Object: Progressive condylar resorption (PCR) is defined as diminishing condylar head volume with changes in condylar shape, often associated with decreased mandibular ramus height, mandibular retrusion and counter clockwise rotation, resulting in progressive Class II basal bone in relation with anterior open bite. Patients are known to have relatively small and retruded mandible. Because of it, PCR patients often undergo inappropriate surgeries or unnecessary orthodontic procedures under misdiagnosis with maxillary protrusion and/or mandibular retrusion.

Another proposed cause of condylar resorption is post orthognathic surgery complication, following excessive traumatic external burden to the temporomandibular joint, TMJ. For clinical diagnosis, many confused concepts were mixed and misused in dealing with those symptoms. The objective of this study is to establish appropriate diagnostic criteria and possible treatment guidelines based on them.

Methods and results: Our group’s clinical and epidemiological investigations showed that female–male prevalence ratio to be approximately 10 times higher for female among Japanese, echoing previous reports from Europe/United States with Caucasian population. The patients were classified in two groups:

• (1)

  young idiopathic patients without any systemic complications, and

• (2)

  cases with autoimmune diseases above age of 50. Biomarkers from patients’ blood and urine samples did not show signs of inflammation, but suggested strong indication of osteoporosis and osteopenia.

Conclusion: Among PCR patients, specific blood biomarkers were elevated. From theses results above, we suggest noble candidates for PCR biomarkers, including RANTES as a potential osteoclastic factor, which may help diagnosing and/or warming early signs of PCR.

Conflict of interest: None declared.