Insulin-like Growth Factor I as a Skeletal Maturity Indicator

Introduction: Accurate determination of skeletal maturity and remaining growth is crucial to many orthodontic, orthognathic and dental implant timing decision. Cervical vertebral stages and hand-wrist radiographs are currently used to identify peak mandibular bone growth. These are highly subjective techniques that not only involve radiographic exposure but also lack the ability to determine the intensity of growth spurt and the end of the growth. Insulin-like growth factor I (IGF-I) is a circulating growth hormone-dependent factor whose level correlates with sexual maturity and is used to diagnose growth hormone deficiency and excess. IGF-I level was correlated with cervical skeletal maturity and would be highest at cervical stages that correspond to the greatest amount of facial growth. Materials and methods: Blood sample of 90 patients between the age group of 10 and 25 years of both sexes and their lateral cephalogram were taken. Results: The results showed that the IGF-I levels were low at prepubertal levels, (CS 1, CS 2, CS 3). It increased gradually, peaking during puberty, showing maximum values (CS 4, CS 5), which later dropped to reach prepubertal values (CS 6). Conclusion: Blood spot IGF-I correlates well with skeletal age as determined by radiographic techniques. IGF-I can act as a potential skeletal maturity indicator without the hazard of additional radiographic exposure.