Dr. Straty Righellis discusses an alternative treatment option for correcting occlusion and smile esthetics with braces
Educational aims and objectives
The purpose of this article is to discuss treating anterior open bite cases with low pulsatile forces and limited or no elastic wear.
Orthodontic Practice US subscribers can answer the CE questions with this quiz to earn 2 hours of CE from reading this article. Correctly answering the questions will demonstrate the reader can:
- Realize how to achieve treatment efficiency through accurate diagnosis.
- Identify three treatment options for open bite cases and the characteristics that are applicable for each.
- Recognize how low pulsatile forces provide a predictable treatment for open bite cases.
Treating anterior open bite patients without surgical solutions presents two challenges for orthodontists. The first challenge is closing the open bite with anterior elastics, and the second is the stability once the bite is closed: This article focuses on the former. Studies show that there is a 35%1 chance of relapse when closing open bites with vertical elastics. While this is the traditional treatment approach for anterior open bites, relying on vertical elastics for closure presents a significant treatment barrier to orthodontists that is out of their control. Typically, there is low compliance and lack of cooperation among patients when they are instructed to wear anterior elastics for the amount of time prescribed. Patients find the elastics cumbersome to work with, unattractive, difficult to fit in their daily routines, and painful.
As an alternative, the author found that it is possible to achieve high-quality clinical results in anterior open bite braces (fixed appliances) cases by incorporating low pulsatile forces and reducing or eliminating reliance on vertical elastics to close the bite. The four adolescent patients in these case reports were treated with Forestadent FACE™ Evolution self-ligating brackets, and each of them was instructed to use AcceleDent®, an FDA-cleared, noninvasive vibratory orthodontic device that employs low pulsatile forces to increase the rate of tooth movement. Patients bite down on the device’s acrylic mouthpiece for 20 minutes daily, and the gentle vibrations stimulate bone movement at the cellular level.2 Patients in this private practice have been more accepting of a 20-minute daily routine with gentle vibrations that make their teeth and gums feel better instead of the nearly all-day routine required for elastic wear.
Closing anterior open bites with low pulsatile forces
When open bite patients present for an orthodontic consultation, it’s important to begin with the end in mind by identifying the patient’s desired end results as well as what must be corrected from a clinical standpoint. While there are several approaches to treating open bite patients, the premise demonstrated in this article of using low pulsatile forces with minimal or no elastics is only being suggested for correcting occlusion and smile esthetics with braces. When the goal is to correct occlusion, facial symmetry, smile esthetics, and airway, orthognathic surgery is the recommended treatment approach. Skeletal anchorage with anchor plates is a viable treatment option for correcting occlusion, facial symmetry, and smile esthetics.
The serendipitous discovery of the effectiveness and efficiency of using low pulsatile forces as a treatment adjunct for this author’s anterior open bite patients started with a noncompliant adolescent female patient —Patient 1. When treatment began, Patient 1 was instructed to wear vertical elastics at night only. One month into treatment, the patient’s mother noted that the patient was not compliant with the elastics and inquired about the low pulsatile vibratory device to speed up the treatment. The patient began using this device during the 2nd month of treatment, which is when she also stopped wearing her elastics, and was finished in 17 months. This garnered the author’s attention because he was able to achieve a quality result with only sporadic elastic wear in the first 2 months of treatment.
Comparing this case with other anterior open bite cases that followed the traditional treatment approach with elastics and without low pulsatile forces, the author deduced that vibration is what is at play at here (Figure 2). For nearly 40 years, there have been studies showing that pulsating forces positively impact the rate of tooth movement.4 Since the 1980s, pulsatile stimulation of bone has helped heal bone fractures and osteoporosis. When orthodontic patients began demanding faster treatment, this led to the commercialization of low pulsatile force vibration.
Under low pulsatile forces, there is engorgement of the blood supplies in the craniofacial sutures.5 This vibration stimulates bone metabolism molecules that regulate the quantity and activity of osteoclasts and osteoblasts.6 The factors that increase the rate of bone remodeling also increase the rate of tooth movement.7 This explains how using the low pulsatile vibratory forces accelerates orthodontic tooth movement by increasing osteoblastic activity and reducing hyalinization formation.
