speech is a dynamic and complex process comprising respiration , phonation , resonation , 
 articulation , and neurologic integration . air emitted from the lungs passes along the 
 trachea and through the vocal tract to produce sounds . these sounds are then formulated 
 into meaningful speech by articulation of the lips , teeth , tongue , palate , and 
 alveolus . mandible 
 participation , more specifically the mandibular movements , enable space modifications , 
 allowing free tongue and soft tissues movements . the freedom involved in 
 these movements depends on the health and integrity of the stomatognathic system 
 structures , mainly the temporomandibular joint ( tmj ) and skeletal muscles . the presence of 
 temporomandibular disorders ( tmd ) can cause reduction in mandibular opening and 
 retrusion ranges , as well as in prevalence of unilateral deviation movements during 
 speech , but pain severity do 
 not seem to determine larger reduction of these values . conversely , phonemic distortions seem to be related also 
 to tongue thrust , but tmd seem to 
 produce changes in speech articulation as a protective adaptive mechanism , probably 
 triggered by pain . in addition , it has been suggested that speech alterations can be due to dental 
 occlusal , muscular and intra - articular alterations in individuals with tmd . excessive overjet predisposes to large 
 mandibular movements , most probably due to functional reasons , speech articulation , and 
 bite , which may stress the masticatory muscles . it is well accepted that the etiology of tmd is multifactorial , but there is still a 
 need to describe the relationship between tmd signs and symptoms and orofacial functions 
 ( mastication , swallowing , and speech ) during growth , since these disorders tend to occur 
 in the same children and are closely 
 related to each other . thus , considering that differences in study designs have impacted 
 greatly on the findings of these relationships , added to the fluctuation in speech 
 misarticulation with age and signs 
 and symptoms of tmd , as well as lack 
 of any clear evidence directly relating malocclusions to speech discrepancies , further 
 studies in this field are required . therefore , the aim of this study was to evaluate the 
 influence of tmd on speech in children , and to verify the influence of occlusal 
 characteristics . a cross - sectional study design was used with subjects attending two public schools in 
 piracicaba , state of so paulo , brazil . permission to carry out the research was 
 obtained and the children 's parents signed a written informed consent . the ethics committee of the piracicaba 
 dental school , university of campinas , so paulo , brazil , approved the research ( process 
 034/2006 ) . initially , 350 children aged 8 to 12 years having the same socioeconomic 
 background were selected . the inclusion criteria were a healthy status or absence of 
 systemic disturbance in the masticatory system , presence of all primary and/or permanent 
 teeth without anomalies and alterations of form , structure , or number . the exclusion 
 criteria included anterior open bite , anterior cross bite , short lingual frenulum ( when 
 the tip of the tongue could not be protruded beyond the lower incisor teeth and the 
 mobility of the tongue was restricted ) , presence of nutritive and non - nutritive sucking 
 habits , neurological disturbances ( such as cerebral palsy , movement disorders , speech 
 and language disorders , and behavioral / cognitive syndromes ) , any type of orthodontic 
 treatment prior to or during the research examination period and uncooperative behavior . open bite was considered an exclusion criterion , since this malocclusion can determine 
 speech alterations by itself , and so the influence of tmd could be masked , causing a 
 bias in the results . the parents / guardians were asked personally at the school or by phone about the presence 
 of parafunctional habits in their children , such as bruxism , pacifier and thumb / finger 
 sucking . after applying the exclusion criteria , 152 children ( 78 boys and 74 girls , mean 
 age 10.051.39 years ) were enrolled in the study . the research diagnostic criteria for tmd ( rdc / tmd ) exam and the speech evaluation 
