A lingual arch space maintainer or lingual holding arch is indicated for space maintenance when there is premature loss of multiple primary molars and the permanent incisors have erupted. It is usually removed after the eruption of second premolars is completed and their proper positioning has been achieved.
From an orthodontic viewpoint, it is primarily indicated in patients where maximum molar anchorage is to be maintained.
- Class I malocclusion where in arch space is to be stabilised.
- Class III malocclusion to maintain the molar position and prevent their forward movement and facilitate more posterior eruption of the mandibular premolars.
Function
A conventional lingual arch, attached to bands on the primary second or permanent first molars and contacting the maxillary or mandibular incisors, helps in sustaining the canine-premolar segment space i.e., the leeway space.
- It stabilises the lower molar positions from moving mesially and hence, prevent anterior movement of the posterior teeth
- It also prevents posterior movement of the anterior teeth by stabilising the incisor relationships from retroclining lingually.
Design and Fabrication
- It is made of 0.036- or 0.040-inch SS wire, that extends along the lingual contour of the mandibular dentition from the first molar on one side to that on the other side.
- Adjustment loops: These are optional and can be placed in the region of the second deciduous molars (mesial to the permanent first molars), providing added ability to adjust arch vertical position and size.
- The lingual arch should have an ideal arch form, so the teeth can align if they have space. Making the arch conform to the dental irregularities is not appropriate.
- The lingual arch is stepped to the lingual in the canine region, to remain away from the primary molars and unerupted premolars, so that there is no interference with their eruption (results in a keyhole design).
- The lingual arch should be positioned to rest on the cingula of the incisors, approximately, 1-1.5 mm off the soft tissue at all points.
- The lingual arch is usually soldered to the molar bands but can be fabricated as removable space maintainer, e.g., those that fit into attachments welded onto the bands.
Fixed vs. Removable Lingual arch
- Removable lingual arch: More prone to breakage and loss.
- Fixed lingual arch: Stable, not easily broken and wear is not dependent on the child.
Maxillary Lingual Arch
Many clinicians are not familiar with maxillary lingual arch as space maintainer, but it is contraindicated only in cases where deep bite causes lower incisors to contact the arch wire on the lingual aspect of the maxillary incisors.
- A maxillary lingual arch is used when the overbite is not excessive.
- When deep bite does not allow the use of a conventional design, either the Nance palatal arch or a transpalatal arch can be used.
- Nance arch with acrylic button in the palatal vault is indicated if the overbite is excessive. The palatal button must be monitored because it may cause soft tissue irritation.
- Transpalatal arch is indicated when one side of the arch is intact and more than one primary tooth is missing on the other side. In this situation, the rigid attachment to the intact side usually provides adequate stability for space maintenance and prevents rotation and mesial migration of the molar tooth.
- When primary molars have been lost bilaterally, however, both permanent molars can tip mesially despite the transpalatal arch and a conventional lingual arch or Nance arch is preferred.
Points to Note
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The greatest concern is to ensure that the appliance is passive and does not cause unwanted tooth movement.
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The bilateral design and use of permanent teeth as abutments, allow the use of lingual arch during the complete transitional dentition period of the buccal segments.
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The lower lingual arches should not be placed before the eruption of the permanent lateral incisors, because,
- The incisors frequently follow a lingual eruption path and the wire may interfere with normal incisor positioning.
- Abutting the lingual arch against primary incisors as anterior stops does not offer sufficient anchorage to prevent significant loss of arch length.
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Approximately 25-30% of lingual arch type appliance fail, usually because of cement loss and solder joint breakage. Their survival time is estimated at less than 24 months. Careful instructions to parents and patients can reduce these problems, but regular recall is advisable.
References
- William R. Proffit- Contemporary Orthodontics, 6th Edition, Elsevier Mosby.
- Orthodontics Current Principles and Techniques, 5th Edition, Xubair, Graber, Vanarsdall, Vig, Elsevier Mosby.
- McDonald and Avery's Dentistry for the Child and Adolescent, 11th Edition, Jeffrey A. Dean, Elsevier Mosby.
*This article is an excerpt from the above mentioned books and Medical Sutras does not make any ownership or affiliation claims.