Two-point discrimination values vary depending on test site, sex and test modality in the orofacial region: a preliminary study.

OBJECTIVE: The aims of the present study were to determine the normal values of TPD in the six trigeminal sites (the forehead, cheek, mentum, upper lip, lower lip, and the tongue tip) and to investigate the effect of the site, sex, and test modality on the TPD perception. MATERIAL AND METHODS: Forty healthy volunteers consisting of age-matched men (20) and women (20) with a mean age of 27.1 years were recruited. One examiner performed the TPD test using a simple hand-operated device, i.e., by drawing compass with a blunt or sharp-pointed tip. The static TPD with a blunt-pointed tip (STPDB), moving TPD with a blunt-pointed tip (MTPDB), and static TPD with a sharp-pointed tip (STPDS) were measured. The predictors were the site, sex, and test modality, and the outcome variable was the TPD value. Three-way ANOVA was used for statistics. RESULTS: The analysis showed a significant effect of the site, sex and test modality on the TPD values. Significant differences between the test sites were observed with the descending order from the forehead and cheek>mentum>upper lip and lower lip>tongue tip and index finger. Women showed lower TPD values than those of men. The STPDS measurements were consistently lower than those of the STPDB and MTPDB. CONCLUSIONS: The normal values of TPD in this study suggest that the cheek and forehead were less sensitive than other regions evaluated and women were more sensitive than men. The STPDS was the most sensitive test modality.

Two-point discrimination values vary depending on test site, sex and test modality in the orofacial region: a preliminary study

Abstract The two-point discrimination (TPD) test is one of the most commonly used neurosensory tests to assess mechanoperception in the clinical settings. While there have been numerous studies of functional sensibility of the hand using TPD test, there have been relatively not enough reports on TPD in the orofacial region. Objective The aims of the present study were to determine the normal values of TPD in the six trigeminal sites (the forehead, cheek, mentum, upper lip, lower lip, and the tongue tip) and to investigate the effect of the site, sex, and test modality on the TPD perception. Material and Methods Forty healthy volunteers consisting of age-matched men (20) and women (20) with a mean age of 27.1 years were recruited. One examiner performed the TPD test using a simple hand-operated device, i.e., by drawing compass with a blunt or sharp-pointed tip. The static TPD with a blunt-pointed tip (STPDB), moving TPD with a blunt-pointed tip (MTPDB), and static TPD with a sharp-pointed tip (STPDS) were measured. The predictors were the site, sex, and test modality, and the outcome variable was the TPD value. Three-way ANOVA was used for statistics. Results The analysis showed a significant effect of the site, sex and test modality on the TPD values. Significant differences between the test sites were observed with the descending order from the forehead and cheek>mentum>upper lip and lower lip>tongue tip and index finger. Women showed lower TPD values than those of men. The STPDS measurements were consistently lower than those of the STPDB and MTPDB. Conclusions The normal values of TPD in this study suggest that the cheek and forehead were less sensitive than other regions evaluated and women were more sensitive than men. The STPDS was the most sensitive test modality.

A new evaluation of heat distribution on facial skin surface by infrared thermography.

OBJECTIVE: The aim of this study was to identify the facial areas defined by thermal gradient, in individuals compatible with the pattern of normality, and to quantify and describe them anatomically. METHODS: The sample consisted of 161 volunteers, of both genders, aged between 26 and 84 years (63 ± 15 years). RESULTS: The results demonstrated that the thermal gradient areas suggested for the study were present in at least 95% of the thermograms evaluated and that there is significant difference in temperature between the genders, racial group and variables "odontalgia", "dental prothesis" and "history of migraine" (p < 0.05). Moreover, there was no statistically significant difference in the absolute temperatures between ages, and right and left sides of the face, in individuals compatible with the pattern of normality (ΔT = 0.11°C). CONCLUSIONS: The authors concluded that according to the suggested areas of thermal gradients, these were present in at least 95% of all the thermograms evaluated, and the areas of high intensity found in the face were medial palpebral commissure, labial commissure, temporal, supratrochlear and external acoustic meatus, whereas the points of low intensity were inferior labial, lateral palpebral commissure and nasolabial.

The marginal branch triangle: Anatomic reference for its location and preservation during cosmetic surgery.

