Direct bond hooks are placed on the buccal surface of the maxillary molar and the lingual surface of the mandibular molar. Inter-arch elastics are then used to correct the crossbite. Reciprocal force is applied, moving both molars. If only one tooth needs to be moved, the other must be tied to an anchor unit or this approach will not work. If desired, buttons can be used in place of hooks; however, hooks retain the elastic better. Note: If the patient is already in the adult dentition stage, slight occlusal adjustment of the molars or use of a bite plane is often required during treatment — and can be accomplished by using a Hawley with an anterior bite plane or a bruxism splint. Once the condition is corrected, normal intercuspation is usually sufficient to maintain the results.

Choosing the best appliance to correct this problem is dependent upon the depth of the bite, the space available, and whether or not an occlusal interference is involved. With this appliance, there is plenty of arch space to move the central forward. There are no occlusal interferences causing a mandibular shift…and the depth of the patient’s bite is ideal. A simple Hawley with a posterior occlusal bite plane and a recurved spring is used. The occlusal bite plane clears the occlusion sufficiently to let the recurved spring move the anterior forward, while preventing any unwanted change in the patient’s ideal vertical dimension. It also aids in appliance retention. Once the crossbite is corrected, the bite plane can be removed and the appliance can serve as a retainer. Note: If the spring is riding up the lingual incline of the central instead of pushing it forward, we recommend that you clear the acrylic away from the spring and add a small composite ledge on the lingual surface of the tooth to act as a positive sprint-stop. Removing the acrylic will also make it easier to adjust the spring with 139 bird-beak pliers.

Causal factors can included abnormal tongue posture, irregular swallowing pattern, and an obstructed airway due to allergies. The Standard Schwarz with Occlusal Coverage is ideal for addressing this condition. It is designed with a smooth posterior bite plane to allow the posterior teeth to move free of any occlusal interference.

Turning the expansion screw one-quarter turn a week exerts a slow, constant pressure on the teeth and bone. This develops the arch and moves both posterior segments buccally out of crossbite — and drops a high vaulted palate, opening the nasal airway. As the palate drops, it will be necessary to adjust the palatal acrylic throughout treatment. Important: Recognition and treatment of a posterior crossbite early in a child’s development is essential. When left untreated, it can lead to numerous serious medical complications, e.g. Class II skeletal deformity, TMJ dysfunction, airway obstruction.

An alternative approach that has shown to be equally as effective is the use of rapid expansion to open the mid-palatal suture. The Hyrax High Palate Rapid Palate Expander can be used successfully in patients with mild-to-moderate transverse constriction when they are in the late mixed or early permanent dentition. In this case, sutures are presumably still patent — and the appliance works best when the crossbite is caused by a deficiency of the maxillary apical base.

Rapid expansion is obtained over a two-to-three week period by means of turning the expansion screw once a day. This creates enough pressure to separate the mid-palatal suture and the appliance is then worn for another three to five months to allow time for osseous healing. Framework is all-stainless metal. The expansion screw is positioned high in the palate for greater comfort. Bands are placed on the first molars and rests are bonded to the occlusal surface of the primary molars. Path of insertion problems, e.g. that which occurs when four bands are used, are eliminated. Extra heavy support wires are also used to prevent the appliance from flexing as pressure is applied. If you find that the posterior crossbite is locked due to a deep bite or tight intercuspation, it is recommend that a lower occlusal splint be placed temporarily to expedite treatment — without affecting the mandibular dentition.

During construction, careful attention must be paid to the angle of the slide in order to ensure comfort as well as effectiveness. Clear acrylic may be used to make the appliance less conspicuous. No adjustment is typically necessary — aside from occasional spot grinding on the acrylic to facilitate movement. Because it is necessary to actively function against the incline to achieve optimum results, a very cooperative patient is also necessary.

A true single tooth crossbite (midlines concomitant no visible mandible shift), can easily be corrected with this simple appliance. Maxillary and mandibular bands are made for the two molars. Hooks are placed on the buccal of the maxillary band and the lingual of the mandibular band, so an elastic force can be used to correct the crossbite. A reciprocal force is applied, moving both molars. If the patient is already in the adult dentition stage, slight occlusal adjustment of the molars (or the use of a bite plane) is often needed during treatment. Once the condition is corrected, normal intercuspation is usually sufficient to maintain the results. Bands (as opposed to direct bond hooks alone) are recommended when significant occlusal interferences are present. Said presence may cause a direct bond bracket to be sheared off the tooth. Note: If only one tooth needs to be moved, the other must be tied to an anchor unit or this approach will not work.

