**2. Material and methods**

#### **2.1. Vibrotactile stimulation apparatus**

The vibrotactile stimulation apparatus consists of an oscillating body and control unit, as shown in **Figure 1A** [2]. The oscillating body is composed of the headset equipped with vibrators as a substitute for positions of the bilateral microphones and vibrators utilizing the vibration electric motor (VEM) (Rekishin Japan Co., LE12AOG), as shown in **Figure 1A**. The VEM *is* covered in silicon rubber (polyethyl methacrylate, dental mucosa protective material, Shyofu Co.) for conglobating the parts under stimulation and preventing the warming of the VEM's temperature produced by the vibration of long periods [2]. The control unit consists

Salivary Effects of Facial Vibrotactile Stimulation in Patients with Sjogren's Syndrome and Poor Salivation http://dx.doi.org/10.5772/intechopen.72383 107

**Figure 1.** (A) Apparatus for facial vibration and (B) position of cotton rolls.

**1. Introduction**

as reported by Hiraba et al. [2, 9, 10].

106 Salivary Glands - New Approaches in Diagnostics and Treatment

tion based on these results.

**2. Material and methods**

**2.1. Vibrotactile stimulation apparatus**

When we treat patients with reduced salivation (hyposalivation), we provide treatments such as artificial saliva, humectant, massage on the salivary glands, and so on [1]. However, treatment *with* the artificial saliva and humectant is the symptomatic treatment, and patients with handicaps *experience difficulties when they do massage*. We previously reported about *the* relationship between facial vibratory effects in normal subjects and promotion of salivation. *We performed this method* for facial vibratory effects *on* Sjögren's syndrome patients with poor salivation. We focused *on increase of* salivation with the use of facial vibrotactile stimulation,

When patients continuously utilize the apparatus in future *the decrease or increase of salivation is examined from this result* [3]. *In this experiment*, it was necessary to make a comparison between the resting and *stimulated* salivations and to investigate the most effective frequency for increasing the salivary secretion. We examined the amount of salivation during vibrotactile stimuli with one vibrating motor (1.9 μm amplitude) on the bilateral masseter muscle belly (on the parotid glands), and in patients of Sjögren's syndrome, we asked twice practice during 15 min of morning and night. Furthermore, *the* amount of salivation *was* explored by using a dental cotton roll positioned at the opening of the secretory duct for *3 min*. After this experiment was performed, *we made* a comparison between the resting and *stimulated* salivations and *investigated* the most effective frequency for increasing salivary secretion. *When we examined normal subjects, the effect of the increased salivation determined the difference between the resting and stimulated salivations. We think that total salivation after the resting phase shows conditions of day-to-day* 

We defined 5-min intervals as the recovery time between the resting and *stimulated* salivations from the previous pre-examinations. Furthermore, we examined temperature effects *on* patients with poor salivations (affected by Sjogren's syndrome) and others by the use of facial vibrotactile stimuli. Increased facial temperature by the vibrotactile stimulation showed changes of metabolism around facial skins. We will discuss the effects of vibrotactile stimula-

The vibrotactile stimulation apparatus consists of an oscillating body and control unit, as shown in **Figure 1A** [2]. The oscillating body is composed of the headset equipped with vibrators as a substitute for positions of the bilateral microphones and vibrators utilizing the vibration electric motor (VEM) (Rekishin Japan Co., LE12AOG), as shown in **Figure 1A**. The VEM *is* covered in silicon rubber (polyethyl methacrylate, dental mucosa protective material, Shyofu Co.) for conglobating the parts under stimulation and preventing the warming of the VEM's temperature produced by the vibration of long periods [2]. The control unit consists

*salivation, and they after the stimulating are effects of vibrotactile stimulation.*

of three parts: the pulse width modulation (PWM) circuit, LCD monitor circuit and power supply circuit, and *interfaces* with a PWN electric motor, *delivers* vibration frequencies in the 60–182 Hz range [4].

As shown in **Figure 1**, we examined the amount of salivation during vibrotactile stimuli by two kinds of methods: on the bilateral masseter muscles belly (parotid glands) and on the bilateral parts of submandibular angle (submandibular glands). We examined the amount of salivation using a dental cotton roll (1 cm across and 3 cm length) positioned at the opening of the secretory ducts (right and left sides of parotid glands and right and left sides of submandibular and sublingual glands), during the vibrotactile stimuli on the bilateral parotid and submandibular glands, and wet cotton rolls measured for 3 min. These weights were then compared to their initiatory weights, as shown in **Figure 1B** [2].

