|Year : 2017 | Volume
| Issue : 3 | Page : 180-185
The prevalence, radiographic appearance and gender predilection of bifid mandibular condyles in Punjabi population of North India: A retrospective study
Bhawandeep Kaur, Sarfaraz Padda
Department of Oral Medicine and Radiology, Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab, India
|Date of Submission||10-Aug-2016|
|Date of Acceptance||07-Nov-2017|
|Date of Web Publication||20-Nov-2017|
Department of Oral Medicine and Radiology, Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Aim: The aim of this study was to determine the prevalence and gender predilection of bifid mandibular condyle (BMC) in Indian population using extra oral radiographs. Material and Methods: Previous record of 800 patients was evaluated by the observers who had undergone extra oral radiography for any diagnostic or treatment purposes between years 2012 and 2014. Results: Out of 800 extra oral radiographs, bifid condyles were found in 28, giving an overall prevalence of 3.5%. Out of 28 bifid condyles, 20 were in females (2.5%) and eight were in males (1.7%). The prevalence of BMC was found to be more in females as compared to the males and this difference was statistically significant with P value equivalent to 0.001. Among 28 bifid condyles, 19 were unilateral (2.4%) and nine were bilateral 1.5%. Chi-square test shows non-significant P value. Conclusion: It is possible that BMC is a more frequent condition than is commonly perceived. However, because of the minimal symptoms associated with this condition, the authors believe that it will remain an incidental finding upon routine radiographic examination, rather than a clinical observation.
Keywords: Bifid mandibular condyle, double-headed condyle, extra oral radiography
|How to cite this article:|
Kaur B, Padda S. The prevalence, radiographic appearance and gender predilection of bifid mandibular condyles in Punjabi population of North India: A retrospective study. J Indian Acad Oral Med Radiol 2017;29:180-5
|How to cite this URL:|
Kaur B, Padda S. The prevalence, radiographic appearance and gender predilection of bifid mandibular condyles in Punjabi population of North India: A retrospective study. J Indian Acad Oral Med Radiol [serial online] 2017 [cited 2020 Jul 8];29:180-5. Available from: http://www.jiaomr.in/text.asp?2017/29/3/180/218725
| Introduction|| |
Bifid mandibular condyle (BMC) is a rare condition characterized by a division of the mandibular condylar head. Two articulating surfaces of the bifid condyle are divided by a groove that can be oriented mediolaterally or anteroposteriorly.,,, The condylar split can range from a shallow groove to two distinct condyles with a separate neck. It was first reported by Hrdlieka (1941), who detected 21 cases (18 cases were unilateral and three were bilateral) of this anomaly while analyzing male and female dried human skulls. After this, only a few clinical cases have been reported. BMC is usually detected in routine panoramic radiographs. The etiology of bifid mandibular condyle remains uncertain. Developmental anomalies, trauma, nutritional disorders, infection, irradiation, genetic factors, teratogenic embryopathy, and surgical condylectomy may all be causal factors. Poswillo (1972) suggested that a bifid condylar head may develop after remodeling of a condylar head fracture. In patients with incomplete remodeling, a defective resorption of the smaller fragment may lead to bifidism. As the condyle becomes ankylosed, the cartilage cannot become an effective growth center leading to hypoplasia of the same and may alter the facial appearance of the person. BMC usually affects only one condyle, but bilateral cases have also been reported. Recent digital imaging techniques as compared to the conventional techniques bring information that leads to more accurate and specific diagnosis of mandibular condyle conditions. While reviewing literature regarding BMC using the PubMed Database (National Library of Medicine), the authors found that it listed only 65 cases in living individuals. Although, the number of reports continues to accumulate, BMC remains a relatively uncommon condition. However, because of the lack of epidemiological data, there is insufficient information about the actual frequency of this malformation. It may be the case that the condition occurs more frequently than is presently supposed. Due to lack of clinical symptoms, BMC is usually discovered as an incidental finding during routine radiographic examination. The prevalence of BMC obtained in the previous studies done by Miloglu et al. and Sahman et al. was 0.3% to 0.5%.,
Aims and objectives
The aim of this study was to determine the frequency of BMC using previous record of the extra oral radiographs.
