Posterior scissors‐bite: masticatory jaw movement and muscle activity

Scissors‐bite is a malocclusion characterised by buccal inclination or buccoversion of the maxillary posterior tooth and/or linguoclination or linguoversion of the mandibular posterior tooth. This type of malocclusion causes reduced contact of the occlusal surfaces and can cause excessive vertical overlapping of the posterior teeth. This case–control study is the first to evaluate both masticatory jaw movement and masseter and temporalis muscle activity in patients with unilateral posterior scissors‐bite. Jaw movement variables and surface electromyography data were recorded in 30 adult patients with unilateral posterior scissors‐bite malocclusion and 18 subjects with normal occlusion in a case–control study. The chewing pattern on the scissors‐bite side significantly differed from that of the non‐scissors‐bite side in the patients and of the right side in the normal subjects. These differences included a narrower chewing pattern (closing angle, P < 0·01; cycle width, P < 0·01), a longer closing duration (P < 0·05), a slower closing velocity (P < 0·01) and lower activities of both the temporalis (P < 0·05) and the masseter (P < 0·05) muscles on the working side. In 96% of the patients with unilateral posterior scissors‐bite, the preferred chewing side was the non‐scissors‐bite side (P = 0·005). These findings suggest that scissors‐bite malocclusion is associated with the masticatory chewing pattern and muscle activity, involving the choice of the preferred chewing side in patients with unilateral posterior scissors‐bite.     

Analysis of brain activity involved in chewing‐side preference during chewing: an fMRI study

The aim of this study was to investigate the activation characteristics of cerebral cortex in participants with CSP during rhythmic chewing movement. Sixteen right‐handed participants with left (two males: 29·0 ± 8·4 years old, six females: 32·3 ± 4·8 years old) or right (four males: 31·0 ± 6·1 years old, four females: 30·8 ± 4·7 years old) CSP were scanned by functional magnetic resonance imaging during rhythmic chewing. The on‐off sequence of scanning was 30 s of rhythmic chewing and 30 s of rest (off) a total of five times. The results showed that blood oxygen level‐dependent signals in the contralateral (to the CSP) primary sensorimotor cortex increased more than in the ipsilateral primary sensorimotor cortex in participants with both left and right CSP (P ≤ 0·001). Moreover, the BOLD signal within the right substantia nigra of midbrain, brainstem was more significantly (P ≤ 0·001) activated than its left counterpart in participants with left CSP, while no activation was observed in those with right CSP. The similar activation of the cerebellum was in participants with right CSP. The inferior parietal lobule, inferior frontal gyrus and left insular cortex were significantly (P ≤ 0·001) activated in participants with CSP. These findings suggest a relationship between hemispheric dominance and CSP in the primary sensorimotor cortex responsible for rhythmic chewing movement. The brainstem and the cerebellum might also play important role in the regulation of CSP. Furthermore, the IFG, IPL and insular may contribute to higher cognitive information processing for participants with CSP.     

The effects of chewing‐side preference on human brain activity during tooth clenching: an fMRI study

Summary Chewing‐side preference (CSP) may be associated with dominant cerebral hemispheric organisation. However, little information exists regarding whether CSP is reflected by preferential activity in the opposite (to the CSP) cerebral hemisphere. The aim of this study was to investigate the effects of CSP on cerebral cortex response to bilateral tooth clenching. Sixteen right‐handed participants with left (two men: 29·0 ± 8·4 years old, six women: 32·3 ± 4·8 years old) or right (four men: 31·0 ± 6·1 years old, four women: 30·8 ± 4·7 years old) CSP were scanned by functional magnetic resonance imaging during moderate levels of voluntary tooth clenching. The on‐off sequence of scanning was 30 s of clenching (on) and 30 s of rest (off) a total of five times. The results showed that blood oxygen level–dependent signals in the contralateral (to the CSP) primary sensorimotor cortex increased more than in the ipsilateral primary sensorimotor cortex in participants with both left and right CSP (P ≤ 0·001). The supplementary motor area was activated in participants with left (P ≤ 0·001) but not right CSP. Activation of the inferior frontal gyrus and inferior parietal lobule was greater in participants with right versus left CSP (P ≤ 0·001). Significant (P ≤ 0·001) activation was observed in the parahippocampal gyrus in five of eight participants with left CSP, whereas no activation was observed in those with right CSP. These findings suggest a relationship between hemispheric dominance and CSP in the primary sensorimotor cortex responsible for bilateral tooth clenching.     

