Lastly oxygen shortage combined with low birth weight is suspected to be a contributing factor

Diagnosis
Differential diagnosis
It is essential to exclude other causes of enamel opacities, differentiating MIH from them, to ensure an appropriate treatment plan is made. These conditions include:

Dental caries, which is the most common cause of destruction of dental hard tissues. This is more unlikely in a patient with a previously intact primary dentition. White spot lesions are also uncommon on incisors, hence ruling out dental caries. Fluorosis, which can result from an intake of a high fluoride concentration while the tooth is still undergoing mineralisation. Fluorosis presents as irregular, diffuse enamel opacities which affect more than 1 tooth, in contrast to the well-demarcated borders of hypomineralised enamel seen in MIH. Amelogenesis imperfecta, a genetic condition, and thus there may be a history of similar defects in other family members. This condition affects both the primary and permanent dentition, and all surfaces tend to be equally affected, differentiating it from MIH. Trauma to primary incisors resulting in discolouration of permanent incisors. Administration of tetracycline during pregnancy and to children under 6 resulting in tooth staining (grey or yellow). Enamel hypoplasia, caused by defective enamel matrix formation, is a quantitative defect which presents as a localised reduction in enamel thickness. This differs from hypomineralisation, which is a qualitative defect affecting the translucency of enamel. Classification
MIH examination should be carried out on clean, wet teeth.
The HVLA tests verbal learning and memory by presenting a series of words and assigning points based on the number recalled, and digit span measures attention efficiency by asking the examinee to repeat back digits spoken by the tester in the same order as they are presented. In addition, neuropsychological tests may be performed to detect malingering (exaggerating or making up symptoms) . Differential diagnosis
PCS, which shares symptoms with a variety of other conditions, is highly likely to be misdiagnosed in people with these conditions. Cognitive and affective symptoms that occur following a traumatic injury may be attributed to mTBI, but in fact be due to another factor such as posttraumatic stress disorder, which is easily misdiagnosed as PCS and vice versa. Affective disorders such as depression have some symptoms that can mimic those of PCS and lead to a wrongful diagnosis of the latter; these include problems with concentration, emotional lability, anxiety, and sleep problems. Depression, which is highly common in persistent PCS, can worsen other PCS symptoms, such as headaches and problems with concentration, memory, and sleep. PCS also shares symptoms with chronic fatigue syndrome, fibromyalgia, and exposure to certain toxins. Traumatic brain injury may cause damage to the hypothalamus or the pituitary gland, and deficiencies of pituitary hormones (hypopituitarism) can cause similar symptoms to post-concussion syndrome; in these cases, symptoms can be treated by replacing any hormones that are deficient.