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 Table of Contents  
ORIGINAL ARTICLE
Year : 2016  |  Volume : 15  |  Issue : 1  |  Page : 14-17

Pattern of impacted mandibular third molars in Calabar, Nigeria


Department of Dental Surgery, University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria

Date of Web Publication10-Jun-2016

Correspondence Address:
Otasowie D Osunde
Department of Dental Surgery, Maxillofacial Unit, University of Calabar Teaching Hospital, Calabar, Cross River State
Nigeria
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2384-5589.183886

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  Abstract 


Background: The study examines the pattern of impacted lower third molars in Calabar, Southern Nigeria. Patients and Methods: A retrospective analysis of the medical record of all patients, who were treated for symptomatic impacted lower third molar at the Dental and Maxillofacial Surgery Clinic of our institution over a 3-year period was undertaken. Information obtained included patients' demographics, location, type of impaction, presence of caries in the second molar, and indication for extraction. Results: A total of 2,156 patients were seen at the Dental and Maxillofacial Surgery Clinic over the 3-year period of study and of these patients, 118 impacted mandibular third molars were surgically extracted in 97 patients and thus giving a prevalence of 4.7%. The patients' ages ranged 18-48 years, the mean (SD) age was 27.5 (5.60) years. Impaction of the lower third molar occurred equally in both gender with an approximate ratio of 1:1. Mesioangular impaction was the most common type (N = 53; 44.9%), followed by horizontal impaction (N = 34; 28.8%). About half of the impacted teeth were located on the left side (N = 51; 43.2%). There was bilateral location in 21 (17.8%) cases. Recurrent pericoronitis (N= 65; 55.1%) and apical periodontitis (N= 41; 34.7%) were the most common indications for extraction. Conclusion: The prevalence of impacted mandibular third molar in Calabar is lower than previous reports from other urban cities in Nigeria. Mesioangular impaction was the most common impaction type, but unlike previous reports, horizontal impactions constitute a great proportion of third molar impactions seen in this environment.

Keywords: Impaction, mandibular, Nigeria, third molar


How to cite this article:
Osunde OD, Bassey GO. Pattern of impacted mandibular third molars in Calabar, Nigeria. Afr J Med Health Sci 2016;15:14-7

How to cite this URL:
Osunde OD, Bassey GO. Pattern of impacted mandibular third molars in Calabar, Nigeria. Afr J Med Health Sci [serial online] 2016 [cited 2020 Oct 23];15:14-7. Available from: http://www.ajmhs.org/text.asp?2016/15/1/14/183886




  Introduction Top


An impacted tooth is one that follows an abortive path of eruption and fails to reach a proper functional location in the mouth.[1] The object of impaction may be soft tissue, dental hard tissue, or bone.[2] The mandibular third molar is the most common impacted tooth followed by the maxillary canine and first permanent molars.[3] The frequency distribution of impacted mandibular third molar differs for different parts of the world. In the developed countries, varying incidence range of 9.5-25% has been reported.[4],[5] Odusanya [6] reported a prevalence rate of 9.2% among Nigerian adult population. In a review of 1,200 patients from each area of the urban and rural population of south-western Nigeria, Olasoji and Odusanya [7] reported a prevalence rate of 10.7% and 1.1%, respectively. Mwaniki and Guthua [8] reported an incidence rate of 15.8% among the Kenyans.

Symptomatic impacted third molars are often treated by surgical extraction. Globally, and especially in the UK, a great deal of human and material resources is spent on third molar surgery and its related sequelae. This procedure has been estimated to cost the National Health Service (NHS) in England up to £30 million per year, and approximately £20 million is spent annually in the private sector.[9],[10] Knowledge of epidemiology of impaction of mandibular third molars in a society is important as it helps in identifying its prevalence and in the provision of the necessary human and material resources. In Nigeria, a bulk of the work on impacted mandibular third molars has been from the south-western [11],[12],[13] and north-western parts [14],[15] with very little information from the south-south geopolitical zone.[16]

An epidemiological study of impacted lower third molars at the Dental and Maxillofacial Surgery Clinic of the University of Calabar Teaching Hospital may be representative of the occurrence of impacted wisdom tooth in Calabar. This institution serves as the only referral center for oral and maxillofacial surgical services in the whole of Cross River State of Nigeria. All cases of impacted third molar requiring surgical extraction are usually referred here from both private and other government hospitals within the locality. There is no previous published report on the prevalence, types, and pattern of impaction of the mandibular third molars from this center.

