Significance of the Frankfort-mandibular plane angle to prosthodontics.
Cephalometric information, specifically, vertical facial types and the Frankfort-mandibular plane angle, pertinent to prosthodontics has been discussed. The Frankfort-mandibular plane angle (FMA) is formed by the intersection of the Frankfort horizontal plane and the mandibular plane. This angle can be traced and measured by means of a diagnostic overlay. An FMA of 25 +/- 5 degrees is within normal range. A high-angle patient has an FMA of 30 degrees or more, and a low-angle patient has an FMA of 20 degrees or less. A high FMA is characterized by open-bite skeletal patterns, and a low FMA by closed-bite skeletal patterns. The clinical manifestations pertinent to prosthodontics in high- and low-angle (FMA) patients are shown in Table I. However, not all clinical characteristics are present in a given patient. The classification in Table I is a beginning. The authors consider the prosthodontic study of cephalometrics an unexploited research tool. Hopefully, in the future, it will help to bridge the gap of the biological-technical interplay that is such an integral part of prosthodontics.
D000539:Alveolar Process / Q000254:growth & development; D002508:Cephalometry; D003799:Dental Stress Analysis; D003778:Dentures; D005145:Face / Q000033:anatomy & histology; D006801:Humans; D008310:Malocclusion / Q000473:pathology / Q000503:physiopathology; D008334:Mandible / Q000033:anatomy & histology*; D013704:Temporomandibular Joint / Q000033:anatomy & histology; D014061:Tongue Habits