OVERVIEW

What is primary tooth eruption?

Primary tooth eruption refers to the process of a child growing their first set of teeth, commonly known as "teething." In a broader sense, "teething" includes both "primary tooth eruption" and "permanent tooth eruption."

When does primary tooth eruption typically begin?

The first primary tooth usually emerges around 6 to 10 months of age, with most children teething before their first birthday.

Which tooth emerges first during primary tooth eruption?

The first to appear are the lower central incisors, the two front teeth located at the very center of the lower jaw.

What is the sequence of primary tooth eruption?

Teeth usually emerge in pairs (left and right), with the lower teeth often appearing before the upper ones. On average, a new pair emerges every two months.

• The first to emerge are the lower central incisors (front teeth), followed by the upper central incisors.

• Next are the adjacent teeth, called the lateral incisors.

• After the upper and lower lateral incisors, the first set of molars, known as the first primary molars, appear.

• Then come the upper and lower canines, also called cuspid teeth.

• Finally, the second set of molars, the second primary molars, emerge.

When is primary tooth eruption usually complete?

A full set of primary teeth consists of 20 teeth, typically all erupted by around 30 months of age.

SYMPTOMS

What symptoms occur before baby teeth erupt?

Before teething, children may exhibit: increased drooling, irritability, a tendency to bite objects or people, swollen gums, light sleep, and increased crying.

What symptoms will a child have when baby teeth erupt?

During teething, especially when the first baby tooth emerges, a child may develop a low-grade fever with a temperature around 38°C.

Frequent bowel movements are also common.

CAUSES

What could be the reasons for delayed eruption of primary teeth?

• Dental germ development defects: If the dental germ is missing, the corresponding primary tooth will not erupt.

• Certain systemic diseases: Such as nutritional deficiencies, hypothyroidism, Down syndrome, rickets, ectodermal dysplasia, hypopituitarism, etc., may all lead to delayed tooth eruption.

• Abnormal dental arch development: Lack of space for primary teeth eruption can also cause slow eruption of primary teeth.

DIAGNOSIS

What to do if teeth grow right after birth?

Some babies are born with teeth already erupted, a condition called "natal teeth." The most common are the lower central incisors. This occurs because the tooth bud is positioned too far forward or due to abnormal development of the tooth bud itself.

If the natal teeth are normally developed and simply erupted early, no additional treatment may be needed. Possible issues include: the erupted teeth irritating the opposing gums, leading to ulcers, or causing breastfeeding difficulties due to the presence of teeth. These can be managed with care.

If the natal teeth have short or absent roots, they may loosen and fall out. In such cases, extraction may be necessary to prevent accidental swallowing. Whether extraction is required depends on the specific condition of the teeth, as assessed by a doctor.

Under what circumstances is primary tooth eruption abnormal?

The following situations indicate delayed primary tooth eruption and require prompt medical attention:

• No first tooth erupted by 12 months of age;
• A gap of more than 6 months between the eruption of the same teeth on the left and right sides;
• Failure to grow all 20 primary teeth by 36 months of age.

What tests might a doctor perform if there are issues with primary tooth eruption?

The doctor will first conduct a thorough oral examination and may recommend an X-ray of the tooth buds to assess their condition beneath the gums.

If the doctor suspects that abnormal tooth eruption is related to other conditions, they may also refer the child to a pediatrician for developmental evaluation, thyroid function tests, 25-hydroxyvitamin D levels, and other tests to diagnose systemic diseases.

TREATMENT

Which department should I visit for issues related to baby teeth eruption?

Go to the pediatric dentistry department or consult a general dentist with experience in treating children's oral health.

Is it a problem if my baby's teething order differs from others?

The mentioned teething sequence is the most common scenario. If your child's teething order differs or is asymmetrical, it may not necessarily indicate an abnormality. Continue monitoring the subsequent teething progress.

If no baby teeth emerge in the corresponding positions after 6 months, consider visiting a dentist.

How to relieve a baby's discomfort during teething?

• Focus on soothing the child. Safe teething toys can be used for chewing, which helps massage the gums.

• Avoid using easily breakable foods to comfort the child to prevent choking or accidental ingestion.

• If the child develops a fever and feels very uncomfortable or experiences severe teething pain, ibuprofen or acetaminophen can be used to manage fever or relieve pain.

• Diarrhea during teething will resolve on its own. If the baby's urine output remains normal, it indicates no dehydration, and no treatment is needed.

DIET & LIFESTYLE

What should be noted in diet during primary tooth eruption?

• During teething, children may resist chewing food. You can temporarily feed them liquid food and avoid adding solid food.

• After teeth erupt, solid food can be gradually introduced to help train the child's chewing and swallowing.

• After teeth erupt, sugar intake should be controlled to prevent primary tooth decay.

• Avoid letting the child fall asleep with a bottle, as sleeping with formula milk can easily cause tooth decay.

What should be noted in daily life during primary tooth eruption?

• After teeth erupt, brush the baby's teeth morning and night with a toothbrush. Choose fluoride toothpaste that is safe to swallow—a rice-sized amount is sufficient.

• For cleaning between adjacent teeth, dental floss or floss picks can be used.

• After teeth erupt, regular dental check-ups every 3 to 6 months are recommended to assess the child's dental health, provide appropriate protection (such as fluoride application and pit and fissure sealing), and offer daily oral care guidance.

PREVENTION

How to Prevent Delayed Eruption of Deciduous Teeth?

• Daily vitamin D supplementation at a routine dose of 400 units per day can promote the mineralization of teeth and bones.

• For babies over 6 months old, even if no deciduous teeth have erupted, solid complementary foods can be introduced. Chewing food with the gums can stimulate the eruption of deciduous teeth.