An accident is an unintended, normally unwanted event that was not directly caused by humans. The term accident implies that nobody should be blamed, but the event may have been caused by unrecognized or unaddressed risks. Most researchers who study unintentional injury avoid using the term accident and focus on factors that increase risk of severe injury and that reduce injury incidence and severity. For example, when a tree falls down during a wind storm, its fall may not have been caused by humans, but the trees type, size, health, location, or improper maintenance may have contributed to the result. Most car wrecks are not true accidents; however English speakers started using that word in the mid-20th century as a result of media manipulation by the US automobile industry. Types
Physical and non-physical
Physical examples of accidents include unintended motor vehicle collisions, falls, being injured by touching something sharp or hot, or bumping into something while walking. Non-physical examples are unintentionally revealing a secret or otherwise saying something incorrectly, accidental deletion of data, or forgetting an appointment. Accidents by activity
Accidents during the execution of work or arising out of it are called work accidents. According to the International Labour Organization (ILO), more than 337 million accidents happen on the job each year, resulting, together with occupational diseases, in more than 2.3 million deaths annually. In contrast, leisure-related accidents are mainly sports injuries. Accidents by vehicle
Vehicle collisions are not usually accidents; they are mostly caused by preventable causes such as drunk driving and intentionally driving too fast.
There is literature indicating that DE is an isolated anomaly. During the bell stage of tooth formation, DE may occur as a result of an unusual growth and folding of the inner enamel epithelium and ectomesenchymal cells of dental papilla into the stellate reticulum of the enamel organ. Diagnosis
Diagnosis of DE can be difficult when there is no signs and symptoms of necrotic or infected pulp. It is a challenging task to differentiate between a true periapical lesion and a normal periapical radiolucency of a dental follicle of an immature apex. Pulp tests (test results of immature teeth can be misleading, as they are known to give unreliable results)
Check and see if there is an elevated, flat wear facet on the occlusal surface of the tooth
Test cavity which has an absence of pain sensation and has an empty pulp chamber/ canal. Radiographs (usually periapical) - a V-shaped radiopaque structure could be seen superimposing on top of the affected crown. It could detect DE before tooth eruption. However, DE presentation on the radiograph can be quite similar to a mesiodens or a compound odontoma. Classification
The anterior DE tubercles have an average width of 3.5mm and length of 6.0mm, while posterior tubercles have an average 2.0mm in width and length of up to 3.5mm. If the cusp of Carabelli is present, the tooth associated are often larger mesiodistally and it is not uncommon that a DE involved tooth has an abnormal root pattern.There are 4 different ways to classify/ categorize DE involved teeth.