Short answer: Permanent front teeth usually erupt between the ages of 6 and 9. If there is a marked difference between the right and left sides, or if the permanent tooth has not appeared even though months have passed since the baby tooth fell out, an X-ray assessment is needed. The most common causes are an extra (supernumerary) tooth, lack of space, trauma to the baby tooth and an impacted tooth. Depending on the cause, treatment may involve waiting, removing the extra tooth, creating space or orthodontic eruption.
Parents who notice that months have passed since their child's baby front tooth fell out without a new one coming in often come to us saying: "The permanent tooth is not coming in; should we wait?" Because eruption times can vary from child to child, a delay of a few months is often normal. In some cases, however, the delay may be caused by an extra tooth, lack of space or a tooth that has lost its way inside the bone. In this article we explain the normal eruption times for permanent front teeth, the causes of delay, how the assessment is done and the treatment options.
What is the normal eruption time for permanent front teeth?
In most children, permanent front teeth erupt between the ages of 6 and 9; usually the lower central incisors come in first, followed by the upper central incisors and the lateral incisors. The approximate order is as follows:
- Lower central incisors: around age 6-7,
- Upper central incisors: around age 7-8,
- Lower lateral incisors: around age 7-8,
- Upper lateral incisors: around age 8-9.
These ages are averages; in girls, teeth usually erupt a little earlier, and family traits also play a role. What matters is that the same tooth on the right and left sides erupts at around the same time. If a tooth has erupted on one side but its counterpart on the other side has not come in within a few months, or if the permanent tooth has not appeared even though a long time has passed since the baby tooth fell out, an assessment is recommended.
Why is the permanent tooth not coming in? Causes of delay
The most common causes of a delayed permanent front tooth are an extra tooth, lack of space, problems related to the baby tooth and the tooth developing in the wrong direction inside the bone. The main causes are:
- Extra tooth (supernumerary tooth): An extra tooth called a "mesiodens," seen especially between the upper central incisors, can block the path of the permanent tooth and prevent it from erupting. It is one of the common causes of delayed upper front teeth.
- Lack of space: If there is not enough room in the jawbone, the permanent tooth may have difficulty erupting, may be delayed or may come in outside the arch.
- Early loss of the baby tooth: When a baby tooth is lost early due to decay or trauma, the gum over it can thicken and harden, slowing the eruption of the permanent tooth.
- Trauma to the baby tooth: Blows to the front teeth at a young age can affect the position or shape of the permanent tooth developing underneath; they can lead to changes such as bending of the root (dilaceration).
- A baby tooth that stays in place too long: If the root of the baby tooth has not resorbed, the permanent tooth may not be able to find its way.
- Cyst or odontoma: Cysts or benign tooth-like growths developing in the jawbone can prevent eruption.
- Missing tooth: In some children, a permanent tooth, especially the upper lateral incisor, may never have formed (congenitally missing).
- General health conditions: Some hormonal and genetic conditions can delay tooth eruption in general; such conditions are evaluated together with the pediatrician.
How is the X-ray assessment done?
The basic way to understand the cause of the delay is through dental X-rays taken along with a clinical examination; only in this way can the presence and position of the tooth and whether anything is blocking it be seen. At first, a panoramic X-ray or small localized X-rays are usually used. A panoramic X-ray shows all the teeth and the developing tooth buds together.
If the tooth's position requires more detailed information, for example to understand whether the tooth is on the palate side or the lip side, how close it is to the roots of neighboring teeth or whether its root is bent, low-dose three-dimensional imaging (cone beam computed tomography) may be recommended. In children, X-rays are taken only when truly necessary and with as low a dose as possible.
In the X-ray assessment, the dentist looks for answers to these questions: Is the permanent tooth present? How far has its root developed? Is it moving in the right direction? Is there an obstacle in its path, such as an extra tooth, a cyst or a baby tooth root? Is there enough space in the jaw?
What are the treatment options?
Treatment is determined by the cause of the delay, the position of the tooth and the child's age; sometimes simply waiting is enough, while in other cases surgical and orthodontic intervention are planned together.
- Monitoring: If the tooth is moving in the right direction and its root has not yet developed sufficiently, it can be checked at set intervals while waiting for it to erupt on its own.
- Extraction of the baby tooth: Removing a baby tooth whose root has not resorbed and that is blocking the permanent tooth often makes eruption easier.
- Removal of the extra tooth: If an extra tooth such as a mesiodens is creating an obstacle, it is removed surgically. Once the obstacle is gone, many permanent teeth can erupt on their own over time; if not, additional treatment may be needed.
- Creating space: If there is not enough room in the jaw, space can be created for the tooth to erupt using orthodontic appliances.
- Removal of a cyst or odontoma: Growths that create an obstacle are removed surgically and, if necessary, sent for examination.
How is orthodontic traction (guided eruption) done?
Orthodontic eruption is the gradual guiding of an impacted tooth that cannot come in on its own into its place, using light, controlled forces through a small attachment placed on it. The procedure is usually carried out in two stages.
First, an oral surgeon opens the gum and, if necessary, a thin layer of bone over the impacted tooth and bonds a small button or bracket to the tooth's surface. The orthodontist then applies a light force to this attachment using a fixed appliance or wire system that takes support from the other teeth in the mouth. Over months, the tooth is gradually guided into the mouth and into its place in the arch. The aim during this process is for the gum to heal healthily and for the tooth to reach the correct position together with the surrounding tissues.
How long eruption treatment takes and what the outcome will be depend on the tooth's position, its depth, the condition of the root and the child's age. In very rare cases, for example when the tooth is in a very unfavorable position or its root is markedly bent, extracting the tooth and closing the gap later with other methods may be considered among the options.
After treatment of an impacted front tooth is complete, comprehensive orthodontic treatment may be needed to align the teeth. In suitable cases and at suitable ages, clear aligner treatment may also be considered at this stage; you can find general information on which option suits which age on our at what age clear aligners page, and options specific to the mixed dentition stage on our Invisalign First for children page.
When should you have an examination in Ankara?
If a permanent tooth has not come in for months even though the baby front tooth has fallen out, if there is a marked difference in eruption between the right and left sides, if a tooth is coming in in the wrong place or if your child injured their front teeth when they were younger, an early assessment can help keep treatment simpler. This is one of the reasons orthodontic organizations recommend that children have their first orthodontic check-up around age 7. At our clinic in Oran, Çankaya, the course of action is planned together with the family after an examination and any necessary imaging.
Frequently asked questions
How long after a baby tooth falls out does the permanent tooth come in?
This varies from child to child; the permanent tooth sometimes appears within a few weeks and sometimes within a few months. If the permanent tooth has not come in even though a long time has passed since the baby tooth fell out, or if its counterpart on the other side erupted long ago, a dental assessment is recommended.
What is a mesiodens, and does it always need to be removed?
A mesiodens is an extra (supernumerary) tooth located between the upper central incisors. If it is preventing the permanent teeth from erupting, displacing them or causing another problem, removal is usually recommended. In some cases where it causes no problems, monitoring may be considered.
Will an impacted front tooth come in on its own?
When the obstacle is removed and the tooth is moving in the right direction, some impacted teeth can erupt on their own. If the tooth's position is unfavorable or root development is advanced, surgical exposure and orthodontic eruption may be needed. The decision is made based on an X-ray assessment.
How long does orthodontic eruption treatment take?
The duration varies with the depth and position of the tooth and the child's age, and can generally range from a few months to a longer period. After eruption is complete, additional orthodontic treatment may be needed to align the teeth.
