The effect of an interocclusal appliance on bite force and masseter electromyography in asymptomatic subjects and patients with temporomandibular pain and dysfunction

Abstract

The aims of this study were to assess the effect of clenching with or without the presence of an interocclusal appliance (IOA) on bite force (BF) and masseter electromyography (EMG) in patients with temporomandibular pain dysfunction disorders (TMPD) and to compare these results with an asymptomatic age- and gender-matched control group. Ten patients with TMPD (mean age 26.9 years) were compared with eight healthy controls (mean age 25.3 years). Bilateral masseter EMG activity was recorded at rest, while clenching on the BF meter, while clenching on an IOA and while clenching on an IOA together with the BF meter. Significant left to right EMG activity asymmetry was found in the patient group at rest and during multiple clenching tasks in the control group. The patient group had significantly greater EMG activity at rest than controls. For all other tasks, the control group EMG activity was greater than the patient group. Use of an IOA significantly decreased EMG activity in both patient and control groups. BF was significantly greater in the control group on the right side for the different clenching tasks. Insertion of the IOA significantly increased BF in the control group. The results of this study indicate differences in EMG activity and BF during different clenching tasks and between patients with TMPD and asymptomatic subjects.

Maximal bite force and its association with temporomandibular disorders

“…The association between the presence of TMD and reduced MBF is contradictory in the literature and may be dependent on the severity of the TMD in the given sample (14)(15)(16)(17). Our results agree with those of previous studies (2,18,19), where no association between TMD and bite force was observed, and neither subjective symptoms nor clinical signs of TMD correlated significantly with MBF values (14).…”

Effects of increasing the jaw opening on the maximum bite force and electromyographic activities of jaw muscles

“…18 It was stated that the effectiveness of splints is achieved by redistributing the oral forces 19 or reducing the hyperactivity of the muscles. 13,20,21 Many studies evaluated the efficiency of occlusal splints 11,13,14,19,20 ; however, an optimal occlusal splint thickness was not defined in any of them. The occlusal splint thickness is an important consideration when treating patients and may directly influence the clinical effects.…”

“…4,5,8,9 Decreased EMG activity of the jaw muscles with an increased jaw opening is one of the hypotheses that explains the clinical efficiency of occlusal splints for treating masticatory muscle hyperactivity generally seen in patients with temporomandibular (TMD) disorders and bruxism. 1,10,11 It was suggested that adjusting the thickness of splints to or near the vertical dimension that produced the least EMG activity may be effective in reducing masseteric muscle hyperactivity and related symptoms. 1 It is assumed that insertion of an occlusal splint increases the jaw opening, helps relax muscles, 12,13 and redistributes intraoral forces more evenly throughout the masticatory system.…”

Centric relation in prosthetic rehabilitation

“…Jest on zaopatrzony w wał nagryzowy, który kontaktuje w jednym miejscu z przyśrodkowym zębem siecznym dolnym, prostopadle do długiej osi zęba. [17][18][19][20] Wskaźnik ten, jak i jego modyfikacje, działają na zasadzie obronnego odruchu nocyceptywnego z receptorów czuciowych nerwu trójdzielnego znajdują-cych się w obrębie dolnych zębów przednich. 6 Nagryzanie na twardy wskaźnik hamuje aktywność mięśni przywodzących żuchwę i aktywuje mięśnie odwodzące, na skutek czego powstaje ochronna równowaga mięśniowa.…”