What is Class I, II, III (occlusion)
Dental occlusion is the relationship between the upper and lower teeth when the mouth is closed. It is classified into three main types: Class I, Class II and Class III. These classifications are based on the position of the teeth and the relationship between the dental arches. In this glossary, we will explore each of these classes in detail, providing a comprehensive understanding of the subject.
Class I
Class I is considered a normal occlusion, in which the upper teeth fit correctly with the lower teeth. In this type of occlusion, the upper first molars fit perfectly with the lower first molars, and the other teeth are also properly aligned. This is the most common occlusion and generally does not require orthodontic treatment.
However, even in Class I, problems such as tooth crowding, crossbite or excessive spacing between teeth can occur. These conditions can affect the aesthetics and function of teeth, and can be corrected with orthodontic treatments, such as the use of fixed braces or clear aligners.
Class II
Class II is characterized by an abnormal relationship between the upper and lower teeth, in which the upper teeth are positioned further forward in relation to the lower teeth. This condition is known as deep bite or mandibular retrognathism.
There are two types of Class II: Class II Division 1 and Class II Division 2. In Class II Division 1, the upper incisors are projected forward, partially covering the lower incisors. In Class II Division 2, the upper incisors are tilted backwards, leaving a gap between them and the lower incisors.
Class II can cause aesthetic and functional problems, such as difficulty chewing and speaking, as well as increasing the risk of tooth wear and temporomandibular joint problems. Orthodontic treatment is commonly used to correct Class II, and may involve the use of fixed appliances, elastics and even orthognathic surgery in more serious cases.
Class III
Class III is characterized by an abnormal relationship between the upper and lower teeth, in which the lower teeth are positioned further forward in relation to the upper teeth. This condition is known as mandibular prognathism or anterior crossbite.
Class III can be divided into two categories: skeletal Class III and dental Class III. In skeletal Class III, the mandible is positioned in front of the jaw, causing more pronounced facial disharmony. In dental Class III, the lower teeth are inclined forward, causing an anterior crossbite.
Class III can cause aesthetic and functional problems, such as difficulty chewing, speaking and breathing, in addition to increasing the risk of tooth wear and temporomandibular joint problems. Orthodontic treatment is commonly used to correct Class III, and may involve the use of fixed appliances, elastics and even orthognathic surgery in more serious cases.
Conclusion
In summary, Class I occlusion is considered normal, while Classes II and III are considered abnormal. Orthodontic treatment is often necessary to correct Classes II and III, aiming to improve the aesthetics and function of teeth, as well as preventing future problems. It is important to consult an orthodontist to evaluate the occlusion and determine the best treatment plan for each specific case.
