Caries and periodontal disease in patients with Parkinson's disease

Parkinson's disease (PD) has been associated with aging, reduced fine motor skills, and malnutrition caused by eating soft sticky foods and a decreased liquid intake, which may contribute to the onset of caries, periodontal disease, and tooth loss. The objective of this study was to investigate the oral health of 101 patients with PD (mean age: 66.2 ± 10.5 years) and compare them to 75 control subjects (CO) (mean age 71 ± 10.53). Patients with PD had poorer oral health than the control group (papilla bleeding index: PD 6.97 ± 8.34; CO 2.12 ± 2.73). Lower frequencies of daily toothbrushing (PD: 1.69 ± 0.83; CO: 2.08 ± 0.80), longer time since the last dentist visit (PD: 1.94 ± 1.49; CO: 1.21 ± 0.60 years), and reduced salivary flow (PD: 2.69 ± 0.94; CO: 3.53 ± 1.11 ml). All of these factors may be related to the gingival recession and tooth mobility found in our patients with PD. Individuals with PD, their caregivers, and their physicians need to focus more on their oral health and quality of oral hygiene.     

Effect of an impaired oral stage on swallowing in patients with Parkinson's disease

We investigated the swallowing function in patients with Parkinson's disease (PD) using deteriorated tongue control because patients with PD frequently exhibit an impaired oral stage of swallowing and the tongue movement affects oral and pharyngeal stage. In total, 201 patients with PD (106 men, 95 women; mean age 70·6 ± 8·0 years; median Hoehn‐Yahr Stage III) were studied. The patients swallowed 10 mL of liquid barium under videofluorography, and their oral transit time (OTT) was measured. Based on 20 healthy controls (mean age 70·3 ± 7·8 years) with an OTT + 2 standard deviation (0·89 + 2 × 0·46) of 1·81 s, the patients with PD were divided into 167 patients with an OTT < 1·81 s and 34 patients with an OTT ≥ 1·81 s. Swallowing function was compared between the groups and assessed using logistic regression analysis. The following factors were significantly associated with oral stage impairment in both groups: tongue‐to‐palate contact, tongue root‐to‐posterior pharyngeal wall contact, premature spillage into the pharynx, aspiration and onset of swallowing reflex. Logistic regression analysis showed that tongue root‐to‐posterior pharyngeal wall contact, onset of swallowing reflex and aspiration were independent factors. PD patients with prolonged OTT displayed poor lingual control and decreased range of motion of the tongue due to bradykinesia and rigidity. Such problems in the oral stage affected the subsequent pharyngeal stage of swallowing with aspiration. Lingual movement in the oral stage thus appears to play an important role in the sequential movement of swallowing in PD.     

Effects of water viscosity and tongue ingestion site on tongue pressure during food bolus propulsion

The purpose of this study was to help provide data to help to implement effective rehabilitation following surgery for oral cancer by comparing tongue pressure production for water and thickened water from the anterior and posterior parts of the tongue during swallowing. Ten healthy volunteers (7 men, 3 women; age 27.6 ± 1.5 years) participated in the experiments. Tongue pressure during 3 mL water and 3 mL thickened water at the anterior and posterior tongue during swallowing was measured using a sensor sheet system with five measuring points on the hard palate. The sequential order of the points, maximal magnitude and duration of tongue pressure at each point were compared based on water viscosity and tongue ingestion site. There was a common pattern in the sequential order of tongue pressure generation among the two swallowing conditions. The maximal magnitude of tongue pressure was significantly higher when swallowing thickened water than when swallowing water at all points except for the anterior‐median and mid‐median part. Moreover, the pressure at all sites during posterior ingestions was significantly lower than that during anterior ingestion. The present results provide mean values of tongue pressure during voluntarily triggered swallowing in anterior ingestion and posterior ingestion in young, healthy dentate individuals; these values can be clinically referenced for tongue pressure measurement in the evaluation of patients with dysphagia. The use of reference values may help streamline the diagnosis, treatment and rehabilitation of dysphagia.     

