Musculo-articular disorders of the stomatognathic system in school children examined according to clinical criteria

Temporomandibular joint innervation: Anatomical study and clinical implications

BACKGROUND

Temporomandibular disorders and related pain are commonly seen in clinical practice. Due to its recurrent nature, they adversely affect a patient's social life. Current knowledge on the temporomandibular joint (TMJ) innervation is debatable and insufficient to ensure optimal treatment for the underlying pathology. This study aimed to elucidate the pathophysiology of temporomandibular pain by revealing the TMJ innervation topography, its variations, and its relationships with the surrounding anatomical structures. This will aid in creating a guide for temporomandibular, infratemporal, and preauricular interventions.

METHODS

A total of 20 cadaver half heads, 10 fresh frozen and 10 embalmed, were used. The TMJ nerves were dissected together with the surrounding anatomical structures.

RESULTS

We showed that the TMJ is mainly innervated by the auriculotemporal nerve posteriorly, the masseteric nerve anteriorly, the posterior deep temporal nerve anteromedially, and the TMJ branch originating directly from the mandibular nerve medially, and that there are variations in these innervation pathways. Additionally, we emphasized how these nerves might be affected in certain clinical conditions based on their anatomical relationships and pathophysiological mechanisms. To our knowledge, this is the first study showing the existence of a branch of the mandibular nerve directly innervating the TMJ.

CONCLUSION

In light of our findings, elucidating TMJ pain based on the anatomical characteristics of the region will allow precise treatment algorithms and better clinical outcomes in these patients. Based on this study, new clinical studies and interventions can be designed to reduce healthcare costs and alleviate the burden of temporomandibular disorders.

Application of additional anthropometric and functional methods in children undergoing orthodontic treatment using braces

Background

Occlusal interference causes instability in temporomandibular joint and hyperactivity of mastication muscles which eventually leads to temporomandibular joint dysfunction. Therefore, achieving stable occlusion is important in young patients. It is key factor in optimizing functional occlusion in adulthood.

Aim

Application of «The ABO Model Grading System» and Mandibular Position Indicator as an additional diagnostic method in children undergoing orthodontic treatment using braces.

Methods

Thirty-two patients aged 14 to 18 diagnosed with teeth crowding on the upper and lower jaws were examined, then separated in two groups of 16 people each. All patients underwent orthodontic treatment using braces.

Results

In group 2, due to application the anthropometrical system of quantitative evaluation ABO with re-fixing the incorrectly arranged braces by indirect bonding method, occlusal interferences were eliminated. MPI analysis showed discrepancy between the central occlusion and the central relation which was not as relevant as in the group 1 (p > 0.05).

Conclusion

Using the anthropometric system of quantitative assessment of ABO with subsequent re-fixation of incorrectly placed braces by indirect bonding, effectively improves the MPI. This determines the unity of position between articular condyles on the lower jaw in the centric occlusion and in the centric relation, which allows to get a stable result of orthodontic treatment.

Prediction of painful temporomandibular joint osteoarthritis in juvenile patients using bone scintigraphy

The study aims to evaluate whether bone scintigraphy is effective in diagnosing temporomandibular joint (TMJ) osteoarthritis (OA) in juvenile patients. A retrospective study was conducted with 356 consecutive patients with TMJ-OA who were clinically assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders. Patients were assigned to three groups based on their ages: Group 1: aged 12-16 years; Group 2: aged 17-19 years; and Group 3: aged 20 years. Additionally, we performed qualitative and quantitative analyses of bone scintigraphy images for the TMJ uptake ratio of the involved joint. The diagnostic rate of TMJ-OA (n = 356, 100%), and the overall presence of subjective pain (n = 282, 77.3%) was closest to the results of bone scintigraphy (n = 333, 91.2%). In addition, reported TMJ pain was significantly associated only with the results of bone scintigraphy and not with the results of panoramic radiography or cone beam computed tomography (CBCT) in all age groups. With CBCT as the reference standard, the optimal cutoff values of the uptake ratio for the diagnosis of TMJ-OA were 2.171 and 2.017 in Groups 1 and 2, respectively (P value < 0.05). Our results suggest that bone scintigraphy can be considered a useful modality for diagnosing TMJ-OA in juvenile patients.

Prevalence of temporomandibular disorder in children and adolescents from public schools in southern portugal

BACKGROUND

The prevalence of temporomandibular disorder (TMD) in children and adolescents is in the range of 6-68% and can be triggered or aggravated by emotional stress.

AIM

The study was to investigate the prevalence of TMD in Portuguese children and adolescents and its association with emotional stress.

MATERIALS AND METHODS

The sample comprised 3,260 students aged 5-19 years. The questionnaire was used to assess the presence of TMD, and was applied in a single moment.

RESULTS

TMD was observed in 821 (25.2%) students. The most common symptoms of TMD were: if considered tense or nervous (52%), have headaches (36.8%), and habit of clenching or grinding teeth (27.3%). The girls had a 1.36 higher probability of developing TMD than boys (95% CI: 1.14-1.63; p < 0.001); moreover, students from the older age group had a 2.31 higher probability of developing the disorder (95% CI: 1.85-2.89; p < 0.001). Students who considered themselves tense or nervous presented 8.74 higher probability (95% CI: 7.03-10.86; p < 0.001) of developing TMD.

CONCLUSION

This study showed a high prevalence of TMD in children and adolescents in southern Portugal, and revealed a significant association between this dysfunction and the levels of emotional stress. Female students, older students, and those considered tense or nervous have a higher probability of developing TMD.

