Three-dimensional motion analysis - an exploratory study. Part 1: assessment of facial movement

Authors – Popat H, Richmond S, Playle R, Marshall D, Rosin PL, Cosker D Objectives – To objectively quantify facial movement in response to facial expression and spoken word. Design – Experimental study. Setting – Department of Dental Health and Biological Sciences, University Dental Hospital, Cardiff, UK. Experimental Variable – Facial movement was assessed in response to a standardized smile expression and the utterance ‘puppy’. The sequences were recorded using a non‐invasive, three‐dimensional motion analysis image capture system (3dMDface? Dynamic System) at 48 frames per second. Outcome Variable – To quantify the facial movement, sequential frames of a sequence were aligned to the baseline/reference frame three‐dimensionally using best fit on non‐moveable points in the upper half of the face. Accuracy of the alignment process for each sequence was tested using the percentage of stable points (i.e. within ±0.5 mm) within the upper half of the face. Results – Quantifiable changes in facial topology were seen during both the standardized smile expression and the utterance ‘puppy’. The mean percentage of points (SD) that remained stable within the upper half of the face during the utterance ‘puppy’ was 88.8% (4.7). During the standardized smile expression, there were a much lower percentage of stable points in the upper half of the face with a mean (SD) of 60.9% (3.2). Conclusion – The 3dMDface? Dynamic System allows objective, three‐dimensional, non‐invasive assessment of facial movement. The utterance ‘puppy’ is a more appropriate measure of facial movement when compared with the standardized smile expression.     

Changing face of orofacial pain: The diagnostic impact of working with Neurology on an orofacial pain clinic

This study assessed the impact of collaborative working with a headache neurologist on diagnoses of patients attending orofacial pain (OFP) clinic. Patient diagnostic data was collected from adult patients attending an Orofacial Pain Service from January 2013 to January 2017. A liaison headache neurologist was appointed late 2015; OFP clinics were co-run with the neurologist specialist thereafter. Overall, 639 patients attended the service; 315 in 2013–2015 and 324 in 2016–2017. Compared to 2013–2015, there were increased rates of diagnoses related to neurovascular (27.5% vs. 19.0%; P = .012) and musculoskeletal pain (36.9% vs. 26.0%; P = .003) in the 2016–2017 cohort and decreased rates of neuropathic (55.6% vs. 70.2%; P < .001) and atypical/idiopathic pain (1.3% vs. 5.4%; P = .003) diagnoses. There was a trend towards an increased rate of comorbid diagnoses (26.3% vs. 20.3%; P = .077), especially those relating to headache conditions. The findings suggest that introduction of a specialist headache neurologist into the OFP clinic widened its remit of assessment, increasing recognition of (co-morbid) neurovascular-related pain and decreasing atypical/idiopathic pain diagnoses in patients with complex OFP. The increase rate of musculoskeletal pain diagnosis in the later cohort is likely attributable to service expansion and normalisation of diagnostics reportedly seen in other OFP services.Statement of clinical relevance: Orofacial pain is a complex diagnosis, it requires a multidisciplinary approach that includes neurological input.     

Three-dimensional motion analysis - an exploratory study. Part 2: reproducibility of facial movement

Authors – Popat H, Richmond S, Playle R, Marshall D, Rosin PL, Cosker D Objectives – To investigate the reproducibility of using spoken word as a measure of facial movement. Design – Experimental study. Setting and Sample Population – Department of Dental Health and Biological Sciences, University Dental Hospital, Cardiff. 22 normal subjects. Experimental Variable – Subjects were asked to say the word ‘puppy’ in a normal, relaxed manner twice within a 10‐second time interval. The sequence was recorded using a non‐invasive, three‐dimensional motion analysis image capture system (3DMDface? Dynamic System) at 48 frames per second. Outcome Variable – Corresponding frames between the two utterances were aligned three‐dimensionally using best fit on non‐moveable points on the upper half of the face. Reproducibility was measured as the percentage point deviation between ± 0.5 mm between two corresponding frames. Results – Mean intrasessional reproducibility (SD) for the group was recorded at 86.2% (5.8). The reproducibility ranged from a minimum of 66.8% to a maximum of 97.5%. When the utterance was split into its two separate viseme segments (/p//u//p/ and /p//y/), the second part of the utterance was seen to be more reproducible than the first. The male group were more reproducible than the female group. Conclusion – Intrasessional reproducibility of the utterance ‘puppy’ shows high intra‐ and intersubject variability in this group of normal subjects and therefore further research needs to be conducted before being able to confidently use this word as a reproducible measure of facial movement.     