The influence of partial implant‐supported restorations on chewing side preference

Summary This study aimed at determining whether the individual’s chewing side preference is affected by local effects, produced by the presence of implant‐supported restorations. The test group included 81 patients with partial implant‐supported prosthesis. The control group included 108 subjects with no implants. All subjects went through a series of laterality tests for chewing and tasks (hand, foot, eye and ear) side preference. The preferred chewing side (PCS) was determined by observing the first stroke of the chewing cycle during chewing a gum. A positive and significant correlation between the chewing side preference and the subject’s sidedness during the different tasks was examined, by performing four Phi correlation tests for: chewing and handedness(r = 0·54; P < 0·001); chewing and footedness (r = 0·49; P < 0·001); chewing and eyedness (r = 0·65; P < 0·001) and chewing and earedness (r = 0·66, P < 0·001). Of the subjects, 78·3% preferred the right side for chewing, 19·1% preferred the left and 2·1% had no clear side preference. There was no statistical difference in chewing side preference distribution between genders. The distribution of chewing side preference was not significantly affected by the location of missing teeth or implants. In conclusion, implant placement will not affect PCS. Therefore, information on chewing side preference should be part of the routine preoperative examination for implant‐supported restorations to provide a better treatment plan in those cases that the implant‐supported restoration will be on the PCS.     

Periodontal treatment and HbA1c levels in subjects with diabetes mellitus

It has earlier been reported that individuals with poorly controlled diabetes have severe periodontal disease (PD) compared to well‐controlled diabetes. This longitudinal interventional study compared periodontal treatment outcomes with HbA1c level changes in four groups of diabetic and non‐diabetic patients with or without PD, respectively. HbA1c, bleeding on probing (BOP), plaque index and periodontal pocket depth (PPD) 4 < 6 mm and ≥6 mm were recorded at baseline to 3 months after non‐surgical treatment and 3–6 months for surgical treatment in subjects with or without T2D, and with or without PD. A total of 129 patients were followed from baseline to 6 months. Diabetics with PD and without PD showed reductions in HbA1c levels with a mean value of 0·3% after 3 months and mean values of 1% and 0·8%, respectively, after 6 months. Diabetics with PD showed higher levels of BOP versus non‐diabetics without PD (P < 0·01) and versus diabetics without PD (P < 0·05) at baseline. After 6 months, diabetics with PD showed higher number of PPD 4 < 6 mm versus diabetics without PD (P < 0·01) and non‐diabetics with PD (P < 0·01). Diabetics without PD showed higher levels of PPD 4 < 6 mm versus non‐diabetics without PD (P < 0·01). Surgical and non‐surgical periodontal treatment in all groups improved periodontal inflammatory conditions with a decrease in HbA1c levels in a period of three and 6 months. No change was seen in the number of pockets PPD 4 < 6 mm in diabetic subjects with PD after non‐surgical and surgical treatment.     

Influence of intra‐oral sensory impairment by anaesthesia on food comminution and mixing in dentate subjects

Sensory input from sensory receptors regarding food morsels can affect jaw motor behaviours during mastication. The aim was to clarify the effects of intra‐oral sensory input on the food‐comminuting and food‐mixing capacities of dentate subjects. Eleven dentate subjects without sensory dysfunction in their oro‐facial region participated in this study. Local anaesthesia was achieved on the periodontal structures and on the oral mucosa of the subjects' preferred chewing side by injecting a lidocaine solution with adrenalin. At baseline (control) and after anaesthesia, data on the subjects' food‐comminuting and food‐mixing capacities were gathered. The food‐comminuting capacity was quantified by measuring the degree of pulverisation of peanuts (objective hardness; 45·3 [Newton, N]) after a prescribed 20 chewing strokes. The food‐mixing capacity was measured as the degree of immixture of a two‐coloured paraffin wax cube after 10 chewing strokes. Wax cubes of three different hardness levels were used (soft, medium and hard: 20·3, 32·6 and 75·5 [N], respectively) and were chewed in random order. After anaesthesia, the subjects' food‐comminuting capacity significantly decreased (P < 0·001), as did the food‐mixing capacity for each hardness level of the wax cubes (P < 0·01). A significant correlation was observed between the objective hardness values and the anaesthesia effects for the food‐mixing capacity (P < 0·05), indicating that after anaesthesia, deterioration of the mixing capacity increased as the hardness increased. In conclusion, intra‐oral sensory input can affect both food‐comminuting and food‐mixing capacities.     

