The tooth eruption timings differ from one child to another. One child may start teething when only a few months old, while another may not until age 12 months or more.
Tooth eruption
Tooth eruption is defined as “The physiological movement of the tooth from its site of development within the jaw to its functional position in the oral cavity”. In simpler terms, it is the process of teeth entering the mouth and becoming visible.
Dentition periods
The tooth eruption process occurs twice during human life.
Primary dentition: The primary dentition is when only “milk” teeth are present in the mouth. This period starts at approximately six months and lasts until six years of age.
Mixed dentition: Around six, the first secondary (permanent) tooth erupts, usually the lower first molar. It marks the beginning of the mixed dentition period, i.e. when we see primary and secondary teeth in the oral cavity.
Permanent dentition: The permanent dentition period followed the mixed dentition stage, i.e., when only secondary teeth are present in the mouth, and it usually begins at twelve years of age.
Timeline for primary (milk) teeth
Humans typically have twenty primary teeth. Most children acquire a complete set of primary teeth by the time they are three years old. Usually, the lower central incisor is the first tooth to erupt at six months of age. The eruption of upper central incisors follows it. Then around nine to sixteen months, upper and lower lateral incisors are appreciated in the oral cavity. Next to erupt are the upper and lower first molars, from thirteen to nineteen months. In between sixteen to twenty-three months, the baby canines emerge in the cavity. Lastly, the lower and upper second molars erupt at around 23 to 33 months.
Timeline for secondary (permanent) teeth
There usually are thirty-two permanent teeth. Firstly, the lower and upper first molars erupt between six and seven years of age. Then, the lower and upper incisors erupt until the age of nine. The eruption of the lower canine follows this at nine to ten years of age. Later, the lower and upper premolars erupt from the ages of ten to twelve.
The upper canine erupts at eleven to twelve years. Afterwards, the lower and upper second molars appear from eleven to thirteen years of age. Lastly, the lower and upper third molars, colloquially termed “wisdom teeth”, emerge from seventeen to twenty-one years of age.