The aim of the present study is to determine the prevalence and pattern of impacted mandibular third molar in Calabar and to compare the results with that of previous studies from Nigeria and other parts of the world.


  Patients and Methods Top


A retrospective analysis of the medical record of all patients, who were treated for symptomatic impacted lower third molar at the Dental and Maxillofacial Surgery Clinic of the University of Calabar Teaching hospital, Calabar, from January 2012 to December 2014, was undertaken. The information obtained included the age, gender, location, type of impaction, presence of caries in the second molar, and indication for extraction. The type of impaction was categorized using the Winter's classification of impacted third molars.

The data were analyzed using the Statistical Packages for the Social Sciences (SPSS) version 13 (SPSS-Inc., Chicago, US). The results were presented as frequencies and percentages for categorical variables and as mean and standard deviation for the continuous variable. Statistical significance was set as P< 0.05.


  Results Top


A total of 2,156 patients were seen at the Dental and Maxillofacial Surgery Clinic over the 3-year period of study and of these, 118 impacted mandibular third molars were surgically extracted in 97 patients and thus giving a prevalence rate of 4.7%. The patients' ages ranged 18-48 years; the mean (SD) age was 27.5 (5.60) years. Impactions of the lower third molar occurred equally in both genders with an approximate ratio of 1:1. Mesioangular impaction was the most predominant impaction type (N = 53; 44.9%), followed by horizontal impaction (N = 34; 28.8%) [Table 1]. About half of the impacted teeth were located on the left side (N = 51; 43.2%). There was bilateral location in 21 (17.8%) cases. Second molar dental caries was present in 27 (22.9%) cases. The most common indication for surgical extraction was recurrent pericoronitis (N = 65; 55.1%). This was followed by apical periodontitis (N = 41; 34.7%) [Table 1].
Table 1: Demographic and clinical characteristics of 118 impacted lower third molars

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  Discussion Top


In the present study, a prevalence rate of 4.7% was obtained for impacted lower third molars, which is much lower than the result of Odusanya [6] who reported a prevalence rate of 9.2% and those of Olasoji and Odusanya [7] who observed a prevalence rate of 10.7% among urban population of south-western Nigeria. Whether the observed low prevalence of impacted third molars is a reflection of the dietary nature of major tribes that made up the population of Calabar is not known. The average diet of people from this part of the country is largely composed of vegetables, and sea foods in the form of fish, crabs, prawn, crayfish, periwinkle and other dairy products that are very rich in calcium, iron, and other essential nutrients necessary for bodily growth and development of the bones.[17] Apart from directly affecting bone development, the process of chewing these natural foods may result in increased activity of the muscles of mastication, and over the years, this may in turn act as a stimulus for the development of the jaw bones via functional adaptation.[18] Adequate development of the mandible with provision of enough space to accommodate the third molar, which is usually the last tooth to erupt, may reduce the prevalence of impaction commonly associated with the lower wisdom tooth.[18]

Apart from the possible dietary influence on the observed physique of the average Calabar residents, the role of genetic factors, or a combination of genetic and dietary factors, on the relatively low prevalence of impacted third molars cannot be ruled out. This is in keeping with the theory propounded by Seward et al.[19] who stated that a combination of environmental and genetic factors were responsible for impaction of the lower third molar. On the other hand, the observed prevalence rate of 4.7% of third molar impaction in this environment may have been underrepresented. First, some persons with third molar impaction may be asymptomatic and so there may not have been any reason to seek medical advice. Secondly, some persons with symptomatic impacted teeth may rather choose to present at other health institutions in the adjoining states that may be closer to them instead of the logistics of travelling long distances that may sometimes last up to 4-6 h to access our dental facility.