Reliability of intra‐oral quantitative sensory testing (QST) in patients with atypical odontalgia and healthy controls – a multicentre study

The reliability of comprehensive intra‐oral quantitative sensory testing (QST) protocol has not been examined systematically in patients with chronic oro‐facial pain. The aim of the present multicentre study was to examine test–retest and interexaminer reliability of intra‐oral QST measures in terms of absolute values and z‐scores as well as within‐session coefficients of variation (CV) values in patients with atypical odontalgia (AO) and healthy pain‐free controls. Forty‐five patients with AO and 68 healthy controls were subjected to bilateral intra‐oral gingival QST and unilateral extratrigeminal QST (thenar) on three occasions (twice on 1 day by two different examiners and once approximately 1 week later by one of the examiners). Intra‐class correlation coefficients and kappa values for interexaminer and test–retest reliability were computed. Most of the standardised intra‐oral QST measures showed fair to excellent interexaminer (9–12 of 13 measures) and test–retest (7–11 of 13 measures) reliability. Furthermore, no robust differences in reliability measures or within‐session variability (CV) were detected between patients with AO and the healthy reference group. These reliability results in chronic orofacial pain patients support earlier suggestions based on data from healthy subjects that intra‐oral QST is sufficiently reliable for use as a part of a comprehensive evaluation of patients with somatosensory disturbances or neuropathic pain in the trigeminal region.     

Smoothness of chewing jaw movements in adults with mandibular prognathism

Summary Indices such as smoothness, movement time, peak velocity, and symmetry of the velocity profile have been shown to be effective in explaining the degree of skilfulness of human saccadic eye, limb, and jaw motions. We investigated whether adult subjects with mandibular prognathism show impaired smoothness of the masticatory jaw movements. Forty‐nine adults with skeletal Class III malocclusions and 52 healthy adults with acceptably good occlusions were selected respectively as Test and Control subjects. Subjects of the Test Group were subdivided into two groups: Class III_closed showed full occlusal contact between the upper and lower teeth at the habitual intercuspal position, whereas Class III_open showed inability of occlusal contact between the upper and lower anterior teeth. Each subject was asked to chew a piece of chewing gum. The normalised jerk‐cost (NJC), movement duration, and tangential velocity profile during jaw‐closing movements were compared between groups. Test Groups showed greater NJC (P < 0·01) with longer movement duration (P < 0·01) and lower peak velocity (P < 0·01) than the Control Group did. Class III_closed showed greater NJC (P < 0·01) with longer movement duration (P < 0·01) and lower peak velocity (P < 0·01) than Class III_open did. Results show that the mandibular movements made by the Test Groups exhibit lower skilfulness than those made by the Control Group. The jaw movement skilfulness of the prognathic patients decreases most drastically with existence of malocclusal contact between upper and lower anterior teeth.     

Gabapentin therapy in patients with orofacial neuropathic pain: Report of 12 cases

Objective

There are several types of orofacial neuropathic pain and some of these types are often refractory to treatment. Gabapentin is an oral antiepileptic agent with a proven analgesic effect in various traumatic neuropathic pain syndromes. We retrospectively examined the analgesic effect of gabapentin on non-dental and non-traumatic orofacial neuropathic pain.

Subjects and methods

This study included 12 patients. All patients showed an excessive response to noxious (hyperalgesia) and/or innocuous (allodynia) stimuli in the affected region. Gabapentin therapy was initiated with a dosage of 200–600 mg/day. Pain intensity was assessed using a modified numerical rating scale (m-NRS) (0, no pain; 10, pain equal to that experienced on the day gabapentin therapy was initiated). In addition, the side effects were also recorded.

Results

All the patients had received medications for their pain prior to referral, but the drugs failed to provide adequate relief from their neuropathic pain. The m-NRS scores for all patients started decreasing within 7 days after internal use was initiated. The average time taken for the m-NRS score to decrease to half was 3.3 (1.7) days. Side effects were observed in 2 patients.

Conclusion

We concluded that gabapentin therapy is efficacious for the treatment of orofacial neuropathic pain in selected patients.     

