Category 7: Class II skeletal malocclusion with transverse maxillary constriction in an adult patient

Introduction: Teeth eruption is important for the development of alveolar process which increases vertical height of the face and third molar is the last tooth to erupt in the oral cavity after birth. The aim of this study was to determine relationship between skeletal malocclusion and dental anomalies in Nepalese population. Materials & Method: A sample of 170 patients with agenesis of at least one third molar was divided into four groups according to the third-molar agenesis pattern. Panoramic radiographs, lateral cephalograph and cast models were used to determine the skeletal malocclusion and associated dental anomalies. The Pearson chi-square test was used for stastical analysis. Result: Among 170 patients more than half of the patients were female with the average age being 18.15 ± 3.64 years. Majority of the patients had Class I skeletal malocclusion followed by Class II and III but on group wise comparison of patients with different skeletal patterns Class I skeletal malocclusion had highest prevalence of dental anomalies followed by Class III and Class II malocclusion. Conclusion: Prevalence of third-molar agenesis was more in skeletal class I malocclusion followed by class II and III but skeletal Class I malocclusions had more dental anomalies followed by class III and class II malocclusion.

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IRF6, MSX1, TGFA, dental anomalies, and skeletal malocclusion

European Journal of Orthodontics ◽

10.1093/ejo/cjaa064 ◽

2020 ◽

Author(s):

Clarissa C A Fernandez ◽

Christiane V C A Pereira ◽

Fernanda F C F Ferreira ◽

José V B Maciel ◽

Adriana Modesto ◽

...

Keyword(s):

Transforming Growth Factor ◽

Class Ii ◽

Growth Patterns ◽

Tooth Agenesis ◽

Dental Anomalies ◽

Chi Square ◽

Significance Level ◽

Transforming Growth Factor Α ◽

Skeletal Malocclusion ◽

Factor Α

Summary Objective Verify the presence of association between four variables—transforming growth factor α (TGFA; C/T rs1523305), interferon regulatory factor 6 (IRF6; A/C rs2013162), muscle segment homeobox 1 (MSX1; A/G rs12532), and dental anomalies—with skeletal malocclusion by comparing these four variables with Angle Classes I, II, and III, and normal, hyperdivergent, and hypodivergent growth patterns. Methods A total of 505 orthodontic records of patients older than 8 years were evaluated. The sample consisted of 285 (56.4 per cent) females, 220 (43.6 per cent) males, 304 (60.2 per cent) Whites (the rest were mixed Blacks with Whites), with a mean age of 20.28 (±10.35) years (ranging from 8 to 25 years). Eight cephalometric points, which served as the anatomical framework for obtaining angles and cephalometric measurements, were used for skeletal characterization using the Dolphin Software. Samples of saliva were collected and the DNA was extracted, diluted and quantified. Markers in TGFA, IRF6, and MSX1 were used and genotypes were obtained using TaqMan chemistry. Odds ratio (OR) and 95 per cent confidence interval (CI) calculations, chi-square, Fisher’s Exact, Mann–Whitney, and correlation coefficient tests (significance level: 95 per cent) were performed. Bonferroni correction was applied and an alpha of 0.0006 was considered statistically significant. Results There was no statistically significant associations between markers in TGFA or IRF6 with skeletal malocclusions. Tooth agenesis was associated with facial convexity (P < 0.001). MSX1 was associated with Class II skeletal malocclusion (P = 0.0001, OR = 0.6, CI = 0.46–0.78). Conclusion Individuals with tooth agenesis were more likely to have a convex face. MSX1 was associated with Class II skeletal malocclusion.

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