The result of this study showed that there was no gender difference in the distribution of impacted lower third molars among the population seen at the dental clinic of our institution. While the result agrees with that of Bamgbose et al.[13] from Lagos, Nigeria, it differs from those of other authors who consistently found female predominance.[12],[19],[20] In contrast, Stanley et al.[21] reported a male-to-female ratio of 2:1 in the 1,756 patients reviewed. Their observed gender ratio may probably be due to the fact that the study was partly conducted in a veteran hospital where males are likely to predominate. Generally, the higher incidence of third molar impaction in females may be because they tend to present earlier at the clinic probably due to their lower levels of tolerance and lower pain threshold, compared to their male counterparts.[22]

Majority of impacted mandibular third molars are diagnosed and extracted during the second and third decades of life.[8],[11],[12] The mean age of 27.5 years observed in the present study, supports the assertion. The consistently reported age of occurrence for impacted lower third molar may be a reflection of the fact that its eruption normally occur within the second and third decades of life, and tooth impaction may present at this time, if there is interference with the process. The other possible reason may be due to the fact that majority of the authors' work including the present one, was carried out either in a university community or in an urban setting where a good number of the population fall within this age group.

The high frequency of occurrence for mesioangular impactions, in the present study, lends credence to the results of previous studies that found it to be the predominant impaction type.[7],[8],[13],[23] In contrast to the observation by a majority of the studies reviewed where distoangular ranked behind mesioangular impactions, horizontal impactions were the second most common type of impacted lower third molar in the present study. The reason for the relatively high frequency of horizontal impaction among our study population is not known. Stanley et al.[21] and Benediktsdottir et al.[23] found vertical impactions as the most common impaction type in their studies.

Second molar caries (N = 27; 22.9%) was surprisingly high in this study. This contrasts with the report of previous studies that indicated that the incidence of dental caries of the second molars arising due to the presence of impacted third molar was low. Stanley et al.[21] reported that dental caries accounted for 0.72% in the series of impacted teeth analyzed. Daley,[24] on the other hand, gave slightly higher estimates of 1-4.5% for second caries resulting from the presence of impacted third molar. The relatively high incidence of caries in the second molar associated with the presence of impacted third molar, in the present study, may be accounted for by the large collections of mesioangular and horizontal impactions that are believed to be associated with more second molar caries than the other types of impaction.[25] Another reason for the observed seemingly high frequency of caries in the second molars may be the relatively small sample size in the present study when compared with the report of other authors.[7],[21],[24] Although the high percentage of second molar caries observed in this study appears to justify prophylactic extraction, the potential risk and morbidity associated with impacted third molar surgery may contraindicate this procedure when viewed from the background of the high cost-benefit ratio.[26]

Recurrent pericoronitis was observed as the most common indication for impacted mandibular third molar surgery that strengthens earlier observations in the literature.[11],[16] Mesioangular impactions, especially those with partial mucosa coverage, have been observed to present with recurrent episodes of pericoronitis.[27] The large numbers of mesioangular impactions combined with the high proportions of impacted teeth with partial mucosa coverage probably explained the observed episodes of recurrent pericoronitis in the present study.