Chewing movements altered in the presence of temporomandibular joint internal derangements

Aims:

The objectives were to find specific factors that are mathematically distinct between the chewing timings, movement pattern shapes, variability, and movement velocities of: (1) normal asymptomatic subjects and (2) a group of subjects with verified temporomandibular joint (TMJ) internal derangements.

Methodology:

Left- and right-sided chewing movement recordings of 28 subjects (34·5±14·0 years) were randomly selected from a large database of patients exhibiting verified unilateral or bilateral TMJ internal derangements. The chewing movements of an age- and gender-matched control group of 20 asymptomatic subjects (32·5±11·6 years, P>0·60) with verified normal TMJ function were also recorded. Means and standard deviations of the opening, closing, turning point, terminal chewing position, and velocity patterns were calculated. A two-tailed Student’s t-test with unequal variances was used to compare the parameters between the two groups (alpha?=?0·05).

Results:

The dysfunctional group functioned significantly slower and with greater variability than the control group. The vertical dimension was consistently smaller in the dysfunctional group (P<0·00001). The terminal chewing position was significantly less precise in the dysfunctional group (vertical: P<0·002 and lateral: P<0·037). The maximum lateral width was significantly less (P<0·0071), and the peak and the average velocities were significantly lower (P<0·00001 for both) in the dysfunctional group.

Conclusions:

This group of dysfunctional subjects exhibited significantly slower, smaller, and more variable chewing patterns than the control group. The functional pattern of mastication appears to be significantly altered in the presence of an internal derangement of the TMJ.     

Influence of culture on pain comorbidity in women with and without temporomandibular disorder‐pain

Evidence on cultural differences in prevalence and impact of common chronic pain conditions, comparing individuals with temporomandibular disorders (TMD) versus individuals without TMD, is limited. The aim was to assess cross‐cultural comorbid pain conditions in women with chronic TMD pain. Consecutive women patients (n = 122) with the index condition of chronic TMD pain diagnosed per the research diagnostic criteria for TMD and TMD‐free controls (n = 121) matched for age were recruited in Saudi Arabia, Italy and Sweden. Self‐report questionnaires assessed back, chest, stomach and head pain for prevalence, pain intensity and interference with daily activities. Logistic regression was used for binary variables, and ancova was used for parametric data analysis, adjusting for age and education. Back pain was the only comorbid condition with a different prevalence across cultures; Swedes reported a lower prevalence compared to Saudis (P < 0·01). Saudis reported higher prevalence of work reduced >50% due to back pain compared to Italians or Swedes (P < 0·01). Headache was the most common comorbid condition in all three cultures. The total number of comorbid conditions did not differ cross‐culturally but were reported more by TMD‐pain cases than TMD‐free controls (P < 0·01). For both back and head pain, higher average pain intensities (P < 0·01) and interference with daily activities (P < 0·01) were reported by TMD‐pain cases, compared to TMD‐free controls. Among TMD‐pain cases, Italians reported the highest pain‐related disability (P < 0·01). Culture influences the associated comorbidity of common pain conditions. The cultural influence on pain expression is reflected in different patterns of physical representation.     

Subjective food intake ability related to oral health‐related quality of life and psychological health

Reduced food intake ability can restrict an individual's choice of foods and might have a significant impact on the individual's quality of life and mental health. The aim of this study was to evaluate the correlations between self‐reported masticatory ability and oral health‐related quality of life (OHRQOL) and psychological health. The study included 72 (26 men, 46 women) adults with a mean age of 26·4 ± 8·6 years. Each participant completed the key subjective food intake ability (KFIA) test for five key foods, the Korean version of the Oral Health Impact Profile‐14 (OHIP‐14K) and three questionnaires for measuring anxiety, depression and self‐esteem. The participants were distributed into two groups by sex (a mean age of 23·9 ± 5·2 for men and 27·9 ± 9·8 for women) and by the median KFIA score. There were no significant differences in any of the variables according to sex. Thirty‐two participants (12 men, 20 women) in the lower KFIA group had a higher total OHIP‐14K (P < 0·001) and depression level (P < 0·05) than the 40 participants (14 men, 26 women) in the higher KFIA group. As the KFIA decreased, OHRQOL worsened (P < 0·001) and depression increased (P < 0·05). Participants with lower KFIA scores were more than 4·3 times as likely as to have a poor OHRQOL than the reference group (odds ratio, 4·348; 95% confidence interval, 1·554–12·170, P < 0·01). Lower subjective food intake ability is associated with a poor oral health‐related quality of life and higher depression level.     