Malocclusion and TMJ disorders in teenagers from private and public schools in Mexico City

Objective: To identify, among Mexican teenagers from public and private schools, the frequency, severity of malocclusion and orthodontic treatment needs, and their possible association with temporomandibular joint disorders. Material and Methods: Fifteen-year-old students were recruited from public and private schools. Clinical findings were registered as follows: oral hygiene status with the Oral Hygiene Index-Simplified, malocclusion using the Dental Aesthetic Index (DAI), and TMJ disorders following WHO criteria. Negative binomial and logistic regression models were constructed for data analysis. Results: A total of 249 fifteen-year old students were included in the study (118 female 47.4%). 68% had a DAI score ≤ 25 (minor or no occlusal anomalies), 18% scored 26-30 (mild anomalies), 7% scored 31-35 (evident anomalies), and 6% scored ≥ 36 (major malocclusion). The most frequent anomalies were dental crowding in 50%, maxillary dental irregularity in 44.6%, mandible irregularity in 41.2% and excessive maxillary overjet in 37.8%. Among the students, 26.1% had clicking/muscle or TMJ pain, of these 12.3% showed pain during palpation. OHI-S > 1 was found in 34% of the participants. The negative binomial model showed an association between DAI score and TMJ disorders (P=0.041). Also the logistic regression model showed an association between malocclusion (DAI>25) and TMJ disorders (OR=2.58, p=0.002). Malocclusion was associated also with poor oral hygiene (OR=1.65, p=0.007), and with attendance to public schools (OR=1.97, p=0.039). Conclusions: TMJ disorders and DAI scores were significantly associated. Screening/Diagnostic programs for ortho-dontic and TMJ-disorders are needed, to identify and offer treatment to teenagers with major malocclusion and TMJ/muscle pain.

Key words:Dental Aesthetic Index, DAI, crowding, Temporo Mandibular Joint disorders (TMJ disorders), Temporo Mandibular Disorders (TMD), occlusal anomalies, OHI-S.

A Study on Prevalence of Dental Attrition and its Relation to Factors of Age, Gender and to the Signs of TMJ Dysfunction

A study was planned to determine the severity of dental attrition in adults of both sexes in different age groups and its possible relationship to temporomandibular disorders. 500 subjects comprising of 260 females and 240 males in the age group of 18-55 years were clinically examined for bruxism, attrition, and signs of temporomandibular disorders. Tooth sensitivity, tooth or restoration fracture, scalloping of tongue, ridging of buccal mucosa, TMJ sounds, muscle tenderness, TMJ tenderness, referred pain, pain on mouth opening and limitation of mouth opening were recorded along with attrition score in a proforma. The basic data was then analysed to arrive at certain conclusions. A high prevalence of attrition (88.0%) with increase in age (P < 0.00) and was seen more in males as compared to females (P < 0.01). On comparing attrition with some of the signs of bruxism it was shown that tooth or restoration fracture and scalloping of tongue had no relation to the severity of attrition score. Whereas a significant relation was seen between attrition and tooth sensitivity (P < 0.00), and ridging of buccal mucosa (P < 0.05). Muscle tenderness (P < 0.00), pain on mouth opening (P < 0.05) and deviation of mandible on mouth opening (P < 0.00) had significant relation to attrition. Other signs of temporomandibular disorders such as joint tenderness, referred pain, joint sounds and limitation of mouth opening had no relation to attrition score. This study showed a limited association between the severity of attrition and TMJ dysfunction.

Signs and symptoms of temporomandibular disorders and oral parafunctions in urban Saudi Arabian adolescents: a research report

BACKGROUND

The aim of this study was to evaluate the prevalence of signs and symptoms of temporomandibular disorders (TMD) and oral parafunction habits among Saudi adolescents in the permanent dentition stage.

METHODS

A total of 385 (230 females and 155 males) school children age 12-16, completed a questionnaire and were examined clinically. A stratified selection technique was used for schools allocation.

RESULTS

The results showed that 21.3% of the subjects exhibited at least one sign of TMD and females were generally more affected than males. Joint sounds were the most prevalent sign (13.5%) followed by restricted opening (4.7%) and opening deviation (3.9%). The amplitude of mouth opening, overbite taken into consideration, was 46.5 mm and 50.2 mm in females and males respectively. TMJ pain and muscle tenderness were rare (0.5%). Reported symptoms were 33%, headache being the most frequent symptom 22%, followed by pain during chewing 14% and hearing TMJ noises 8.7%. Difficulty during jaw opening and jaw locking were rare. Lip/cheek biting was the most common parafunction habit (41%) with females significantly more than males, followed by nail biting (29%). Bruxism and thumb sucking were only 7.4% and 7.8% respectively.

CONCLUSION

The prevalence of TMD signs were 21.3% with joint sounds being the most prevalent sign. While TMD symptoms were found to be 33% as, with headache being the most prevalent. Among the oral parafunctions, lip/cheek biting was the most prevalent 41% followed by nail biting 29%.

