Diagnostic criteria for Angle's Class I, Class II, and Class III malocclusion
May 12, 2023
Source: Cainiu Health
Dr. Zhang Liwen
Introduction
In general, orthodontic cases are classified into Class I, Class II, and Class III based on the condition being treated. The classification criteria depend on specific dental conditions. Anterior crossbite or posterior open bite, also known as simple dental malocclusion, refers to an abnormal occlusal relationship between the upper and lower jaws. This condition typically involves only the position of teeth and their occlusal relationship, without affecting the growth and development of the jaw bones.
In general, orthodontic treatment is classified into three categories—Class I, Class II, and Class III—based on the specific condition being treated. The classification criteria are determined by the precise condition of the teeth. A detailed analysis is as follows:
1. Class I
This involves anterior crossbite or posterior open bite, also known as "simple dental malocclusion," meaning an abnormal occlusal relationship between the upper and lower jaw teeth. This condition typically only affects the position of the teeth and their occlusal relationship, without influencing the growth and development of the jawbones.
2. Class II
This occurs when there is a size discrepancy between the upper and lower jaws, resulting in dental malocclusion, also referred to as "skeletal malocclusion." Class II malocclusion is divided into two types: one characterized by excessive development of the upper jaw, and the other by excessive development of the lower jaw.
3. Class III
This also involves a size discrepancy between the upper and lower jaws leading to dental malocclusion, but differs from Class II in that it results from inherent jawbone problems—specifically, a disproportionate size relationship between the upper and lower jaws. This condition usually requires treatment to begin during the jawbone development phase to better correct the proportional imbalance of the jaws.
Depending on the specific condition, orthodontic treatment methods and duration may vary. Generally, treatment for Class I malocclusion is shorter, typically requiring 6 months to 1 year. Treatment for Class II and Class III malocclusions takes longer, usually 1 to 3 years, and may involve various treatment approaches such as braces, crowns, or dental implants. The specific treatment plan should be determined based on the patient's individual condition and the dentist's recommendations.
