Assessment of 2D:4D in subjects with anteroposterior mandibular dysplasia.

Objectives: To compare 2D:4D ratio which is determined by testosterone levels with patients having orthognathic, retrognathic and prognathic mandibles.

Materials And Methods: The study was performed at Chennai, on 320 subjects of which, 60 subjects (32 males and 28 females) had retrognathic mandible; 55 subjects (25 males and 30 females) had prognathic mandible and 205 subjects (98 males and 107 females) had normal mandible. All the subjects had a normal maxilla and were in the age group of 18 to 25 years. 2D:4D ratio was determined using the photocopies of the ventral surface of right hand made with vernier calipers of 0.01 mm accuracy. Statistical analysis was undertaken using Student's t- test, ANOVA test and TukeyHSD test.

Results: (i) Low 2D:4D is seen in subjects with mandibular prognathism, (ii) Among females, low 2D:4D is seen only in prognathic mandible.

Conclusion: These findings highlight the fact that testosterone plays an important role in mandibular growth. Thus 2D:4D, a least invasive and reproducible procedure can be used as an early marker for mandibular progathism, and as a diagnostic tool in correlating the mandibular growth with causal relations between hormones and craniofacial development.