It does not recognise deviations in other spatial axes, asymmetric deviations, functional faults and other therapy-related features. Angles classification system also lacks a theoretical basis; it is purely descriptive. Its much-discussed weaknesses include that it only considers static occlusion, it does not account for the development and causes (aetiology) of occlusion problems, and it disregards the proportions (or relationships in general) of teeth and face. Thus, many attempts have been made to modify the Angle system or to replace it completely with a more efficient one, but Angles classification continues be popular mainly because of its simplicity and clarity.Well-known modifications to Angles classification date back to Martin Dewey (1915) and Benno Lischer (1912, 1933). Alternative systems have been suggested by, among others, Simon (1930, the first three-dimensional classification system), Jacob A. Salzmann (1950, with a classification system based on skeletal structures) and James L. Ackerman and William R. Proffit (1969). Incisor classification
Besides the molar relationship, the British Standards Institute Classification also classifies malocclusion into incisor relationship and canine relationship. Class I:
The lower incisor edges occlude with or lie immediately below the cingulum plateau of the upper central incisors
Class II:
The lower incisor edges lie posterior to the cingulum plateau of the upper incisors
Division 1 – the upper central incisors are proclined or of average inclination and there is an increase in overjet
Division 2 – The upper central incisors are retroclined. The overjet is usually minimal or may be increased. Class III:
The lower incisor edges lie anterior to the cingulum plateau of the upper incisors.
Gonococcal arthritis – Neisseria gonorrhoeae is a common cause of septic arthritis in people who are sexually active and under 40 years old. The bacteria is spread through the blood to the joint following sexual transmission. Other symptoms of disseminated gonococcal infection can include migration of joint pain, tenosynovitis and dermatitis. Synovial fluid cultures are positive in 25 to 70% of the cases while blood cultures are seldom positive. Apart from blood and joint cultures, swabs from urethra, rectum, pharynx, and cervix should also be taken. Polymerase chain reaction (PCR) is another useful way of identifying gonococcal infections if diagnosis is difficult and clinical presentation is similar to reactive arthritis. Others – Fungal and mycobacterial infections are rare causes of septic arthritis and usually have a slow onset of joint symptoms. Mycobacterial joint infection most commonly affects hip and knee joints, caused by reactivation of past mycobacterial infections, with or without signs and symptoms of tuberculosis in lungs. Synovial fluid cultures will be positive in 80% of the cases. However, acid fast smears are not useful. Histology is not specific to myocobacterial infection as there are other granulomatous diseases that can show similar histology. Borrelia burgdorferi, a bacterium that causes lyme disease, can affect multiple large joints such as the knee. Confirmation of Lyme disease is done through enzyme-linked immunosorbent assay (ELISA) followed by confirmation using Western Blot test. It cannot be cultured from synovial fluid. However, PCR testing yields 85% positive result from synovial fluid.