This Master's thesis is a systematic review about the class II subdivision: aetiology and diagnosis.

It aims to identify and analyse the aetiological factors and diagnostic approaches related to Class II subdivision malocclusion based on the existing scientific literature. Twenty studies including a total of 1,807 participants were selected following a systematic search of nine databases. The findings indicate that the aetiology of Class II subdivision is multifactorial, involving dental, skeletal and functional components, with a clear predominance of dental asymmetries. Skeletal and condylar asymmetries are present in a smaller proportion of cases and are often subtle, while functional factors such as mandibular shifts may contribute to the clinical presentation. Advanced imaging techniques, including CBCT and 3D imaging, allow more accurate detection of asymmetries compared to conventional two-dimensional methods. In conclusion, accurate and individualized diagnosis is essential, and three-dimensional imaging should be reserved for complex cases or when skeletal involvement is suspected.