Gap maintainer refers to a device used to maintain the normal physiological gap of the child in order to maintain the vacancy after the early loss of the child's teeth, in order to prevent the adjacent teeth from tilting to the loss site and elongating the jaw teeth, it is used to maintain the mesiodistal and vertical gap of the premature loss teeth in the dentition, and maintain the normal eruption of the inherited permanent teeth. Our commonly used gap retainers can be divided into fixed, semi-fixed and detachable functional retainers, among which semi-fixed retainers are divided into far-middle guide plate gap retainers, sinter retainers with rings, full crown sinter retainers, and filled strainers. Fixed retainers are divided into tongue arch gap maintainers and nance gap retainers. They all have their own indications, mainly according to the patient's oral situation, the selection of a reasonable gap retainer, directly affects the growth and development of the child's teeth and face.
The following are commonly used gap holders.
1) Wire loop type gap retainer. Band loops are made on the adjacent teeth at one end of the gap, and the band ring is generally placed on the adjacent teeth distal to the gap, such as after the premature loss of the second deciduous molar, the band loop is made on the first permanent molar. Then welded on the mesial surface of the band ring or buccal lingual surface has been used with a diameter of 0An 8 mm steel wire is bent into close contact with the adjacent teeth at the other end of the gap. Finally, zinc phosphate adhesive powder is used to glue the band ring to the tooth. This type of retainer is a non-functional gap retainer, which can only maintain the mesiodistal and middle width of the gap, and cannot restore masticatory function or prevent the elongation of the jaw teeth. Therefore, it is suitable for children with a short retention time.
2) Restore the gap holder. If the gap has been narrowed, the gap width should be restored first, and then the gap should be maintained. It can be used as a ** spring, a longitudinal spring movable appliance or a coiled loop gap holder with a wound spring and a local fixed retainer. When the gap width is restored, stop the afterburner and continue to wear the retainer to maintain the gap.
3) Fix the lingual arch. In mixed dentition, multiple primary molars are often lost in the late stages, and fixed lingual arches can be used for other types of retainers that are not easy to achieve. It consists of a permanent molar band ring on each side and a lingual arch welded to the band ring. The band ring is generally made on the first permanent molars on both sides. The lingual arch is bent with a steel wire with a diameter of 1 mm and is in contact with the anterior tongue of the tongue neck, but not the soft tissue, and the bicuspid area passes through the alveolar ridge lingual side so as not to affect the eruption of the bicuspids. The fixed lingual arch maintains the arc and length of the dental arch between the first permanent molars on both sides, and does not prevent the permanent canines and bicuspids from being replaced, so they can be maintained until the canines and bicuspids erupt.
4) Tooth support gap retainer. It is a functional gap retainer. It not only maintains the gap between the missing teeth, but also restores the chewing function of the missing teeth and prevents the extension of the jaw teeth. It is suitable for patients who have a large number of missing deciduous teeth, and the subsequent permanent teeth will not erupt in a short period of time, and need to restore function and prevent the elongation of the jaw teeth, and the decay and loosening of the adjacent teeth of the gap, and cannot be placed with retainers.
5) Bud-guided gap retainer. When the first permanent molars are not erupting or are erupting, the second primary molars fall out. At this time, the first permanent molars are very prone to proximal oblique movement, encroaching on the missing tooth gap, resulting in dislocation or impaction of the second bicuspid, and at the same time, the first permanent molars also cause occlusion disorder after the mesial oblique movement. Therefore, wearing the germination guide in time can not only maintain the gap between missing teeth, but also guide the first permanent molars to erupt on the normal eruption tract. It can be designed as a dental support or fixed germination retainer.
6) Tooth support type germination type gap retainer. At the gap of the second deciduous molar, the distal extension and guide surface of the artificial crown are in contact with the mesial surface of the first permanent molar, which can achieve the purpose of maintaining the gap and inducing germination.