#### **2.2. Estimation of the stimulating salivation in normal subjects**

First, we use three different frequencies, 89, 114 and 180 Hz as the vibrotactile frequency from the character of the oscillating body on the parotid glands. **Figure 1** *shows the apparatus and position of rolls. To begin with, we put an exercise into practice for avoiding foreign-body sensation on the cotton rolls while setting for 3 min.* Next, after 5 min of *resting,* we examined the amount of salivation during the 89 Hz vibrotactile stimulation for 3 min. *Furthermore, after every 5 min of rest, we examined next amount of salivation during the 114 and 180 Hz vibrotactile stimuli for 3 min, respectively.* We decided on 3 min *for* the measurement *of* salivation and 5 min *for* recovery time from the previous experiment [2]. We carried out the examinations and used 19 normal subjects (male: 6 and female: 13, average age 22) for the resting-stimulating examination. This experiment was performed between 3 and 5 pm in a temperature-controlled room.

normal subjects (male: 11 and female: 15, average age 25) for the resting-stimulating examination. This experiment was performed between 3 and 5 pm in a temperature-controlled room. *In particular, we find that 89 Hz frequency and 1.9 μm amplitude is most effective for salivation.*

Salivary Effects of Facial Vibrotactile Stimulation in Patients with Sjogren's Syndrome and Poor Salivation

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109

As shown in **Figure 1**, we examined the difference between vibrotactile stimuli on the parotid glands and the submandibular glands. First, we tried three different vibrotactile stimuli, 89, 114, and 180 Hz, on the parotid glands and explored the frequency for the most effective salivation, as shown in **Figure 2**. Next, we inferred the most effective salivation of 89 Hz with the one motor depending on vibrotactile stimuli on the parotid or submandibular glands [2]. Furthermore, we investigated the most effective salivation depending on the difference of amplitudes (1.9 and 3.5 μm amplitudes). We inferred the most effective salivation of 89 Hz with the one motor (1.9 microm amplitude) on the submandibular glands (significant difference *P* < 0.05, 89 Hz with 1.9 μm amplitude and 114 Hz with 1.9 and 3.5 μm amplitude), as

In 89 Hz vibrotactile stimulation with 1.9 μm amplitude on the parotid glands, we observed the most effective salivation in each gland, the right parotid, left parotid, right submandibular and sublingual, and left submandibular and sublingual glands. *Vibrotactile stimuli on the parotid or submandibular glands in any case showed that at 89 Hz more effective salivation in the right and left parotid and in the left and right submandibular and sublingual glands happened in comparison with the resting salivation in each gland.* On the other hand, vibrotactile stimuli with 1.9 μm (89 and 114 Hz—1) or 3.5 μm amplitudes (89 and 114 Hz—2) on the parotid or submandibular glands were examined. The 89 Hz with one motor, was the most effective salivation in the parotid, and the submandibular and sublingual glands, and the 89 Hz with double motors, was the more effective salivation in the parotid, and submandibular and sublingual glands, as shown in Hiraba et al. [2]. From these reasons, we suggested that vibrotactile stimulation at

89 Hz with 1.9 μm amplitude showed the most effective salivation in many glands.

**2.5. Information of patients with poor salivation affected by Sjögren's syndrome** 

Finally, we assumed that 89 Hz with 1.9 μm amplitude vibrotactile stimulation *produced the most effective salivation,* and then the vibrotactile stimuli on the parotid and submandibular glands *showed* hardly any difference. We then decided to use the apparatus to patients affected

In **Figure 3**, we showed information of patients: eight women were *diagnosed with* Sjögren's syndrome and two women's symptoms were unexplained*. Patients with Sjögren's syndrome were diagnosed by contrast and/or scintigraphic studies. In particular, the patients with indefinite complaints were not given a definite diagnosis*; *nevertheless, they had poor salivation as their chief complaint.*

**2.3. Vibrotactile stimuli on the parotid and submandibular glands**

**2.4. Total salivation after the vibrotactile stimulation on the parotid or** 

shown in Hiraba et al. [2].

by poor salivation.

**and others**

**submandibular and sublingual glands**

*Second, as shown in* **Figure 2**, *we used three different frequencies (89, 114 and 180 Hz) and two different amplitudes (1.9 and 3.5 μm) on the parotid and/or submandibular glands. Amplitudes of vibrotactile stimuli were measured by the CCD laser displacement gauge (LK-G3000, KEYENCE Co.). After three different frequencies were attempted on the parotid glands, we explored the most effective frequency, and we arrived at a frequency of 89 Hz. We examined the frequency of 89 and 114 Hz and we used also oscillating bodies added as the frequency with double motors (one motor is 1.9 μm amplitude and double motors is 3.5 μm amplitude). Namely, the second experiment was practiced by 89 and 114 Hz with one motors (1.9 μm amplitude), and 89 and 114 Hz with double motors (3.5 μm amplitude). We examined the amount of salivation in four different trials, as shown in* **Figure 2***. We carried out the examinations and used 17 normal subjects (male: 15 and female: 2, average age: 22) for the resting-stimulating examination. This experiment was performed between 3 and 5 pm in a temperature-controlled room.*

Finally, as shown in **Figure 2**, since the most effective salivation by vibrotactile stimuli was at 89 Hz frequency with one motor (1.9 μm amplitude), we examined salivations on 89 Hz vibrotactile stimulation *continuously for* 4 or 5 days. *As patients continuously utilized the apparatus, we examined if adaptation develops with everyday usage and whether or not the decrease of salivation arises*. We investigated the adaptation of periods with the continuous use of vibrotactile stimuli for 4 continuous days in the same subjects. We carried out *this examination* and used 26

**Figure 2.** Salivations in each vibration frequency.

normal subjects (male: 11 and female: 15, average age 25) for the resting-stimulating examination. This experiment was performed between 3 and 5 pm in a temperature-controlled room. *In particular, we find that 89 Hz frequency and 1.9 μm amplitude is most effective for salivation.*
