|Year : 2012 | Volume
| Issue : 1 | Page : 24-27
Frequency of impacted and missing third molars among orthodontic patients in the population of Punjab
Sumit Bansal1, Kanav Gupta2, Sandeep Garg3, Shrish Charan Srivastava4
1 Department of Orthodontics & Dentofacial Orthopedics, Dasmesh Institute of Research & Dental Sciences, Faridkot, Punjab, India
2 Private practitioner, Jagraon, India
3 Department of Oral and Maxillofacial Surgery, Gian Sagar Dental College & Hospital, Rajpura, India
4 Department of Orthodontics and Dentofacial Orthopedics, Rama Dental College, Kanpur, India
|Date of Web Publication||27-Sep-2012|
Department of Orthodontics & Dentofacial Orthopedics, Dasmesh Institute of Research & Dental Sciences, Faridkot, Punjab
Source of Support: None, Conflict of Interest: None
Background : The pattern of third molar impactions and agenesis varies in different population groups. The frequency of mandibular third molar impaction and agenesis is quite frequent in the population of Punjab.
Materials and Methods : Pretreatment records of 400 patients, who underwent orthodontic treatment in the Punjab population (aged 13 to 25 years; mean age = 17.5 years) were entered into the study for checking the frequency of missing third molars and out of those, 200 patients with presence of third molars and more than 2/3 rd root formation (aged 18 to 25 yrs; mean age = 22.5 yrs) were evaluated for frequency of impacted third molars. The prevalence of third molar impactions and agenesis was calculated in terms of gender and jaw involvement.
Results : Among the 400 subjects studied, 167 third molars were missing in 104 patients (26%). Among the 200 subjects with more than 2/3 rd root formation who were studied for impacted third molars, 64 subjects (32 %) were diagnosed with 112 third molar impactions. It was found that the frequency of impacted third molars was more in mandible than in the maxilla.
Conclusion : These results suggest that impaction and agenesis of the third molar is a relatively common finding these days. Frequency of impacted third molar teeth is more than the missing third molars.
Keywords: Impaction, mineralization, third-molar agenesis
|How to cite this article:|
Bansal S, Gupta K, Garg S, Srivastava SC. Frequency of impacted and missing third molars among orthodontic patients in the population of Punjab. Indian J Oral Sci 2012;3:24-7
|How to cite this URL:|
Bansal S, Gupta K, Garg S, Srivastava SC. Frequency of impacted and missing third molars among orthodontic patients in the population of Punjab. Indian J Oral Sci [serial online] 2012 [cited 2017 Sep 25];3:24-7. Available from: http://www.indjos.com/text.asp?2012/3/1/24/101672
| Introduction|| |
Third molars are most likely to be impacted than any other teeth in the oral cavity. , The third molars can vary considerably in size, contour and relative position to the other teeth. All mandibular and maxillary third molars show more variation in development than any of the other teeth in the mouth. Most of the mandibular third molars are undersized. Mandibular third molars are the most likely to be impacted, wholly or partially in the jaw. The lack of space accommodation has been proposed as the chief cause.  During the correction of the malocclusion, it is the duty of the orthodontist to correct all the possible tooth malalignments and as most of the orthodontic patients are in the growing age group, early knowledge of the third molar eruption status will help in better treatment of the patient. Castella et al, found that the impaction of third molars in the mandible was a predictable event both in extraction and non-extraction patients.  Agenesis of the third molar is also a common occurrence, but its frequency varies in different studies. ,, The frequency of the third molar agenesis in decreasing order of occurrence is two, followed by one, three and all four third molars  and in another study, it is referred to as one missing third molar followed by two, three and all the four third molars. 
