Effect of mouth breathing on condylar position in children: A CBCT retrospective study
This retrospective CBCT study of 244 children aged 7–12 found that mouth breathing significantly alters condylar position, causing a more posterior, superior, and medial displacement with increased bilateral asymmetry compared to nasal breathing, thereby highlighting the need for early orthodontic monitoring to prevent temporomandibular joint dysfunction.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Every child has a natural way of breathing. For most, air flows quietly through the nose, a process that helps keep the jaw in a relaxed, forward position while the face grows. But for some children, the habit of breathing through the mouth takes over. This shift is not merely a matter of comfort; it changes the way the jaw muscles work and how the lower jaw sits within the skull. Over time, this altered posture can reshape the face, often leading to a longer, narrower appearance. While dentists have long known that mouth breathing affects the alignment of teeth, a new question has emerged: does this habit also change the position of the jaw's hinge itself? This hinge, known as the condyle, is a small, rounded bone at the back of the jaw that fits into a socket in the skull, much like a ball in a cup. It is the engine of jaw movement and a critical growth center during childhood. If this joint is forced into an unusual position, it could lead to pain, clicking, or long-term dysfunction.
Researchers at Zhejiang University in China set out to investigate this specific relationship. They wanted to see if children who breathe through their mouths have a different jaw joint position compared to those who breathe through their noses. To do this, they looked at the records of 244 children, aged 7 to 12, who had visited a dental hospital for orthodontic evaluation. The team divided these children into two groups: 124 who were mouth breathers and 120 who breathed through their noses. Using a specialized type of three-dimensional X-ray called a cone-beam computed tomography scan, the researchers created detailed digital models of the children's jaws. This technology allowed them to measure the tiny gaps of space around the jaw joint with great precision, looking at the space in front of, behind, above, and to the sides of the jaw bone.
The results revealed a clear and distinct difference between the two groups. In the children who breathed through their noses, the jaw joint tended to sit slightly forward within its socket, a position that is considered normal and healthy for this age group. In contrast, the children who breathed through their mouths showed a different pattern. Their jaw joints were pushed backward, upward, and slightly inward. The space in front of the joint was noticeably wider, while the space behind it was narrower. This shift suggests that the jaw is being pulled back and up, likely as a way to open the airway for easier breathing. The study also found that this backward shift was not perfectly symmetrical; the left and right joints in mouth-breathing children showed different amounts of space, indicating an uneven strain on the jaw.
The researchers were careful to account for other factors that could influence the jaw, such as the child's age, gender, body weight, and the general shape of their face. Even after adjusting for these variables, the breathing pattern remained a strong predictor of the joint's position. The data showed that mouth breathing independently drives the jaw joint into this posterior and superior location. While the study did not measure pain or diagnose joint disorders directly, the position of the joint is a known risk factor for future problems. When the jaw sits too far back, it can put pressure on the soft tissues inside the joint, potentially leading to dysfunction later in life.
This work highlights a connection between a simple daily habit and the structural development of a child's face. It suggests that the way a child breathes is a powerful force in shaping their jaw joint. For parents and clinicians, the findings offer a reason to pay close attention to children who breathe through their mouths. Identifying this habit early and addressing it could help prevent the jaw joint from settling into a position that might cause trouble down the road. The study does not claim to have solved the problem of jaw pain, but it provides a clear map of how breathing habits can alter the anatomy of the growing child, urging a closer look at the mouth-breathing child's jaw before orthodontic treatment begins.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.