Space maintainers

SPACE MAINTAINERS

1. SPACE MAINTAINERS Dr . ANIL KOHLI

2. Contents Introduction Definition Requirements for space maintainers Planning for space maintainers Classification Fixed space maintainers Removable space maintainers Summary references

3. Introduction Premature loss of primary teeth is unfortunately a very common occurrence in children mainly due to lack of knowledge regarding oral hygiene procedures & apathy towards the maintenance of dental health. Dental caries is one of the most common disease in children & teeth are affected due to extensive decay. The parents also tend to neglect the health of primary teeth thinking that they will exfoliate & do not require attention. This neglect in early childhood has a profound effect on the oral health of the child even after eruption of the permanent teeth, which often tends to erupt late, ectopically or may get impacted due to closure of space previously occupied by the primary teeth. ( as teeth have the tendency to migrate)

4. Sequelae of premature loss of primary teeth age at the bone covering the stage of root space aberrant ectopic of tooth loss succedaneous teeth development closure habits eruption More than more than 1mm of less than half of 2 years of bone cover the root development normal eruption of the permanent tooth Succedaneous teeth Surrounding structures Malocclusion Delayed Eruption Compromised Dentofacial Development

5. A primary tooth with proper mesiodistal width is considered as the best space maintainer. As a primary tooth occupy the physiologic space & guide the eruption of its permanent successor.

6. Sequelae of premature loss of primary teeth without space maintainer

7. space maintainer

8. Requirements:- A space maintainer should fulfill the following requirements:- It should maintain the entire mesio-distal space created by a lost tooth. It must restore the function as far as possible & prevent over eruption of opposing teeth. It should be simple in construction. It should be strong enough to withstand the functional forces. It should not exert excessive stress on adjoining teeth It must permit maintenance of oral hygiene. It must not restrict normal growth & development & natural adjustments that take place during the transition from deciduous to permanent dentition. The space maintainer should not come in the way of other functions.

9. Planning for space maintenance The following factors should be considered when space maintainer is planned following the early loss of primary teeth. Time elapsed since loss of tooth – it is usually advisable to place a space maintainer as soon as the primary teeth are removed. Dental age of the patient - dental age should be considered rather than the chronological age. This is because of too much variation in eruption of teeth are observed. It is usually observed that the permanent teeth erupt once3/4 th of their root development is complete. This criterion can be used to predict the age of eruption of the permanent teeth Thickness of bone covering the unerupted teeth - more the bone covering the unerupted tooth, the more would be the time it would take to erupt & therefore space maintenance is indicated.

10. Sequence of eruption of teeth - whenever a space maintainer is planned , adequate consideration should be given to the adjacent developing & erupting teeth. The neighbouring dentition can greatly influence the closure of the extraction space. Congenital absence of permanent tooth - if permanent teeth are congenitally missing , the dentist should decide if he is going to retain the space untill a replacement can be given or allow the other erupting teeth to drift & close the space.

11. Classification According to Hitchcock: Removable or fixed or semi – fixed With bands or without bands Functional & non functional Active or passive Certain combinations of the above According to Raymond C. Thourow : Removable Complete arch lingual arch extra-oral anchorage Individual tooth

12. According to Hinrichsen: Fixed space maintainers : class І Non-functional types Bar type Loop type Functional types Pontic type Lingual arch type class ІІ – cantilever type ( distal shoe, band&loop) Removable space maintainers : acrylic partial dentures

13. Fixed S pace Maintainers Space maintainers that are fixed or fitted on to the teeth are called fixed space maintainers . Advantages Disadvantages Require minimum or no tooth preparation. Elaborate instrumentation with expert skill is needed. Do not interfere with passive eruption of abutment teeth. Results in decalcification of tooth material under the bands. Jaw growth is not hampered. Supra eruption of opposing teeth can take if pontics are not used. Permanent teeth are free to erupt into the oral cavity. Can be used in unco-operative patients.

14. Fabrication of fixed space maintainers Steps of fabrication

15. Armamentarium Stainless steel band or preformed bands Pliers- contouring pliers, band forming pliers, band seater or pusher, band adapter, hoe pliers straight & curved, band cutting scissors, bird beak pliers, crimping pliers, three pronged pliers, universal pliers Stainless steel wires (round) Spot welding unit, soldering unit, silver solder, flux Wire cutter Finishing burs, polishing stones

16. BAND CONSTRUCTION Place separators interdentally for the ease of band adaptation Select the band material Check the band for dull & shiny side 2⅔ inch of band material is cut off , loop is made & spot welded Band is then slipped down the tooth structure & trial pinching is made for the better adaption , mark the excess & trimming is done Now the new closer seam is spot welded, festooning is done Band is now ready for final seating , final pinching is done Remove the band & spot weld at the new contact , trim if excess present Now refit the band & fold the seam in distal direction Remove it & solder the seam. Trim & any sharp points & polish the band before refitting