Signs and symptoms of temporomandibular disorders in adolescents

The aim of this study was to verify the prevalence of signs and symptoms of temporomandibular disorders (TMD) in adolescents and its relationship to gender. The sample comprised 217 subjects, aged 12 to 18. The subjective symptoms and clinical signs of TMD were evaluated, using, respectively, a self-report questionnaire and the Craniomandibular Index, which has 2 subscales; the Dysfunction Index and the Palpation Index. The results of muscle tenderness showed great variability (0.9-32.25%). In relation to the temporomandibular joint, tenderness of the superior, dorsal and lateral condyle regions occurred in 10.6%, 10.6% and 7.83%, respectively, of the sample. Joint sound during opening was present in 19.8% of the sample and during closing in 14.7%. The most prevalent symptoms were joint sounds (26.72%) and headache (21.65%). There was no statistical difference between genders (p > 0.05), except for the tenderness of the lateral pterygoid muscles, which presented more prevalence in girls. In conclusion, clinical signs and symptoms of TMD can occur in adolescents; however, gender influence was not perceived.

Temporomandibular disorders in 19-year-old Korean men

PURPOSE

The purpose of this study was to determine the prevalence and the nature of the relationships between 3 temporomandibular joint disease (TMD) symptoms and symptoms of associated structures.

MATERIALS AND METHODS

This study was designed to rule out the effect from the uneven composition of the samples on TMD symptoms. The samples were collected from subjects who were of the same age, gender, district, and race. Nineteen-year old men (n = 27,978) were selected and investigated by means of questionnaires and clinical examinations. The prevalence of each symptom was studied and tried to determine the effects of the TMD-associated signs on the TMD signs. The indices allocated to reflect the TMD signs and symptoms and the others were dichotomized for bivariate analysis. The predictor variables were headache, neck pain, referred pain, stress, past trauma history in the TMJ, past TMJ dislocation, bruxism, and clenching. The outcome variables were mouth opening limitation, TMJ pain on rest, and TMJ pain during function.

RESULTS

The incidence of masticatory muscle stiffness was 17.8%; TMJ sounds, 14.3%; headache, 7.2%; neck pain, 13.5%; bruxism, 8.4%; and clenching, 9.9%. Stress occurred in 12.8%, past trauma history in 11%, and previous joint dislocation in 2.5%. The experience of dislocation in the TMJ was found to be the most important risk factor in terms of mouth opening limitation (odds ratio, 4.08, P <.0001), joint pain during function (odds ratio, 5.50, P <.0001), and joint pain in the rest state (odds ratio, 4.63, P <.0001). Referred pain and the experience of trauma in TMJ were the secondary risk factors in terms of joint pain and referred pain and the stress in terms of mouth opening limitation. Considering referred pain can be induced by TMD, stress may be more related to mouth opening limitation (odds ratio, 2.18, P <.0001), and the experience of trauma in TMJ may be more related to pain in the rest state (odds ratio, 2.56, P <.0001) and during function (odds ratio, 2.47, P <.0001).

CONCLUSIONS

The prevalence of TMD signs and symptoms as determined by this examination was in accord with the findings in women or mixed samples of other workers. Prior experience of a dislocated disc was found to be the most risky factor in TMD. Stress was related to limitations of mouth opening, and the experience of trauma in the TMJ was found to be related to pain in the joint region. Bruxism may not be a direct risk factor in TMD, and the clenching habit found to be more harmful than bruxism.

Relationship between premature loss of primary teeth and the development of temporomandibular disorders in children

AIM

This study evaluated the prevalence of signs of temporomandibular disorders (TMD) in children with and without premature loss of primary teeth.

SAMPLE

Fifty-eight children, aged 4-6 years, with missing primary molars, were compared with 58 age- and sex-matched control children with complete primary dentitions.

METHOD

All the children underwent an examination that consisted of palpation and assessment of the joints and associated muscles for tenderness and joint sounds. Maximum vertical opening and deviation during jaw opening were also recorded. Children with any single anomalous finding were designated positive for TMD signs.

RESULTS

There were no statistically significant differences in the prevalence of single or collective TMD signs between the two groups.

CONCLUSION

The results of this study show that premature loss of primary teeth, uncomplicated by other factors, does not appear to be an aetiological factor for TMD development.

Age and gender differences in temporomandibular joint radiographic findings before orthodontic treatment in adolescents

OBJECTIVE

The purpose of this study was to determine whether there is a relationship between abnormal temporomandibular joint radiographic findings and age or gender in a sample of young preorthodontic patients.

STUDY DESIGN

A total of 491 consecutive patients, aged 9 to 15 years, were referred for orthodontic records. Routine preorthodontic radiographs, including corrected sagittal tomographs, were taken for each patient and viewed by an observer blinded to clinical records. Temporomandibular joint radiographic findings were classified as normal or abnormal. For comparative purposes, the study population was divided into 2 age groups (9-11 years and 12-15 years).

RESULTS

Frequency of abnormal findings ranged from 2.4% to 11.5% and was similar for both sides. Temporal component abnormalities correlated with abnormalities of condylar position, joint space, and condylar osseous morphology. The frequency of osseous abnormalities was higher in girls and highest in older girls.

CONCLUSIONS

There are significant differences between genders for some temporomandibular joint radiographic abnormalities, and in our study sample the frequency of abnormalities was highest in 12-to-15-year-old girls.

Crepitation and clicking as signs of TMD in preschool children

Children [N = 540, age 5.1 +/- 0.72 (SD)], were tested for association between temporomandibular (TM) joint sounds and symptoms of TM disorder (TMD). The prevalence of TMJ sounds as found by auscultation and confirmed by self-report was 16.7%. There was significant association after Bonferroni correction between the presence of TM joint sounds, as reported by the children, and all but one of the eleven pain/dysfunction variables. There was significant association also between crepitation as heard at auscultation and palpation tenderness in the TMJ and masseter areas (p < 0.001), but not between clicking and any of the TMD variables. Agreement between subjects and examiners regarding the presence of TMJ sounds was poor (kappa = 0.097). The results indicate that joint sounds and TMD symptoms are common already in small children and thus demonstrate a possible early onset of TMD. Patients' own reports of TMJ sounds may have more clinical relevance than auscultation findings.

