Absolute Maximum Bite Force Changes in Orofacial Pain Patients Immediately Following Disclusion Time Reduction (DTR) using Innobyte.

INTRODUCTION

Occlusion is one of the most divisive and misunderstood topics in all of dentistry because dental school occlusion education is basic, focused on the occlusal biomechanics and not on the occlusal neurophysiology. Commonly assessed biomechanical occlusal parameters are over-bite, over-jet and Angle’s classification, while most restorations are made to “fit within the patient’s existing occlusion scheme.” This is not to minimize occlusion’s importance, despite the lack of neurophysiologic understanding or interest. Even one prominent anti-occlusion author has pointed out that “Dental occlusion is the core of dentistry.”¹ And, other authors have reported that the effects of a poor occlusion reach far to compromise other areas of the body away from the mouth.^2–4

The stomatognathic system can be objectively quantified with biometric bite force measurements, Disclusion Time analyses, mandibular kinematics, mastication analyses, and muscle electromyographic activation. However, biometric technologies are not widely clinically or academically employed, despite their growing contribution into the understanding of functional occlusal science.^5–7 With the ready availability of today’s advanced biometric data, it is clinically inadequate to rely on a visual evaluation of the occlusion or the results of manual muscle palpation.⁸ The clinical utilization of biometric technologies has a longstanding literary track record of improving dysfunctional patient’s lives,^9,10 making these technologies the occlusal analysis “Gold Standard,” despite dentistry’s lack of widespread adoption.¹¹

Normal masticatory function is dependent on several contributory factors,¹² with one being the capacity to exert maximum bite force (MBF).¹³ Bite force itself results from the synchronized activation of the masticatory musculature, whereby a stable occlusion enables these muscles to operate efficiently, allowing the stomatognathic system to meet its’ functional demands.¹⁴ It has been well established that TMD patients demonstrate a reduced MBF compared with healthy controls.^15–18

The Innobyte device (Kube Innovation, Inc., Montreal, QC, Canada) is a biometric technology that measures absolute bite force in engineering units (Newtons, N) as a patient forcefully closes their teeth into an arch-shaped silicone pad (Figure 1-AB.). In a recent non-treatment study, Innobyte measured the bite force differences in Class I and Class II malocclusion patients, whereby the Class II patients exhibited lower occlusal force values.¹⁸ Earlier, Innobyte bite force measurements were obtained before and after guided occlusal adjustments were made to digitally fabricated anatomic orthotics with T-Scan 10 (Tekscan Inc., Norwood, MA, USA). Innobyte determined the T-Scan-guided anatomic orthotic adjustments statistically improved patients’ MBF compared to the “as fabricated but unadjusted” occlusal orthotics.¹⁹

Figure 1a.Innobyte (Kube Innovation, Inc., Canada) includes a silicone bite pad that subjects forcefully bite into that is connected to a digital display which output each subject’s absolute bite force in Newtons (N).

Figure 1b.The range of bite force reference values in Newtons as reported by Kube International.

T-Scan-guided Disclusion Time Reduction is a well-studied, splintless, high precision, data driven occlusal adjustment method for TMD patients.^9,10,20–26 DTR has been shown in 2 studies to increase chewing speed, improve chewing strength, shorten chewing duration, and normalize chewing motion mechanics while lessening chewing muscle jerkiness.^7,27 And in 2006, 1-month after initial DTR treatment, subjects’ clenching EMG outputs statistically increased, suggesting the subject group’s bite forces increased.²⁸

OBJECTIVE

As to date only one study has measured absolute bite force from pre and post T-Scan-guided occlusal adjustments on anatomic orthotics.¹⁹ The objective of this cohort study was to evaluate maximum bite force (MBF) changes pre to post ICAGD computer-guided occlusal adjustments performed on the natural teeth of painful chronic TMD patients.

MATERIALS AND METHODS

109 consecutive orofacial patients with various diagnoses (TMD, MD, TN, MH and UD) who sought out DTR therapy comprised the subject pool.

