Macro and Microdontia: Alterations in Tooth Size

Macrodontia and microdontia are alterations in the size of teeth that can affect the esthetics and functionality of a person's smile. We'll tell you what they are and how dentists approach this condition here.
Macro and Microdontia: Alterations in Tooth Size
Vanesa Evangelina Buffa

Written and verified by the dentist Vanesa Evangelina Buffa.

Last update: 03 August, 2023

Given today’s beauty standards, anomalies in the mouth can be a cause for concern for many people. Alterations in the size of the teeth, such as microdontia or macrodontia, are one of those situations that can affect the aesthetics of the smile.

Each person has teeth of a particular shape and size. In certain cases, the teeth may be larger or smaller than normal. For some, these characteristics are a distinctive feature of their smile; but for others, this is a reason for displeasure that they want to change.

Thanks to recent advances in cosmetic dentistry, alterations in the size of teeth can be resolved. In this article, we’ll tell you everything you need to know about macrodontia and microdontia in detail, as well as the alternatives to treat them.

The normal size of teeth and their alterations

For a smile to look attractive, all the components of the mouth must be in balance and harmony. The shape of the lips, the amount of gum tissue, and the arrangement and size of the teeth influence the appearance of this area of the face.

As mentioned above, the size and shape of the teeth are different for everyone. Therefore, there’s no normal size of teeth, but there is a certain range that tends to be repeated in most people.

Several experts have studied the most common dimensions of the different types of teeth. They analyze the length of the crown, the root, and the totality of each dental element in the mouth. With this, they’ve been able to arrive at an average.

When the teeth are outside these ranges – that is, they are larger or smaller than usual – then we’re talking about size alterations or anomalies. However, as we explained at the beginning, a smile is harmonious thanks to the conjunction of several features.

People have teeth of dimensions and shapes proportional to the size of their jaws. However, sometimes this balance doesn’t occur, and the teeth are perceived as too large or too small for the arch that contains them.

Both macrodontia and microdontia are usually anomalies of hereditary origin. Genes determine the size of the teeth and jaws, but they’re transmitted independently. This means that the same person is susceptible to inheriting a large jaw and small teeth, or vice versa.

In order for the dentist to diagnose alterations in the size of the teeth, there must be a disproportion between the teeth and the jaw. In these cases, we will be facing a case of macrodontia or microdontia. We’ll tell you more about these anomalies in the next section.

DNA can influence Microdontia or macrodentia
Genetic inheritance is capable of determining the size of the teeth, as well as the size of the jaws.

Microdontia or small teeth

Microdontia is an anomaly in the size of the teeth that manifests itself with teeth that are too small. This decrease in the dimensions of the teeth can occur in an element of the mouth that is perceived to be much smaller than the rest or in the entire dentition.

In general, the roots of these teeth have a normal size, but their crowns are smaller than usual. They also usually have conical shapes.

Depending on the number of teeth affected, we can distinguish between several different types of microdontia:

  • Partial microdontia: This is the most common type. It only affects one or a few teeth that are smaller than the rest of the dentition. It usually occurs in the upper lateral incisors, premolars, third molars, and supernumerary teeth. It’s common that the teeth also have alterations in their shape.
  • Generalized microdontia: In this not-so-frequent case, all the teeth of the arch are a smaller size than usual. This is usually linked to certain diseases, such as pituitary dwarfism and other genetic disorders.
  • Relative microdontia: In this case, the patient has a large maxilla that causes the teeth to appear smaller. This is only an assessment due to the lack of proportion between the size of the bone and the teeth.

The causes of small teeth

Microdontia usually occurs in isolation in one or two teeth. Genetic and environmental factors influence the origin of these alterations in tooth size.

However, there are rare cases in which a genetic syndrome is an underlying cause. We’ll tell you about the conditions associated with the appearance of microdontia:

  • Pituitary dwarfism: Pituitary dwarfism can cause truly generalized microdontia. All teeth are smaller than average.
  • Chemotherapy or radiation: Receiving these treatments during early childhood, before the age of 6, can affect tooth development and cause microdontia.
  • Cleft lip or cleft palate: Children born with clefts in the lip or palate often have dental abnormalities in the cleft area.
  • Congenital deafness syndrome with labyrinthine aplasia, microtia, and microdontia (LAMM): This is a developmental condition of the teeth and ears. The outer and inner ear structures are very small and underdeveloped, and the teeth are small and widely spaced.
  • Down syndrome: Small, peg-shaped teeth are common in people with Down syndrome.
  • Ectodermal dysplasias: In this genetic condition, the formation of skin, hair, nails, and teeth is affected and may be smaller. The teeth are usually conical in shape, and many may even be missing.