Symptoms and signs of temporomandibular disorders in girls with normal occlusion and Class II malocclusion

Mandibular function, headaches, and symptoms and signs of temporomandibular disorders (TMD) were studied in one group of girls with a well-defined normal occlusion (n = 60) and another group with class II malocclusion (n = 123). Frequent headaches and temporomandibular joint clicking, muscle tenderness to palpation, pain on mandibular movement, awareness of tooth clenching, and grinding were commoner in the class II malocclusion group. Awareness of tooth clenching had the largest influence on the odds for symptoms and signs of temporomandibular disorders (TMD) in a logistic regression analysis. Occlusal variables that increased the odds for symptoms and signs of TMD were large overjet, frontal open bite, few occlusal contacts, lateral sliding retruded-intercuspal contact position, crowding, and non-working side interferences. We concluded that normal occlusions have lower odds for symptoms and signs of TMD, whereas some occlusal characteristics, more frequently found in the class II malocclusion group, increased the odds for symptoms and signs of TMD.

Temporomandibular joint radiographic findings in adolescents

Radiographic findings in temporomandibular joints (TMJ) of asymptomatic adolescents have been reported, probably because such patients are unlikely to undergo routine TMJ radiography. The purpose of this prospective study was to document radiographic findings in TMJ's of adolescents without a history of TMJ dysfunction to determine prevalence of osseous, positional and functional abnormalities. Corrected sagittal TMJ tomographs in closed and open positions from pre-orthodontic records of 498 adolescent patients aged 8 to 15 years old were studied by one observer. Positional, functional or osseous abnormalities were each found in less than 10% of TMJ's. One percent of joints demonstrated marked limited mobility. There was no significant difference between right and left sides. Our results suggest that routine radiography of TMJ's in adolescents is not a useful screening too although longitudinal studies are necessary to determine whether asymptomatic adolescent patients with radiographic abnormalities will develop signs and symptoms of TMJ dysfunction.

Race and gender as TMD risk factors in children

The aim of this study was to record the prevalence in preschool children of oral/facial pain symptoms of clinical interest in the diagnoses of temporomandibular disorders (TMD) and to analyze the association with the race and gender factors. Children, 525 4-6 year olds, mean age 5.1 +/- 0.65 (SD), 326 Caucasian and 199 African American, from a preschool and kindergarten program in a low income industrial area, who participated in a voluntary oral health examination, were examined. Comparisons were made using Chi-Square test. An alpha-level of 5% was chosen, and the effect of making multiple comparisons was compensated for by Bonferroni correction. No gender differences were found, but racial differences were observed regarding six of the 10 variables. Twenty-five percent of the children had recurrent (at least one to two times per week) headache. Thirteen percent had recurrent earache, African-American children more often than Caucasian children (p approximately 0.0038). Thirteen percent had recurrent temporomandibular joint (TMJ) pain, and 11% had recurrent neck pain. Pain or tiredness in the jaws during chewing was reported by 29% of the children, more often by African-American than by Caucasian (p < 0.00001). Pain at jaw opening occurred in 13% of the children, more often in the African-American than in the Caucasian children (p approximately 0.00004). Palpation pain was found in the posterior TMJ area in 28%, in the lateral TMJ area in 22%, in the masseter area in 19%, in the anterior temporalis area in 15% and was found more often in all of those regions in the African-American than in the Caucasian children (p approximately 0.00001), except for the temporalis area. In conclusion, this study showed that mild, but distinct, TMD-related oral/facial pain symptoms occur already by ages 4-6 with significant differences in distribution observed between the African-American and the Caucasian races. While gender seems to play a negligible role in this age group, this does not necessarily mean that race is a causative factor. The pain symptoms may be caused by other factors with different distribution in the two racial subgroups.

Radiographic structural findings in the mandibular condyles of young individuals receiving orthodontic treatment

Radiographic findings in mandibular condyles were studied from the pre- and post-treatment panoramic radiographs of 625 orthodontic patients. The subjects' mean age was 11 years at the start and 14 years at the end of active orthodontic treatment. Radiographic condylar findings were seen in 14 (2%) subjects before treatment and in 54 subjects (9%) after treatment (p < 0.001). In age-related controls (n = 783) condylar findings were seen in 3% (p < 0.001). The condylar finding was 'flattening only' in half of the patients and in one-third of the controls with condylar findings. Activator treatment was associated with condylar findings (p < 0.05). Condylar findings increased with age in the orthodontically treated subjects (p < 0.05) but not in the unselected population controls. This may mean that condyles become more sensitive with age in children. Increase with age may be partly due to the radiographic interpretation, since minor condylar findings are difficult to observe in young children, and partly due to differences in treatment modalities and the duration of treatment.

