A lack of tooth display, characterized by insufficient visibility of the upper central incisors when speaking or smiling, can create an appearance of premature aging or a less vibrant smile. This condition is often a symptom of underlying issues related to tooth wear, gum tissue height, or jaw structure. An ideal smile generally reveals some upper tooth structure at rest and a greater display upon animation. Addressing this concern requires accurate diagnosis of the cause, which may involve solutions ranging from simple dental additions to complex surgical corrections.
Restorative and Orthodontic Methods
When the cause is related to the actual size or position of the teeth, dentists often employ methods that physically add length to the tooth structure. Teeth that have been shortened over time due to grinding or are naturally small can be lengthened using porcelain veneers or crowns. These thin, custom-made restorations are bonded to the front surface of the tooth to effectively increase the incisal edge length, with additions of up to 2 millimeters being common.
Precise planning ensures the new length harmonizes with the surrounding soft tissues and the patient’s bite. For a significant increase in length, the porcelain material is often prepared with an incisal butt joint, which ensures strength and a seamless look at the biting edge. This technique protects the remaining natural tooth structure from further wear.
For teeth positioned too high within the jawbone, orthodontic treatment moves them vertically into a more favorable position. This process, known as orthodontic extrusion, involves applying light, continuous forces using braces or clear aligners. The controlled movement gradually brings the entire tooth and its supporting structures downward, increasing the amount of tooth visible beneath the upper lip. This non-surgical approach achieves a few millimeters of added display, providing a stable, natural result.
Addressing Gum and Lip Interference
Sometimes, the teeth themselves are an appropriate length, but they are covered by excessive gum tissue, a condition known as altered passive eruption. In such cases, procedures that modify the soft tissues are necessary to expose the full anatomical crown of the tooth. Gingivectomy is a straightforward procedure that involves removing only the excess soft gum tissue to reveal more of the underlying tooth.
If the underlying bone supporting the gum tissue is positioned too far toward the biting surface, a more involved procedure called esthetic crown lengthening is necessary. This surgery involves gently repositioning both the gum tissue and the underlying bone to establish a healthy biological distance around the tooth neck. Removing a small amount of bone prevents the gum tissue from growing back over the tooth, ensuring the long-term stability of the new, more visible tooth length.
A hypermobile or short upper lip can rise too far when smiling, exposing excessive gum tissue. Lip repositioning, a minor surgical procedure, restricts the upward pull of the lip’s elevator muscles. This technique involves removing a small band of tissue from the inner surface of the lip and suturing the lip lining lower down. Lip repositioning is a conservative alternative that can reduce excessive gum exposure, often by 3 to 4 millimeters.
Correcting Skeletal Causes
The most complex cases of minimal tooth display are often rooted in the underlying jaw structure, a condition frequently related to vertical maxillary deficiency, sometimes referred to as Short Face Syndrome. This is a skeletal pattern where the vertical height of the upper jaw (maxilla) is deficient, causing the entire middle and lower face to appear vertically short. The lack of proper vertical dimension means the upper teeth are physically located too high to be adequately visible.
The definitive solution for this structural issue is orthognathic surgery, specifically a Le Fort I osteotomy. This procedure allows the oral surgeon to separate the tooth-bearing portion of the maxilla from the rest of the facial skeleton. The maxilla is then surgically moved downward, often with a slight forward rotation. This movement effectively lengthens the lower third of the face and brings the entire upper dental arch into a position of proper tooth display.
Severe wear and tear can collapse the back teeth, reducing the vertical dimension of occlusion (VDO). This shortens the face and minimizes anterior tooth display. Full mouth reconstruction addresses this by re-establishing the correct VDO. This process involves using provisional restorations to gradually increase the height of the bite, creating space for the anterior teeth to be restored to their ideal length, often with crowns or veneers across both arches.