Effect of a brief episode of experimental muscle pain on jaw movement and jaw‐muscle activity during chewing

The aims of this study were to determine whether: (i) the jaw motor system develops a new pattern of jaw movement and/or jaw‐muscle activity after resolution of an acute episode of jaw‐muscle pain; and (ii) if jaw‐muscle activity and jaw‐movement features change progressively with repetition of a chewing sequence. Jaw movement and jaw muscle (masseter, anterior temporalis, and digastric) activity were recorded during free and rate‐standardized chewing in eight asymptomatic participants (pain infusion group), before and at three time blocks up to 45 min after a single 0.2‐ml bolus infusion of 5% hypertonic saline into the right masseter muscle. The same procedure, without infusion, was performed in another eight participants (control group). There were no significant main effects of group on jaw movement and muscle activity, suggesting that there were no persistent post‐pain effects on chewing. Across groups, repetitions of free and unstandardized chewing movements were associated with progressive increases in velocity and amplitude of jaw movement and masseter and temporalis electromyographic (EMG) activity. These findings suggest that factors unrelated to pain, such as practice effects, may be playing a role in the changes in jaw movement and jaw‐muscle activity observed after resolution of an acute episode of jaw‐muscle pain.     

Association of depressiveness with chronic facial pain: A longitudinal study

Abstract

Objective. Depression and pain are often co-morbid. Temporomandibular disorders (TMD) include facial pain as one main symptom. Reports are lacking on the association between chronic facial pain and earlier depressiveness. The aim of the study was to investigate whether depressiveness increases the risk for chronic facial pain in a longitudinal population-based study. Materials and methods. Subjects included in the Northern Finland Birth Cohort 1966 (n = 5696) answered a questionnaire on facial pain and depressiveness using the Symptom Checklist-25 depression sub-scale at the age of 31 years. In addition, reported depression diagnosed by a doctor was enquired about. Three years later a sub-sample of the cohort, including 63 cases with chronic facial pain and 85 pain-free controls, was formed based on the question concerning facial pain. Results. Of the chronic facial pain cases 17.5% and of the pain-free controls 7.1% were depressive 3 years earlier at baseline (p = 0.050, χ ² test, crude OR = 2.8, 95% CI = 1.0–8.0). Of the chronic facial pain cases 6.3% and of the pain-free controls 1.2% reported having had diagnosed depression (p = 0.085, crude OR = 5.7, 95% CI = 0.6–52.2). After adjusting the gender, the association between depressiveness reported at the baseline and chronic facial pain was significant (OR = 4.2, 95% CI = 1.1–16.2). When widespread pain was included in the analysis, the association was not significant. Conclusions. Depressiveness increases the risk for chronic facial pain in a 3-year follow-up. This association seems to be mediated through widespread pain.     

Somesthetic,gustatory, olfactory function and salivary flow in patients with neuropathic trigeminal pain

Oral Diseases (2010) 16 , 482–487 Objectives: To determine somesthetic, olfactory, gustative and salivary abnormalities in patients with burning mouth syndrome (BMS), idiopathic trigeminal neuralgia (ITN) and trigeminal postherpetic neuralgia (PHN). Subjects and Methods: Twenty patients from each group (BMS, ITN, PHN) and 60 healthy controls were evaluated with a systematized quantitative approach of thermal (cold and warm), mechanical, pain, gustation, olfaction and salivary flow; data were analyzed with ANOVA, Tukey, Kruskal–Wallis and Dunn tests with a level of significance of 5%. Results: There were no salivary differences among the groups with matched ages; the cold perception was abnormal only at the mandibular branch of PHN (P = 0.001) and warm was abnormal in all trigeminal branches of PHN and BMS; mechanical sensitivity was altered at the mandibular branch of PHN and in all trigeminal branches of BMS. The salty, sweet and olfactory thresholds were higher in all studied groups; the sour threshold was lower and there were no differences of bitter. Conclusion: All groups showed abnormal thresholds of gustation and olfaction; somesthetic findings were discrete in ITN and more common in PHN and BMS; central mechanisms of balance of sensorial inputs might be underlying these observations.     

Prevalence of cervical spinal pain in craniomandibular pain patients

It has often been suggested that patients with a craniomandibular disorder (CMD) more often suffer from a cervical spine disorder (CSD) than persons without a CMD. However, in most studies no controlled, blind design was used, and conclusions were based on differing signs and symptoms. In this study, the recognition of CMD and CSD was based upon the presence of pain. The aim of this study was to determine the prevalence of cervical spinal pain in persons with or without craniomandibular pain, using a controlled, single-blind design. From 250 persons, a standardised oral history was taken, and a physical examination of the masticatory system and the neck was performed. Three classification models were used: one based on symptoms only; a second on signs only; and a third one based on a combination of symptoms and signs. The CMD patients were also subdivided in three subgroups: patients with mainly myogenous pain; mainly arthrogenous pain; and both myogenous and arthrogenous pain. Craniomandibular pain patients more often showed cervical spinal pain than persons without craniomandibular pain, independent of the classification model used. No difference in the prevalence of cervical spinal pain was found between the three subgroups of craniomandibular pain patients.     