Prevalence of signs and symptoms of craniomandibular disorders and orofacial parafunction in 4-6-year-old African-American and Caucasian children

Children, 4-6 years old, 153 Caucasian and 50 African-American, from a pre-school and kindergarten programme in a low income industrial area, who participated in a voluntary oral health examination, were questioned and examined for signs and symptoms of craniomandibular disorders (CMD) and of oral parafunctions. Most of the CMD signs and symptoms were mild. Eight per cent had recurrent (at least 1-2 times per week) TMJ pain, and 5% had recurrent neck pain, African-American children more often than Caucasian children (P < 0.05). Seventeen per cent had recurrent headache. Three per cent had recurrent earache. Pain or tiredness in the jaws during chewing was reported by 25% of the children, more often by African-American than by Caucasian children (P < 0.001) and more often by girls than by boys (P < 0.05). Pain at jaw opening occurred in 10% of the children, more often in the African-American than in the Caucasian group (P < 0.001). Thirteen per cent of the children had problems in opening the mouth. Deviation during opening was observed in 17% and reduced opening in 2%. Reduced lateral movements, locking or luxation were not observed in any child. Palpation pain was found in the lateral TMJ area in 16%, in the posterior TMJ area in 25%, in the temporalis and masseter areas in 10%, and pain for all regions was found more often in the African-American than in the Caucasian children (P < 0.01). Thirty-four per cent of the African-American, and 15% of the Caucasian children admitted to having ear noises (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of cardinal TMJ dysfunction symptoms and its relationship to occlusal factors in Japanese female adolescents

Cross-sectional data were obtained from 1182 Japanese high school girls of 12 and 15 years old. The data were analysed for the prevalence of specific occlusal features and the prevalence of cardinal Temporomandibular Joint Dysfunction (TMJD) symptoms in different occlusion groups. The associations between occlusal features and TMJD symptoms were analysed by the Z-analysis. The results were as follows: the prevalence of TMJD symptoms (total) was about 23% in both age groups examined. Noise had the highest prevalence of the specific TMJD symptoms in both age groups (16% and 11%). With age and for different occlusion groups, there was a significant increase in deviation on opening (P < 0.001) and a decrease in pain and noise (P < 0.05). No significant associations were found between the occurrence of TMJD symptoms (total) and occlusal features in all the examined occlusion groups. With respect to specific TMJD symptoms, however, the investigation of the different groups revealed a significant association (P < 0.05) of intra-arch occlusal (crowding) features with the occurrence of deviation on opening and with the occurrence of the combined TMJD symptoms which include deviation on opening. This indicates that crowding may be an important sign for predisposing TMJD. For the other single disorder symptoms (except pain), we did not find a significant relationship (P < 0.05) with aspects of occlusion, which may confirm a multifactorial TMJD problem wherein occlusal features can have a contribution to TMJD.

Longitudinal changes in craniomandibular dysfunction in an elderly population in northern Sweden

Longitudinal changes and cohort differences in craniomandibular dysfunction (CMD) were studied in a 79-year-old cohort (n = 65) and in 70-year-old cohorts in 1981 (n = 62) and 1990 (n = 60) by means of interview and clinical examination. Although the frequency of reported CMD symptoms decreased, many clinical signs of CMD increased during the 9-year observation period. Women reported more symptoms and showed more signs of CMD than men, and a great many of the clinical signs registered in 1981 still persisted in 1990. The 70-year-old cohort studied in 1990 showed a lower frequency of reported symptoms of CMD and of temporomandibular joint pain on palpation and a higher frequency of muscle pain and mandibular deviation than the 70-year-olds examined in 1981.

Changes in function of the masticatory system from 7 to 10 years of age in relation to articulatory speech disorders

The aim of the present study was to determine changes in function of the masticatory system in children with articulatory speech disorders and in the controls by re-examining a sample of 287 previously studied children from 7 to 10 years of age. Articulatory speech disorders were diagnosed by the same speech therapist during spontaneous speech and test words using the Remes Articulation Test. Mandibular movement capacity, occlusal interferences, slide between retruded and intercuspal positions, and signs and symptoms of the craniomandibular disorders (CMD) were recorded by a dentist. The follow-up results showed that mandibular movement capacity increased in almost all individuals, decreasing only in about 10% of cases. However, among children with speech disorders lateral jaw movements decreased in about 30% of subjects. During growth the prevalence of CMD increased while single signs and symptoms fluctuated. Differences between the groups for expression of CMD, mandibular movement capacity and occlusal recordings mainly levelled off. Higher constancy of subjective symptoms and retrusive interferences in children with speech disorders than in the controls supports our previous findings that, in growing individuals, different orofacial dysfunctions seem to be associated with each other.

The functional impact of extraction and nonextraction treatments: a long-term comparison in patients with "borderline," equally susceptible Class II malocclusions

Discriminant analysis was used to identify in retrospect a sample of 63 patients who had presented initially with Class II malocclusions that, according to then prevailing standards of specialty practice, could have been treated either with or without the extraction of premolars. These "borderline" subjects (33 extraction, 30 nonextraction) were then recalled for a long-term evaluation (on average, about 14 years after treatment) of the functional status of both the head and the neck musculature and the temporomandibular joints. In terms of a menu of 62 signs and symptoms (muscle palpation, joint function) that are commonly thought to be characteristic of craniomandibular disorders, there were no significant differences between the extraction and nonextraction samples. The present data therefore fail to support the popular notion that "premolar extraction causes 'TMJ'".