BACKGROUND: Many studies have been dedicated toward bettering the understanding of the anatomy of this branch and the relative danger zone. However, most of these articles have focused on identifying the location of this branch based on its trajectory and associations with deep structures, causing some difficulties for aesthetic surgeons to identify its location during facial aesthetic surgery. Here, we present the concept of the marginal nerve triangle; its contents, relations and clinical applications in cosmetic surgery are discussed. METHODS: This is an anatomical study performed using 64 hemifaces from 32 Peruvian fresh cadavers (25 men and 7 women). They were dissected manually and observed macroscopically by the authors. The marginal nerve and the related structures were dissected from its origin to the terminal branches and associated with the described triangular area. RESULTS: The marginal branch of the facial nerve was found to lie in the described triangle in all cases. This is a triangular area formed by the intersection of three points located at the lateral commissure of the mouth, the mastoid apophysis and a point located over the anterior border of the extracellular matrix (ECM) muscle with a line which intersects the lateral commissure of the mouth and the mandibular groove. CONCLUSIONS: The trajectory of the marginal and cervical branches of the facial nerve can be reliably and easily found at the described triangle following the reference points. This study will help guide surgeons to these branches of the facial nerve as it applies to aesthetic surgery.

Excitatory and inhibitory innervation of the mouse orofacial motor nuclei: A stereological study.

Neurons in the trigeminal (Mo5), facial (Mo7), ambiguus (Amb), and hypoglossal (Mo12) motor nuclei innervate jaw, facial, pharynx/larynx/esophagus, and tongue muscles, respectively. They are essential for movements subserving feeding, exploration of the environment, and social communication. These neurons are largely controlled by sensory afferents and premotor neurons of the reticular formation, where central pattern generator circuits controlling orofacial movements are located. To provide a description of the orofacial nuclei of the adult mouse and to ascertain the influence of excitatory and inhibitory afferents upon them, we used stereology to estimate the number of motoneurons as well as of varicosities immunopositive for glutamate (VGluT1+, VGluT2+) and GABA/glycine (known as VIAAT+ or VGAT+) vesicular transporters in the Mo5, Mo7, Amb, and Mo12. Mo5, Mo7, Amb, and Mo12 contain ∼1,000, ∼3,000, ∼600, and ∼1,700 cells, respectively. VGluT1+, VGluT2+, and VIAAT+ varicosities respectively represent: 28%, 41%, and 31% in Mo5; 2%, 49%, and 49% in Mo7; 12%, 42%, and 46% in Amb; and 4%, 54%, and 42% in Mo12. The Mo5 jaw-closing subdivision shows the highest VGluT1+ innervation. Noticeably, the VGluT2+ and VIAAT+ varicosity density in Mo7 is 5-fold higher than in Mo5 and 10-fold higher than in Amb and Mo12. The high density of terminals in Mo7 likely reflects the convergence and integration of numerous inputs to motoneurons subserving the wide range of complex behaviors to which this nucleus contributes. Also, somatic versus neuropil location of varicosities suggests that most of these afferents are integrated in the dendritic trees of Mo7 neurons.

Endodontic-related facial paresthesia: systematic review.

Paresthesia is a neurosensitivity disorder caused by injury to the neural tissue. It is characterized by a burning or twinging sensation or by partial loss of local sensitivity. Paresthesia related to endodontic treatment can occur because of extravasation of filling material or the intracanal dressing, as a consequence of periapical surgery or because of periapical infection. A literature review of paresthesia in endodontics was undertaken, with a view to identifying and discussing the most commonly affected nerves, the diagnostic process and the treatment options. Among reported cases, the most commonly affected nerves were those passing through the jaw: the inferior alveolar nerve, the mental nerve and the lingual nerve. To diagnose paresthesia, the endodontist must carry out a complete medical history, panoramic and periapical radiography, and (in some cases) computed tomography, as well as mechanoceptive and nociceptive tests. To date, no specific treatment for endodontic-related paresthesia has been described in the literature, since the problem may be related to a variety of causes.

Trigeminal pain and quantitative sensory testing in painful peripheral diabetic neuropathy.

