Experts call attention to health and developmental impact of overbite and underbite

Dental problems range from mild plaque build-up and temporary sensitivity to advanced gum disease and oral cancer. Dentists say one of the most common but overlooked concerns, especially in children is malocclusion or misalignment of the teeth and jaws.

According to the World Health Organization, oral diseases affect nearly 3.5 billion people globally. Malocclusion is among the most prevalent oral conditions worldwide. The Global Burden of Disease Study 2019 lists severe malocclusion as a leading cause of non-fatal oral health burden. Studies also estimate that between 20% and 40% of school-going children show some degree of bite irregularity.

“People think it is only about appearance,” says Vijayalakshmi Padmanaban, consultant in oral and maxillofacial surgery, Kauvery Hospital, Chennai. “But bite alignment affects chewing, speech, jaw joint health and even how the face grows.”

Underbites and overbites

An overbite refers to the vertical overlap of the upper front teeth over the lower front teeth. A small overlap of about 2 mm is normal. When the overlap becomes excessive, it is called a deep overbite. An underbite, on the other hand, occurs when the lower front teeth protrude beyond the upper teeth, often giving the chin a forward appearance.

“In children, the upper teeth should gently overlap the lower teeth,” explains Pavani Thota, consultant in paediatric dentistry at Rainbow Children’s Hospital, Chennai. “If the overlap is too much, or if the lower teeth are sitting in front, it needs assessment. These patterns reflect jaw growth, not just tooth position.”

R. Poonkuzhali Suresh, consultant orthodontist, SIMS Hospital, Chennai, adds, “Underbite usually happens when the upper jaw is underdeveloped or the lower jaw grows excessively. Overbite may be due to vertical growth imbalance between the jaws.”

What causes these issues

Experts stress that both heredity and environment influence jaw alignment. “Jaw structure is largely inherited,” says Dr. Padmanaban. “If parents have jaw disorders , children may show similar growth patterns.”

However, habits during early childhood can worsen or modify this growth. Prolonged thumb sucking, pacifier use beyond infancy, tongue thrusting and mouth breathing can change pressure on developing teeth and bones. “When such habits continue for years, they alter normal growth direction,” says Dr. Pavani. She also points to prolonged bottle feeding and frequent sipper use as contributing factors in some deep bite cases. Dietary habits matter as well. “Children today consume softer foods,” says Dr. Poonkuzhali Suresh. “Chewing firmer foods stimulates jaw development. Reduced chewing may affect arch formation.” Early loss of milk teeth due to decay, jaw injuries and birth defects such as cleft lip and palate can also contribute to malocclusion.

Health impacts

Untreated bite issues can lead to multiple functional problems. Children may find it difficult to bite or chew food properly. Uneven pressure can cause enamel wear and gum injury. “There is also strain on the temporomandibular joint, the joint that allows the jaw to move,” says Dr. Padmanaban. “Misalignment can result in joint pain, clicking sounds and even headaches.” Airway concerns are increasingly recognised. Reduced tongue space in deep bite cases may lead to mouth breathing. Certain jaw patterns are associated with sleep-disordered breathing in children. Studies estimate that paediatric obstructive sleep apnoea affects between 1% and 5% of children globally.

Speech difficulties may arise in severe cases. “Pronunciation of certain sounds can become difficult,” says Dr. Pavani.

Why early screening matters

Experts recommend that children undergo orthodontic screening by age seven. At this stage, jaw growth can still be guided. “Early interceptive treatment allows us to modify growth rather than only align teeth later,” says Dr. Poonkuzhali Suresh. Growth-modifying appliances, palatal expanders and habit-breaking devices are commonly used between six and thirteen years of age.

“The upper jaw has a growth suture that remains flexible in younger children,” explains Dr. Pavani. “If we intervene during this window, we can avoid severe discrepancies that might otherwise require surgery in adulthood.” For teenagers and adults, braces and clear aligners are effective in many cases. Severe skeletal imbalances may require orthognathic (jaw) surgery combined with orthodontic treatment. “Early correction often reduces the need for invasive procedures later,” says Dr. Padmanaban.

While public dental programmes focus largely on cavities and gum disease, specialists believe bite alignment should receive more attention.

Experts recommend limiting prolonged pacifier use, encouraging children to chew age-appropriate foods and seeking dental evaluation if there is excessive overlap of teeth, a protruding chin or difficulty in biting.

Published – March 10, 2026 12:46 pm IST