Effects of Sex Hormones Deficiency on Craniofacial Growth in Rats

Objectives: To examine the effects of sex hormones deficiency on craniofacial growth in rats. It is well – known that sex hormones regulate bone metabolism. Sex steroids increase osteoblasts activities and affect growth, remodeling and bone homeostasis. Its effect on linear growth and growth plate maturation and closure has been investigated but its effect on craniofacial growth is not known. The increased use of hormone therapy in children and also the abuse of primary testosterone and its derivatives (anabolic steroids) require a detailed understanding of the basic effects of hormones on skeletal growth.

Methods: Fifty, thirty – day – old Wistar rats comprised the sample. 25 male rats were divided into 2 groups: Experimental group, ORX, (n = 15) and control group, sham- operation, (n = 10) and also 25 female rats were divided in the same way into 2 groups: Experimental group, OVX, (n = 15) and control group, sham- operation, (n = 10). Measurements of general growth (body length and weight) were registered monthly. These rats were sacrificed 6 months after the surgery. Direct millimetric measurements of the skeletodental variables and the tibial length were obtained by using electronic caliper.

Results: In the ORX group, some measurements such as body length and weight, coronoid height, mandibular length, mandibular arch length, midfacial width, midfacial length, midfacial height, calvarial width, maxillary arch width, premaxillary length, nasal bone height, facial width, basisphenoid bone length and tibia bone length were significantly (p<0.01) smaller than in the male sham- operated group. Structures showing cartilaginous growth were influenced more than structures showing sutural growth.

Conclusion: In conclusion, it was strongly suggested that the suppression of sex hormones secretion in the growth phase might inhibit craniofacial growth and result in poor craniofacial development in the growth phase.