OBJECTIVE: To evaluate patients with Diabetes Mellitus type 2 and painful peripheral neuropathy in order to investigate oral complaints and facial somatosensory findings. RESEARCH DESIGN AND METHODS: Case-control study; 29 patients (12 women, mean age 57.86 yo) with Diabetes Mellitus type 2 and 31 age-gender-matched controls were evaluated with a standardized protocol for general characteristics, orofacial pain, research diagnostic criteria for temporomandibular disorders, visual analogue scale and McGill Pain questionnaire, and a systematic protocol of quantitative sensory testing for bilateral facial sensitivity at the areas innervated by the trigeminal branches, which included the thermal detection by ThermoSensi 2, tactile evaluation with vonFrey filaments, and superficial pain thresholds with a superficial algometer (Micromar). Statistical analysis was performed with Wilcoxon, chi-square, confidence intervals and Spearman (p<0.05). RESULTS: Orofacial pain was reported by 55.2% of patients, and the most common descriptor was fatigue (50%); 17.2% had burning mouth. Myofascial temporomandibular disorders were diagnosed in 9 (31%) patients. The study group showed higher sensory thresholds of pain at the right maxillary branch (p=0.017) but sensorial differences were not associated with pain (p=0.608). Glycemia and HbA(1c) were positively correlated with the quantitative sensory testing results of pain (p<0.05) and cold (p=0.044) perceptions. Higher pain thresholds were correlated with higher glycemia and glycated hemoglobin (p=0.027 and p=0.026). CONCLUSIONS: There was a high prevalence of orofacial pain and burning mouth was the most common complaint. The association of loss of pain sensation and higher glycemia and glycated hemoglobin can be of clinical use for the follow-up of DM complications.

Mechanisms operated by endothelin ETA and ETB receptors in the trigeminal ganglion contribute to orofacial thermal hyperalgesia induced by infraorbital nerve constriction in rats.

Endothelins, acting through specific endothelin ET(A) and/or ET(B) receptors, participate in nociceptive processing in models of cancer, inflammatory and neuropathic pain. The present study investigated which cell types express endothelin receptors in the trigeminal ganglion, and the contribution of mechanisms mediated by endothelin ET(A) and ET(B) receptors to orofacial heat hyperalgesia induced by unilateral constriction of the infraorbital nerve (CION). Both receptor types were identified by immunohistochemistry in the trigeminal ganglion, ET(A) receptors on small-sized non-myelinated and myelinated A-fibers and ET(B) receptors on both satellite glial cells and small-sized non-myelinated neuronal cells. CION promoted ipsilateral orofacial heat hyperalgesia which lasted from Day 2 until Day 10 after surgery. Ongoing CION-induced heat hyperalgesia (on Day 4) was reduced transiently, but significantly, by systemic or local treatment with antagonists of endothelin ET(A) receptors (atrasentan, 10 mg/kg, i.v.; or BQ-123, 10 nmol/lip), endothelin ET(B) receptors (A-192621, 20 mg/kg, i.v.; or BQ-788, 10 nmol/ lip), or of both ET(A)/ET(B) receptors (bosentan, 10 mg/kg, i.v.; or BQ-123 plus BQ-788, each at 10 nmol/lip). On the other hand, CION-induced heat hyperalgesia was transiently abolished over the first 90 min following i.p. injection of morphine hydrochloride (2.5 mg/kg), but fully resistant to reversal by indomethacin (4 mg/kg, i.p.) or celecoxib (10 mg/kg, i.p.). Thus, heat hyperalgesia induced by CION is maintained, in part, by peripheral signaling mechanisms operated by ET(A) and ET(B) receptors. Endothelin receptors might represent promising therapeutic targets for the control of trigeminal neuropathic pain.

Avaliação tardia da sensibilidade da face pós-fratura do complexo órbito zigmático / Late evalution of facial sensibility post orbitozygomatic complex fractures

O nervo infra-orbital está freqüentemente envolvido em fraturas do complexo órbito-zigomático, o que resulta, tanto na fase aguda do traumatismo quanto tardiamente, em alteração da sensibilidade no território cutâneo inervado por ele. A lesão nervosa ocorre por trauma direto, compressão, isquemia ou lacerações nos vários pontos de seu trajeto. Com o objetivo de avaliar as alterações tardias da sensibilidade no território cutâneo do nervo infra-orbital em vítimas de fraturas do complexo órbito-zigomático, foram incluídos no estudo 25 pacientes com fraturas unilaterais do complexo (9 mulheres e 16 homens). O tipo de fratura mais freqüente no grupo em estudo foi o tipo 3 da classificação de Knighte North. Oitenta por cento dos pacientes foram submetidos a tratamento que, em sua grande maioria, cosistiu de exploração cirúrgica e fixação dos focos de fratura com fio de aço ou miniplacas e parafusos. Quando houve necessidade, o assoalho da órbita foi explorado, o conteúdo orbital foi reduzido para a cavidade orbital e o enxerto de cartilagem ou osso autógeno foi colocado. todos os pacientes foram abordados em um período pós-traumatismo de, no mínimo, 24 meses. A avaliação da sensibilidade baseou-se no estudo das fibras de adaptção lenta e das fibras de adaptação rápida do grupo A beta no território do nervo infra-orbital e foi realizada de três maneiras: a) determinação da distância para discriminação de dois pontos; b) determinação do limiar cutâneo de pressão; c) questionamento ao paciente quanto a alterações da sensibilidade local percebidas no seu dia-adia (sensação subjetiva). O lado da face contralateral, onde não ocorreu fratura, foi usado como grupo controle. Observou-se diferença estatisticamente significante entre o lado fraturado e o lado controle nos testes de discriminação de dois pontos e na aferição do limiar cutâneo de pressão para um ponto dinâmico. Observou-se ainda quando inquirido a respeito da sensibilidade de sua face.

