A slanted/uneven jaw can be either the upper jaw or the lower jaw. More commonly a slanted/uneven jaw refers to the lower jaw and is also known as mandibular asymmetry. The aetiology of mandibular asymmetry can be:
- Developmental - disturbance/disruption in growth or excessive growth on one side e.g hemimandibular hyperplasia
- Pathological - due to the presence of tumours or cysts or condylar resorption
- Traumatic - history of fracture at the jaw resulting in impeded growth on the side with the trauma
- Functional - teeth that are in crossbite may result in occlusal interferences and cause the jaw to shift to one side to achieve a better bite
Facial asymmetry can also be due to the soft tissue e.g muscles. A facial asymmetry due to the difference in the size of the jaw muscle can also occur if one favours chewing on one side more than the other.
From the photo that you have sent, it appears that there may be a mild asymmetry of the lower jaw to the left, though it is hard to tell from an open mouth posture. Your lower dental midline does appear more shifted to the left. However, to get a more accurate diagnosis, one would require a thorough clinical examination supplemented with X-rays to determine if the jawbones are truly asymmetric. Your dentist/orthodontist may also check for any presence of crossbites and ascertain any prior history of trauma to the jaws.
