Molar incisor hypomineralisation (MIH) is a type of enamel defect affecting, as the name suggests, the first molars and incisors in the permanent dentition. MIH is considered a worldwide problem and usually occurs in children under 10 years old. This developmental condition is caused by the lack of mineralisation of enamel during its maturation phase, due to interruption to the function of ameloblasts. Many factors have been suggested, such as genetics and medical problems during pregnancy, but only childhood illness, fever in particular, seems to be associated with MIH. However, further studies on the aetiology of MIH are required because it is believed to be multifactorial.MIH often presents as discolouration on one to four affected permanent molars and the associated incisors. The enamel of the affected teeth appears yellow, brown, cream or white and thus are sometimes referred to as ‘cheese molars’. These teeth are deemed less aesthetically pleasing, hence causing distress in children with MIH and their parents. It is important to note that although there is difference in enamel translucency in the affected teeth, there should not be any changes to the enamel thickness, unlike in enamel hypoplasia.As a consequence, children with MIH are more likely to experience tooth decay compared to those without the condition. Moreover, the development of tooth decay is very rapid due to the less mineralised enamel. MIH only becomes visible once the permanent molars start to erupt and that is when opacities on the tooth can be observed if it is affected.
Antisocial personality disorder (ASPD or infrequently APD) is a personality disorder characterized by a long-term pattern of disregard of, or violation of, the rights of others as well as a difficulty sustaining long-term relationships. Lack of empathy is often apparent, as well as a history of rule-breaking that can sometimes include law-breaking, a tendency towards substance abuse, and impulsive and aggressive behavior. Antisocial behaviors often have their onset before the age of 8, and in nearly 80% of ASPD cases, the subject will develop their first symptoms by age 11. The prevalence of ASPD peaks in people age 24 to 44 years old, and often decreases in people age 45 to 64 years. In the United States, the rate of antisocial personality disorder in the general population is estimated between 0.5 and 3.5 percent. In a study, a random sampling of 320 newly incarcerated offenders found ASPD was present in over 35 percent of those surveyed.Antisocial personality disorder is defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM), while the equivalent concept of dissocial personality disorder (DPD) is defined in the International Statistical Classification of Diseases and Related Health Problems (ICD); the primary theoretical distinction between the two is that antisocial personality disorder focuses on observable behaviours, while dissocial personality disorder focuses on affective deficits. Otherwise, both manuals provide similar criteria for diagnosing the disorder. Both have also stated that their diagnoses have been referred to, or include what is referred to, as psychopathy or sociopathy.