Oral contraceptive pill use and abnormal menstrual cycles in women with severe condylar resorption: A case for low serum 17β-estradiol as a major factor in progressive condylar resorption

IntroductionProgressive condylar resorption has been described for many years. Because condylar resorption favors women over men, many have thought that a prominent systemic factor for the pathogenesis of this disease might be related to sex hormones.MethodsOver a 3-year period, 27 women without autoimmune disease came to our office for orthognathic surgical correction of their skeletal deformity secondary to severe condylar resorption. They all showed radiographic evidence of severe condylar resorption. Sex hormone dysfunction was evaluated, and midcycle serum levels of 17β-estradiol were measured. Use of exogenous hormones was also documented.ResultsTwenty-six of the 27 women with severe condylar resorption had either laboratory findings of low 17β-estradiol or a history of extremely irregular menstrual cycles. Of the 27 women, 25 showed abnormally low levels of serum 17β-estradiol at midcycle. Two subsets were identified in the group with low 17β-estradiol. The first did not produce estrogen naturally (8 of 27), and the second had low 17β-estradiol levels secondary to oral contraceptive pill (OCP) use (19 of 27). Of the 19 OCP users, all 19 reported that chin regression and open bite changes occurred after starting OCP use. Nine of the 19 reported these condylar resorption symptoms within the first 6 months of starting the OCP.ConclusionsWhether induced by ethinyl estradiol birth control or by premature ovarian failure, low circulating 17β-estradiol makes it impossible for the natural reparative capacity of the condyle to take place in the face of local inflammatory factors. This leads to cortical and medullary condylar lysis.