The cause of a bad bite can be due to mandibular dysplasia, tooth extraction, and periodontal disease. 1. Mandibular dysplasia: When teeth develop, there is no space for teeth to erupt because of mandibular dysplasia, and the teeth will be staggered and erupt in various parts, resulting in a malocclusion. 2. Tooth extraction: misalignment of bite occurs after tooth extraction, when one of the teeth is extracted and the missing tooth is not repaired for a long time, the neighboring teeth will be tilted towards the gap and the opposite jaw teeth will extend towards the gap, which will lead to misalignment and elongated occlusal relationship. 3. Periodontal disease: After periodontal disease, due to the recession of alveolar bone, the roots of the teeth are exposed, and the front teeth are fan-like and outward, which will lead to misalignment of the teeth bite. If the symptoms of poor dental occlusion persist without relief, affecting the appearance and normal chewing function, it is necessary to seek medical treatment in a timely manner.