 were performed by a speech - language pathologist ( author r.a.p . ) , who was trained by a 
 member of the international rdc / tmd consortium . a self - report questionnaire was used to assess subjective symptoms , regarding pain in 
 the jaws when in function , unusually frequent headaches ( more than once a week ) , 
 stiffness / tiredness in the jaws , difficulty in opening the mouth wide , grinding teeth 
 and tmj sounds . moreover , three questions of the axis ii of the 
 research diagnostic criteria for tmd ( rdc / tmd ) were considered for further tmd 
 diagnosis : ( 1 ) have you had pain in the face , jaw , temple , in front of the ear or in the ear in 
 the past month ? : only pains of unknown etiology were considered ) ( 2 ) have you ever had your jaw lock or catch so that it would not open all the 
 way ? ( 3 ) was this limitation in jaw opening severe enough to interfere with your ability 
 to eat ? the clinical signs were assessed using the rdc / tmd criteria , including : pain on 
 palpation , mandibular range of motion ( mm ) , associated pain ( jaw opening pattern , 
 unassisted opening , maximum assisted opening , mandibular excursive and protrusive 
 movements ) , sounds from the tmj , and tenderness induced by muscle and joint 
 palpation . the rdc / tmd criteria classify the most common forms of tmd into 3 
 diagnostic categories and allow for multiple diagnoses to be given for a single 
 patient , as follows : group i - muscle disorders ( group ia with myofascial pain and 
 group ib - myofascial pain with limited opening ) ; group ii , with disc displacement 
 ( group iia - with reduction ; group iib- without reduction with limited opening ; group 
 iic without reduction limited opening ) ; and group iii , with arthralgia ( group iiia ) 
 or arthritis ( group iiib /iiic ) . the rdc / tmd specifies distinct operational criteria 
 for each tmd subtype ; for example , a myalgia diagnosis is made if a person reports 
 pain in the face or mastication muscles at rest or during function , as well as the 
 presence of pain upon palpation of 3 or more sites . the arthralgia diagnosis includes 
 pain upon palpation of the tmj and joint - related pain during the movements of opening 
 mouth , mandibular excursive and protrusive movements ; the diagnosis of arthritis 
 includes pain in addition to the reported clicking sounds upon palpation . thus , every 
 tmd subject could have both a masticatory muscle pain diagnosis and/or a tmj pain 
 diagnosis . children presenting at least one sign and/or symptom of tmd , but not 
 classified as having tmd in accordance with rdc / tmd , were allocated in groups " sign 
 and symptom " or " sign or symptom " , being the first one considered more severe . the intraoral examination consisted of evaluation of the following occlusal 
 characteristics in the clenching position : sagittal permanent first molar relationship : in accordance with angle 's 
 classification with reference to the position of these teeth and how their biting 
 surfaces fit together : class i : normal biting relationship between the maxillary and mandibular teeth and 
 jaw ( balanced bite ) . class ii : the mandibular first molar is posterior or more towards the back of the 
 mouth than the maxillary first molar . class iii : the mandibular first molar is anterior or more towards the front of the 
 mouth than the maxillary first molar . posterior crossbite : one or more teeth in the maxillary buccal segment are lingual to 
 one or more of the opposing teeth in the mandibular buccal segment in maximum 
 intercuspation . overbite : vertical overlap of maxillary over mandibular central incisor teeth ( mm ) . children with 
 negative values ( anterior open bite ) were not included ( exclusion criterion ) . overjet : horizontal projection of maxillary central incisor teeth beyond the 
 mandibular central incisor teeth ( mm ) . children with negative values ( anterior cross 
 bite ) were not included ( exclusion criterion ) . a list of five easily recognizable pictures of the phonological assessment of child 
 speech , for sequential 
 naming , containing all of the phonemes of the brazilian portuguese language in 
 several positions , was used . the respective places of phoneme articulation are : 
 bilabial : [ p , b , m ] ; labiodental : [ f , v ] ; linguodental : [ t , d , n ] ; alveolar : [ s , z , 