Evaluation of the sensation in patients with trigeminal post-herpetic neuralgia.

BACKGROUND: Post-herpetic neuralgia (PHN) is one complication after herpes zoster infection, which may affect the facial superficial sensitivity. METHODS: Eighteen patients with PHN were interviewed and evaluated according to a systematized sensitivity approach, including mechanical, thermal and pain. RESULTS: The pain location was V1 in 15 patients. All trigeminal branches from both facial sides were evaluated; we compared the affected with the opposite side. There was a significant difference at V1 with cold (P=0.038), vonFrey (P=0.008) and pinpricks (P=0.022); at V2, the statistical difference occurred with cold (P=0.034), heat (P=0.019) and pinpricks (P=0.037); at V3, differences occurred with cold (P=0.042) and heat (P=0.036). Only V1 and oral mucosa (V2-3) presented pain threshold differences between both sides (P=0.001, P=0.021). CONCLUSION: Age, predominance of trigeminal PHN in V1 and continuous burning pain was common and similar to literature. Sensation was hampered with evident deficits of all sensory modalities in the affected trigeminal areas, especially V1.

Manifestaçoes fonoaudiologicas em um grupo de doentes de Hanseniase / Manifestations fonoaudiologicas in a group of patients from leprosy

A Hansenise, doença cronica infecto-contagiosa e de nofificaçao compulsoria, e causada pelo bacilo de Hansen (Mycobacterium leprae), e pode apresentar multiplas lesoes em qualquer local do corpo...

Proposal for a standardized protocol for the systematic orofacial examination of patients with Hereditary Sensory Radicular Neuropathy.

AIM: To apply a standardized protocol for the orofacial evaluation of two adult siblings (one male and one female) with Hereditary Sensory Radicular Neuropathy (HSRN) that presented with dental problems. SUMMARY: The systematic evaluation consisted of (a) clinical questionnaire; (b) radiographs [orthopantomography and computarized tomography (CT)]; (c) orofacial psychophysical tests (pain, thermal, mechanical and electrical sensation); and (d) histology of gingiva and pulp (optical and transmission electronic microscopy). The female patient had complete insensitivity to orofacial pain and partial facial heat sensitivity, and received dental treatment without anaesthesia or pain. She had a severe and painless jaw infection due to pulp necrosis in tooth 37. The male patient had partial insensitivity to orofacial pain and required anaesthesia for dental treatment. Histological examination of gingivae and pulpal tissue revealed an altered proportion of unmyelinated and myelinated sensory nerve fibres. KEY LEARNING POINTS: * Patients with HSRN may present with significant, silent dental disease. * A standard protocol is helpful when evaluating such patients. * If the opportunity arises, evaluation of pulp tissue may reveal an altered proportion of myelinated and unmyelinated nerve fibres. This may avoid the more estabilished sural nerve biopsy.

Reducing unnecessary morbidity from percutaneous thermocoagulation in the treatment of trigeminal neuralgia--part C: a starting point for a somatotopic map of the human Gasserian ganglion.

OBJECTIVES: An original method and technique has been designed to reduce the significant morbidity associated with techniques currently used for percutaneous thermocoagulation in the treatment of trigeminal neuralgia. The current report deals with the mathematical and biostatistical analysis of verbal responses gathered using such a method in an attempt, as a starting point, to establish the somatotopic organization of the human gasserian ganglion. METHOD: A correspondence analysis was used to validate verbal responses. These were ordered in three 34 x 34 matrices, according the initial sequence of 34 subsegments of the face, which was based on the operative experience of one of the authors. After using a filter for the consistency of responses, and a maximum threshold below 0.5 V, 967 responses from 99 patients were selected for analysis. The frequencies obtained from each subsegment were compared, using all the possible pairwise combinations of the subsegments of the face, and the sequences were ordered using the least contradictory criterion. RESULTS: The incidence of each verbal response within each trigeminal division was analysed, resulting in a proposal of a sequence of 20 subsegments of the gasserian ganglion, listed from the depth to the surface. DISCUSSION: From the strict clinical point of view, the somatotopic map of each individual is invariant and easily analysed over long time periods. Its precise knowledge is critical for inducing smaller, properly placed lesions, in order to avoid unnecessary morbidity from percutaneous thermocoagulation in the treatment of trigeminal neuralgia. The proposed sequence of the gasserian somatotopic organization will be hopefully a useful guide for those interested in trigeminal physiological organization as well as for the therapeutic exploration of gasserian trigeminal fibers.