Endurance to physical strain in patients with temporomandibular disorders: a case-control study

Abstract

Objective. The hypothesis tested was whether patients with temporomandibular disorders (TMD) have an impaired endurance to motor tasks, under physical strain. Material and methods. The study population included 81 cases with TMD and 75 controls. After giving their informed consent, the participants filled out a questionnaire and performed five endurance trials. Each trial was measured in seconds from start to termination. The tests included: (a) holding the arm in a straight out position with a 2 kg weight in the hand, (b) lifting and lowering the arm with a 2 kg weight in the hand, (c) opening and closing the mandible repeatedly against a resistance of 1.6 kg during the jaw-opening phase, (d) protruding and retracting the mandible repeatedly against a resistance of 1.6 kg during the protruding phase and (e) unilateral chewing of three pieces of chewing gum. Analysis of differences between cases and controls for endurance were evaluated with Mann-Whitney U-test. A p-value < 0.05 was considered statistically significant. Results. The cases had statistically significantly (p < 0.0001) lower endurance time than controls for all tests. Conclusions. Patients with TMD compared to those without signs and symptoms of TMD have an impaired capacity to endure motor tasks that involve physical demand of the jaw muscles and shoulder girdle muscles.     

Effect of stabilization splint therapy on pain during chewing in patients suffering from myofascial pain

Masticatory myofascial pain (MFP) condition is a musculoskeletal disorder that compromises the functional capacities of the masticatory system. As such, the incorporation of an intensive chewing test as a discriminatory exercise for the diagnosis of this condition and evaluation of treatment success has considerable potential. Various splint designs have been used successfully, which have posed a question of whether the therapeutic effect of the splint is a placebo or has some other curative properties. The purpose of this study was to evaluate the efficacy of the stabilization appliance to reduce signs and symptoms in MFP patients and to compare the pain experience during the chewing test between two groups of patients, with and without splints. Myofascial pain patients (n = 37) who reported exacerbation of pain in function participated in the study. Patients perfomed a 9-min chewing test, followed by 9-min rest and marked their pain intensity on a visual analogue scale every 3 min. Of the 37 patients, 21 received a stabilization flat occlusal splint for night use and 16 were equally monitored clinically without a splint. At the end of 8 weeks, a second clinical examination and chewing test were performed. Student's t-test was used to analyse differences between study groups. Analysis of variance and covariance (ancova) with repeated measures was applied to analyse the effect of treatment. Level of pain at baseline prior to the chewing test (P0) was introduced as a co-variant. At baseline both groups showed relatively high scores of pain intensity and did not show any significant differences among the collected variables. At the end of the experiment, the splint group had a statistically significant reduction in pain intensity, in mean muscle sensitivity to palpation and in the pain experience during the chewing test compared with no change in the controls. A stabilization splint has a therapeutic value beyond its placebo effects. Thus, it should be an integral part of the treatment modalities in MFP disorder patients. An intensive chewing test is an effective tool to evaluate the treatment modality efficacy in MFP patients.     

Orofacial pain assessment and management for patients with dementia: A meta‐ethnography

Delivering dental treatment for patients with dementia can be challenging, and the complexity of treatment provision can increase as dementia progresses. Treatment at the later stages of dementia can be associated with ethical challenges and procedural risk meaning that a comprehensive patient assessment is crucial; the presence of orofacial pain is a key indication for active intervention from dental teams. To explore the process of oro‐facial pain assessment and management, a comprehensive review of qualitative literature was undertaken by searching six electronic databases. No literature specific to orofacial pain assessment was identified. The inclusion criteria were widened to explore assessment and management of pain in general for patients with dementia. Meta‐ethnography with reciprocal translation was used to identify key concepts and themes and synthesise information applicable to the dental setting. Three major themes arose as follows: challenges with pain assessment, challenges with pain management and logistics and education. Healthcare teams struggle with pain identification in patients with dementia though many signs were identified which may suggest a patient is experiencing pain. The long‐term knowledge of individual patients held by family members and care teams can allow identification of deviation from patients’ normal states; this knowledge can assist healthcare professionals in determining whether to provide specific treatments or interventions. Pain assessment tools were found to be problematic and are unlikely to be a practical solution to use for complex patients in dental settings. Education for dental and wider care teams on orofacial pain would be highly valuable; yet, this needs to be based on suitable evidence.