 l , r ] ; palatal : [ x , j , lh , nh ] ; velar : [ c ( = k ) , qu , g ( = gu ) , rr ] . the exam was 
 undertaken with the participant seated on an armless chair , in a room with good 
 acoustic conditions . speech samples were obtained in a situation of spontaneous 
 speech ( visual stimulus ) . after a period of interaction between speech - language pathologist and participant , the figures were presented one at a time to the participant together with the 
 following request : " please , look at this figure and tell me all about it " . the speech 
 was interrupted with questions and/or comments only in cases in which it was 
 necessary to encourage the production of speech for obtaining 125 words . a list of 40 
 phonological balanced words , read by the speech pathologist and repeated by the 
 children was also applied to verify the improvement of the possible articulatory 
 errors detected during spontaneous speech , since the repetition gives an acoustic 
 support . the speech samples were recorded using an audio cassette and transcribed literally , 
 excluding the questions and comments and analyzed by a trained speech - language 
 pathologist , who listened to the voice records for three times and made phonetic 
 transcriptions of the words for documenting the absence or presence of the 
 articulatory disorders . the identification of speech disorders was based on the auditory perceptual analysis 
 by the researcher and on the visual inspection of the tongue movements during 
 evaluation . it was considered as results the common findings or the predominant ones 
 among the three analyses . if a phoneme , contained in a word list , was wrongly 
 pronounced in a rate of 50% or more , the articulatory error was computed . in those 
 evaluations , the articulatory disorders were 
 considered substitutions ( when one sound is replaced by another ) , omissions ( sound is 
 omitted from a word ) , and distortions ( sound is not produced appropriately , but still 
 understood ) of the phonemes . moreover , tongue protrusion in phonemes /t/ , /d/ , /n/ , 
 /l/ ( tongue tip positioned through the incisal edges of maxillary and mandibular 
 anterior teeth ) , frontal lisp in phonemes /s/ and /z/ , as well as the lateral 
 deviations in jaw movements and reduction of vertical amplitude were observed . lateral deviations were considered as a deviation in mandibular movement from central 
 to lateral region ( right or left ) during speech . the vertical amplitude was 
 considered restricted when there was articulation with small opening and decreasing 
 of facial muscle movements , leading to an unclear speech . replicate measurements of clinical signs of tmd and occlusal variables were performed 
 in twenty children randomly selected , for assessing intra - examiner reliability . for 
 this , intraclass correlation coefficients ( iccs ) were calculated for both continuous 
 and dichotomous variables of rdc / tmd examination . the considered icc values were : icc<0.04 , poor 
 reliability ; 0.04icc0.075 , fair to good reliability ; icc>0.75 excellent 
 reliability . for occlusal variables , which were considered as dichotomous ( presence or absence of 
 alteration ) , the agreement between the two examinations was calculated . the groups were distributed in accordance with rdc / tmd diagnostic criteria and 
 presence of signs and/or symptoms of tmd . furthermore , due to the number of subjects 
 in some groups , four major groups were formed to allow appropriate statistical 
 analysis . fisher 's exact or chi - square tests at 5% significance level were applied to 
 verify the proportions of the independent variables ( speech disorders and occlusal 
 alterations ) among the groups . the research diagnostic criteria for tmd ( rdc / tmd ) exam and the speech evaluation 
 were performed by a speech - language pathologist ( author r.a.p . ) , who was trained by a 
 member of the international rdc / tmd consortium . a self - report questionnaire was used to assess subjective symptoms , regarding pain in 
 the jaws when in function , unusually frequent headaches ( more than once a week ) , 
 stiffness / tiredness in the jaws , difficulty in opening the mouth wide , grinding teeth 
 and tmj sounds . moreover , three questions of the axis ii of the 