Effect of nasal speaking valve on speech intelligibility under velopharyngeal incompetence: a questionnaire survey

Velopharyngeal incompetence is known as a contributing factor to speech disorders. Suwaki et al. reported that nasal speaking valve (NSV) could improve dysarthria by regulating nasal emission utilising one‐way valve. However, disease or condition which would be susceptible to treatment by NSV has not been clarified yet. This study aimed to evaluate the effect of NSV by questionnaire survey using ready‐made NSV. Subjects were recruited through the internet bulletin, and NSV survey set was sent to the applicant. Sixty‐six participants, who agreed to participate in this study, used NSV and mailed back the questionnaire which included self‐evaluation and third‐party evaluation of speech intelligibility. Statistical analysis revealed that the use of NSV resulted in significant speech intelligibility improvement in both self‐evaluation and third‐party evaluation (P < 0·01). Regarding the type of underlying disease of dysarthria, significant effect of NSV on self‐evaluation of speech intelligibility could be observed in cerebrovascular disease and neurodegenerative disease (P < 0·01) and that on third‐party evaluation in neurodegenerative disease (P < 0·01). Eighty‐six percent of subjects showed improvement of speech intelligibility by shutting up nostrils by fingers, and the significant effect of NSV on both self‐evaluation and third‐party evaluation of speech intelligibility was observed (P < 0·001). From the results of this study, it was suggested that NSV would be effective in cerebrovascular disease and neurodegenerative disease, as well as in subjects whose speech intelligibility was improved by closing nostrils.     

Effects of interocclusal distance on bite force and masseter EMG in healthy participants

The aim of this study was to investigate effects of interocclusal distance (IOD) on bite force and masseter electromyographic (EMG) activity during different isometric contraction tasks. Thirty‐one healthy participants (14 women and 17 men, 21·2 ± 1·8 years) were recruited. Maximal Voluntary Occlusal Bite Force (MVOBF) between the first molars and masseter EMG activity during all the isometric‐biting tasks were measured. The participants were asked to bite at submaximal levels of 20%, 40%, 60% and 80% MVOBF with the use of visual feedback. The thickness of the force transducer was set at 8, 12, 16 and 20 mm (= IOD), and sides were tested in random sequence. MVOBF was significantly higher at 8 mm compared with all other IODs (P < 0·001). Only in women, IOD always had significant influence on the corresponding root‐mean‐square (RMS) value of EMG (P < 0·011). When biting was performed on the ipsilateral side to the dominant hand, the working side consistently showed higher masseter EMG activity compared with the balancing side (P < 0·020). On the contralateral side, there was no difference between the masseter EMG at any IODs. The results replicated the finding that higher occlusal forces can be generated between the first molars at shorter IODs. The new finding in this study was that an effect of hand dominance could be found on masseter muscle activity during isometric biting. This may suggest that there can be a general dominant side effect on human jaw muscles possibly reflecting differences in motor unit recruitment strategies.     

The influence of bilateral sagittal split ramus osteotomy on submental‐cervical aesthetics

