Spring Back the Lost Space: Fixed Space Regainer for E Space Loss- A Case Report

Introduction

The changing lifestyle of society has led to an increased incidence of dental caries in children, with caries experience starting as early as the primary dentition and progressing through adolescence. Although various measures are being taken by pediatric dentists worldwide for the conservative prevention and management of dental caries, there are some clinical situations where the gross destruction of teeth due to caries is such that it warrants the extraction of the same. This process leads to the hindrance in the normal physiology of a primary tooth and in turn dental arches, during its transition to permanent dentition.¹

Early loss of primary molars leads to various complications such as space loss and arch changes, which may be indirectly detrimental to the growth of the child. There is a need to restore physiological harmony. which can be achieved by pediatric dentists through occlusal guidance with the use of space maintainers. 

However, improper patient education or misinformed patient decisions regarding the importance of space maintenance following deciduous teeth loss have led to cases of space loss due to the mesial migration of the teeth, especially the mandibular first permanent molar, midline shift due to migration of anterior teeth, both of which may disturb the arch integrity and can cause impaction or ectopic eruption of the succedaneous teeth.² Of all the deciduous teeth, the mandibular second molar has been said to have a mesiodistal diameter which is comparable to the Leeway space of Nance in the mandibular arch and is said to be the most important contributor of late mesial shift rather than the canine and the first molar.³ Hence, management of “E” space is a vital cog in interception of space loss.

The use of fixed-space regainers is preferred over removable space regainers in cases of severe space loss because it eliminates the need for patient compliance and allows better precision and control to the clinician. A comprehensive space assessment needs to be performed by the pediatric dentist before the use of such appliances to ascertain the amount of space lost and intervene at the correct age to ensure maximum benefits to the patient. This is a clinical case report on management of the “E” space loss using a combination of a lingual arch and NiTi open coil spring in a bonded fixed appliance.

Case Presentation

A 9-year-old male patient reported to the Department of Pediatric and Preventive Dentistry with a chief complaint of pain in the left lower back tooth region for the past 2 days, which was gradual in onset, mild, intermittent, aggravated during food consumption, and relieved by over-the-counter medications, and had no history of night pain. The patient’s mother gave a history of extraction of his lower back tooth 4 years ago in a private clinic. Medical history was non-contributory.

Extra-oral examination revealed that the patient had an orthognathic profile with no other significant findings. The patient was found to have late mixed dentition stage with normal overjet and overbite with no significant soft tissue findings. Hard tissue examination revealed, deep dentinal caries in relation to 74 and exfoliated 75. Incidentally, severe space loss was observed in the right mandibular posterior teeth region because of an extracted deciduous mandibular second molar (85). Intraoral periapical radiographs were obtained, which revealed that dental caries was involving the enamel, dentin and approximating the coronal pulp in relation to 74. Also, an Orthopantomogram was made and it was revealed that the mandibular right second premolar was at Nolla Stage 6 with no space available for eruption with complete mesial migration of mandibular first molar in the same quadrant (Figure 1). 

Maxillary and mandibular impressions were made, and Moyer’s mixed dentition analysis revealed space loss of 5.9 mm. Indirect pulp capping was performed in relation to 74, and the patient was taken up for treatment of space loss with a fixed space regainer. During the first visit, banding (0.005x0.180 inch) was performed on the mandibular permanent first molars on both sides and the deciduous mandibular first molar on the side of space loss and impressions were made. Molar buccal tubes (0.7 mm, 10 mm length) were welded on the buccal side of the bands of 84 and 46. An anchor unit comprising of lingual arch from 84 to 36 was constructed using 0.9 mm orthodontic stainless-steel wire which also acted as the space maintainer for preventing mesial migration of 36 into the space left by exfoliated 75. The lingual arch was cemented in the next visit, after which orthodontic brackets (Pre Adjusted Edgewise- MBT prescription and 0.022 slots) were bonded to the mandibular permanent incisors. The NiTi open-coil spring was cut to a length of 2 mm more than the available space between the buccal tubes of 84 and 46. This was incorporated between the two buccal tubes on a 0.014 NiTi mandibular arch wire placed from 46 to 36, and the modules were placed on mandibular incisor brackets (Figure 2).

The patient was recalled after 2 weeks and a change to a 0.016 NiTi wire was made with an increase of 2 mm more than the space regained, in the length of the open coil spring. This protocol was followed, and the wire dimensions were increased to 0.018 NiTi wire and subsequently to 0.019x0.025 Stainless steel archwire. After two months, a space of 7 mm was regained, which was a slight over-correction for safety. Lace ties and elastomeric chains were placed with a 0.019x0.025 stainless steel wire in place for the purpose of correction. of midline shift which was achieved in one month. (Figure 3).

Intraoral periapical radiographs revealed complete uprighting of 46. Following this, the lingual arch was placed from 36 to 46 to maintain the regained space, and the patient is being followed up for eruption of the right mandibular second premolar (Figure 4).

Discussion

Improper patient education regarding the importance of a deciduous tooth and the role it plays as natural space maintainer, can consequentially lead to missed follow-up visits for appropriate space management procedures after the extraction of a deciduous teeth. Various studies have shown that the dimension of the deciduous canine and first molar of the mandibular arch are almost the same as those of their permanent successors and the second deciduous molar plays the most significant role in ensuring the establishment of Angle’s class I molar relation in patients where it has not been established by early mesial shift.^3,4,5 Hence, management of E space loss is not only important for the proper eruption of mandibular second premolars, but also has an impact on the dentition as a whole.

The severity of space loss in the current case, warrants the need for an alternative approach. as conventional methods such as Gerber’s space regainer cannot be used because of the unavailability of space for the U-loop framework. In addition, the Hotz lingual arch and lip bumpers were ruled out, as the amount of space required was greater than that achieved by such appliances.

A fixed appliance is a versatile method for uprighting permanent molars. When combined with the lingual arch, entire dentition serves as the anchor unit and a Ni-Ti open coil spring can provide optimum forces for distalisation due to its innate potential of shape memory and super-elasticity. Bonding of the mandibular anterior teeth with a pre-adjusted edgewise appliance also helped correct the midline shift in our case using elastomeric chains. which may serve as an added advantage of using a fixed orthodontic appliance. The risks of arch distortion owing to the NiTi spring were avoided by a staggered increase in the size of the arch wires, and finishing with a rectangular stainless-steel wire ensured stable results in our treatment.

The use of lingual arch anchorage combined with a straight wire and a coil spring was first introduced by King in 1977.⁶ One millimetre of space gain was achieved monthly with this appliance. With advances in orthodontics, a novel unilateral spring space regainer combined with a fixed orthodontic appliance was shown to produce a pure translatory type of bodily movement of the molars without any unnecessary rotations even after the eruption of second permanent molars.⁷ Also, a simple appliance was constructed with a 0.016 NiTi archwire inserted into a composite dimple between the molars has been shown to be a rapid and less cumbersome method of space regaining.² NiTi open coil springs can also be combined with a lingual arch and curved wire in a cross bow design to regain space lost due to missing deciduous canines while simultaneously preventing the mesial migration of the permanent molars.⁸ The use of NiTi space regainers in interceptive orthodontics has revolutionized the field, providing exceptional outcomes for molar distalisation and uprighting. When used judiciously with proper clinical judgement, pediatric dentists can achieve exemplary results.

Sources of Support

Nil

Conflicts of interest

No conflicts of interest