 research diagnostic criteria for tmd ( rdc / tmd ) were considered for further tmd 
 diagnosis : ( 1 ) have you had pain in the face , jaw , temple , in front of the ear or in the ear in 
 the past month ? only pains of unknown etiology were considered ) ( 2 ) have you ever had your jaw lock or catch so that it would not open all the 
 way ? ( 3 ) was this limitation in jaw opening severe enough to interfere with your ability 
 to eat ? the clinical signs were assessed using the rdc / tmd criteria , including : pain on 
 palpation , mandibular range of motion ( mm ) , associated pain ( jaw opening pattern , 
 unassisted opening , maximum assisted opening , mandibular excursive and protrusive 
 movements ) , sounds from the tmj , and tenderness induced by muscle and joint 
 palpation . the rdc / tmd criteria classify the most common forms of tmd into 3 
 diagnostic categories and allow for multiple diagnoses to be given for a single 
 patient , as follows : group i - muscle disorders ( group ia with myofascial pain and 
 group ib - myofascial pain with limited opening ) ; group ii , with disc displacement 
 ( group iia - with reduction ; group iib- without reduction with limited opening ; group 
 iic without reduction limited opening ) ; and group iii , with arthralgia ( group iiia ) 
 or arthritis ( group iiib /iiic ) . the rdc / tmd specifies distinct operational criteria 
 for each tmd subtype ; for example , a myalgia diagnosis is made if a person reports 
 pain in the face or mastication muscles at rest or during function , as well as the 
 presence of pain upon palpation of 3 or more sites . the arthralgia diagnosis includes 
 pain upon palpation of the tmj and joint - related pain during the movements of opening 
 mouth , mandibular excursive and protrusive movements ; the diagnosis of arthritis 
 includes pain in addition to the reported clicking sounds upon palpation . thus , every 
 tmd subject could have both a masticatory muscle pain diagnosis and/or a tmj pain 
 diagnosis . children presenting at least one sign and/or symptom of tmd , but not 
 classified as having tmd in accordance with rdc / tmd , were allocated in groups " sign 
 and symptom " or " sign or symptom " , being the first one considered more severe . the intraoral examination consisted of evaluation of the following occlusal 
 characteristics in the clenching position : sagittal permanent first molar relationship : in accordance with angle 's 
 classification with reference to the position of these teeth and how their biting 
 surfaces fit together : class i : normal biting relationship between the maxillary and mandibular teeth and 
 jaw ( balanced bite ) . class ii : the mandibular first molar is posterior or more towards the back of the 
 mouth than the maxillary first molar . class iii : the mandibular first molar is anterior or more towards the front of the 
 mouth than the maxillary first molar . posterior crossbite : one or more teeth in the maxillary buccal segment are lingual to 
 one or more of the opposing teeth in the mandibular buccal segment in maximum 
 intercuspation . overbite : vertical overlap of maxillary over mandibular central incisor teeth ( mm ) . children with 
 negative values ( anterior open bite ) were not included ( exclusion criterion ) . overjet : horizontal projection of maxillary central incisor teeth beyond the 
 mandibular central incisor teeth ( mm ) . children with negative values ( anterior cross 
 bite ) were not included ( exclusion criterion ) . a list of five easily recognizable pictures of the phonological assessment of child 
 speech , for sequential 
 naming , containing all of the phonemes of the brazilian portuguese language in 
 several positions , was used . the respective places of phoneme articulation are : 
 bilabial : [ p , b , m ] ; labiodental : [ f , v ] ; linguodental : [ t , d , n ] ; alveolar : [ s , z , 
 l , r ] ; palatal : [ x , j , lh , nh ] ; velar : [ c ( = k ) , qu , g ( = gu ) , rr ] . the exam was 
 undertaken with the participant seated on an armless chair , in a room with good 
 acoustic conditions . speech samples were obtained in a situation of spontaneous 
 speech ( visual stimulus ) . after a period of interaction between speech - language pathologist and participant , the figures were presented one at a time to the participant together with the 
