Retrognathic maxilla in "Habsburg jaw". Skeletofacial analysis of Joanna of Austria (1547-1578).

OBJECTIVE

To evaluate the dentoskeletal features of the "Habsburg jaw" by analyzing the skull of Joanna of Austria.

MATERIALS AND METHODS

The skull, the panoramic radiograph, and the lateral cephalogram of Joanna of Austria were analyzed. The cephalometric values of Joanna were compared to cephalometric standards for adult female subjects.

RESULTS

The analysis of the dentition on the dry skull and on the panoramic radiograph showed a generalized horizontal alveolar bone resorption with severe bone loss that was interpreted as a sign of severe periodontal disease with respect to the young age (31 years). The cephalometric analysis revealed the presence of a skeletal Class III disharmony associated with maxillary retrusion and normal sagittal position of the mandible. The maxilla exhibited a reduction in the sagittal dimension while the mandible presented with increased dimensions both in total mandibular length (Co-Gn) and in the mandibular body (Go-Gn). The skeletal open bite contributed to the lack of mandibular protrusion though in presence of increased mandibular sagittal dimensions.

CONCLUSION

Joanna of Austria appeared to be affected by a peculiar type of "Habsburg jaw" as the Class III skeletal disharmony was due to a retrognathic maxilla rather than to a prognathic mandible.