Functional Appliances

Most children with crowded teeth and bad bites have narrow jaws and underdeveloped lower jaws, which could be corrected with functional appliances. Functional appliances help correct the bone problems, while the tooth problems are corrected with the orthodontic braces.

The ideal age for the use of functional appliances is between ages seven and eleven, when the cooperation level is the highest. However, functional appliances can be utilized as early as age 4, if the upper jaw is too narrow and is having a negative effect on the child’s breathing and speech. Arch development (functional appliances) can also be used in adults to develop the arch to a more normal shape and size before applying the braces.

The use of functional appliances can reduce the time the child must wear fixed braces and also can reduce the need for the extraction of permanent teeth. Functional appliances develop the dental arches so that all the permanent teeth can erupt, which ensures an outstanding profile, broad smile and healthy jaw joints.

Please feel free to click on any of the Functional Appliances below for more information.

Twin Block Appliance
example of what the twin block appliance can do


This functional appliance consists of two bite blocks, upper and lower, which interlock at 70°. Twin Blocks™ are designed so the mandible is held in a protrusive position. This appliance is ideal in cases with large overjets when the mandible is recessive.

This is a comfortable appliance to wear as patients rarely have problems speaking or eating with the appliance.

It can be used in combination with vertical elastics to correct deep overbite.

The activation of the midline screws assist with the transverse development. Since 80% of Class II malocclusions have deficient mandibles, the Twin Block™ is a must for the treatment of the majority of Class II cases for patients under age 11 who are good co-operators.

Mara appliance example


The new MARA™ (Mandibular Anterior Repositioning Appliance) is ideal for non-compliant patients with Class II skeletal malocclusions and deficient mandibles.

It is well tolerated by the patient since the attachments are soldered to stainless steel crowns on the first molars. It is a fixed-functional appliance that is worn 24 hours per day which virtually guarantees success.

The MARA™ appliance is the appliance of choice for patients over age 11. Since 70% of all malocclusions are Class II and the vast majority have deficient mandibles, this is the ideal fixed appliance for the treatment of Class II skeletal malocclusions.


The anterior sagittal is an upper removable orthodontic appliance that is used in the mixed or permanent dentition to correct anterior crossbites. The bite may be opened either with occlusal pads on the appliance or with composite buildups on the lower posterior teeth (primary molars if possible).

The primary function is to move the upper incisors forward to correct the anterior crossbite.

The appliance cannot be used if the upper incisors are flared. Ideally the anterior sagittal has 4 Adam’s clasps for retention and 2 side screws with the cuts in the acrylic distal to the upper lateral incisors.

The anterior sagittal is adjusted twice per week to avoid any discomfort for the patient. Early orthodontic treatment can correct early Class III malocclusions and prevent more serious and more costly procedures later on. Mothers want their children treated early in an effort to avoid orthognathic surgery when they are teenagers.


The posterior sagittal is a removable orthodontic appliance that can be used on the upper or lower arches primarily to distalize the molars.

Ideally the posterior sagittal has 4 clasps and a side screw for every molar that needs to be distalized. The cut in the acrylic is mesial to the molar being distalized. This is an ideal appliance to be utilized if there is an arch length discrepancy and the first molar has drifted mesially and possibly blocked out a bicuspid or a cuspid.

The posterior sagittal is adjusted twice per week to avoid any discomfort to the patient. The utilization of the posterior sagittal appliance can make space for the bicuspid and cuspids therefore preventing the need for the extraction of permanent teeth.

Maxillary Banded Hyrax


This is one of the most popular fixed arch expansion appliances for mixed and permanent dentition. Since it is fixed, cooperation is guaranteed.

The hyrax appliance consists of a midline hyrax screw, first molar bands, mesial rests on the first primary molars or first bicuspids usually. These mesial rests must be secured with flowable composite for added retention.

The hyrax is adjusted slowly, twice per week. After the desired amount of expansion has been achieved the appliance must be left in for an additional 6 months to avoid a relapse.


This is the most popular fixed appliance to be used mainly in mixed dentition to help develop the upper arch to normal width as well as to use a fixed crib to stop the tongue or thumb habit. To prevent habits, particularly at night, when the patient is asleep, you need a fixed appliance to successfully correct the habits.

This appliance consists of a hyrax screw, a habit crib, first molar bands, mesial rests on the first primary molars. These mesial rests must be secured with flowable composite for added retention.

The hyrax with a crib must be adjusted slowly twice per week. The crib should be left in for 5 months in order to correct the tongue or thumb habit. Usually the open bite will be corrected as the incisors will erupt when the habit has been corrected.

After 5 months, remove the crib but leave in the appliance for 6 months after the last adjustment of the hyrax screw to prevent a relapse.


The new Tandem™ appliance is ideal for Class III skeletal patients in mixed dentition who have retrognathic maxillas and normal mandibles.

The upper part is fixed and consists of a Maxillary Banded Hyrax Appliance with two hooks for Class III elastics mesial to the first primary molars.

The lower portion is similar to a removable splint with a lower bow which inserts into a Buccal tube in the acrylic in the area of the first permanent molars.

The lower bow has hooks for the Class II elastics. Correction of a Class III malocclusion in mixed dentition can minimize the possibility of orthognathic surgery.


This popular fixed functional appliance consists of an incisal ramp located lingual to the maxillary anteriors, connected to the maxillary first molar bands via two .050 connector wires.

Patients compliance is excellent and this appliance is ideal for mandibular advancement when the overjet is less than 4 mm. Deep overbite correction is made easier with the Rick-A-Nator and vertical elastics.

It dramatically improves the patient’s profile and health of the TMJ.

When worn in combination with a straight wire appliance, treatment time is significantly shortened.


This is a removable orthodontic appliance with acrylic contacting the palate and the lingual of the anterior teeth and the occlusal and buccal surfaces to the height of contour of the buccal of the posterior teeth. The appliance has a split down the mid palatal suture area and the two parts are joined by one or two expansion screws. The retention of the appliance is by using a number of clasps, including balls clasps, finger clasps or Adam’s clasps. In certain cases an anterior labial bow may be utilized to detorque maxillary anteriors.


This is a removable orthodontic appliance consisting of a lingual arch of acrylic with a split at the midline and the two parts joined by a single expansion screw. No acrylic contacting the incisal or the occlusal of the teeth. The retention of the appliance is by using balls clasps, C-clasps or Adam’s clasps. Anterior labial bow is optional. Sometimes lingual lap springs (crossover wires) are utilized to help move the lower anteriors more labially.