Figure 1: “Righellis Theory” on how it works in open bite cases
Additionally, pre- and posttreatment cephalometric analysis demonstrated there was no molar extrusion that can happen in treating anterior open bites (Figure 1). Typically, the upper and lower molars extrude with brackets unless also using headgear or skeletal anchorage. With the application of low pulsatile forces in these cases, the molars actually intruded slightly as the incisors moved toward each other. From these results, the author also infers that vibration helps flexible archwires to move the anterior teeth.
In clinical practice, using the low pulsatile vibratory device shortens the length of treatment during Stage 1 (aligning, leveling, and arch coordination) and Stage 2 (group and AP movements), giving orthodontists plenty of time to detail during the finishing stage. Treatment time for anterior open bites in this author’s practice, using the traditional approach with elastics and without this device, averaged between 16 to 18 months. Using low pulsatile forces and limited or no elastic wear, these cases can be finished within 12 months. As is the case with Patient 1, using low pulsatile forces offered improved predictability, regardless of acceleration of treatment time, when low patient compliance could foster unpredictable treatment results.
Adapting wire sequencing and patient appointments with accelerated tooth movements,
When using the low pulsatile force alternative treatment approach to correct anterior open bites, it’s critical to change the archwires more frequently. During Stage 1 of anterior open bite treatment with low pulsatile forces, teeth are going to move faster than normally expected, so the archwires need to be changed every 4 weeks to advance the wire sequences. The goal is to place the .0195 x .025 stainless steel wire within 4 months from initial bracket placement.
In Stage 2 with a .0195 x .025 stainless steel wire, the patients are scheduled every 6 to 7 weeks. Stage 2 goals are transverse, vertical, and AP changes. In the finishing stage, Stage 3, the focus is on detailing to ensure patient satisfaction and a high-quality clinical result is achieved.
Figures 2A-2H: A-B. Patient 1. Treatment time: 17 months. Months 1-2: Sporadic elastic wear. Months 3-17: No elastics. C-D. Patient 2. Treatment time: 14 months. Months 1-2: Nighttime wear Class III elastics for 1 month. Month 3: Nighttime wear triangular elastics for 1 month. Months 4-14: No elastics. E-F. Patient 3. Treatment time: 10 months. Months 1-3: Nighttime wear box elastics cuspids and first bicuspids. Months 4-10: No elastics. G-H. Patient 4. Treatment time: 12 months. Months 1-3: No elastics. Month 4: Left side vertical elastics at first bicuspids for 1 month. Months 5-12: No elastics
All cases are diagnosed from models mounted in seated condylar position (SCP) with additional measurements quantifying the distance from maximum intercuspation to SCP. The next step in treatment planning is diagnosing the position of the upper incisor relative to the relaxed upper lip both vertically and antero-posteriorly from the “converted” lateral cephalometric image. Various smile and relaxed facial images are used to cross-check our cephalometric data.
Figure 3: Patient 1
Patient 1 (14-year-old female) treatment highlights
Diagnosis: Class I skeletal and dental open bite with vertical growth history. Non-extraction. (Figure 3)
Conventional approach: Band upper and lower teeth, vertical control with TPA and vertical elastics.
Mechanics and actual treatment approach: Self-ligating brackets, infrequent elastic wear (<2 months), AcceleDent (16 months)
- Months 1-2: Sporadic elastic wear
- Month 2: Patient given AcceleDent
- Month 4: Orthodontist eliminated use of vertical elastics (Figure 4)
- Treatment progression was slowed at this point because of the delay in LL5 eruption. Typically, the orthodontist would have waited to begin this case until the second bicuspids were fully in, but the patient was anxious because of the high cuspids.
- Total treatment time = 17 months, including 16 months with AcceleDent and sporadic elastic wear during first 2 months (Figures 5 or 7)
- No radiographic evidence of root resorption (Figure 6)