Prevalence in the Dutch adult population and a meta-analysis of signs and symptoms of temporomandibular disorder

A nationwide survey of oral conditions, treatment needs, and attitudes toward dental health care in Dutch adults was carried out in 1986. One of the aims of the study was to assess the prevalence of signs and symptoms of temporomandibular disorder (TMD). A sample of 6577 persons (from 15 to 74 yr of age), stratified for gender, age, region, and socio-economic status, was contacted. Of this sample, 4496 persons participated in the behavioral part of the study, of whom 3526 were examined clinically. The TMD prevalence was based on (1) perceived signs and symptoms of TMD and (2) clinical examination of joint sounds, deviation, and pain on mandibular movements. A total of 21.5% of the Dutch adult population perceived some dysfunction, and 44.4% showed clinically assessed signs and symptoms of TMD. In nearly all age groups, the signs and symptoms of TMD appeared more in women than in men. Agreement between the results of the clinical examination and the anamnestic dysfunction index was significant (p < 0.0001); however, the Pearson's correlation coefficient was low (r = 0.29). The odds-value (risk-ratio) that subjects who perceived signs and symptoms of TMD would present with clinically assessed signs and symptoms of TMD was 2.3. The results of the survey were compared with results of a meta-analysis performed on 51 TMD prevalence studies. The analysis revealed (1) a perceived dysfunction rate of 30% and (2) a clinically assessed dysfunction of 44%, both based on compound samples of, respectively, over 15,000 (23 studies) and over 16,000 (22 studies) randomly selected subjects.

Craniomandibular dysfunction in children and adolescents: a review

The purpose of this paper is to show that temporomandibular disorders manifest as much in children and adolescents as in adults. Objective signs, such as pain in the temporomandibular joint area to palpation or function, were found to be 40.6% on average from ages 6-18 years. Subjective signs reported by patients or their parents, such as clicking, pain to function and muscle tenderness, had an average prevalence of 38.7%. All but one researcher reported no difference between signs and symptoms as related to sex. These same articles concurred that the symptoms in children and adolescents, though less severe, were slightly higher in incidence than the adult population. Since the prevalence of signs and symptoms of temporomandibular disorders is the same in children and adolescents as in adults, more attention needs to be placed on its recognition in this age group. In addition, more research into treatment modalities and possible preventive measures in this age group is required to prevent sequelae in later years.

A study of clinical signs and symptoms of temporomandibular dysfunction in subjects with normal occlusion, untreated, and treated malocclusions

In the light of the universally growing concern over the suggested relationship between orthodontic treatment and temporomandibular (TM) dysfunction, the purpose of the present investigation was to compare the status of signs and symptoms of TM disorders in three groups of adolescents and young adults. The groups consisted of 30 persons with normal occlusions, 41 with untreated malocclusions, and 31 with treated malocclusions. The clinical status and subjective symptoms of TM dysfunction were recorded according to the principles introduced by Helkimo. The results showed that the normal occlusion group had the maximum number of persons free from any dysfunction, but the differences between the groups in the distribution of persons according to the anamnestic and clinical dysfunction indices were not significant. The only statistically significant finding was the difference in the clinical dysfunction index scores of the persons with normal occlusions and untreated malocclusions. According to anamnesis, the most frequently reported symptoms were related to periods of stress. Among the clinical signs and symptoms, the most commonly occurring were crepitations on palpation and sounds on auscultation of the joints in all the three groups. In conclusion, the absence of substantial differences between the three groups indicates that the role of orthodontic treatment in either precipitation or prevention of TM dysfunction remains questionable.

Longitudinal study of signs of temporomandibular disorders (TMD) in orthodontically treated and nontreated groups

This study measured the prevalence and incidence of signs of temporomandibular (TM) disorders in both a group undergoing orthodontic treatment in the University of Florida graduate orthodontic program and a control group. A questionnaire pertaining to the patients' reports of signs and symptoms of TM disorder and a clinical examination were administered by a trained dental examiner. Data collection sessions occurred at baseline (before treatment) and at 12-month intervals to 24 months. Data were also collected for the control group at the same time intervals. There were 102 patients (43 boys, 59 girls) mean age 15.3 years. An untreated control group of 41 nonorthodontically treated subjects mean age 16.2 years was used. The incidence of TM signs for the treatment group and control group were not significantly different. Preliminary results are in agreement with the contention that orthodontically treated patients are not more likely to develop TM signs while undergoing treatment. Results underscore the changing, inconstant, and ephemeral nature of TM signs in many persons over the course of time.

Etiologic theory and prevention of temporomandibular joint disorders: reaction paper

The treatment of patients with temporomandibular joint pain and dysfunction remains a controversial issue. Strong evidence exists that the occlusion of the teeth may not be a significant contributor to the overall etiology of the disorder. This now presents clinicians and researchers with a problem. What factors are responsible for the pain and dysfunction? Today, no solid evidence exists to substantiate the etiology of this disorder.

The relationship between craniomandibular disorders and otitis media in children

Most of the literature written about temporomandibular joint (TMJ) or craniomandibular dysfunction has looked at the problem in adults, probably because most of the patients we see with problems are adults. This article first establishes the fact that young children also exhibit signs and symptoms of craniomandibular dysfunction, almost at the same percentage as seen in adults. A review of otitis media with effusion (OME) in children establishes that malfunction of the eustachian tube is the underlying cause of this disease process. Because of the close anatomical and embryological relationship between the TMJ and the middle ear, there exists the possibility that a dysfunctioning TMJ may initiate the bout of OME, primarily by its relationship to the tensor veli palatini muscle. This muscle controls the function of the eustachian tube. This author feels that we might be able to decrease the incidence of OME by improving the function of the eustachian tube. This could be done by altering the relationship between the TMJ and the muscles of mastication, similar to the way we treat craniomandibular (TMJ) dysfunction in adults.