 following request : " please , look at this figure and tell me all about it " . the speech 
 was interrupted with questions and/or comments only in cases in which it was 
 necessary to encourage the production of speech for obtaining 125 words . a list of 40 
 phonological balanced words , read by the speech pathologist and repeated by the 
 children was also applied to verify the improvement of the possible articulatory 
 errors detected during spontaneous speech , since the repetition gives an acoustic 
 support . the speech samples were recorded using an audio cassette and transcribed literally , 
 excluding the questions and comments and analyzed by a trained speech - language 
 pathologist , who listened to the voice records for three times and made phonetic 
 transcriptions of the words for documenting the absence or presence of the 
 articulatory disorders . the identification of speech disorders was based on the auditory perceptual analysis 
 by the researcher and on the visual inspection of the tongue movements during 
 evaluation . it was considered as results the common findings or the predominant ones 
 among the three analyses . if a phoneme , contained in a word list , was wrongly 
 pronounced in a rate of 50% or more , the articulatory error was computed . in those 
 evaluations , the phonetic component was observed . the articulatory disorders were 
 considered substitutions ( when one sound is replaced by another ) , omissions ( sound is 
 omitted from a word ) , and distortions ( sound is not produced appropriately , but still 
 understood ) of the phonemes . moreover , tongue protrusion in phonemes /t/ , /d/ , /n/ , 
 /l/ ( tongue tip positioned through the incisal edges of maxillary and mandibular 
 anterior teeth ) , frontal lisp in phonemes /s/ and /z/ , as well as the lateral 
 deviations in jaw movements and reduction of vertical amplitude were observed . lateral deviations were considered as a deviation in mandibular movement from central 
 to lateral region ( right or left ) during speech . the vertical amplitude was 
 considered restricted when there was articulation with small opening and decreasing 
 of facial muscle movements , leading to an unclear speech . replicate measurements of clinical signs of tmd and occlusal variables were performed 
 in twenty children randomly selected , for assessing intra - examiner reliability . for 
 this , intraclass correlation coefficients ( iccs ) were calculated for both continuous 
 and dichotomous variables of rdc / tmd examination . the considered icc values were : icc<0.04 , poor 
 reliability ; 0.04icc0.075 , fair to good reliability ; icc>0.75 excellent 
 reliability . for occlusal variables , which were considered as dichotomous ( presence or absence of 
 alteration ) , the agreement between the two examinations was calculated . the groups were distributed in accordance with rdc / tmd diagnostic criteria and 
 presence of signs and/or symptoms of tmd . furthermore , due to the number of subjects 
 in some groups , four major groups were formed to allow appropriate statistical 
 analysis . fisher 's exact or chi - square tests at 5% significance level were applied to 
 verify the proportions of the independent variables ( speech disorders and occlusal 
 alterations ) among the groups . sample distribution according to tmd diagnosis and presence or absence of signs and 
 symptoms of tmd is shown in table 1 . sample distribution according to research diagnostic criteria for 
 temporomandibular disorders ( rdc / tmd ) diagnosis and signs and symptoms of tmd ( 1 ) , ( 2 ) , ( 3 ) , ( 4 ) : major groups . sd= standard deviation table 2 shows the distribution of children with 
 speech disorders in each group , as well as their distribution in relation to occlusal 
 characteristics . although no differences were observed among groups , it was verified 
 that group n presented only 2 children ( 18% ) with two kind of speech disorders , whereas 
 for other three groups the percentage ranged from 33% to 45% . the proportion of children 
 with overjet was significantly higher for group tmd and group s and s than the other two 
 groups ( p<0.05 ) . moreover , between group tmd and group s and s , the respective 
 proportion was similar ( p>0.05 ) , as well as for group s or s and group n ( p>0.05 ) . 
