Acromegaly (pituitary gigantism) is a disease that causes enlargement of the bones of the face. There is interest in computerizing facial measurements to catch subtle enlargements and prompt testing for the disease.
Sixteen patients in remission of acromegaly for over 24 months (50 %
male, mean age 56.0 ± 10.7 years, mean body mass index 29.3 ± 5.5
kg/m(2)) were compared to 16 matched control subjects. A 3D cone beam
computed tomography scan and 3D stereophotograph of each individual
were acquired and analyzed using 3D cephalometry. In addition to an
accurate quantification of the classical craniofacial characteristics,
3D cephalometry, shows that many typical soft tissue deformities
persist, even after long-term remission. Furthermore, we found that,
compared to controls, the patients in remission of acromegaly have a
wider face at the level of the zygoma and longer maxilla (p < 0.05)
Apocryphally, enlarging hat size goes along with acromegaly.
Pagets disease of bone causes enlargement of the skull and also an increase in hat size (so bitemporal dimension); the hat size increase was one of the chara eristics first described in the disease.
Thalassemia is a group of blood diseases characterized by ineffective red blood cell production. The body compensates by making more marrow anywhere it can. Some people wind up with expanded bones in the skull or maxilla as a result.
These are all systemic diseases that affect the bone. Of course one can have a tumor of bone (primary or metastatic) that expands it and changes the shape of the face or the head.