The effect of orthodontic‐surgical treatment on submental‐cervical region was evaluated in a very limited number of studies. The aim of this study was to evaluate submental‐cervical soft tissue contour changes following mandibular advancement and set‐back procedures via bilateral sagittal split ramus osteotomy. Sixty‐seven patients were included in this study. Group 1 consisted of 27 skeletal Class II patients who underwent mandibular advancement surgery, whereas Group 2 consisted of 40 skeletal Class III patients who underwent mandibular set‐back surgery. Various linear and angular measurements were performed on pre‐operative and sixth month post‐operative cephalometric radiographs. A new method was used to evaluate the amount of sagging at submental region. The submental length did not change in Group 1; however, it decreased significantly in Group 2 (P < 0·05). The angle between submental plane and facial plane decreased to 95·9° from 98·8° in Group 1(P < 0·05), whereas it increased to 93·1° from 88·2° in Group2 (P < 0·05). The change of submental soft tissue sag was almost stable in Group 1, while 0·34 mm increase of sag was observed in Group 2. This increase was not statistically significant (P > 0·05). Mandibular set‐back and advancement procedures do not remarkably change the submental sag following approximately 6 mm jaw movement. Although mandibular advancement did not significantly effect submental length, soft tissue followed mandibular set‐back with a ratio of 1:1 at C‐point to projection of soft tissue pogonion and 1:0·7 at C‐point to soft tissue menton distances.     

Normative values for the oro‐facial Esthetic Scale in Sweden

This study reports the findings and challenges of the assessment of oro‐facial aesthetics in the Swedish general population and the development of normative values for the self‐reporting Orofacial Esthetic Scale (OES). In a Swedish national sample of 1406 adult subjects (response rate: 47%), OES decile norms were established. The influence of sociodemographics (gender, age, and education), oral health status and general health status on OES scores was analysed. Mean ± standard deviation of OES scores was 50·3 ± 15·6 units (0, worst score; 70, best score); <1% of the subjects had the minimum score of 0, and 11% had the maximum score of 70 OES units. Orofacial Esthetic Scale score differences were (i) substantial (>5 OES units) for subjects with excellent/very good versus good to poor oral or general health status; ii) small (2 units), but statistically significant for gender (P = 0·01) and two age groups (P = 0·02), and (iii) absent for subjects with college versus no college education (P = 0·31) or with and without dentures (P = 0·90). To estimate normative values for a self‐reporting health status, instrument is considered an important step in standardisation, and the developed norms provide a frame of reference in the general population to interpret the Orofacial Esthetic Scale scores.     

SEMG activity of jaw‐closing muscles during biting with different unilateral occlusal supports

Summary The aim of this study was to test the hypothesis that experimental and reversible changes of occlusion affect the levels of surface electromyographic (SEMG) activity in the anterior temporalis and masseter areas during unilateral maximal voluntary biting (MVB) in centric and eccentric position. Changes were achieved by letting 21 healthy subjects bite with and without a cotton roll between the teeth. The placement alternated between sides and between premolar and molar areas. The SEMG activity level was lower when biting in eccentric position without than with a cotton roll between teeth (P < 0·043). It was always lower with premolar than with molar support when biting with a cotton roll (P < 0·013). In the anterior temporalis areas, the SEMG activity was always lower on the balancing than on the working side (P < 0·001). Such a difference was also found in the masseter areas but only during molar‐supported centric biting (P = 0·024). No differences were found when comparing the SEMG levels in masseter areas between centric and eccentric biting (P > 0·05). In the anterior temporalis area, the balancing side SEMG activity was lower in eccentric than in centric but only in molar‐supported biting (P = 0·026). These results support that the masseter and anterior temporalis muscles have different roles in keeping the mandible in balance during unilateral supported MVB. Changes in occlusal stability achieved by biting with versus without a cotton roll were found to affect the SEMG activity levels.     

Electromyographic assessment of jaw muscles in patients with All‐on‐Four fixed implant‐supported prostheses

This study evaluated the electromyographic (EMG) characteristics of masticatory muscles in patients with fixed implant‐supported prostheses according to All‐on‐Four^® principles and in control healthy dentate subjects. Twenty‐six subjects aged 50–74 years were examined. Eighteen were edentulous and had been successfully rehabilitated with (i) mandibular All‐on‐Four^® implant‐supported fixed prostheses and maxillary complete dentures (10 patients) and (ii) mandibular and maxillary All‐on‐Four^® implant‐supported fixed prostheses (eight patients). Eight reference subjects had natural dentition. Surface EMG recordings of the masseter and temporalis muscles were performed during maximum voluntary teeth clenching and during unilateral gum chewing. All values were standardised as percentage of a maximum clenching on cotton rolls. During clenching, a good global neuromuscular equilibrium was found in all participants. During chewing, all groups had similar values of working‐side muscle activities and of chewing frequency. No significant differences in the analysed EMG parameters were found between the patients with mandibular and maxillary All‐on‐Four^® implant‐supported prostheses and the reference subjects. In contrast, standardised pooled muscle activities and standardised muscular activities per cycle were larger in patients with a maxillary removable prosthesis than in control subjects (Kruskal–Wallis test, P < 0·01). Also, patients wearing a complete maxillary denture showed a poor neuromuscular coordination with altered muscular pattern and lower values of the index of masticatory symmetry than dentate control subjects (P < 0·01). EMG outcomes suggest that All‐on‐Four^® implant‐supported prostheses may be considered a functionally efficient treatment option for the rehabilitation of edentulous patients with reduced residual bone volume.     