17. Impression taking & cast preparation - an alginate impression of the banded tooth is made. After taking the impression band remover plier is used to remove the band & place it into the impression in the same position that is occupied on the tooth. Stabilize & pour the cast. Loop fabrication - this is formed using round stainless steel wire. The thickness & the design of loop is different for all space maintainers. Soldering – quick set plaster is used to position the adapted wire o n the working model. Reducing zone of the solder torch is used for soldering . A generous amount of flux should be applied above & below the point where wire contacts band. Joint is heated till it is red hot & solder flows evenly. Immediately dip it in water & remove the appliance. Finishing & polishing - a finished solder joint should be smooth & free of porosity. A green stone is used to contour the soldered joint to a smooth transition with the band. Rubber wheels are relief upon to reduce surface roughness & gold rouge or rag wheel is used for final polishing.

18. Commonly used space maintainers Band/crown & loop Lingual arch space maintainer Nance palatal arch space maintainer Transpalatal arch Distal shoe space maintainer

19. Band & Loop Space Maintainer It is a unilateral, nonfunctional, passive, fixed appliance indicated for space maintenance in the posterior segments when single tooth is lost. Indications In premature loss of single primary molar. Bilateral loss of single primary molar before eruption of permanent incisors. When 2 nd primary molar is lost after the eruption of 1 st permanent molar.

20. Modifications Crown & loop, crown-band & loop, reverse band & loop, band & bar, bonded band & loop, long band & loop Advantages Disadvantages Construction is easy & faster Cannot stabilize the arch Few appointments by patients nonfunctional Many modifications are possible Slippage of loop by masticatory forces Cannot be used for multiple loss of teeth

21. Lingual Arch Space Maintainer It is a bilateral, nonfunctional, passive/active, mandibular fixed appliance. It is the most effective appliance of space maintenance & minor tooth movement in lower arch’ Indication In multiple loss of primary molars when there is no loss of space in the arch Bilateral loss of primary molars after eruption of lower lateral incisors. Unilateral loss of primary molars after eruption of lower incisors. Minor space regaining.

22. Modifications Hotz lingual arch, removable lingual arch, Omega bends Advantages Disadvantages Many modifications are possible Construction is difficult Can also be used to regain space More chances of distortion of appliance by tongue pressure Arch holding space maintainer May cause unwanted movements

23. Nance Palatal Arch Space Maintainer Bilateral, nonfunctional, passive, maxillary fixed appliance that does not contact the anterior teeth, but approximates the anterior palate via an acrylic button that contacts the palatal tissue, which provides resistance to the anterior movement of posterior teeth in a horizontal direction.

24. indications Advantages disadvantages modification Bilateral premature loss of primary molar Arch stabilizing May cause tissue hyperplasia Modified Nance appliance Maintaining the maxillary 1 st permanent molar position Cannot be used in patients allergic to acrylic Pressure effects Irritation to palatal tissues

25. Transpalatal Arch Unilateral, nonfunctional, passive, ,maxillary fixed appliance that has been recommended for stabilizing the maxillary 1 st permanent molars when primary molars require extraction.

26. indications Advantages disadvantages When one side of arch is intact & several primary teeth on the other side are missing. Used in multiple unilateral loss Rotation molars When primary molars are lost bilaterally Can be used for expansion Both molars may tip together Prevent the molars from rotation In arch expansion

27. Distal Shoe Space Maintainer Also called intra alveolar appliance. One of the early designs of distal shoe space maintainers was Willet’s distal shoe. This appliance is rarely used these days because of the increased cost of the materials, difficulties in tooth preparation, & more complicated fabrication procedure. The appliance, which is in practice, is Roche’s distal shoe or modifications of it using crown & band appliances with a distal intra gingival extension.

28. Criteria for appliance fabrication In the lower arch , the contact area of the distal extension should have a slight lingual position over the crest of the alveolar ridge. By contrast, the area of distal extension of the maxillary appliance should be slightly facial . This is important to prevent rotation of tooth & appliance WIDTH – If no adequate width is provided. The tooth may slip. It should be approximately the width of the contact area. DEPTH OF GINGIVAL EXTENSION – The gingival extension of the appliance should be constructed to extend 1mm below the marginal ridge so as to just “capture” the mesial marginal ridge of the tooth.

29. LENGTH OF THE DISTAL EXTENSION Ideally, measure the 2 nd molar before extraction & remove the same from model. If the 2 nd molar is already missing, a recommended practice is to measure on a radiograph, the distance between the distal surface of 1 st primary molar to the 1 st permanent molar. This carries the disadvantage of the appliance being overextended, especially in the maxillary arch as the molar erupts from a more distal direction to swing mesially. thus the best way is to measure M-D width of the 2 nd primary molar on the opposite side.