  Conclusion Top


Impacted mandibular third molar in Calabar is not as common as in reports from other urban cities in Nigeria. Mesioangular impaction is the most common impaction type, but unlike previous reports, horizontal impactions constitute a great proportion of third molar impactions seen in this environment.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

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Alling CC 3rd, Catone GA. Management of impacted teeth. J Oral Maxillofac Surg 1993;51(Suppl 1):3-6.   Back to cited text no. 1
    
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Andreason JO. Epidemiology of third molar impactions. In: Andreasen JO, Petersen JK, Laskin DM, editors. Textbook and Colour Atlas of Tooth Impactions. Copenhagen: Munksgaard; 1997. p. 222-3.  Back to cited text no. 3
    
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Odusanya SA. Third molar impaction among older Nigerians. Odontostomatol Trop 1986;4:247-51.  Back to cited text no. 6
    
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Olasoji HO, Odusanya SA. Comparative study of third molar impaction in rural and urban areas of south-western Nigeria. Odonstomatol Trop 2000;23:25-8.  Back to cited text no. 7
    
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Mwaniki D, Guthua SW. Incidence of impacted mandibular third molars among dental patients in Nairobi, Kenya. Trop Dent J 1996;19:17-9.  Back to cited text no. 8
    
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Bamgbose BO, Akinwande JA, Adeyemo WL, Ladeinde AL, Arotiba GT, Ogunlewe MO. Effects of co-administered dexamethasone and diclofenac potassium on pain, swelling and trismus following third molar surgery. Head Face Med 2005;1:11.  Back to cited text no. 13
    
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Osunde OD, Saheeb BD, Adebola RA. Comparative study of the effect of single and multiple suture techniques on inflammatory complications following third molar surgery. J Oral Maxillofac Surg 2011;69:971-6.  Back to cited text no. 14
    
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Osunde OD, Adebola RA, Saheeb BD. A comparative study of the effect of suture-less and multiple suture techniques on inflammatory following third molar surgery. Int J Oral Maxillofac Surg 2012;41:1275-9.  Back to cited text no. 15
    
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Saheeb BD, Obuekwe ON. An audit of mandibular third molar surgery. Niger J Surg Res 2001;3:66-74.  Back to cited text no. 16
    
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Vatanparast H, Baxter-Jones A, Faulkner RA, Bailey DA, Whiting SJ. Positive effects of vegetable and fruit consumption and calcium intake on bone mineral accrual in boys during growth from childhood to adolescence: The University of Saskatchewan Pediatric Bone Mineral Accrual Study. Am J Clin Nutr 2005;82:700-6.  Back to cited text no. 17
    
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Odusanya SA, Abayomi IO. Third molar eruption among rural Nigerians. Oral Surg Oral Med Oral Pathol 1991;71:151-4.  Back to cited text no. 18
    
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Santamaria J, Arteagoitia I. Radiologic variables of important clinical significant in the extraction of impacted mandibular third molars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997;84:469-73.  Back to cited text no. 20
    
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Stanley HR, Alattar M, Collett WK, Stringfellow HR Jr, Spiegel EH. Pathological sequelae of “neglected” impacted third molars. J Oral Pathol 1988;17:113-7.  Back to cited text no. 21
    
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Colorado-Bonnin M, Valmaseda-Castellón E, Berini-Aytés L, Gay-Escoda C. Quality of life following lower third molar removal. Int J Oral Maxillofac Surg 2006;35:343-7.  Back to cited text no. 22
    
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Benediktsdóttir IE, Wenzel A, Petersen JK, Hintze H. Mandibular third molar removal: Risk indicators for extended operation time, postoperative pain, and complications. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;79:434-46.  Back to cited text no. 23
    
24.
Daley TD. Third molar prophylactic extraction: A review and analysis of the literature. Gen Dent 1996;44:310-22.  Back to cited text no. 24
    
25.
Sheikh MA, Riaz M, Shafiq S. Incidence of distal caries in mandibular second molars due to impacted third molars — A clinical and radiographic study. Pak Oral Dental J 2012;32:364-70.  Back to cited text no. 25
    
26.
Adeyemo WL. Do pathologies associated with impacted lower third molars justify prophylactic removal? A critical review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:448-52.  Back to cited text no. 26
    
27.
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 Path Oral Radiol Endod 2006;102:725-32.  Back to cited text no. 27
    



 
 
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