A "weak" chin is a sign of a skeletal class 2 pattern. This may be because the upper jaw is protruding, so the normal chin appears deficient. The lower jaw may be underdeveloped and the chin is receded as a result.
There are standardized methods of assessing the source of the weak chin. Radiographic cephalometric markers are used to assess the skeleton and the soft tissues, so that an objective conclusion can be made, since this will affect the choice of appropriate treatment.
A protruding mouth is something not that commonly described. Most often, what patients mean by this is that their lips are protruding. This is very common in the Asian (non-Caucasian) population but usually does not negatively affect the aesthetics of the profile. However, what is considered the ideal profile changes over time in response to trends.
Also, it pays to be aware that most cephalometric norms are based on white Caucasian males from the early 20th century. It would be a stretch to make this the standard for all peoples around the world.
However, if the lip protrusion really bothers you, then compensatory extractions may be considered as part of orthodontic treatment.
The end goal or all orthodontic treatment is to optimize the teeth and the face, so that everything sits in harmony. A good practitioner will be able to guide you through the different treatment options available to achieve this.
