Editor’s Intro: Dr. Donald J. Rinchuse shows various ways to expedite space closure to give treatment closure to patients with braces.
Dr. Donald J. Rinchuse discusses various solutions for maintaining a timely debonding
Alice is here for her 9:00 a.m. “debonding” appointment in operatory number 3. Alice and her mom are so excited that she is finally getting her braces off. The orthodontic assistant comes to Dr. K to inform him that Alice is here, and he needs to check to make sure it is okay to remove her braces. When Dr. K looks into Alice’s mouth, he notices that there is about 1/12 mm of space between her maxillary central incisors (Figure 1A). At Alice’s prior appointment, the orthodontic assistant failed to place a chain elastic and instead placed single tooth O-ring ligature ties.
So now here are two considerations for Dr. K: 1) Should he tell Alice and her mother that the braces will not come off this morning because of the space and re-appoint Alice to come back in 1 week and then place a chain elastic in the upper arch? 2) Is there any way to close the space within 15-20 minutes and still remove Alice’s braces today?
As the old saying goes, “when there is a will, there is a way.” And there may be a solution for the conundrum that faces Dr. K. So Dr. K searches into his bag of tricks and finds a technique that has worked well for him for several cases in the past. The technique is the placement of a double (closed) chain — that is, one chain under (Figure 1B) and then the second chain over the archwire (Figure 1C). In about 15 to 20 minutes, the space is closed (Figure 1D). Some judgment must be made in deciding when the space is too large to close in an expedited manner. I think the threshold is 2 mm. Beyond this limit, the patient should have a single, closed chain placed over the archwire, and then schedule the patient back in 1 to 2 weeks for a final check. If the space is closed, a debond can be performed.
Figure 1A: Space present between the maxillary central incisors at the debonding appointment (left) and Figure 1B: Application of double chain (closed) elastics; this photo shows the chain elastic that is placed under the archwire (right)
Figure 1C: Chain elastic placed over the archwire (left) and Figure 1D: Correction of the maxillary diastema (right)
Figure 2A: Buttons placed (left), Figure 2B: Elastic placed (middle), and Figure 2C: Ligature wire placed (right)
There are a host of incidents when space opens between the maxillary central incisors when a patient is in retention with no brackets on the teeth. Some of the reasons for “spacing relapse” are poor cooperation in wearing removable retainers, misplaced retainers, broken retainers, and so forth. There is also the situation when a fixed lingual retainer breaks with similar consequences. And at times, the space opening is more or less due to the bite and not totally due to a lack of retainer wear. That is, there is space opening caused by a “Class III edge-to-edge-type” bite or where there is a tooth size discrepancy (Bolton analysis) with relatively smaller maxillary incisors. In both cases, there are undue traumatic bite forces on the maxillary incisors when coming into occlusion (and contact) with the mandibular incisors. In these instances, it is not a simple matter of expedited space closure but a treatment-planning decision that may involve placing brackets on again with “interproximal reduction” of the mandibular incisors, removing a lower incisor, and/or having the family dentist build up (crowns, veneers) the maxillary incisors (centrals, laterals, or all). If the maxillary incisor teeth need to be enlarged via cosmetic dentistry, then the maxillary incisor spacing may need to be “positioned” and orthodontically moved in a way that the cosmetic dentist can most easily enlarge the four maxillary incisor teeth.
When the space opening is due to a typical relapse issue, there are several ways to close the space(s). Some are recommended ways; others are possible ways, but not generally recommended. Buttons can be bonded to the mesial of the central incisors (to avoid rotations) and positioned vertically based on the angulation position of the central incisors crowns. If the central incisor crowns are tipped outward, then the buttons should be placed incisally, and vice versa (Figure 2A). Not so highly recommended ways to close maxillary central incisor space would be to place (lasso) “circle” elastic (Figure 2B) or ligature wire (Figure 2C) around the incisal edges of the central incisors. As known, there is the danger of the elastic or ligature wire migrating gingivally, with dire consequences, if it is not monitored. Patients should never leave the operatory with an elastic or ligature wire in place.
Figure 3A: Dental cast with maxillary diastema (cast turned upside-down to make the modification) (left) and Figure 3B: Dental cast with blue “block-out” resin between the maxillary central incisors (right)
Figure 3C: Dental cast showing distal-incisal edges of the maxillary incisors shaved (left) and Figure 3D: Vacuum-formed retainer fabricated after modification of the dental cast (right)
In addition, an impression (or scan) can be made and the dental cast (3D-printed model) modified prior to fabricating a “vacuum-formed retainer” (VFR) (Figures 3A through 3D). The space between the central incisors needs to be blocked out (Figure 3A and 3B) in order to provide space for the maxillary central incisors to be moved mesially, and then the distal incisal edges of the maxillary central incisors need to be “shaved” in order to induce a mesial-incisal force within the VFR. The same can be done to include the maxillary lateral incisors as the need arises. The VFR is then fabricated over the altered dental cast (Figure 3D) and subsequently delivered to the patient. The patient is re-appointed in a few weeks to evaluate the outcome of treatment.
This article provides a number of ways to close maxillary incisor spacing in an expedited manner, but obviously, there are many more ways for expedited space closure. The possibilities are more or less based on the imagination, creativity, and experience of the orthodontist. Readers of this article are encouraged to brainstorm the potentialities for expedited space closure.
Need some more CE credits? Dr. Mark McDonough discusses a different type of space closure in his CE, “Congenitally missing mandibular premolars — treatment options for space closure” here.