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. 2014 Jun 26;9(6):e101157.
doi: 10.1371/journal.pone.0101157. eCollection 2014.

Multivariate analysis of factors affecting presence and/or agenesis of third molar tooth

Mohammad Khursheed Alam  1 , Muhammad Asyraf Hamza  1 , Muhammad Aizuddin Khafiz  1 , Shaifulizan Abdul Rahman  2 , Ramizu Shaari  2 , Akram Hassan  3
Affiliations

Multivariate analysis of factors affecting presence and/or agenesis of third molar tooth

Mohammad Khursheed Alam et al. PLoS One. .

Abstract

To investigate the presence and/or agenesis of third molar (M3) tooth germs in orthodontics patients in Malaysian Malay and Chinese population and evaluate the relationship between presence and/or agenesis of M3 with different skeletal malocclusion patterns and sagittal maxillomandibular jaw dimensions. Pretreatment records of 300 orthodontic patients (140 males and 160 females, 219 Malaysian Malay and 81 Chinese, average age was 16.27±4.59) were used. Third-molar agenesis was calculated with respect to race, genders, number of missing teeth, jaws, skeletal malocclusion patterns and sagittal maxillomandibular jaw dimensions. The Pearson chi-square test and ANOVA was performed to determine potential differences. Associations between various factors and M3 presence/agenesis groups were assessed using logistic regression analysis. The percentages of subjects with 1 or more M3 agenesis were 30%, 33% and 31% in the Malaysian Malay, Chinese and total population, respectively. Overall prevalence of M3 agenesis in male and female was equal (P>0.05). The frequency of the agenesis of M3s is greater in maxilla as well in the right side (P>0.05). The prevalence of M3 agenesis in those with a Class III and Class II malocclusion was relatively higher in Malaysian Malay and Malaysian Chinese population respectively. Using stepwise regression analyses, significant associations were found between Mx (P<0.05) and ANB (P<0.05) and M3 agenesis. This multivariate analysis suggested that Mx and ANB were significantly correlated with the M3 presence/agenesis.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Angular cephalometric measurements relating to sagittal and vertical malocclusion and linear cephalometric measurements relating to sagittal jaw dimensions (descriptions are in Table 1).
Figure 2
Figure 2. Distribution of Subjects with M3 Presence/Agenesis in Malysian Malay and Chinese.
Figure 3
Figure 3. Distribution of Subjects with M3 Presence/Agenesis in male and female.
Figure 4
Figure 4. Distribution of Subjects in Total (Malaysian Malay and Chinese) population With M3 Agenesis, Jaw and side involvement.
Figure 5
Figure 5. Distribution of Subjects with M3 Presence/Agenesis in Sagittal Skeletal Malocclusions.
Figure 6
Figure 6. Distribution of Subjects with M3 Presence/Agenesis in Vertical Skeletal Malocclusions.
Figure 7
Figure 7. Global Distributions of prevalence of M3 Agenesis.
See this image and copyright information in PMC

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