The subject Inclusion Criteria were:

• 28 teeth with symmetrically missing teeth (if one molar was missing on the left, one had to be missing on the right)

• Near normal occlusal relations with molars and premolars in contact during the right and left excursions

• Angles Class I and Class III occlusal relations, with guiding anterior teeth that were either in contact, or near to contact

• Non-TMD Patients that had been previously treated for their respective diagnosis, but did not receive adequate symptom resolution

• Patients 18 years of age or older

The subject Exclusion Criteria were:

• Severe Class II malocclusions

• Anterior open bite where anterior guidance contact could not be achieved

• A previous history of TMJ trauma

• The presence of unstable Temporomandibular Joint internal derangements verified by CBCT and/or Joint Vibration Analysis (JVA).

• Patients that had been previously treated with any therapy that resolved symptoms

• Patients who had undergone prior TMD, including prior occlusal adjustment treatment.

Each subject’s absolute maximum bite force (MBF) was recorded twice pre-ICAGD occlusal adjustments by subjects self-closing into the Innobyte silicone bite pad (Figure 2A). Next, DTR therapy was executed to visit 1 completion, after which 2 more Innobyte self-closure bite force measurements were re-recorded on the same subject in the same visit. The pre and post Innobyte MBF raw data was averaged to report a single MBF value.

Figure 2AB. (A.) The Innobyte (left) technology measures the subjects absolute occlusal force in Newtons. (B.) The T-Scan 10/BioEMG III (right) technologies simultaneously measure the subject’s relative occlusal forces, excursive Disclusion timing, and muscle activity levels, which are all used to guide the ICAGD adjustments.

T-Scan 10/BioEMG III data was obtained prior to subjects undergoing the ICAGD Coronoplasty (Figure 2B), which is briefly described here.^20–27,29 The synchronized technologies diagnosed subject’s occlusal force imbalances and long disclusion times. Teeth were then dried on one side of the mouth (maxillary and mandibular) and subjects closed into their Maximum Intercuspal Position (MIP) with 21-micron thick articulating paper (Accufilm II, Parkell Inc., Englewood, NY, USA) interposed between their teeth. Each subject moved into a right excursion all the way out to the tip of the canine, then back into MIP, then moved outwards into a left excursion all the way out to the tip of the canine, and then finally back into MIP. The pre-treatment T-Scan 10/BioEMG III recordings guided the clinician to treat the frictionally-engaged areas of the involved occlusal surfaces that necessitated corrective adjustments. All posterior working and non-working lateral interferences were completely removed up to and including the 1^st premolars bilaterally, and the remaining centric stop contacts were revised into small pinpoint contacts located on supporting cusps, marginal ridges and central fossae. When visual complete posterior disclusion was achieved on the 1^st treated side, the same process was repeated on the opposite side.^21,22

Post ICAGD recordings were made in the same fashion as the pre ICAGD recordings to confirm the treated Disclusion Times were correctly shortened to < 0.5 seconds/excursion.^21,22,30

DTR visit 1 treatment was considered complete when:

1. All lateral posterior excursive interferences were removed

2. Disclusion Times had measurably been reduced to < 0.5 seconds in both right and left excursions

3. Habitual closure contacts were located solely on cusp tips, fossae and on marginal ridges

4. T-Scan revealed that patient self-closure into MIP achieved bilateral simultaneous force rise

5. The right to left occlusal force balance was 50/50 +/- 5%, and 25% by quadrant +/-2%.^21,22,30

Once the Disclusion Times were confirmed as properly shortened, subjects closed twice again into the Innobyte silicone bite pad to record their post ICAGD absolute force levels. The 2 trials were averaged before the Wilcoxon Signed-Rank Test was used to calculate significant differences between the pre DTR and post DTR MBF values in Newtons.

RESULTS

Statistically significant increases in MBF were obtained following high precision DTR occlusal corrections in all 5 of the diagnostic groups (TMD, p < 0.0054; TN, p < 0.00043; MD, p < 0.0357; MH, p < 0.034012; UD, p < 0.00001). The neurologic response to DTR was immediate, as the subject groups’ MBF pre to post DTR values increased within the same treatment visit. This study’s findings illustrate a relationship exists between muscle weakness/inhibition and malocclusion, where once the bite force and timing were corrected following T-Scan/BioEMG III-guided occlusal adjustments, immediate increases in MBF were obtained.

