The space maintainer is a device customized by dentists or orthodontists with resin or metal materials. It can be fixed in children's mouth or removable. The purpose of wearing a space maintainer is to maintain a space for the subsequent permanent teeth to erupt.
From 6 to 12 years old is the "replacement period" of children, which is called "mixed dentition period" in medicine. From the eruption of the first permanent tooth - the sixth age tooth to the fall off of the last deciduous tooth, the teeth and face are rapidly changing, which is an important stage in the development of occlusal relationship. Under normal circumstances, the inherited permanent teeth erupt from the root of the corresponding primary teeth, and the primary teeth gradually loosen and fall off. The newly erupted permanent teeth replace the original position of the primary teeth in the dental arch. If this "shift" can be successfully completed, the dentition development can maintain continuity and integrity. This process seems to be simple, but in fact it is the result of the interaction of various forces. If these factors lose balance, they will change the position relationship between teeth and lead to tooth dislocation.
Premature loss of deciduous teeth is one of the main reasons for the malalignment of teeth arrangement and malocclusion. The causes of early loss of deciduous teeth may be traumatic tooth loss or congenital tooth loss. Of course, the most common cause in clinical practice is that there is no timely treatment for caries of deciduous teeth, which leads to large-scale damage to teeth or uncontrollable inflammation around roots. Finally, the deciduous teeth that have not reached the time of loss have to be extracted in advance. If there is no permanent teeth in the gap after early loss of deciduous teeth, there may be inclination or displacement of adjacent teeth, or elongation of opposite teeth, and finally formation of dentition deformity. It is generally believed that the narrowing of the tooth gap after the loss of deciduous teeth occurs as soon as 6 months after extraction. If the inherited permanent teeth can not erupt in time, it is necessary to make a gap maintainer to prevent the reduction of the eruption gap. Due to the characteristics of jaw and tooth development, the early loss of primary incisors (i.e. incisors) will rarely cause the space to become less or disappear, generally without intervention; while the early loss of primary canine and primary molar (i.e. big teeth) will cause the displacement of adjacent anterior teeth and the displacement of posterior teeth, respectively. Whether it is necessary to maintain the gap should be judged according to the expected eruption time of inherited permanent teeth. Theoretically, the deciduous canine and deciduous molar will fall off and replace in succession between the ages of 10 and a half to 12 years. That is to say, the early loss of deciduous canine or deciduous molar before the stage of 10-11 and a half should be used as a space maintainer, and the early loss of deciduous teeth after this stage does not need a space maintainer. But in fact, there are significant individual differences in children's growth and development. The time of eruption of permanent teeth is affected by many factors, such as age, tooth age, thickness of bone on the surface of permanent teeth embryo, position in bone, time of missing primary teeth, number of missing teeth, occlusion relationship and so on. The necessity of maintaining the gap cannot be judged by age alone. It is suggested to go to the hospital for treatment, and the professional should make a comprehensive judgment according to the results of clinical examination and X-ray examination.
In today's society, there are still many parents generally believe that children's teeth need to be changed sooner or later. It doesn't matter if their primary teeth are decayed, so it's better to change them. In fact, each primary tooth has a corresponding permanent tooth, which plays an important guiding role. If the deciduous teeth lose early, the possibility of permanent teeth eruption will be very large. Early loss of deciduous teeth will also reduce the masticatory function and affect the digestive system. If the teeth beside the missing teeth incline or shift, occupying the eruption position of permanent teeth under the missing teeth, the eruption of permanent teeth will be blocked.
When the baby's deciduous teeth fall off prematurely or have to be removed due to caries, it is the space maintainer that works. The purpose of space maintainer is to maintain the physiological space of teeth, provide space for eruption of permanent teeth, and prevent adjacent teeth from inclining to the lost part and extending to the opposite teeth.
1、 Classification of gap holders
Fixed type: ring type, full crown type, far and middle guide plate, filling type, tongue bow type, nance bow gap holder.
Movable: detachable functional retainer.
2、 Indications of retainer:
1. Ring and coil type or full crown and coil type space maintainer:? ① early loss of unilateral first primary molar.
② After the eruption of the first permanent molar, the second primary molar lost its unilateral early rise. After removing the far and middle guide plate type gap holder, the device should also be replaced.
③ Early loss of bilateral deciduous molars and difficulty in using other space maintainers.
Conclusion: unilateral early loss of D, early loss of E, 6 eruption, bilateral early loss of de.
2. Distal guide plate type space maintainer: it is applicable to the early loss of the second primary molar and the eruption or eruption of the first permanent molar.
The first primary molars were used as abutments, and a pre-made alloy full crown was worn. The distal end of the crown was welded with a curved guide plate, which was inserted into the alveolar fossa. The distal guide plate was attached to the proximal surface of the first permanent molars without eruption. (summary: e early loss, 6 not sprouting)
3. Filling type space maintainer: one end of the steel wire is buried in the filling body, and the other end is bent into an arc to contact the adjacent surface of the missing tooth and the adjacent tooth. It is suitable for the early loss of single primary molars, the teeth in the front of the space have distal and middle adjacent caries, or the teeth in the back end have proximal and middle adjacent caries, and the caries affects the pulp and needs to be treated by root canal. (summary: early loss of unilateral D / E, adjacent caries or treatment needed)
4. Tongue bow type space maintainer:
Apply to
① Cases with bilateral second primary molars or first permanent molars.
② Because of the early loss of primary molars, the medial fangs can erupt in the near future.
③ When it is necessary to maintain the space of the second primary molar due to timely extraction.
④ The patients with early loss of multiple teeth on both sides were not cooperative in wearing mobile retainers. ?
(4, 5 Summary: recent eruption; bilateral D / 6; D extraction)
5. Nance arch (palatal arch) space maintainer:? It is the same as the lingual arch. It is used to maintain the gap between the missing teeth in the upper jaw. Its front should not contact with the cutting edge of the mandibular anterior teeth.
6. Removable space maintainer?: it is suitable for two or more primary molars missing, or both primary molars missing, or with anterior teeth missing. The functional mobile retainers are equivalent to partial dentures.
(summary: Design of removable partial denture, more than 2 De's are missing; more than 1 De's are missing on both sides; with anterior teeth missing)
In the process of wearing the space maintainer, it should be noted that if there is a new permanent tooth eruption, it is necessary to check and see a doctor in time, remove the maintainer or use other types of maintainer according to different situations. It is recommended to check in the hospital every three months.