An alternate approach: closing anterior open bites with low pulsatile forces without relying on vertical elastics

Dr. Straty Righellis discusses an alternative treatment option for correcting occlusion and smile esthetics with braces

Abstract/Introduction

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

Case summaries

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.

Results

• 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)

Figures 4A-4C: Patient 1. A. No low pulsatile force device on braces placement day (6/2014). B. Second month: Triangular elastics, no low pulsatile force device, patient admitted elastics worn infrequently. C. Fourth month: Low pulsatile force device and no elastics

Figures 6A-6B: Patient 1. A. No radiographic evidence of root resorption. B. Vertical control with no high pull headgear and <2 months’ wear of vertical elastics

Figure 5: Patient 1

Figure 7: Patient 1

Patient 2 (14-year-old female) treatment highlights

Diagnosis: Midface deficiency with anterior open bite. (Figure 8)

Conventional approach: Band upper and lower teeth with extensive use of Class III and vertical elastics

Mechanics and actual treatment approach: Self-ligating brackets, Class III elastics (1 month of nighttime wear), AcceleDent

• Months 1-2: Nighttime wear Class III elastics for 1 month (Figure 9)
• Month 3: Nighttime wear triangular elastics for 1 month (Figure 9)
• Months 4-14: No elastics

Results

• Total treatment time = 14 months (Figure 10 or 11)
• No radiographic sign of root resorption (Figure12)

Figure 8: Patient 2

Figure 10: Patient 2

Figures 9A-9B: Patient 2. A. Class III elastics for 1 month worn at night only (3/2016). B. Triangular elastics for 1 month worn at night only (5/2016)

Figure 11: Patient 2. Treatment completed in 14 months

Figures 12A-12B: Patient 2. A. No radiographic evidence of root resorption. B. Primarily incisor changes and “holding molars” in space

Patient 3 (17-year-old male) treatment highlights

Diagnosis: Class 1 with anterior open bite and upper arch crowding (Figure 13 or 14)

Conventional approach: Band upper and lower teeth with extensive use of vertical elastics

Mechanics and actual treatment approach: Self-ligating brackets, box elastics (3 months of nighttime wear), AcceleDent

• Months 1-3: Nighttime wear box elastics cuspids and first bicuspids
• Months 4-10: No elastics

Results

• Total treatment time = 10 months (Figure 16)
• No radiographic sign of root resorption (Figure 17)

Figure 13: Patient 3

Figures 15A-15C: Patient 3. A. Initial appliance placement (7/2016). B. Progress 1 month later. C. Progress 2 months later

Figures 14A-14B: Patient 3. A. Maximum intercsupation. B. Seated condylar position

Figure 16: Patient 3. Treatment completed in 10 months with 3 months’ posterior vertical elastics

Figures 17A-17B: Patient 3. A. No radiographic evidence of root resorption. B. Primarily incisor changes and “holding molars” in space

Patient 4 (15-year-old female) treatment highlights

Diagnosis: Class 1 anterior open bite to molars (Figure 18 or 19)

Conventional approach: Band upper and lower teeth and skeletal anchorage to intrude upper molars and allow for auto rotation of the mandible to “close the bite” (Figure 20)

Mechanics and actual treatment approach: Self-ligating brackets, vertical elastics (1 month), AcceleDent

• Months 1-3: No elastics
• Month 4: Left side vertical elastics at first bicuspids for 1 month
• Month 5-12: No elastics

Results

• Skeletal anchorage was initially planned, but not needed as bite was closing traditional (Figure 21)
• Total treatment time = 12 months (Figure 22)
• No radiographic sign of root resorption (Figure 23)

Figures 18: Patient 4

Figure 20: Patient 4. Skeletal anchorage was planned

Figures 23A-23C: Patient 4. A. No radiographic evidence of root resorption. B. Pretreatment. C. Posttreatment

Figures 19A-19B: Patient 4. A. Maximum intercuspation. B. Seated condylar position

Figures 21A-21C: Patient 4. A. Initial appliance placement (6/2016). B. Progress 1 month later. C. Progress 2 months later

Figure 22: Patient 4

Figure 24: Patient 4. Some incisor changes and slight molar intrusion

Figures 25A-25B: Patient 4. A. Some incisor changes and slight molar intrusion. B. Molar intrusion and mandibular autorotation

Summary

The clinical benefit of using low pulsatile forces to help doctors correct anterior open bite cases without elastics is that orthodontists have greater predictability because of the unpredictability of low patient compliance with elastics. In this author’s private practice experience, patients respond more favorably to a 20-minute daily routine of AcceleDent than having to wear elastics for at least 20 hours daily. During follow-up appointments, patients have reported that the device is simple to use and fits into their daily routines easily. Compliance with the device was high among all four patients and is high among all of the author’s patients regardless of their treatment diagnosis.

While scientific publication review of low pulsatile forces is exhaustive,^2-6 the effectiveness of the treatment adjunct for closing anterior open bites can be deduced only from clinical experience. From comparing these four cases to other open bite cases without low pulsatile forces, the author believes the difference results from the vibration (Figure 2). It seems that the low pulsatile, vibratory forces are at work to hold molars from vertical movements as wire form returns to the original form (Figure 1). The vibration provides control to keep the upper and lower molars in space as the incisors come together.

While more case reports and documentation of this intervention is needed, the results of these cases show that orthodontists should consider the realm of possibilities of treating open bite cases with noninvasive, low pulsatile forces without elastics. Other types of vibration are in use for indications such as aligners, but these cases focus on treatment with braces, and AcceleDent is FDA cleared for use with both braces and aligner therapy. The orthodontist maintains contact with these patients to continue monitoring retention and stability of the corrected bite. Additional clinical evidence is now being gathered in the orthodontist’s private practice to observe the effectiveness of low pulsatile forces to treat non-growing, adult patients who present with anterior open bites, as well as the integration of this low pulsatile vibratory device with posterior bite tabs.