Deep Overbite: Causes, Risks, and Correction Methods

A deep overbite, where the upper front teeth excessively overlap the lower front teeth, is a common dental issue affecting both function and aesthetics. While some vertical overlap is normal, excessive overbite can lead to complications if left unaddressed. Understanding its impact on oral health and available treatments is essential for long-term dental well-being.

Addressing significant over-closure is crucial for maintaining proper dental function. Various skeletal, dental, and neuromuscular factors contribute to this condition, and targeted interventions can help restore alignment and prevent complications.

Structural Factors Influencing Bite Depth

Bite depth is influenced by skeletal, dental, and neuromuscular factors that determine how the upper and lower teeth interact. A primary structural contributor is the vertical relationship between the maxilla and mandible. Individuals with a deep overbite often have a shorter lower facial height due to an overdeveloped maxilla or underdeveloped mandible, causing excessive overlap of the upper teeth. Cephalometric studies show that patients with deep overbites frequently have a reduced mandibular plane angle, indicating a more closed vertical dimension that worsens the condition.

Dental positioning also plays a key role. Overeruption of the maxillary incisors or infraeruption of the mandibular incisors can exaggerate vertical overlap, often due to early tooth loss or inadequate posterior support. Research in the Journal of Prosthetic Dentistry highlights that posterior tooth wear or loss can further deepen an overbite by reducing the vertical dimension of occlusion, forcing excessive anterior contact.

Muscle function also affects overbite severity, particularly the activity of the masticatory and perioral muscles. Hyperactivity of the masseter and temporalis muscles can contribute to excessive bite force, deepening the overbite over time. Electromyography (EMG) studies show that individuals with deep overbites often have increased muscle tone in these areas, reinforcing bite over-closure. Parafunctional habits such as bruxism or tongue thrusting can further alter tooth position by applying continuous pressure to the anterior teeth.

Oral Health Issues Linked To Over-Closure

Excessive overbite can lead to various oral health complications beyond misalignment. One major concern is increased enamel wear, particularly on the lingual surfaces of the maxillary incisors and the incisal edges of the mandibular incisors. Constant or excessive contact accelerates mechanical attrition, leading to enamel thinning and, in severe cases, dentin exposure. A study in the Journal of Oral Rehabilitation found that patients with deep overbites experience significantly higher enamel loss rates than those with normal occlusion.

Deep overbites also contribute to temporomandibular joint (TMJ) dysfunction. The altered vertical dimension forces the mandible into a retruded position, placing stress on the TMJs. This can cause jaw pain, clicking, and restricted movement. Research in the Journal of Prosthodontic Research indicates that individuals with deep overbites are more likely to experience myofascial pain syndrome due to increased strain on the masticatory muscles. Chronic TMJ overloading can also lead to disc displacement, further complicating jaw function.

Soft tissue trauma is another common issue, particularly when the lower incisors contact the palatal mucosa. Repeated impingement can cause irritation, ulceration, and even keratinization of the palatal tissue. Clinical reports document cases where prolonged trauma from deep overbites leads to localized inflammation and a higher risk of secondary infections due to compromised mucosal integrity. This irritation can also cause discomfort during speech and chewing.

Occlusal Considerations In Prosthodontics

Managing deep overbite in prosthodontic treatment requires careful assessment of vertical dimension, occlusal stability, and long-term function. The challenge is restoring an appropriate occlusal relationship while preventing excessive forces on anterior restorations, which are particularly vulnerable in cases of significant over-closure. When fabricating prosthetic restorations, clinicians must balance the occlusal plane to evenly distribute masticatory forces, reducing the risk of premature wear or fracture.

Achieving a stable occlusion in deep overbite cases often requires occlusal equilibration, particularly in full-mouth rehabilitations or extensive prosthetic work. Proper anterior guidance is crucial, as inadequate guidance can exacerbate bruxism, further threatening restoration longevity. A systematic review in the International Journal of Prosthodontics highlights that patients with deep overbites benefit from customized anterior guidance to prevent excessive stress on restorations, particularly porcelain veneers or crowns. Adjusting the occlusal scheme helps mitigate wear and ensures a more physiologic force distribution.

Material selection is also key, especially when deep overbite increases occlusal stress. High-strength ceramics such as zirconia or lithium disilicate are preferred for anterior restorations due to their superior fracture resistance compared to traditional feldspathic porcelain. Additionally, occlusal splints for nighttime wear can protect restorations from excessive forces, especially in patients with a history of bruxism. A study in the Journal of Prosthetic Dentistry found that patients with deep overbites who used occlusal splints had significantly lower restoration failure rates.

Orthodontic Adjustments To Correct Vertical Overlap

Correcting a deep overbite through orthodontic treatment requires strategic vertical tooth movement, skeletal alignment, and occlusal stability. Effective interventions focus on reducing excessive overlap while maintaining harmony between the upper and lower arches. One primary technique involves controlled intrusion of the maxillary or mandibular incisors using fixed appliances such as braces with intrusion arches or temporary anchorage devices (TADs). These methods allow precise vertical repositioning, minimizing excessive overlap.

Beyond incisor intrusion, posterior extrusion helps reestablish a balanced occlusal plane. Selectively extruding molars and premolars increases the vertical dimension of occlusion, reducing anterior overbite depth. This approach is particularly beneficial in growing patients, where functional appliances such as bite ramps or mandibular advancement devices encourage favorable skeletal adaptation. Studies in the American Journal of Orthodontics and Dentofacial Orthopedics indicate that early intervention with these appliances significantly improves mandibular positioning, preventing worsening overbite severity in adolescence.