The relationship between craniomandibular dysfunction and malocclusion in white children with unilateral cleft lip and cleft lip and palate

An epidemiologic study was conducted on white children with unilateral cleft lip and cleft lip and palate to investigate the relationship between craniomandibular dysfunction and malocclusion. The results showed no statistically significant correlations between each clinical sign and symptom of craniomandibular dysfunction and each type of malocclusion. When the definitional symptoms of craniomandibular dysfunction were aggregated, a statistically significant correlation was found only with anterior crossbite. Anterior crossbite, in most of the subjects with cleft lip and cleft lip and palate, is associated with skeletofacial growth disturbances. It is suggested, therefore, that the relationship between skeletofacial pattern and craniomandiubular dysfunction be investigated.

Temporomandibular joint noises in infants review of the literature and report of cases

Temporomandibular joint (TMJ) function and dysfunction in infants and children are poorly understood. Some reports of dysfunction in children and adolescents have appeared in the literature; however, no contemporary reports of TMJ dysfunction in infants have been published. Here we describe three cases of TMJ noises that may represent an anatomic abnormality. Patients' ages at onset were 3 days, 5 months, and 6 months. All noises occurred in the apparent absence of trauma and without other clinical findings. Two cases resolved spontaneously over a 2- to 5-month period. One case is still occurring, but the frequency is decreasing with age. In all cases there was no history of distress on the part of the child during mandibular movements or when the noises occurred. Included is a review of the literature and hypotheses of the etiology of TMJ noises in infants.

Prevalence, interrelation, and severity of signs of dysfunction from masticatory system in 14-16-year-old Danish children

A clinical evaluation of the functional status of the masticatory system was performed on 706 14-16-yr-old children who had received a minimum of 9 yr regular dental care and had only natural teeth. Applying a classification system developed for this specific age group, 19% were assigned to the group with moderate and 11% to the group with severe disturbances. An analysis of the association between the signs of dysfunction revealed that TMJ clicking was always associated with some but not necessarily numerous palpatory findings. The localizations of the TMJ clickings were related to specific signs of dysfunction from the masticatory system. Restriction of movement capacity of 2 standard deviations was frequently found as an isolated phenomenon, whereas restriction of 3 standard deviations was always associated with either palpatory findings or sounds from the joints.

Right-left asymmetry of maximum jaw opening

According to several studies on human populations, the mandible deviates on opening significantly more often to the left than to the right. An association between the asymmetry of opening and handedness has been suggested. The present study of 143 left-handed Finnish conscripts showed no significant difference from the asymmetry reported for populations unselected for handedness. It was concluded that the opening asymmetry and handedness are not associated. The asymmetry proved also to be unassociated with the side of first unilateral tooth contact on guided hinge closure, with the side of palpatory tenderness of the muscles of mastication, and with the side of temporomandibular joint sounds.

Masticatory muscle hyperactivity in temporomandibular disorders: is it an extrapyramidally expressed disorder?

Masticatory muscle hyperactivity appears to have an important role in temporomandibular disorders. A pathophysiological model for masticatory muscle hyperactivity is proposed that is centrally mediated, yet maintains support for present peripheral causes and therapies. In this hypothesis, masticatory muscle hyperactivity represents a mild extrapyramidal disorder distantly related to orofacial dyskinesias. Experimental evidence suggests a neurotransmitter imbalance in the basal ganglia, involving dopaminergic preponderance, or cholinergic and GABA-nergic hypofunction as the underlying cause.

Temporomandibular disorders. Part II: Occlusal factors associated with temporomandibular joint tenderness and dysfunction

Two complete classes of freshman dental and dental hygiene students, 120 men and 102 women (mean age 23.9 years) were assessed for the presence of masticatory pain or dysfunction by questionnaire, clinical examination, and evaluation of dental casts according to strict criteria. The purpose was to identify the degree of association between observable signs of TMJ disorders and selected combinations of occlusal variables. TMJ tenderness was more frequent in class II, division 2 than in class I (p less than .05), but overall was not associated with occlusal factors such as deep overbites, length of a symmetric RCP-ICP slide, and unilateral contact in RCP. Overall, clicking was not associated with Angle class, deep overbite, length of symmetric RCP-ICP slide, or unilateral RCP contact. Among subjects with unilateral RCP contact, those with no clinically obvious RCP-ICP slide (p less than .005) and those with asymmetric slides (p less than .05) had more TMJ clicking than subjects with symmetric slides. Luxation clicking of the condyle over the articular eminence on wide opening was absent in class II, division 2 subjects, but was most frequent in subjects with some teeth in unilateral posterior crossbite, particularly when this was a unilateral condition (p less than .001). Certain occlusomorphologic conditions may require less adaptation in the TMJs. This article indicates that an ICP anterior to the RCP in association with bilateral occlusal stability may be protective.

Clinical classification of 14-16-year-old Danish children according to functional status of the masticatory system

The high prevalence of functional disturbances in the masticatory system and the tendency to increasing severity with duration stresses the necessity for a reproducible index. Clinical examination of the masticatory system was performed in 14-16-yr-old children. The sequence of examination, TMJ-muscles-opening capacity was chosen in order to minimize the bias. For the same reason, information on symptoms and occlusal conditions was not available for the examiner. According to the amount and character of the signs of dysfunction, the children were classified into three groups. Both single traits of dysfunction and the classification of the subjects were tested for reproducibility. The reproducibility of the compound clinical index was high. The ability to differentiate between children with moderate/severe signs and without signs was higher but the highest value was reached when differentiation was made between children with no/moderate signs and children with severe signs.