Tongue‐to‐palate resistance training improves tongue strength and oropharyngeal swallowing function in subacute stroke survivors with dysphagia

Tongue function can affect both the oral and pharyngeal stages of the swallowing process, and proper tongue strength is vital for safe oropharyngeal swallowing. This trial investigated the effect of tongue‐to‐palate resistance training (TPRT) on tongue strength and oropharyngeal swallowing function in stroke with dysphagia patients. This trial was performed using a 4‐week, two‐group, pre–post‐design. Participants were allocated to the experimental group (n = 18) or the control group (n = 17). The experimental group performed TPRT for 4 weeks (5 days per week) and traditional dysphagia therapy, whereas the control group performed traditional dysphagia therapy on the same schedule. Tongue strength was measured using the Iowa Oral Performance Instrument. Swallowing function was measured using the videofluoroscopic dysphagia scale (VDS) and penetration–aspiration scale (PAS) based on a videofluoroscopic swallowing study. Experimental group showed more improved in the tongue strength (both anterior and posterior regions, P = 0·009, 0·015). In addition, the experimental group showed more improved scores on the oral and pharyngeal phase of VDS (P = 0·029, 0·007), but not on the PAS (P = 0·471), compared with the control group. This study demonstrated the effectiveness of TPRT in increasing tongue muscle strength and improving swallowing function in patients with post‐stroke dysphagia. Therefore, we recommend TPRT as an easy and simple rehabilitation strategy for improving swallowing in patients with dysphagia.     

Tongue pressure production while swallowing water and pudding and during dry swallow using a sensor sheet system

The tongue assumes an important role in bolus formation and transportation to the oropharynx and in retaining pharyngeal pressure during mastication and swallowing. Although the state of tongue-palate contact during swallowing is thought to change with bolus type, the details of these changes have yet to be clarified under normal physiological conditions. The purpose of this study was to examine the effect of bolus type on tongue pressure production against the hard palate during swallowing. Tongue pressures during swallowing 10 mL of water and 10 g of pudding and during dry swallow were measured with a sensor sheet system with five measurement points to evaluate normal physiological swallowing in 10 healthy dentate individuals. There was a common pattern in the sequential order of tongue pressure generation among the three swallowing conditions: tongue pressure was generated significantly earlier at the anterior-median part, followed by the posterior parts. During swallowing pudding and dry swallow, the duration of tongue pressure tended to increase at all channels except for the posterior-median part. The maximal magnitude of tongue pressure was significantly higher when swallowing pudding than when swallowing water at all channels except for the posterior-median part. The integrated value of tongue pressure was significantly higher when swallowing pudding than when swallowing water at all channels except for the posterior-median part. From these results, it was considered the tongue changed the sequential order, the duration and the magnitude of tongue pressure production according to the swallowing conditions (liquid swallowing, semisolid swallowing, dry swallow).     

Accidental aspiration in a patient with Parkinson's disease during implant-supported prosthesis construction: a case report

This article reports on a case history of an elderly patient with Parkinson's disease (PD) who sought treatment at a private dental office. His chief complaint was "difficulty in eating due to an illfitting prosthesis." Laboratory tests and oral radiographs were made. The surgical placement of an implant was done and, subsequently, an implant-supported prosthesis was fitted for the patient. During the impression for the construction of the implant-supported prosthesis, the patient accidentally aspirated the implant screwdriver. The object was found in the lower right lobe of the bronchus, and its removal was necessary in a hospital using bronchoscopy under general anesthesia. Patients with PD are considered at risk of aspirating and/or ingesting dental instruments. Short treatment periods are recommended, preferably during the morning, when the medication prescribed for PD is most effective. When treating patients who have a risk for aspirating and ingesting small objects, it is important to treat them in a more vertical position, and small-sized objects should be secured with dental floss to aid retrieval.     

Influence of tongue pressure and width on tongue indentation formation

The purpose of this study was to clarify which physiological and anatomical factors were involved in the formation of tongue indentations, which are believed to be a clinical sign of clenching. Twenty-four dentulous subjects were investigated. They were divided into two groups, depending on the presence or absence of tongue indentations: (i) a tongue indentation group and (ii) a no tongue indentation group. Intraoral appliances containing a small pressure sensor were placed at the lingual surfaces of the upper and lower right first molars. Lingual pressure on the lingual surfaces of the upper and lower right first molars was then recorded under different conditions. The tasks selected as physiological factors to be recorded were: (i) silent reading at rest for 10 min, (ii) maximum voluntary clenching (MVC) for 5 s, (iii) 10% of MVC for 1 min and (iv) swallowing. The results for all tasks were compared between groups. Tongue width and dental arch width were also measured as anatomical factors. No significant differences were found between groups during silent reading at rest, clenching, swallowing, or in tongue pressure integration during silent reading at rest. However, a significant difference was found in terms of tongue width (P < 0.05). These results indicate that neither volume of lingual pressure exerted on the lingual surface of the teeth during rest, clenching, nor swallowing are related to the formation of tongue indentations. The results do suggest; however, that tongue width at rest plays an important role in the formation of tongue indentations.     

