June 22, 2016
Tooth eruption follows a distinct pattern and schedule, however, individual differences are the norm. Therefore teeth eruption charts should be taken as a general guide rather than a fixed timetable.
The first set out of the two sets of teeth are known as the milk, deciduous teeth or primary dentition. This dentition has 20 teeth in total with the exception of premolars. The front teeth make their appearance first. The first milk tooth to erupt is the lower central incisor at 6-8 months of age followed by the upper central incisor at 10 months. The upper lateral incisor comes right after at 11 months and the lower lateral incisor at 13 months.
By 16 months, the first molars or the back teeth are visible in the oral cavity which are followed by the upper and lower canines at 19 and 20 months. The last two teeth of the deciduous dentition, the upper and the lower second molars erupt by 27 and 29 months. The deciduous dentition is completed by the age of 3 years and is present only for a small duration of time until it is lost completely by age 11.
It is a well known fact that there are no erupted teeth present when a baby is born, though they are already present within the jawbones. However, sometimes, there are one or more teeth present in the baby’s mouth at the time of birth and these are known as natal teeth. Teeth erupting during the first month of life are known as neonatal teeth. These teeth might pose problems in breastfeeding or may cause ulcers in the mouth of the infant (Riga fede ulcers). A radiograph may confirm whether these are supernumerary (extra) teeth or prematurely erupted deciduous teeth.
With the onset of the eruption of the first permanent tooth begins the mixed dentition phase wherein both the milk and the permanent teeth are present.
The first permanent teeth to erupt are the first molars and the lower central incisors by 6-7 years of age. They are followed by the lower lateral incisors as well as the upper central incisors which are seen by 7-8 years of age. The upper lateral incisors come next by 8-9 years of age. The lower canines erupt by 9-10 years of age. By 10-11 years of age, the upper first premolar replaces the deciduous first molar. Somewhere during the same time period, the upper second premolar and the lower first premolars make their appearance by 10-12 years of age. The lower second premolar and upper canine are seen by 11-12 years of age. The lower second molars erupt by 11-13 years of age while the upper second molars by the age of 12-13 years.
The third molars, or the wisdom teeth, are usually the most variable teeth in the oral cavity ranging in their appearance from 7-21 years of age. Their absence is commonly observed and if space does not permit may remain impacted for as long as they are not infected and cause pain, eventually leading to surgical removal (disimpaction).