| Materials and Methods|| |
This study was undertaken with the pretreatment records of 400 orthodontic patients in the population of Punjab. The patients between 13 to 25 yrs of age and those who had not received previous orthodontic treatment were included in the study. These subjects were evaluated for the frequency of missing third molars. A third molar was classified as developmentally missing when there was no evidence that it had been extracted and when there was no sign of mineralization of the third molar tooth crown on the panoramic radiographs. Radiographs taken at the initial examination were used to determine the presence of third molar germs. The third molar agenesis was calculated with respect to gender predilection and jaw involvement. In a total sample size of 400 patients, 200 patients (aged 18 to 25 yrs; mean age, 22.5 yrs) with presence of 3 rd molars, whose root formation was more than 2/3 rd complete were checked for frequency of impacted third molars. A 3 rd molar tooth was classified as impacted when it has not erupted into oral cavity even after 2/3 rd root completion. The prevalence of third molar impactions and agenesis was again calculated in terms of gender and jaw involvement. Subjects with congenital deformities, such as a cleft palate and patients with any kind of oral pathologies were excluded from the study. In addition, the subjects with a missing tooth other than a third molar were not included in the study. None of the subjects had undergone surgical removal or extraction of third molar in the past.
| Results|| |
In a sample of 400 subjects, present study showed that 167 third molars were missing in 104 patients (26%). The study revealed that the frequency of missing maxillary third molars (60%) is almost 1.5 times more than the mandibular ones (40%). 46 females had 76 and 16 males had 24 missing maxillary third molars respectively. 30 females had 49 and 12 males had 18 missing mandibular third molars respectively [Table 1] and [Figure 1].
Among the 200 subjects with presence of 3 rd molars and more than 2/3 rd root completion, 64 subjects (30%) in total were diagnosed with 112 third molar impactions. Out of these 34 were males and 30 were females. Two males and two female patients had two maxillary impacted third molars each. Frequency of impacted third molars was more in mandible than in the maxilla. More than 90% of the impacted teeth in this study were mandibular third molars. 32 male patients and 28 female patients having impacted teeth despite 2/3 rd root completion had a total of 57 and 51 impacted mandibular third molars respectively. [Table 2] and [Figure 2].
| Discussion|| |
Third molars are most likely to be impacted than any other teeth in the oral cavity. , In this study, mandibular third molars were more often impacted as compared to the maxillary third molars. These results are in conjunction with studies conducted in past which showed impaction rate of mandibular third molars is more than that of maxillary third molars. , Lack of adequate retromolar space may be considered as the main factor in the third molar impactions. ,, Other factors can be the vertical height of the anterior border of the ramus, length of the posterior basal corpus, mesio-distal diameters of the first, second and the third molars, number of third molar roots, inclination of the first molar, vertical height of the posterior border of the ramus, vertical height of alveolar crest, and height and the width of the retro-molar space, which all tend to decrease in direct proportion to the possibility of impaction of the third molar.  Third molar impactions were found to be more common in the female patients as compared to the male patients in previous study as well as present study. 
Among the various factors which demand attention with retained impacted third molars is the fact that the patients are more susceptible to angle fracture of the mandible. , Besides, patients with impacted mandibular third molars may present with pain, caries, gingivitis and oral infections.  These are the reasons, why prophylactic extraction of fully impacted third molar teeth is considered as an ideal approach by many dental surgeons these days. ,
Present study revealed that 167 third molars were missing (26 %) which is more than that reported by Lynham (22.7%),  Sandhu et al. (11.5%)  and Hattab et al (9.1%)  It has been suggested that the frequency of missing third molars was more in females than males , which is again in confirmation with our study. Current study also showed that the third molar agenesis was more common in the maxilla as compared to mandible. It has been found in the previous studies that when a third molar is absent, agenesis of the remaining teeth is 13 times more likely. 
Almost half of the patients had either missing or impacted third molar teeth, thus showing the increased tendency of variability in development of the third molar.
| Conclusion|| |
Third molar impaction and agenesis are relatively common these days owing to the diet pattern and genetic predisposition. ,, We have found in our study that impactions were more common in the mandible than in the maxilla that can be attributed to lack of adequate retromolar space. ,, Third molar impactions were more common in the male patients as compared to the female patients.
Present study also supported previous studies suggesting that third molar agenesis was more common in the maxillary third molars , and that it is more common in the female patients. 
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[Figure 1], [Figure 2]
[Table 1], [Table 2]