Dynamics of posterior tongue during pronunciation and voluntary tongue lift movement in young adults

The lifting-up movement of the posterior part of the tongue to touch the palate, which is a requirement for performing physiological functions such as deglutition and speech, is an important phenomenon that is difficult to objectively evaluate. The purpose of this study was to develop a new modality to evaluate the tongue-lifting function, especially in the posterior part of the tongue, and to elucidate the dynamic properties of the tongue in normal subjects. Twenty-three healthy volunteers (9 men and 14 women; mean age, 27·6years) participated in this study. A new device was developed that could evaluate the up-down movement of the posterior part of the tongue in a non-invasive manner. The experimental tasks were as follows: (i) /a/ pronunciation for 1s followed by /ka/ pronunciation (a-ka task), (ii) /a/ pronunciation for 1s followed by /ga/ pronunciation (a-ga task) and (iii) /a/ pronunciation for 1s followed by a voluntary push-up movement of the posterior part of the tongue (a-lift task). Maximum upward velocity in the a-ga task was larger than that in the a-ka task (P<0·05). The a-lift task showed the highest tongue lift range among the three tasks, and the a-ga task showed a higher range than that of the a-ka task (P<0·05). This study revealed that precise quantification of the motility of the posterior part of the tongue, which would be useful in rehabilitation of articulation and/or swallowing, could be achieved using this new device in a non-invasive manner.     

Computerized analysis of the distribution of occlusal contacts in individuals with Parkinson's disease and temporomandibular disorder

The aims of the present study were to determine the prevalence of temporomandibular disorder (TMD) in a sample of patients with Parkinson's disease (PD) and to analyze the distribution of occlusal contacts.

Method: The sample was composed of patients with PD aged 50–75 years. Temporomandibular disorder was evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The distribution of occlusal contacts was determined using the portable T-Scan III^® occlusal analysis system during maximum voluntary clenching. Fisher's exact test was used to test the association between TMD and occlusal contact symmetry.

Results: Forty-two individuals with PD were analyzed. The prevalence of TMD was 23.8%. No statistically significant association was found between TMD and occlusal contact symmetry. Moreover, no significant difference in the distribution of occlusal contacts was found between the groups with and without TMD.

Discussion: The present data suggest no association between TMD and occlusal contact asymmetry in individuals with PD.

Conclusion: The results of this study identified a prevalence of 23.8% of TMD signs in subjects with PD and a high frequency of occlusal asymmetry in this sample.     

Oral biomarkers in exercise‐induced neuroplasticity in Parkinson's disease

In this article, we review candidate biomarkers for Parkinson's disease (PD) in oral cavity, potential of oral biomarkers as markers of neuroplasticity, and literature on the effects of exercise on oral cavity biomarkers in PD. We first describe how pathophysiological pathways of PD may be transduced from brain stem and ganglia to oral cavity through the autonomic nervous system or transduced by a reverse path. Next we describe the effects of exercise in PD and potential impact on oral cavity. We propose that biomarkers in oral cavity may be useful targets for describing exercise‐induced brain neuroplasticity in PD. Nevertheless, much research remains to be carried out before applying these biomarkers for the determination of disease state and therapeutic response to develop strategies to mitigate motor or non‐motor symptoms in PD.     