- To assess the gender predilection for the prevalence of BMC
- To evaluate the variation among the sides for the occurrence of BMC.
| Materials and Methods|| |
A retrospective study approved by the ethical committee was performed using the various extra oral radiographs of 800 patients who had been radiographed in the Department of Oral Medicine and Radiology during the period of March 2012 to March 2014. These images were taken as part of routine examination, diagnosis, and treatment planning of patients. Radiographs which were of poor quality and undiagnostic were excluded. The radiographs of good contrast and density were included and the radiographs of poor quality having poor contrast, density, and scratch marks were excluded from the study group.
The digital panoramic radiographs were taken using an Orthopantomograph Vatech PAX 400 Digital panoramic X-ray unit [Vatech Co. ld. Korea] with focal spot size 0.5 × 0.5 mm, total filtration 2.5 mm aluminium, anode voltage 54–84 kV ± 5%. The temporomandibular joint (TMJ) views (transcranial and transorbital) were taken with Runyes Dental X-ray machine (Unicorn Pvt. Ltd.) having parameters of 70 KVp, 4 amp, and total filtration of 2.1 mm of aluminium. The BMC was considered from the presence of a shallow groove up to two distinct condyle heads. The radiographic images were evaluated jointly by two oral radiologists. The radiologists were the professors of oral medicine and radiology having more than 10 years of experience in their field and they examined the radiographs collectively.
| Results|| |
Out of 800 radiographs of age group 18–70 years, bifid condyles were found in 28, giving an overall prevalence of 3.5% [Table 1]. Out of 28 bifid condyles, 20 were in females (2.5%) and eight were in males (1.7%) [Table 2]. Pearson Chi-square was used to calculate the sexual predilection. This difference was statistically significant with higher prevalence in females as compared to males with a significant P value equivalent to 0.001 [Table 3]. Among 28 bifid condyles, 19 were unilateral (2.4%) [Figure 1] and [Figure 2] and nine were bilateral 1.5% [Figure 3] and [Figure 4] and bilateral cases were considered as single case.
Among 2.4% unilateral bifid condyles, 1.1% was found on the left side and 1.3% on the right side (1.3%). Of the left side BMC, 1.8% was present in females and only 0.6% was present in males [Table 4]. Chi-square test was used to detect the sexual predilection of the unilateral BMC on left side, which was found to be nonsignificant (P = 0.115) [Table 5]. Out of 1.3% on the right side, 2.4% was present in females and only 0.4% was present in males [Table 6]. Chi-square test was used to compare the prevalence of BMC on the right side among males and females, which showed a nonsignificant P value equals to 0.012 [Table 7]. Observers detected only 1.5% bilateral BMC and out of it, 1.8% were in females and only 0.6% in males [Table 8]. Chi-square test was used to detect the sexual predilection of the bilateral BMC, which showed nonsignificant results (P = 0.115) [Table 9].
|Table 4: Prevalence of bifid condyles on unilateral left side among genders|
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|Table 5: Chi-square test for prevalence of bifid condyles on unilateral left side among genders|
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|Table 6: Prevalence of bifid condyles on unilateral right side among genders|
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|Table 7: Chi-square test for prevalence of bifid condyles on unilateral right side among genders|
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|Table 9: Chi-square test for prevalence of bilateral bifid condyles among genders|
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| Discussion|| |
BMC is an uncommon anomaly. The term “bifid” is derived from the Latin word meaning “cleft into two parts”. Due to lack of clinical symptoms, it is usually discovered as an incidental finding during routine radiographic examination., Bifid condyle is an asymptomatic condition and in most cases does not bring any complications. Epidemiological surveys are very important for gaining knowledge about any disease or pathology in a population. First ever study to detect BMC was done by Hrdlicka on dry human skull (1941). While Schier (1948), reported the first case in a living subject, Szentpetery found seven BMCs on 1882 prehistoric and historic skulls with 2077 condyles.