 for other occlusal characteristics , there were no differences in proportions among 
 groups . distribution of subjects with speech disorders and morphological characteristics 
 of occlusion into groups values followed by different superscript small letters differ significantly 
 ( p<0.05 fisher 's exact test or qui - square ) table 3 shows the most prevalent speech 
 disorders and their distribution in accordance with morphologic characteristics of 
 occlusion . the proportions of overall speech disorders , as well as , for each one 
 evaluated , were similar among the different occlusal characteristics . on the other hand , 
 when excessive overjet and overbite ( 4 mm ) and posterior crossbite were analyzed 
 considering both molar classes together ( table 
 4 ) , children with excessive overjet presented higher proportion of speech 
 disorders than children with posterior crossbite ( p=0.0184 ) , whereas for excessive 
 overbite the respective difference was not detected ( p=0.0633 ) . children with overjet 4 
 mm presented the same proportion of overall speech disorders than children with overbite 
 4 mm ( p=0.6089 ) . on verifying the presence and absence of malocclusions , children with 
 overjet had a higher percentage of speech disorders than the ones without overjet 
 ( p=0.0117 ) . for overbite and crossbite distribution of children with the most prevalent speech disorders according to 
 morphological characteristics of occlusion distribution of children with the overall speech disorders in accordance with 
 morphological characteristics of occlusion independent of molar relationship overjet 4 mm determined higher proportion of speech disorders than 
 posterior crossbite ( p=0.0184 ) overjet 4 mm determined higher proportion of speech disorders than normal 
 overjet ( p=0.0117 ) reliability value for the rdc / tmd clinical exam ranged from fair to excellent ( from 
 0.042 to 1.0 ) . the lowest values were found for some palpation tests . the intra - examiner 
 agreement ranged from 95% to 100% between the two dental examinations . the prevalence of children diagnosed as having tmd by rdc / tmd criteria was 26.32% ( table 
 1 ) . moreover , most of the children presented at least one sign and/or symptom of tmd , 
 without gender differences , in agreement with farsi ( 2003 ) . this finding might merit some thought since different 
 results in the literature about tmd in children can be found . the know fluctuation in 
 signs and symptoms of musculoskeletal disorders in a time - dependent context might be a 
 factor of influence , as well as the 
 dynamism of the stomatognathic system development . signs and symptoms in growing individuals may be due in part to 
 growth changes , phase in which there 
 are both local and central factors associated from time to time with tmd development . however , the prediction of single tmd signs for the development of severe disorder later 
 in life is unclear . moreover , most of signs and symptoms are mild 
 and it is not yet clear whether these represent normal variation , preclinical features 
 or manifestations of a disease state . although tmd signs and symptoms fluctuated , the intraexaminer reliability showed 
 confident results for the collected data . ( 2005 ) , showed the 
 lowest iccs , which can have generate some overestimation of tmd signs and symptoms , but 
 not invalidating the classification adopted , since the signs and symptoms can 
 fluctuate . a low prevalence of speech disorders was observed in all defined groups ( table 2 ) , but 
 it was greater in children with tmd signs and symptoms compared to the tmd - free ones . could be considered 
 as a limitation in the present study , but the fact that the voices were listened 3 
 times , gives a support for reliable results . on the other hand , this fact could be 
 considered as a limitation , since more additional judges would provide a measure of 
 inter - examiner agreement , eliminating possible bias . the results of the present study 
 differ from those of pahkala , et al . ( 1991 ) , who found a higher frequency of subjective symptoms and several clinical signs 
 of tmd related to certain articulatory speech disorders . the controversial results are 
 probably due to the differences in subjects ' ages in the two studies and because their 
 children were referred for speech therapy , whereas in the present study the sample was 
 randomly selected , without considering the severity of speech disorders . moreover , they 
 considered that expression of tmd and disorders in speech sound production seem to 
 reflect , to a considerable extent , immaturity of fine motor control of the orofacial 
 muscles in 6 - 8-year - old children , but in the age range of the sample in the present 
 study , it was expected that all sounds would be produced correctly . in the tmd and tmd signs and/or symptoms groups , a slight prevalence of articulatory 
 disorders , such as substitutions , omissions , and distortions of the sibilants /s/ and 
 /z/ was observed . moreover , there were no different proportions among the four groups 