30. Indications contraindications When the 2 nd primary molar is extracted or lost before the eruption of 1 st permanent molar. Inadequate abutments due to multiple losses of teeth Poor oral hygiene Lack of parent & patient cooperation Medically compromised patients Congenitally missing 1 st permanent molar Advantages Disadvantages Only space maintainer, used in premature loss of primary 2 nd molar before eruption of permanent molars Can cause deviation of permanent tooth bud May permit tipping Interfere with epithelialization of socket Can cause infection Can only be used in specific patients Retention is not good Construction is difficult

31. Modifications A combination of lingual arch & distal shoe appliance was suggested for use in patients in whom both primary molars are lost & the patient’s strong gag reflex prevented the use of a removable appliance. Placing loops in the horizontal arm of the space maintainer. T hese loops permit the precise adjustments needed for accurate placement of molar. When Space maintainer is placed after signs of eruption of 1 st molar are seen. Vertical extension is short & is not placed intra alveolarly. It just touches the mesial surface of erupting permanent molar Gingival saddle appliance.

32. Space maintenance in the primary dentition Missing primary teeth Suggested treatment Reason Maxillary incisor No space maintenance required No consequence ( exception if incisor lost prior to primary canine eruption) Maxillary canine band & loop space maintainer Decrease possibility of midline shift Maxillary 1 st molar Band/crown & loop space maintainer Prevents loss of arch dimension Maxillary 2 nd molar Distal shoe space maintainer Guides 1 st permanent molar into proper position Mandibular incisor No space maintenance required No consequence ( exception if incisor lost prior to primary canine eruption) Mandibular canine Band & loop space maintainer Decrease possibility of midline shift Mandibular 1 st molar Band/crown & loop space maintainer Prevents loss of arch dimension Mandibular 2 nd molar Distal shoe space maintainer Guides 1 st permanent molar into proper position

33. Space maintenance in the mixed dentition Missing primary tooth Suggested treatment reason Maxillary lateral incisor Extract antimere Decrease possibility of midline shift Maxillary canine Removable space maintainer ( prior to eruption of permanent lateral incisor) Extract antimere (after eruption of permanent lateral incisor) Guides permanent lateral incisor into proper position. Prevents loss in arch dimension. Maxillary 1 st molar Nance appliance or Band crown & loop space maintainer Prevent loss in arch dimension. Does not interfere with eruption of permanent laterals Maxillary 2 nd molar Nance appliance Prevent loss in arch dimension

34. Mandibular lateral incisor Extract antimere Decreases possibility of midline shift Mandibular canine Removable space maintainer (prior to eruption of permanent of permanent lateral incisors) Lingual arch space maintainer (after eruption of permanent lateral incisor) Requires only minor adjustments to afford normal positioning of permanent incisors. Prevents lingual tipping of permanent incisor. Mandibular 1 st molar Band/crown loop space maintainer ( prior to eruption of permanent incisor) Lingual arch space maintainer ( after eruption of permanent incisors) Prevent loss in arch dimension No not interfere with eruption of permanent incisor Permits proper position of teeth Mandibular 2 nd molar Band/crown loop space maintainer ( prior to eruption of permanent incisors) Lingual arch space maintainer (after eruption of permanent incisors) Prevent loss in arch dimension Do not interfere with eruption of permanent incisors Prevents mesial tipping of 1 st permanent molar

35. Removable Space Maintainers They are space maintainers that can be removed & reinserted into the oral cavity by the patient.

36. Indications Contra indications Esthetics is of importance Lack of patient parent cooperation Abutment teeth cannot support a fixed appliance Patient allergic to acrylic materials A cleft palate patient Epileptic patients Permanent teeth are not fully erupted for adaptation of bands Multiple loss of deciduous tooth

37. Advantages Disadvantages Easy to clean & permit maintenance of proper oral hygiene May be lost or broken by the patient Restore vertical dimension Cannot be used in uncooperative patients Helps in mastication Patient may not wear them Post insertion checkup is easy Lateral jaw growth may be hampered Stimulate eruption of underlying tooth May cause irritation & allergy to underlying tissues Band construction & elaborate skills & instrumentation are not required Alterations can be made without changing the appliance

38. Some commonly used removable space maintainers Acrylic Partial Dentures

39. Summary P rimary dentition plays an very important role in the future dental health of the child. A healthy & properly aligned deciduous teeth can lay a foundation for the permanent dentition. Hence extra efforts should be put for preservation of the primary teeth till their exfoliation time. Various procedure are available in dentistry for the preservation of primary dentition & Space Maintainer is one of them, which helps in preserving edentulous space created by the premature loss of primary teeth.

40. References Orthodontics The Art and Science - S.I. bhalajhi Textbook of Pediatric Dentistry – Nikhil Marwah