In their review of literature of reported cases in living patients, Daniels and Ali found 45 patients with bifid condyles. They have mentioned a total 45 living cases of bifid condyle with 11 cases bilateral in their review of literature. Although, the number of reports continues to accumulate, the BMC remains a relatively uncommon entity and only a few cases have been reported since the first case in a living person was reported by Schier in 1948. From the available literature authors have come to the conclusion that due to increased use of radiography with the span of time, there is increase in prevalence of BMC cases.
According to Menzes et al. (2008), MEDLINE search was conducted to review literature for case reports of bifid condyles in living humans, and only 50 cases were found., In addition to the total number of bifid condyles, this report brings to the fore nine cases identified in a survey of 50,080 panoramic radiographs taken between years 1999 and 2006 giving the overall prevalence rate of 0.018%, which indicates the rarity of this condition. Miloglu et al. (2010) in Turkish population found BMC in 32 cases out of 10,200 radiographs, giving an overall prevalence of 0.3% in Turkish population. Sahman et al. (2011) also conducted epidemiological study in Turkish population and were able to find BMC in 0.52% of cases. Contrary to above quoted studies, our survey has detected BMC in 3.5% of patients examined between years 2012 and 2014. Based on the obtained results, it may be assumed that BMC is more prevalent in the region. However, further epidemiological studies are required to confirm the supposed fact.
The occurrence of BMC also does not appear to show gender differences according to most of the studies. In literature, current reports reveal an average female-male ratio of 1.1:1. Antoniades et al. (2012) found male-female ratio of 1.5:1. Miloglu et al. and Sahman et al. reported a very similar ratio between the genders (1.13:1 and 1.1:1) respectively,, whereas Menezes et al. (2008) found a significantly higher female-male ratio of 3.5:1 which is in correlation with our results. In our study, out of 28 BMC, 2.5% were in females and 1.7% in males. This sexual difference was statistically significant with higher prevalence in females as compared to males with a significant P value equivalent to 0.001.
In our study, we found 2.4% unilateral and 1.5% bilateral cases of BMC, giving a nonsignificant P value. Out of the unilateral cases, 1.3% were on the right side and 1.1% was on the left side, again giving a nonsignificant P value. Literature also suggests that no statistically significant differences were found between the right and left BMC.,,
The basic etiopathogenesis of BMC is unknown. However, some studies in literature suggest that trauma can be factor for BMC.,, Thomason and Yusuf reported two cases of traumatic condyle fracture with subsequent unilateral BMC. Antoniades et al. also presented a case of unilateral BMC which resulted following a sagittal condylar fracture. On the other hand, minor trauma to the growth center or deficient remodeling of the mandibular condyle may subsequently result in a variation such as BMC.,
TMJ ankylosis is also considered by some authors as a cause of BMC. In a retrospective study, Rehman et al. (2009) reported 10 cases of BMC in 37 patients with TMJ ankylosis. Of those 10 cases, nine were post-traumatic and one was post-infection. In addition, Gulati et al. reported two cases of BMC with joint ankylosis. One of them was developmental and the other occurred secondary to trauma. Although, trauma has been considered as the most common possible etiology, comparative studies have shown that most patients had no history of previous trauma or TMJ complaints.
It is impossible to obtain definite information about the orientation and shape of BMC with conventional radiographs, which depicts two dimensional images of the three dimensional structures. Therefore, further studies with advanced imaging techniques, especially with cone-beam computed tomography (CBCT), may be very informative in this field. Our study suggests that the frequency of BMC is likely to be higher in the Punjabi population of North Indian region than previously considered studies. It is possible that BMC is a more frequent condition than is commonly perceived. However, because of the minimal symptoms associated with this condition, the authors believe that it will remain an incidental finding upon routine radiographic examination, rather than a clinical observation. More varied types of duplicated condylar heads may be observed in further studies using three-dimensional techniques. Epidemiological studies with advanced imaging techniques may provide more information in this field.
| Conclusion|| |
With the advancement in radiological diagnostic tools, the prevalence of BMC is increasing. For further studies, more studies with larger population should be conducted with more recent diagnostic aids like CBCT. This particular anatomical variation may mimic a fracture or tumor. Knowledge and awareness about this entity is important for a general dental practitioner and a further study with a long-term follow-up is the demand of the time.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9]