DEEP Study: does EQ‐5D‐5L measure the impacts of persistent oro‐facial pain?

The EQ‐5D‐5L is a generic quality of life (QOL) measure widely used throughout the world, which has the advantage that it allows health‐state preferences to be elicited. The aim of this study was to examine whether: a) variation in the standardised reference period for EQ‐5D‐5L from ‘today’ to ‘the last month’ had a minimal clinically meaningful difference; (b) EQ‐5D‐5L had convergent validity with a multidimensional pain measure in quantifying the impacts of pain. As part of a larger study into the effectiveness and efficiency of care pathways for persistent orofacial pain (POFP) ( http://research.ncl.ac.uk/deepstudy ), participants with POFP (n = 100) completed two versions of the EQ‐5D‐5L at the same time with different reference periods (‘today’ vs. ‘last month’). Participants also completed the first section of the West Haven–Yale Multidimensional Pain Inventory (v3) to assess convergent validity. Two‐tailed nonparametric inferential statistics, intra‐class correlation coefficients (ICC), and within‐subject change scores were used to compare the two EQ‐5D‐5L versions. Convergent validity was assessed using Spearman's rho correlation coefficients. Health‐state valuations were significantly different (P < 0·01), and there was good similarity between the two versions' ICC 0·86 (95% CI 0·79–0·91). The within‐subject mean change was 0·03 (95% CI 0·01–0·06). For convergent validity, all relationships were significant (P < 0·05) and in the expected directions. EQ‐5D‐5L demonstrates sufficient convergent validity to be used with POFP, and a change in the standard reference period may be unnecessary if a multidimensional pain measure is also used.     

Incidence of temporomandibular joint clicking in adolescents with and without unilateral posterior cross‐bite: a 10‐year follow‐up study

Among different malocclusions, posterior cross‐bite is thought to have a strong impact on the correct functioning of the masticatory system. The association between unilateral posterior cross‐bite (UPCB) and temporomandibular joint (TMJ) clicking, however, remains still controversial. The aim of this study was to investigate whether the presence of UCPB during early adolescence increases the risk of reporting TMJ clicking after a long‐term follow‐up. A longitudinal survey design was carried out in a group of 12‐year‐old young adolescents, who were examined at baseline for TMJ clicking sounds and unilateral posterior cross‐bite. After 10 years, 519 subjects could be reached by a telephone survey. Standardised questions were used to collect self‐reported TMJ sounds and to determine whether participants had received an orthodontic treatment. Logistic regression analysis revealed a significant association between unilateral posterior cross‐bite and subjectively reported TMJ clicking (odds ratio = 6·0; 95% confidence limits = 3·4–10·8; P < 0·0001). The incidence of TMJ clicking was 12%. At a ten‐year follow‐up, self‐reports of TMJ clicking were significantly associated with the presence of UPCB at baseline, but not with the report of having received an orthodontic treatment. Within the limitation of this study, the presence of unilateral posterior cross‐bite in young adolescents may increase the risk of reporting TMJ sounds at a 10‐year follow‐up. The provision of an orthodontic treatment, however, does not appear to reduce the risk of reporting TMJ sounds.     