 for these variables ( p>0.05 ) , meaning that in the studied sample , the alterations 
 could not be associated with tmd , but with other factors . in the visual assessment , /l/ and frontal lisp in /s/ and /z/ , but there was no difference in proportion 
 among groups . the class ii relationship with excessive overjet may be one of the main 
 factors responsible for frontal lisping . in this study , the number of children with excessive overjet and 
 overall speech disorders was significantly higher than children with normal overjet , but 
 no differences with other malocclusion were noted ( tables 3 and 4 ) . this can be 
 attributed to the low prevalence of speech disorders , since the sample was randomly 
 selected , as considered above . moreover , distortions in /s/ and /z/ were more prevalent 
 in children with overjet or overbite in both class molar relationship , showing that 
 malocclusion can play a role in some speech alterations , aside others factors of 
 influence ( table 3 ) . no deviations in jaw lateral movements were observed during the sequential naming of 
 pictures in the present sample , whereas reduction of vertical amplitude was found in the 
 tmd and s and s groups , but only in 10 children . thus , the reference of functional 
 limitations due to the characteristics of tmd in the studied sample was not confirmed , 
 in agreement with others . nonetheless , a discrete number of 
 alterations were assessed visually , which could mean a modulation of motor responses 
 preserving the function in children 
 with tmd and signs and/or symptoms of tmd in this study . although a large number of children were diagnosed with tmd / rdc and signs and/or 
 symptoms of tmd , a small number presented articulatory errors . this suggests either that 
 the errors were undetectable by perceptual and acoustic evaluation or that these 
 subjects had developed some kind of compensatory pattern . in this way , it is important to emphasize , as stated 
 above , the random sample characteristic , since the children were selected from public 
 schools , not taking into consideration the severity of speech disorders . in addition , 
 the quite strict exclusion criteria of the sample can be considered as influence factors 
 on the results . ( 2008 ) established no statistically significant differences for the presence and the 
 range of the deviations in laterality , assessed by computerized electrognathography , 
 during speech between tmd and asymptomatic adult subjects . however , these authors 
 considered that the presence of tmd could determine reduction in mandibular opening and 
 prevalence of unilateral deviation movements during speech . in spite of the differences 
 in results , it should be emphasized that attention should be given to children with tmd 
 and signs and symptoms of tmd , in 
 order to identify patients who should be more closely observed , in view of the high 
 prevalence found in the present study . occlusal alterations may be 
 factors of influence , allowing distortions and frontal lisp in phonemes /s/ and /z/ and 
 inadequate tongue position in phonemes /t/ ; /d/ ; /n/ ; /l/.
objectivesthe aims of this study were to evaluate the influence of temporomandibular 
 disorders ( tmd ) on speech in children , and to verify the influence of occlusal 
 characteristics . 
 material and methodsspeech and dental occlusal characteristics were assessed in 152 brazilian children 
 ( 78 boys and 74 girls ) , aged 8 to 12 ( mean age 10.05  1.39 years ) with or without 
 tmd signs and symptoms . 
 the clinical signs were evaluated using the research 
 diagnostic criteria for tmd ( rdc / tmd ) ( axis i ) and the symptoms were evaluated 
 using a questionnaire . 
 the following groups were formed : group tmd ( n=40 ) , tmd 
 signs and symptoms ( group s and s , n=68 ) , tmd signs or symptoms ( group s or s , 
 n=33 ) , and without signs and symptoms ( group n , n=11 ) . 
 articulatory speech 
 disorders were diagnosed during spontaneous speech and repetition of the words 
 using the " phonological assessment of child speech " for the portuguese language . 
 it was also applied a list of 40 phonological balanced words , read by the speech 
 pathologist and repeated by the children . 
 data were analyzed by descriptive 
 statistics , fisher 's exact or chi - square tests ( =0.05 ) . 
 resultsa slight prevalence of articulatory disturbances , such as substitutions , omissions 
 and distortions of the sibilants /s/ and /z/ , and no deviations in jaw lateral 
 movements were observed . 
 reduction of vertical amplitude was found in 10 children , 
 the prevalence being greater in tmd signs and symptoms children than in the normal 
 children . 
 the tongue protrusion in phonemes /t/ , /d/ , /n/ , /l/ and frontal lips in 
 phonemes /s/ and /z/ were the most prevalent visual alterations . 
 there was a high 
 percentage of dental occlusal alterations . 
 conclusionsthere was no association between tmd and speech disorders . 
 occlusal alterations 
 may be factors of influence , allowing distortions and frontal lisp in phonemes /s/ 
 and /z/ and inadequate tongue position in phonemes /t/ ; /d/ ; /n/ ; /l/.