Browsing by Author "Costa, Isabel M."
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- Clinical analysis in speech and language therapy: Occlusal class and speech productionPublication . Araújo, André; Jesus, Luis M. T.; Costa, Isabel M.Occlusal class refers to the manner that the upper (maxilla) and lower (mandible) dental arches relate. This relation was first described by Angle, who proposed a malocclusion classification based on the relative position of the maxillary first molar. Malocclusion refers to the misalignment of teeth and/or incorrect relation between the teeth of the two dental arches. Class I malocclusion, presents a normal molar relationship, but the other teeth have problems like spacing, crowding, over or under eruption. In Class II malocclusion, or distocclusion, the upper molars are placed not in the mesiobuccal groove but anteriorly to it. The anterior dental relation can vary, originating two subclasses: division 1, when the maxillary incisors are positioned forward to the lower incisors resulting in marked overjet; division 2, when there is linguoversion (retroversion) of the maxillary central incisors. Class III malocclusion, or mesiocclusion, refers to an advancement of the lower dental arch. Occlusal class has been shown to be directly related to articulatory perturbation of speech sounds such as fricatives. Understanding the influence of occlusal class in stomatognathic functions requires a thorough assessment of the craniofacial configuration. The size, form and relative position of the craniofacial bones may be in the origin of malocclusions and functional disorders. X-Ray Microbeam Speech Production Database (XRMB-SPD) is a speech production database, created at Wisconsin University, USA, that uses X-Ray Microbeam technology to collect a vast amount of coordinate data describing articulatory movements, and also includes acoustic and electroglotographic data collected simultaneously [3]. XRMB-SPD articulatory data are presented in a two dimensional xy mid-saggital plane that includes: palate line, posterior pharynx wall line, lips, tongue and mandible. The coordinates of each mobile structure refer to an 8 pellet system distributed through the oral cavity: lower lip, upper lip, mandibular incisor, mandibular first molar and tongue (4 pellets). The speech samples result from different tasks, including word and sentence reading, isolated productions, and non-verbal oral movements. The speaker sample includes 57 male and female speakers of American English, with an average age of 21. The database includes individual parameters characterizing each subject (e.g., dental information), which allowed us to study the relations between speech production and occlusal class. The present study was concerned with the variations of different malocclusion class subjects, namely: (a) the description of articulatory structures involved in speech production; (b) the comparison of acoustic features and articulatory processes in vowel and consonant productions; (c) the characterization of the functional adaptations found.
- Speech Production in Two Occlusal ClassesPublication . Jesus, Luis; Araújo, André; Costa, Isabel M.Background: The influence of the occlusal class in speech production has been studied using the X-ray Microbeam Speech Production Database (XRMB-SPD). Objectives/aims: This study aimed to relate the occlusal classes I and II with speech production adaptations. Methods: The Modified A-Space method was used to select 4 speakers (1 male and 1 female class I, 1 male and 1 female class II). Articulatory and acoustic features of the vowels were studied using different tasks and methods. The articulatory and acoustic features of consonants in male and female speakers of class I and class II from the XRMB-SPD were also described in detail. Measures extracted from multitaper spectra and articulatory data were used, to observe individual differences related with gender and dental occlusion. Results: Results showed some structural differences related to occlusal class and variance in class II subjects' structures and articulatory adaptations. However, subjects showed a high adaptation capacity, being able to adjust their articulations to produce all vowels. Conclusions: Speech production variability is related with orofacial structures' variance. Different structures produce various functional adaptations and distinct speech signals.
- O uso da X-Ray Microbeam Speech Production Database no estudo da influência da oclusão dentária na produção de sons de falaPublication . Araújo, André; Jesus, Luís M. T.; Costa, Isabel M.A fala é uma actividade neuromotora complexa, usada na comunicação humana cujo entendimento continua a despertar interesse. Actualmente, a investigação tende a unir ciências linguísticas e médicas com novas tecnologias. A terapêutica da fala, responsável pela avaliação e tratamento das perturbações da comunicação humana, tem dado contributos para a evolução do conhecimento da fala numa perspectiva funcional. A XRMBSPD é uma base de dados que usa a técnica imagiológica X-ray Microbeam, e permite simultaneamente uma análise acústica, electroglotográfica e articulatória dinâmica, através da localização em tempo real de eléctrodos colocados em vários pontos da face e do sistema articulatório (língua, lábios e dentes). Usou-se a XRMB-SPD para descrever diferenças acústicas e articulatórias em indivíduos com classes de oclusão dentária diferentes.
- Vowel production in two occlusal classesPublication . Araújo, André; Jesus, Luís M. T.; Costa, Isabel M.; Guerreiro Martins Araújo, Pedro AndréThe influence of occlusal class in speech production has been studied using the X-ray Microbeam Speech Production Database (XRMB-SPD). The objective of the study was to relate the occlusal classes I and II with vowel production adaptations. The “Modified A-Space” method was used to select 4 speakers (1 class I male, 1 class I female, 1 class II male and 1 class II female). Articulatory and acoustic features of the vowels [i, {, A, u] were studied using different tasks and methods. Results show some structural differences related with occlusal class and variance in class II subjects’ structures and articulatory adaptations. The major differences found in the vowels’ formants were between male and female groups. Occlusal class also seems to influence acoustical features of vowels produced by female speakers. Structural differences were found, but subjects showed a high adaptation capacity, being able to adjust their articulators to produce all vowels.