Tongue thrusting and Thumb sucking are the most commonly seen oral habits which act as the major etiological factors in the development of dental malocclusion. Fixed habit correcting appliance, Hybrid habit correcting appliance designed to eliminate these habits. This hybrid appliance is effective in less compliant patients and if desired can be used along with the fixed orthodontic appliance. Its components can act as mechinal restrainers and muscle retraining devices. It is also effective in case with mild posterior crossbite.

INTRODUCTION-

Thumb sucking and tongue thrusting are the most commonly seenoral habits. The line of treatment for these habits includes removal of the etiology, retraining exercises anduse of mechanical restraining appliances. Tongue bead appliances are commonly used as retraining exercise devices. In severe tongue thrusting cases and in cases withanterior open bite, a bead appliance alone may not be exective in restricting the habit.Tongue crib appliances are extremely exective in breaking the tongue thrust habit. They create a mechanical barrier and prevent the tongue from thrusting between the incisors. In most of the cases with severe thumb/digit sucking habit, an anterior open bite develops.This will resultin the development of a secondary tongue thrust habit.Hence, in cases with severe prolonged thumb or digit sucking,an appliance which can eliminate both of these habits isappropriate.Patient compliance is another problem associated with removable habit breaking appliances. Hence, habit breaking appliances which can be used along with orthodontic appliances will be of great advantage.which can be used to exectively restrain and correct tongue thrusting as well asthumb sucking habit.

Appliance Design Hybrid

Habit Correcting Appliance (HHCA). A tongue bead, a palatal crib and a U-loop which is attached to the molar bands on either sides.The tongue bead consists of a spinnableacrylic bead of mm diameter. The appliance is designedto position the acrylic bead over the posterior one-third of the incisive papilla.The bead acts as a tongue retrainer.The patient is asked to constantly pull the bead towards the posterior region of the mouth. The patient is also advised to make sure that his tongue wedges between the bead and theroof of the mouth as he swallows.The palatal crib and theU-loop are made of 1 mm stainless steel wire. Free to four spurs are benton either sides of the bead, starting from the canine regionon one side, running anteriorly as a smooth curve (inconventional crib appliances, the cribs run obliquely fromone canine to the other side canine) and lying. lingualto the cervical margin of the maxillary anterior teeth. In theregion of the incisive papilla, the acrylic bead is incorporatedin such a way that it lies over the posterior one-third of theincisive papilla. The tip of the crib should be almost in linewith the incisor tip of the maxillary central incisor or longer without interfering with the lower incisors when inocclusion. In cases with anterior open bite, the crib shouldbe longer and can be up to the interincisal distancebetween the upper and lower central incisors. This is to avoid the tongue from thrusting over the tip of the crib.The palatal crib acts as a barrier against the thrusting tongue and works as a mechanical restrainer.The U-loop is incorporated in the second premolar region and it helps to reposition the applianceposteriorly during the retraction phase, when it is used along with fixed orthodontic appliances.The appliance can be engaged into a lingual sheath on the molar bands or can be soldered directlyto the molar band. If it is engaged in a lingual sheath, a tight ligature tie should be wound around thelingual sheath and the distal end of the appliance to avoidthe appliance from slipping out of the sheath into the oral cavity.

Tongue thrusting is designed as a human behavioral pattern inwhich the tongue protrudes through the anterior teeth duringswallowing, speech and at rest.Thumb sucking usually involves placing the thumb into the mouth and rhythmically repeating sucking contact for a prolonged duration and is considered to be soothing and therapeutic for the person.Both of these habits are considered to be normal up to four to five years of age. But it can lead to deleterious effects in the oral cavity if these habits persists beyond the eruption of the permanent teeth.Tongue thrust can be primary, the etiological factors of which include learned behavior, hyperplastic tonsils, pro-longed thumb sucking, nasal congestion and macroglossia,or can be secondary to early extraction of deciduous teeth oran anterior open bite the anterior tongue position at rest may have greater impact on the toothposition rather than the tongue pressure during thrusting.Hence, the aim of the treatment primarily is to train thetongue to rest in its normal superior position. Elimina-tion of the etiology is the primary and the most importantstep in the correction of the tongue thrusting habit. Once the cause is determined and eliminated,the tongue thrusting habit is usually dealt in two ways: Muscle retraining—an exercise technique that reeducates the muscles associated with swallowing; mechanical restraining method, wherean appliance is placed in the mouth which will prevent thetongue from thrusting forward and thus retrains the tongue to a normal position. Tongue cribs or rakes are valuablemechanical restrainers. Tongue beads placed in the rugaeregion are conventionally used to retrain the tongue.The habit of sucking the finger(orthumb)is considered to be performed for oral gratication and psychological reassurance. Severe thumb sucking can lead to proclination ofmaxillary anteriors, constriction of the maxilla, retroclinationof the mandibular incisors, increased overjet and anterioropen bite. Usually, in cases with anterior open bite due tothumb sucking, a secondary tongue thrust develops leadingto the exaggeration of the condition. The line of treatment for the prolonged digit sucking involves positive reinforcements,developing a desire in the patient to quit the habit, remindersand appliances which act as a mechanical barrier as wellas physical reminders. Appliances consisting of cribs in theanterior region are found to be very efective as reminders aswell as physical restrainers.