DISCUSSION

The findings of this MBF research are unique in that to date, there are no pre-existing studies that have reported on increased MBF following Disclusion Time Reduction (DTR). However, the Results do corroborate an earlier Innobyte anatomical orthotic study, where computer-guided occlusal adjusting increased MBF in subjects using oral appliances.¹⁹ The findings also compliment an earlier 2006 DTR study showing that after treatment, subjects demonstrated increased maximum clench EMG amplitudes.²⁶ In these studies and in this Innobyte/DTR study, the occlusal contacts were optimized with T-Scan/EMG data that lead to increased muscular strength output.

DTR treatment measurably lessens the force and time durations that opposing posterior teeth frictionally engage in excursive movements, which markedly lessens masticatory and swallow muscle hyperfunction neurophysiologically from within the CNS.³⁰ This in turn quickly allows strained muscles to relax from their ischemia and then either strengthen or more likely, suddenly reduce the level of CNS inhibition.^6,28,31 As such, computer-guided occlusal optimization of contact forces, contact time simultaneity, and excursive Disclusion Time durations have been shown in many TMD and occlusal function treatment studies to create physiologic muscular function at the tooth contact level.^{6,7,20–26,31} In this specific MBF Innobyte/DTR study, those same high-precision computer-guided occlusal function controls (outlined in the Methods), afforded subjects to increase their MBF.

Additionally, the significant increase in maximum bite force could have resulted after the pain during function was reduced or removed by the T-Scan/EMG guided occlusal adjustments, allowed the system to work more efficiently. And/or removing the frictional interferences removed each individual subject’s compensatory mechanisms needed to function around these problematic occlusal contacts, which allowed the system to work more efficiently.

This study’s measured MBF improvements could not have been determined without the combined use of the Innobyte absolute force measurement system, and the T-Scan 10 relative force measurement system. It was the T-Scan relative force and timing data that guided the occlusal adjustments to treat the subjects’ occlusions to high-precision numerical outcomes,^21,28 which made it possible for the Innobyte to detect a statistical change in the subjects’ MBF. The Innobyte cannot treat a patient’s occlusion as can T-Scan, because T-Scan detects for targeted treatment individual problematic force and timing contact locations, but does not provide data on absolute force changes like the Innobyte. Importantly, the outcome of this MBF study confirms that occlusal surface morphology directly impacts stomatognathic physiology.

DTR occlusal therapy guided by the T-Scan 10/BioEMG III systems are known for correcting occlusal contact timing and force aberrations utilizing high precision, metrically driven adjustments. It has a long history of being utilized as a splint less TMD therapy, as well for accurately finishing orthodontic and restorative cases. Many published patient treatment studies using T-Scan relative force and timing adjustments have obtained corroborating physiological patient outcomes.^{6,7,20–26,31} The Innobyte system objectively quantified significant MBF increases in maximum bite force levels in all 5 subject groups. Ultimately, Stomatognathic muscle physiology was improved by correcting subjects’ bite force and timing concerns.

LIMITATIONS

One possible limitation was the absence of control subjects. However, the subjects were their own controls, forfeiting many possible confounders when comparing intersubject data. The only condition that changed per subject between Innobyte recordings was the DTR occlusal adjustments to the bite forces and discussion timing. Within each individual subject and within the same single data gathering appointment, all other possible variables remained unchanged. Thus, each subject’s measured outcome had minimal influence from other variables, with only the occlusal adjustment correction treatment being attributed to the MBF increases. This same protocol should be performed on a similar sized subject group followed over a longer period of time to further substantiate this study’s findings.

CONCLUSION

Increased maximum bite force (MBF) can be obtained immediately after the first DTR treatment procedure, by using T-Scan/BioEMG-guided occlusal adjustments that improve bite force percentage balance and reduce Disclusion Times. These high-precision computer-guided occlusal adjustments increased muscular activity that generated increased maximum bite force (MBF).

Statement of Conflicts

No conflicts were reported

Statement of Funding

No funding was provided by any source for this study.