Evaluation of cutaneous sensibility on infraorbital nerve area.

Normal facial sensibility on the area of the infraorbital nerve was determined in 24 healthy subjects. The measurement of two points discrimination distance and the evaluation of cutaneous pressure threshold were assessed on both sides on the zygomatic, paranasal, and superior labial skin. Cutaneous sensibility varied from region to region but was consistent from one normal individual to another. Cutaneous sensibility of the superior labial skin was more accurate than zygomatic and paranasal skin in all tests. Sex and dominant sides did not have significant influence on the results. The measurement of two point discrimination distance and the evaluation of cutaneous pressure threshold provided reliable and reproducible data that can be used as a standard to determine facial cutaneous sensibility.

Facial sensory symptoms in medullary infarcts

OBJETIVO: Investigar a correlação entre alterações de sensibilidade na face e topografia lesional em oito pacientes com infartos bulbares laterais (IBLs). MÉTODO: Revisamos oito casos seqüenciais de IBLs admitidos na Divisão de Clínica Neurológica do Hospital das Clínicas da Universidade de São Paulo entre julho de 2001 e agosto de 2002, exceto por um caso que havia sido admitido em 1996 e estava sendo seguido em 2002. Todos os pacientes foram submetidos a ressonância magnética de encéfalo, incluindo seqüências pesadas em T1, T2 e FLAIR. As ressonâncias foram avaliadas por investigadores que não tiveram acesso às características clínicas. Avaliaram-se as extensões dos infartos em relação às topografias presumidas dos tratos trigeminotalâmico ventral (TTV), espinotalâmico lateral, trigeminal espinhal e do núcleo trigeminal espinhal. RESULTADOS: Sintomas ou sinais sensitivos foram ipsilaterais ao infarto bulbar em 3 pacientes, contralaterais em 4 e bilaterais em 1. Em todos os casos de comprometimento exclusivo da sensibilidade da hemiface contralateral, os infartos tiveram extensões mediais que incluíram a topografia do TTV. Em casos de anormalidades sensitivas faciais exclusivamente ipsilaterais, os infartos afetaram as porções lateral e posterior do bulbo, com pouca ou nenhuma extensão medial. O único paciente que apresentou sintomas faciais bilaterais tinha um infarto comprometendo as porções medial e lateral, além da região posterior do bulbo. CONCLUSÃO: Nossos resultados mostram uma correlação entre extensão medial de IBLs e presença de sintomas sensitivos faciais contralaterais.

Facial sensory symptoms in medullary infarcts.

OBJECTIVE: To investigate the correlation between facial sensory abnormalities and lesional topography in eight patients with lateral medullary infarcts (LMIs). METHOD: We reviewed eight sequential cases of LMIs admitted to the Neurology Division of Hospital das Clínicas/São Paulo University between July, 2001 and August, 2002 except for one patient who had admitted in 1996 and was still followed in 2002. All patients were submitted to conventional brain MRI including axial T1-, T2-weighted and Fluid attenuated inversion-recovery (FLAIR) sequences. MRIs were evaluated blindly to clinical features to determine extension of the infarct to presumed topographies of the ventral trigeminothalamic (VTT), lateral spinothalamic, spinal trigeminal tracts and spinal trigeminal nucleus. RESULTS: Sensory symptoms or signs were ipsilateral to the bulbar infarct in 3 patients, contralateral in 4 and bilateral in 1. In all of our cases with exclusive contralateral facial sensory symptoms, infarcts had medial extensions that included the VTT topography. In cases with exclusive ipsilateral facial sensory abnormalities, infarcts affected lateral and posterior bulbar portions, with slight or no medial extension. The only patient who presented bilateral facial symptoms had an infarct that covered both medial and lateral, in addition to the posterior region of the medulla. CONCLUSION: Our results show a correlation between medial extension of LMIs and presence of contralateral facial sensory symptoms.