 84(6):604-608.

4.        Secic S, Prohic S, Komsic S, Vukovic A. Incidence of impacted mandibular third molars in population of Bosnia and Herzegovina: a retrospective radiographic study. J Health Sci. 2013; 3: 151-58.

5.        Alhaija ESJA, Bhairan HMA, Khateeb SNA. Mandibular third molar space in different antero-posterior skeletal patterns. Eur J Orthod. 2011; 33: 570-76.

6.        Ganss C, Hochban W, Kielbassa AM, Umstadt HE. Prognosis of third molar eruption. Oral Surg Oral Med Oral Pathol.1993; 76(6):688-693.

7.        Gungormus M. Pathologic status and changes in mandibular third molar position during orthodontic treatment. J Contemp Dent Pract.2002; 15 3(2):11-22.

8.        Mollaoglu N, Cetiner S, Gungor K. Patterns of third molar impaction in a group of volunteers in Turkey. Clin Oral Investig. 2002; 6(2):109-113.

9.        Niedzielska IA, Drugacz J, Kus N, kreska J. Panoramic radiographic predictors of mandibular third molar eruption. Oral Surg Oral Med Oral Pathol Oral Radiol Endo 2006; 102(2):154-158.

10.     Chu FCS, Li TKL, Lui VKB, Newsome PRH, Chow RLK, Cheung LK. Prevalence of impacted teeth and associated pathologies — a radiographic study of Hong Kong Chinese population. Hong Kong Med J. 2003; 9: 158-63.

11.     Folayan MO, Ozeigbe EO, Onyejaeka1 N, Chukwumah NM, Oyedele T. Non‑third molar related pericoronitis in a sub-urban Nigeria population of children. Nigerian J ClinPract. 2014; 17:18-22.

12.     Msagati F, Simon ENM, Owibingire S. Pattern of occurrence and treatment of impacted teeth at the Muhimbili National Hospital, Dar es Salaam, Tanzania. BMC Oral Health 2013:13:1-6.

13.     Laskin DM. Evaluation of the third molar problem. JAM Dent Assoc 1971, 82:824-27.

14.     Garcia Rl and Sinclair CJ and Chauncey HH. Inter- nal resorption of an unerupted third molar tooth. Spec Care Dent. 1986; 6:205-7.

15.     Syed KB, Kota Z, Ibrahim M, Bagi MA, Assiri MA. Prevalence of impacted molar teeth among Saudi population in Asir region, Saudi Arabia – A retrospective study of 3 years. J Int Oral Health 2013; 5:43-47.

16.     Razavi SM, Hasheminia D, Mehdizade M, Movahedian B, Keshani F. The relation of pericoronal third molar follicle dimension and bcl-2/ki-67 expression: An immunohistochemical study. Dent Res J 2012;9: 26-31.

17.     Krishnan B, El Sheikh MH, El-Gehani R, Orafi H. Indications for removal of impacted mandibular third molars: a singleinstitutional experience in Libya. J Maxillofac Oral Surg. 2009; 8:246-48.

18.     Ishfaq M, Wahid A, Rahim A, Munim A. Patterns and presentationsof impacted mandibular third molars subjected toremoval at Khyber College of Dentistry Peshawar. Pakistan Oral  and Dent J. 2006; 26:221-26.

19.     Mead SV. Incidence of impacted teeth. IntJOrthod. 1930; 16:885-88.

20.     Bjork A, Jensen E and Palling M. Mandibular growth and third molar impaction. ActaOdont Scand. 1956; 14:231-35.

21.     Shah RM, Boyd MA and Vakil JF. Studies of permanent tooth anomalies in 7886 Canadian individuals, I. Impacted teeth. J Can Dent Assoc. 1978; 44:262-65.

22.     Van der Linden W, Cleaton-Jones P and Lownie M. Diseases and lesions associated with third molars. Review of 1001 cases. Oral Surg Oral Med Oral Pathol 1995; 79:142-5.

23.     Halverson BA, Anderson. The mandibular third molar position as a predictive criteria for risk for pericoronitis a retrospective study. Mil Med 1992; 157(3) : 142-45.

24.     Kay LW. Investigations into the nature of pericoronitis. Br J Oral Surg. 1996; 3(3):188-205.

25.     Leone SA, Edenfield MJ, Cohen ME.Correlation of acute pericoronitis and the position of the mandibular third molar. Oral Surg Oral Med Oral Pathol 62(3): 245-50.

26.     Wallace JR.Pericoronitis and military dentistry. Oral Surg Oral Med Oral Pathol.1996; 22(4):545-47.

 

 

 

Accepted on 12.03.2017           © RJPT All right reserved