Appliance selection to correct this problem is dependent upon the depth of the bite and the existence of adequate arch space to move the tooth back into position. Typically there is plenty of space to move the molar back into the arch. However, if clinical and model examination indicates a significantly deep bite and the tooth is locked lingually, a small anterior bite plane should be added to the appliance. Here a single expansion screw is used to exert pressure on the molar. With this expansion screw, you should expect to get both tipping and some bodily movement of the molar. Note: All expansion screws of this type are adjusted once a week, one-quarter turn. As with all crossbite cases, the lab must be supplied with upper and lower models and a wax bite — this in the express interest of enabling a check for occlusal interference and assistance in selecting the right design.

Easy to adjust, they can effectively upright tipped molars, usually with only two or three adjustments. The rest, placed on the molar with the distal recurved spring, aids in prohibiting super-eruption when an opposing tooth is missing. Note: When using “C” clasps, consider the use of a composite ledge for superior retention.

They appear to be unilateral because the mandible shifts to avoid an occlusal interference. Before beginning treatment for a unilateral posterior crossbite, observe the relationship of the upper and lower teeth to each other — first out of occlusion, then in occlusion. If no shift is observed — and there is not a change anywhere in the occlusal relationship — a true unilateral crossbite exists. The removable appliance shown here is particularly useful for moving an entire posterior segment that is in a unilateral crossbite. Designed to utilize the entire part of the arch that is not in crossbite for anchorage, it ensures that by turning the expansion screw, the segment that is in crossbite will move out buccally. The bite is opened with a posterior bite plane to clear the occlusion. The stationary side of the bite plane is usually ground into occlusion for extra stability. The moving side is left smooth.

Because the anterior part of the arch is narrower, these teeth will often end up in crossbite. The mesial migration of these teeth also creates enough loss in the arch length that the cuspid either remains impacted or is forced to erupt labially from its normal position. To correct the crossbite and make room for the cuspid, the posterior segment needs to be moved distally and buccally. This Witzig Crossbite Appliance accomplishes this. In this design, the expansion screws are angled to provide a disto-buccal movement. The use of two screws is recommended to provide enough force to expedite crossbite correction. To clear the occlusion, the bite is opened with a posterior bite plane. The stationary side of the bite plane is usually ground into occlusion for extra stability while the moving side is left smooth. A cuspid retraction wire is often added to this appliance to begin guiding the cuspid back to its normal position.

By placing Uprighting Lower Posteriors Expansion Device, it is possible to upright this segment. The labial arch wire is incorporated into the non-moving section to create additional anchorage. The expansion screw is adjusted one-quarter turn once each week, providing 1mm of movement a month. This particular design is used to move one posterior quadrant buccally, from the bicuspids distally. Note: If the tipped segment is in crossbite, it will be necessary to either design the appliance with an occlusal plane or make an opposing appliance with an anterior bite plane or occlusal coverage.

Although this allows them to maximize their ability to chew with their posterior teeth, it creates a pseudo Class III Anterior Crossbite or an end-to-end anterior bite. Over time, this abnormal function will direct the mandible to grow forward, inhibit the growth of the pre-maxilla and create a skeletal Class III. Anterior crossbites of this nature need to be treated as early as possible. The simplest way to do so is to first eliminate the source of the interference and then move the inhibited pre-maxilla back to its normal position with an appliance like the one shown here. In this appliance, the entire anterior segment is moved labially with an expansion screw placed in the sagittal position. The labial arch wire moves with the segment as a unit while the posterior teeth are used for anchorage. A posterior bite plane is necessary if the anterior teeth are already lingually locked behind the lower incisors.

The bonded bite plane, along with a rigid framework, creates a movement that is mainly orthopedic in nature — especially suited for those patients who are still in mixed dentition. Besides correcting a crossbite, it has been shown that expansion of the maxilla during the early mixed dentition may lead to a spontaneous correction of other occlusal disharmonies, e.g. expansion of the upper arch in a skeletal Class II can allow the mandible to come forward on its own. Note: When delivering this appliance, make sure to maintain a dry environment. Special instructions (along with all the necessary supplies) can be provided to you through SML Supplies.