The consequences and solutions for alterations in small tooth size

The most visible consequence of microdontia is the esthetic aspect. Since the teeth have different sizes, the smile is not harmonious or balanced.

This situation can be uncomfortable for some people who want to have attractive teeth. There are different alternatives to solve this type of alteration and achieve a beautiful smile:

  • Restorations: The teeth are restored to a smaller size than usual with filling materials, such as composite resins.
  • Dental crowns: The smaller tooth is completely covered by a crown or cap of the appropriate shape and size.
  • Aesthetic veneers: Thin sheets of porcelain or composite resin are bonded to the outer surface of the teeth, improving their shape and size.

It’s also possible that, in many cases, in addition to these solutions, complementary orthodontic treatment may be necessary. With braces, it will be possible to correct the dental position and achieve harmony in the entire dentition.

We think you may be interested in reading this, too: Seven Home Remedies for Removing Plaque From Your Teeth


Macrodontia is another alteration in the size of the teeth in which the teeth are larger than normal. As in the case of microdontia, we can distinguish different types depending on the number of elements affected:

  • Partial macrodontia: This only affects single teeth, which are usually the canines, incisors, or third molars.
  • Generalized macrodontia: This is also known as total macrodontia or macrodontism. In this case, all teeth in the dentition are larger than usual. It’s usually linked to diseases such as pituitary gigantism and hemihypertrophy.

Causes of macrodontia

There is no defined cause of macrodontia. However, as in the case of microdontia, hereditary and genetic origin seems to be the most common causes of this condition. Mutations in the genes that regulate tooth growth could cause the teeth to overgrow.

The action of other factors could also favor the appearance of these alterations in tooth size. Diet, exposure to radiation, or toxins during childhood can predispose a person to develop macrodontia.

Like this article? You may also like to read: 9 Natural and Effective Tips for Taking Care of Your Teeth

Solutions for alterations in the size of very large teeth

When teeth are too large, they not only affect the aesthetics of the smile. They can also generate bite problems, crowding, and dental malposition.

Orthodontics is usually one of the necessary procedures to solve these alterations. With these treatments, the teeth can be positioned in the correct place, or the jaws can be expanded so that the teeth have the space they need.

In addition to braces, other types of treatments are often used to improve the appearance of the teeth:

  • Stripping or dental contouring: This consists of polishing the teeth in a controlled manner to reduce their width. This selective grinding of the teeth allows for gaining space between them. However, it’s only performed on healthy teeth with sufficient enamel thickness. Otherwise, subsequent discomfort may occur.
  • Dental crowns or veneers: In this case, the tooth is first ground down to reduce its volume. Then, it is covered with a crown or a veneer with dimensions similar to the rest of the teeth.
  • Tooth extraction: Some cases require the removal of the larger tooth. This can facilitate the repositioning of the other elements through orthodontic treatment to achieve a more harmonious smile.
Among the many dental esthetic options to resolve problems with small or large teeth, there are some useful alternatives for microdontia and macrodontia, such as veneers.

An important clarification about alterations in the size of teeth

Sometimes, microdontia and macrodontia can be confused with other situations that have nothing to do with each other. It’s very common that at the time of dental replacement in children, for example, some parents may think that they suffer from macrodontia.

At first glance, the new teeth seem too big, but this happens because their jaws are still growing, and these pieces will accompany the child during his or her adulthood. In addition, when comparing them with the baby teeth that remain in the mouth and are smaller, the difference in size can be confusing.

On the other hand, it’s possible to find adults who have a tooth that’s smaller than the others. This could lead us to suspect microdontia. What can happen, in reality, is that they actually still have a baby tooth.

When there’s agenesis of a permanent tooth (the permanent tooth doesn’t exist because it has never been formed), the temporary element persists in the mouth. This baby tooth is sized according to the size of a child’s mouth. Therefore, in an adult dentition, it looks much smaller than the others.

Another situation that’s worth clarifying because it can be confused with a macrodontia is when there’s a tooth in the mouth that’s longer than the others. This is very frequent in the central incisors.

A long tooth can be due to irregularities in the incisal edges or to the retraction of the gum that leaves the root zone exposed. The first case is solved with an esthetic dental contouring and the second with a periodontal treatment.

Professional help for alterations in the size of teeth

If you suspect that you have any of the alterations in the size of your teeth that we’ve told you about here, you should seek professional advice. As we told you, microdontia and macrodontia can affect the aesthetics of your smile and cause dental malposition or bite problems.

With a dental checkup you can remove all doubts and arrive at an accurate diagnosis. The professional will help you find out what’s wrong with the size of your teeth and look for a solution that will allow you to have a healthy smile that you feel comfortable and at ease with.

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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.