Oropharyngeal dysphagia in amyotrophic lateral sclerosis alters quality of life

Dysphagia is one of the most important complications encountered in amyotrophic lateral sclerosis (ALS). Our aim was to determine whether oropharyngeal dysphagia impacted the quality of life (QoL) of patients with ALS. Thirty consecutive patients were recruited (31–82 years, 18 men). Swallowing function was evaluated using a standardised videofluoroscopic barium swallow. All the patients completed a specific questionnaire on quality of life in dysphagia (SWAL‐QoL) immediately after the videofluoroscopy. The results of dysphagia outcome severity scale separated 14 patients with oropharyngeal dysphagia and 16 with normal swallowing function. There was no difference in the average age, weight and body mass index of the two groups (dysphagic patients: 68 ± 11 kg versus non‐dysphagic patients: 69 ± 14 kg). Most of the dysphagic patients had a bulbar affection based on their Norris scores which determine the importance of cranial nerves illness (20 ± 8), significantly lower than those of the non‐dysphagic patients (35 ± 5) (P < 0·0001). There was no difference in the neurological peripheral symptoms evaluated by Amyotrophic Lateral Sclerosis Functional Rating Scale scores (dysphagic patients: 26 ± 7 versus non‐dysphagic patients: 27 ± 8) (ns). The swallowing quality of life questionnaire revealed that the dysphagic patients had significant burden (P < 0·001). They were affected by the necessity to applied a food selection (P < 0·01), by the increase in eating duration (P < 0·05) and described a decrease in eating desire (P < 0·05). They complained of fear regarding the risk of dysphagia (P < 0·05). They also described difficulties with oral communication (P < 0·001). All of those complained about dysphagia which impacted directly mental health (P < 0·05) and social life (P < 0·05). In conclusion, oropharyngeal dysphagia is a common symptom accompanying ALS, which alters the patient's QoL, especially social health.     

Evaluating the masticatory function after mandibulectomy with colour‐changing chewing gum

The aim of this study was to clarify the usefulness of colour‐changing gum in evaluating masticatory performance after mandibulectomy. Thirty‐nine patients who underwent mandibulectomy between 1982 and 2010 at Kobe University Hospital were recruited in this study. There were 21 male and 18 female subjects with a mean age of 64·7 years (range: 12–89 years) at the time of surgery. The participants included six patients who underwent marginal mandibulectomy, 21 patients who underwent segmental mandibulectomy and 12 patients who underwent hemimandibulectomy. The masticatory function was evaluated using colour‐changing chewing gum, gummy jelly and a modified Sato's questionnaire. In all cases, the data were obtained more than 3 months after completing the patient's final prosthesis. The colour‐changing gum scores correlated with both the gummy jelly scores (r = 0·634, P < 0·001) and the total scores of the modified Sato's questionnaire (r = 0·537, P < 0·001). In conclusion, colour‐changing gum is a useful item for evaluating masticatory performance after mandibulectomy.     

A randomised titrated crossover study comparing two oral appliances in the treatment for mild to moderate obstructive sleep apnoea/hypopnoea syndrome

The objective of this study was to compare the efficiency of two oral appliances in patients with mild to moderate obstructive sleep apnoea/hypopnoea syndrome (OSAHS) by the analysis of objective and subjective evaluations and measurement of upper airway parameter. A randomised crossover design trial was carried out on 16 patients with OSAHS. Two different types of oral appliances were tested in each patient, a one‐piece monoblock and the SILENT NITE^® (GlideWell Laboratories, Newport Beach, CA, USA), a two‐piece appliance. Each oral appliance needed to be worn for two 3‐month periods separated by a 2‐week wash‐out period in between. The objective and subjective efficiency and upper airway parameters associated with the oral appliances were assessed. One‐way analysis of variance (anova ) test was performed to compare the changes in upper airway morphology and the treatment efficiency between the appliances. The monoblock and SILENT NITE^® (GlideWell Laboratories) appliances reduced Apnoea Hypopnoea Index (AHI) from 26·38 ± 4·13 to 7·58 ± 2·28 (P < 0·001) and 8·87 ± 2·88 (P < 0·001), respectively. The monoblock appliance was statistically more efficient in reducing AHI and Apnoea Index (AI) than the SILENT NITE^® (GlideWell Laboratories) (P < 0·05). The scores on Epworth's Sleepiness Scale (ESS) and Snoring Scale (SS) were improved significantly by both appliances. The upper airway spaces showed considerable enlargement by both mandibular advancement appliances (MAAs) (P < 0·05), while no significant differences were found between the two appliances (P > 0·05). Both MAAs showed good efficacy in the treatment for mild to moderate OSAHS. Use of the monoblock appliance should be considered when patients with OSAHS choose MAA treatment, as it was more efficient in reducing the AHI and AI compared to the two‐piece appliance and was preferred by most patients. Long‐term efficiency should be evaluated in future prospective studies.