Malocclusion is a condition characterized by the misalignment of teeth in one or both of the arches or the jaws in the mouth. This may or may not be associated with the underlying skeletal problem.
Occlusion is the process of contact or the manner in which both the upper and lower teeth meet when the mouth is closed. When there is a misalignment of teeth the normal occlusion pattern is disrupted leading to malocclusion.
The classical definition of occlusion given by Angles is as following.
“Occlusion is the normal relation of the occlusal inclined planes of the teeth when the jaws are closed”. When that doesn’t happen, the condition can be termed as ‘malocclusion’.
Causes of Malocclusion
Malocclusion can be caused due to a number of reasons. Two main reasons that may cause malocclusion in humans are genetic factors and environmental factors.
Other factors that may hinder the process of development of normal occlusion are dentoalveolar, skeletal and neuromuscular factors.
Then there may be certain local factors that can cause malocclusion.
Hereditary Factors Causing Malocclusion
There are a number of human traits which may be influenced by the genes.
- Abnormalities of tooth size
- Abnormalities of jaw length and width
- Crowding and spacing of teeth
- Tooth shape abnormalities
- Discrepancies in tooth number
- Size, position, and shape of the frenum
Congenital Factors Causing Discrepancy of the Normal Occlusion
- The abnormal state of the mother during pregnancy
- Endocrine diseases
- Infectious diseases
- Cleft lip and palet
- Cleidocranial Dysostosis
- Cerebral Palsy
- Congenital Syphilis
- Maternal rubella infections
Many prenatal and postnatal environmental factors may cause malocclusion.
- Abnormal fetal posture
- Maternal fibroids
- Amniotic lesions
- Maternal diet and metabolism
- Maternal infection
- Use of certain drugs during pregnancy such as Thalidomide
We have written a brief article explaining the problems that can be caused due to malocclusion or crooked teeth. Click the link to read about crooked teeth and the problems associated with them.
Types of Malocclusion
Malocclusions can occur in numerous combinations and it is very difficult to classify them.
Here is a broad classification
Type 1: Intra Arch Mal-occlusions
These include discrepancies in individual tooth position and affects the group of teeth in the same arch/jaw, meaning, only the teeth in either maxilla or mandible may be affected.
Type 2: Inter Arch Mal-Occlusions
In this case, the relation of the upper and lower jaw is compromised but the underlying bony structure is normal.
Type 3: Skeletal Mal-Occlusions
Here the underlying skeletal structure is compromised causing the discrepancy in the normal occlusion.
Angle’s Classification of Malocclusion
Angel’s classification is the universally accepted classification of mal-occlusion right now.
Angle’s Class 1:
Here, there is a normal inter arch molar relationship. Upper teeth overlap the lower teeth normally, with normal bite and slight overlap.
Angle’s Class 2:
This is characterized by the presence of deep overbite. The overlap of upper teeth and jaw over the lower teeth and jaw, in this case, is severe.
Angle’s Class 3:
This class of malocclusion is characterized by protrusion of the lower jaw. Here, the lower teeth may overlap the upper teeth.
How Do You Diagnose Malocclusion
A deviation from the normal occlusion pattern in an individual is easily diagnosed by the dentist with a simple clinical examination.
To look for the level of skeletal involvement and any hidden or impacted teeth the dentist will most probably take the help of radiographs.
Here are some of the factors that indicate the presence of malocclusion.
Symptoms of Defective Occlusion:
An individual may have the following symptoms if he or she is suffering from defective occlusion.
- There will be malalignment (misalignment) of teeth in the person.
- The face may look abnormal or slightly disfigured in some cases.
- The jaws or one of the jaw may be of abnormal length or width.
- Mouth breathing may be present especially in Angle’s class 3 cases.
- Thumb sucking habit is commonly associated with defective occlusion.
- When the person closes the mouth the upper and lower jaws don’t meet completely.
- Difficulty in eating, especially while biting or chewing may be present.
- Speech difficulties may be experienced by the individual
Malocclusion is treated orthodontically. The main goal of the treatment is to correct the alignment of teeth and the relationship of the jaws to improve functionality and the appearance of the face.
The important treatment options may include
- Placement of braces and/or other orthodontic appliances.
- Removal of certain teeth to create space in the jaws.
- Orthognathic surgeries may be required in severe cases.
- Once the orthodontic treatment has been completed a retainer may be given to prevent the relapse.