Inwardly angled teeth, technically called retroclination or linguoversion, are a common orthodontic concern. This alignment issue occurs when one or more teeth are tilted backward toward the tongue or the roof of the mouth instead of standing upright. While appearance is a concern, this misalignment also contributes to functional problems with the bite. Modern orthodontics offers numerous effective solutions, making this issue highly treatable for patients of nearly any age.
Understanding Inward Teeth and Their Causes
The defining characteristic of an inward tooth is its backward lean relative to the jawbone. This positioning is often associated with a deep overbite, particularly in a Class II Division 2 malocclusion, where the upper front teeth are retroclined and excessively overlap the lower teeth. This alignment can result in a lack of lip support, sometimes creating a “sunken” appearance.
The causes of this inward tilt involve a mix of genetic predisposition and environmental factors. Inherited jaw size discrepancies are a frequent contributor, where a mismatch between the size of the teeth and the jawbone leads to crowding that forces teeth inward. Prolonged oral habits during childhood, such as thumb-sucking, pacifier use, or chronic tongue thrusting, can also exert consistent pressure that pushes the teeth out of position.
The premature loss of baby teeth or the natural process of aging (including bite collapse or gum recession) might also lead to the inward shifting of permanent teeth. If left untreated, retroclination can result in uneven wear on the back surfaces of the teeth and potential trauma to the gums or palate from the deep bite. Continuous misalignment places stress on the jaw joints, which may contribute to pain or dysfunction.
Standard Orthodontic Correction Methods
The goal of correcting retroclined teeth is to move the crowns and roots outward into a proper, upright position within the jawbone. This movement is achieved using controlled forces that encourage bone remodeling around the teeth. Orthodontic treatment focuses on two types of movement: tipping and bodily movement, with bodily movement being preferable for long-term stability.
Fixed Appliances (Braces)
Fixed appliances, commonly known as braces, are highly effective for the complex movements required to correct retroclination. Brackets are bonded to the teeth, and the archwire applies continuous pressure to gradually roll the tooth outward. For severe retroclination, the orthodontist aims for bodily movement (or translation), which moves the entire tooth—both the crown and the root—in parallel. This ensures the root follows the crown into the correct position. This controlled movement requires a stronger force than simple tipping and creates a stable, functional result.
Clear Aligners
Clear aligners, such as the Invisalign system, also treat retroclination through a sequence of custom-made plastic trays. To execute the necessary complex movement, especially root rotation, aligners rely on small, tooth-colored composite resin bumps called attachments or engagers. These attachments are temporarily bonded to the tooth surface and act as handles, giving the aligner a better grip to apply force and torque. Aligners may also incorporate specialized features like Power Ridges to help apply the necessary force to the crown and push the root outward (labial root torque).
Auxiliary Components
Auxiliary components are sometimes used alongside braces or aligners to create the necessary space or leverage. For example, a palatal expander may be used in growing patients to widen a narrow upper jaw, alleviating crowding that forces the front teeth inward. Specific springs or specialized archwires can be incorporated into fixed appliances to exert targeted forces on individual teeth, aiding in the complex rotational and uprighting movements.
Advanced and Surgical Interventions
For severe inward teeth involving significant skeletal misalignment, advanced or surgical solutions may be required. These interventions are reserved for adult patients whose jaw growth is complete or for those with complex skeletal malocclusions that cannot be corrected by tooth movement alone. The distinction lies in whether the problem is primarily dental (tooth position) or skeletal (jaw position).
Orthognathic Surgery
Orthognathic surgery, or corrective jaw surgery, is an option when the inward tilt compensates for a severe underlying jaw discrepancy. If the upper jaw is underdeveloped or positioned too far back, causing the upper teeth to angle sharply inward, surgery may be necessary to reposition the jawbones. This process involves pre-surgical orthodontics to align the teeth, followed by the surgery, and then a final phase of post-surgical orthodontics to refine the bite.
Temporary Anchorage Devices (TADs)
Temporary Anchorage Devices (TADs) are an effective advanced tool in orthodontics. These are small, biocompatible titanium alloy mini-screws, typically 1.5 to 2 millimeters in diameter, that are temporarily placed into the jawbone. TADs provide a fixed, stable point of anchorage resistant to unwanted movement.
This stable anchor allows the orthodontist to apply precise forces to move only the teeth requiring correction, without causing reciprocal movement in other teeth. For retroclined teeth, TADs apply force directly to the front teeth to pull them bodily forward. This makes complex movements possible that might otherwise have required headgear or surgery, achieving necessary root torque and translation in complex adult cases.
Maintaining Results After Treatment
The final phase of orthodontic treatment, especially after correcting significant changes in tooth angulation like retroclination, is retention. The goal of retention is to prevent the teeth from shifting back toward their original inward position, known as relapse. Relapse is driven by the recoil of the periodontal ligament fibers, which retain a memory of the tooth’s initial location, and the pressure exerted by the lips, cheeks, and tongue.
Retainers are appliances designed to hold the corrected teeth in their final positions until the surrounding bone and soft tissues have stabilized, a process that can take many months. Two primary types of retainers are used for this long-term stability.
Fixed Retainers
Fixed retainers, also called bonded or permanent retainers, consist of a thin, custom-fitted wire bonded to the tongue-side surface of the front teeth. They are often recommended after retroclination correction because they provide continuous, passive pressure, preventing the teeth from tilting inward again. While offering excellent stability, they require meticulous flossing and hygiene to prevent plaque buildup.
Removable Retainers
Removable retainers include the clear Essix retainers, which fit over the entire arch like a thin mouthguard, and the traditional Hawley retainers, which use a metal wire and acrylic plate. Removable retainers are usually worn full-time for the first few months, followed by nightly wear indefinitely. Long-term compliance is the main factor in preventing the subtle, gradual inward shift that can occur years after treatment.