Tongue pressure production during swallowing in patients with mandibular prognathism

Abnormalities of swallowing in patients with mandibular prognathism have not been evaluated quantitatively. The aim of this study was to compare tongue pressure production for bolus transfer between volunteers with normal occlusion and patients with mandibular prognathism. The control group had 10 female volunteers with normal occlusion, and the patient group had 10 women with mandibular prognathism. Tongue pressure was measured by a palatal sensor sheet at five sites on swallowing 4 mL of a tasteless and odourless jelly. Results: The tongue pressure waveform differed between the control and patient groups. The incidence of a double‐peak tongue pressure waveform was more frequent in the patient group. In both groups, the exertion of tongue pressure began at the anterior point of the sensor sheet, followed by the peripheral parts. Although the order of expression of tongue pressure was the same for the two groups, maximum tongue pressure at all parts of the sensor sheet was lower in the patient group than in the control group. Furthermore, swallowing time was longer in the patient group than in the control group at the peripheral parts of the palate. These results clearly show the difference in tongue pressure production during swallowing between patients with mandibular prognathism and volunteers with normal occlusion. The current findings suggest that maxillofacial morphology may affect tongue movement during swallowing.     

Effects of varying fixed lingual apex positions on tongue pressure during straw drinking

We investigated the impact of tongue‐thrusting on lingual pressure during fluid intake with a straw. In this study, 12 healthy young dentate individuals (two women and 10 men; 19–33 years) were instructed to drink 15 mL of water with a regular drinking straw at 37 °C, when indicated by the investigator. Participants drank after adjusting tongue position to one of the following patterns: (i) Holding the tip of the straw between the lips (Normal Position: NP), (ii) Sticking out the tongue to the vermilion zone of the lower lip and inserting the straw 1 cm past the front teeth (Tongue‐thrusting Position: TP). Five recordings were conducted for each participant in a randomised order. To measure tongue pressure during swallowing, a specially designed 0·1‐mm thick sensor sheet (Nitta, Osaka, Japan) with a tactile system for measurement of pressure distribution (I‐SCAN; Nitta) was used. Duration, maximal magnitude and integrated value of tongue pressure were analysed based on the wave of tongue pressure recorded while water was swallowed. Magnitude, duration and integrated value of tongue pressure were significantly lower in TP than in NP at the median line (Ch1–3). Magnitude and integrated value of tongue pressure at the lateral part of the tongue (Ch5) were significantly lower in TP than in NP. When duration, maximal magnitude and integrated values were compared by channel, no significant differences were observed in NP, but a significant difference was found between Ch3 and the lateral areas Ch4/Ch 5 in TP. When the tongue was thrust forward, movement dynamics of the entire tongue changed and influenced contact between the tongue and palate during liquid intake with a straw. The impact was noticeably weaker on the median line than in lateral areas.     

异常吞咽与口周力相关性的研究

目的：定量分析异常吞咽口周力的分布特征。方法：用微力传感器和计算机辅助口周力测量系统对12名异常吞咽患者和12名正常吞咽错He患者上下颌中切牙、尖牙、第一磨牙颊、舌侧进行口周力的测量，对测量数据进行了统计学分析。结果：正常吞咽时男女之间各牙位的口周边值无显著性差异；异常吞咽时男性口周力大于女性，口周力与性别有相关性；异常吞咽组口周力大于正常吞咽组，其间差异有显著性。无论正常吞咽组还是异常吞咽组同侧上下颌同名牙位唇、颊侧与舌侧压力相比有显著性差异，下颌唇舌侧压力大于上颌唇舌侧压力。结论：异常吞咽时口周力与性别有相关性；异常吞咽组口周力大于正常吞咽组；舌的功能运动影响口周力，口周力会因吞咽方式的改变而发生适应性的变化。     

Handy measurement for tongue motion and coordination with laryngeal elevation at swallowing

At the oral stage of swallowing, the tongue plays a major role and proper tongue performance is necessary to form the bolus and transfer it to the pharynx. For the present study we built a prototype device for safe and handy objective estimation of tongue motion and coordination with laryngeal elevation at swallowing. The device records tongue pressure by means of two strain gauge pressure transducers aligned 20 mm apart on a brass strap placed along the palatal midline. Laryngeal vibration is recorded with piezo-electric acceleration transducers. Time differences between pressure onset at the anterior and posterior transducers and the first spike from laryngeal vibration are measured. Ten healthy subjects were asked five times to swallow 5 mL of water. Pressure onset at the anterior transducer preceded posterior pressure by 294 +/- 164 ms. Given the distance between the transducers, the tongue contracted (squeezed) at a speed of 93 +/- 60 mm s(-1). Laryngeal vibration occurred 671 +/- 175 ms after the onset of anterior pressure. There was considerable variation in these parameters between subjects. Though the data is limited, the device successfully and easily revealed certain aspects of tongue motion and coordination with laryngeal elevation.