Differential diagnosis of Skeletal Class III

Abstract

Summary Skeletal Class III is a relatively rare malocclusion of the craniofacial complex and the accurate differential diagnosis of its aetiology is necessary so that it may be correctly treated. Differential diagnosis of Class III aetiopathogenesis should distinguish between: a) true skeletal Class III as opposed to pseudo Class III; b) three forms of Skeletal Class III, in which there is either maxillary deficiency only or mandibular excess only or combination of both; and c) skeletal Class III that may be treated with orthodontic treatment alone, as opposed to Class III that is difficult to manage with orthodontic treatment alone and requires combine orthodontic and surgical approach. Differential diagnosis is mainly based on clinical examination and cephalometric analysis. The aim of this paper is to present the basic principles and modes of achieving differential diagnosis in skeletal Class III cases.

Orofacial Cleft and Mandibular Prognathism—Human Genetics and Animal Models

“…It has been reported that in US population class III malocclusion mostly occurs as a maxillary hypoplasia and protrusion. In contrast, in Asians, this deformation is predominantly diagnosed with a normal upper jaw and the overgrowth of the mandible [83,84]. To avoid the misdiagnosis of improper upper jaw or mandible development, a lateral cephalometric radiograph with cephalometric analysis should be performed [84]; this is a standardized orthodontic method and a part of the diagnostic process of malocclusion and treatment planning.…”

“…In contrast, in Asians, this deformation is predominantly diagnosed with a normal upper jaw and the overgrowth of the mandible [83,84]. To avoid the misdiagnosis of improper upper jaw or mandible development, a lateral cephalometric radiograph with cephalometric analysis should be performed [84]; this is a standardized orthodontic method and a part of the diagnostic process of malocclusion and treatment planning. Angular and linear measurements carried out on a radiograph allow for the assessment of the positions of various anatomical structures [85].…”