Comparison between normal jaw and protruding jaw

Under normal circumstances, the position and angle of the upper and lower jawbones and teeth are relatively parallel. In cases of protruding mouth (protrusion), however, the position and angle of the upper and lower jaws and teeth may deviate. A detailed analysis is as follows:

Mouth shape is one of the external features of the human body. Some individuals have a protruding mouth, while others have a flatter, straighter appearance, depending on the development and structure of the oral cavity and craniofacial bones. The difference between a normal mouth and a protruding mouth lies in the position and angle of the upper and lower jawbones and teeth. In a normal mouth, the upper and lower jawbones and teeth are relatively parallel, with proper overlap and occlusion between the upper and lower dental arches, and the chin is positioned normally. In contrast, in a protruding mouth, deviations in the position and angle of the jawbones and teeth may occur, resulting in a retruded lower jaw, a protruding upper jaw, lower jaw retrognathia, and forward projection of the lips—leading to an outwardly prominent appearance of the lower jaw and upper lip.

A protruding mouth can affect both facial aesthetics and oral health. Individuals with a protruding mouth often have a more prominent facial profile and misaligned teeth, which may negatively impact self-confidence and social interactions. Additionally, a protruding mouth may contribute to various oral health problems, such as malocclusion, gingivitis, oral ulcers, and temporomandibular joint disorders. Therefore, if a protruding mouth is present, it is advisable to seek medical attention promptly to prevent potential adverse effects on health.