Temporomandibular disorders. Part I: Functional status, dentomorphologic features, and sex differences in a nonpatient population

Freshman dental and dental hygiene students, 120 men and 102 women (mean age 23.9 years), were assessed for the presence of masticatory pain or dysfunction by questionnaire, clinical examination, and evaluation of dental casts according to strict criteria. The purpose was to identify and analyze the level of signs and symptoms in a nonpatient population and describe occlusal variation. The prevalence of TMJ signs and symptoms was notable even though two thirds reported only mild or early symptoms, with only 3% reporting severe symptoms. This population was noted for the absence of locking, the low frequency of severe pain or severe TMJ dysfunction, and the low prevalence of restricted ranges of mandibular movement and TMJ crepitation. Women showed significantly more headache, TMJ clicking and tenderness, and muscle tenderness than men. Men were noted for the absence of severe and widespread muscle tenderness and severe TMJ tenderness. TMJ clicking was not always clinically confirmable in subjects with widespread muscle tenderness. This group was considered compatible with previous epidemiologic findings, and also matches the age range of most subjects seeking treatment for TMJ disorders. Therefore, the subjects in the study were considered a representative group of young adults and suitable for study of the possible associations between early signs of TMJ disorders and variables of morphologic malocclusion, which are discussed in Parts II and III of this article.

Associations between occlusal characteristics and signs and symptoms of TMJ dysfunction in children and young adults

Cross-sectional data were obtained from 1,342 subjects 6 to 17 years of age and analyzed for the prevalence of (1) specific types of occlusion, and (2) subjective symptoms and clinical signs of TMJ dysfunction. The results, as they pertained to occlusion and clinical signs, were as follows: functional shift was negatively associated with TMJ and muscle tenderness; open bite was positively associated with TMJ and muscle tenderness; excessive or negative overjets were more likely to have joint tenderness; older subjects with a cusp-to-cusp or a Class II molar relationship were more likely to experience TMJ and muscle tenderness, and restricted opening; and buccal crossbites had a significantly higher prevalence of joint sounds in older children. Results pertaining to occlusion and subjective symptoms were as follows: Class II molar relationship was positively associated with joint noise in the 6 to 8 and 15 to 17-year age groups; and subjects with negative overjet were more likely to report joint noise. Our conclusions were that (1) statistical associations exist between certain features of occlusion and TMJ signs/symptoms, and (2) such associations are greater in the older groups tested.

Signs and symptoms of craniomandibular disorders in a series of Finnish children

The prevalences of subjective symptoms and clinical signs of craniomandibular (CM) disorders, orofacial parafunctions, and occlusal conditions were determined in a series of Finnish children (n = 166). All were first interviewed, and then 156 of them were examined clinically. Fifty-two per cent of the children reported at least one subjective symptom, and 75% at least one parafunctional habit. Clinical signs were common but rarely severe in accordance with Helkimo's clinical dysfunction index (Di). Both the number of subjective symptoms (p less than 0.001) and the number of orofacial parafunctions (p less than 0.05) correlated with the clinical dysfunction index.

Mandibular dysfunction related to dental filling therapy. A comparative anamnestic and clinical study

A group of 96 individuals, 13 to 15 years of age, with intact teeth was compared with a control group of 129 individuals with dental restorations, with regard to occurrence of mandibular dysfunction. Statistically significant differences between the groups were established at both the anamnestic and the clinical examination, with a lower frequency and degree of dysfunction among those with intact teeth. Conforming with the findings of a previous study on 17- to 23-year-olds, these findings indicate that filling therapy may be associated with mandibular dysfunction.

Mandibular dysfunction in adolescents. I. Prevalence of symptoms

The prevalence of symptoms of mandibular dysfunction was studied in 285 17-year-old adolescents living in the municipality of Skellefteå. They answered a questionnaire concerning general state of health and occurrence of headache, facial pain, or temporomandibular problems. A fifth of the subjects reported some symptoms involving the masticatory system. There was no statistically significant difference between sexes. Of the sample 13% had mild symptoms and 7% had severe symptoms of dysfunction. The most frequent symptoms were clicking sounds from the temporomandibular joint (13%) and a feeling of fatigue in the jaws (6%). Recurrent headache (once a week or more) was reported by 12% and appeared significantly more often among the girls (p less than 0.001). Three-quarters used both sides for chewing, and oral parafunctional habits were reported by 68%. Since mild and moderate symptoms of mandibular dysfunction and headache obviously make an early appearance, a routine dental examination should include screening of these symptoms to identify patients who should be observed more closely.

Mandibular dysfunction in adolescents. II. Prevalence of signs

The prevalence of signs of mandibular dysfunction was studied in 285 17-year-old adolescents living in the municipality of Skellefteå. They were subjected to a functional examination of the masticatory system. The commonest clinical signs were tenderness to palpation of the masticatory muscles (41%) and clicking sounds from the temporomandibular joints (22%). The tenderness to palpation was generally located to the lateral pterygoid muscle and the insertion of the temporal tendon. Girls were tender to palpation oftener (p less than 0.05) than boys. Unilateral contact in the retruded position was recorded in 77% of the subjects. Mediotrusion interferences were found in 30% of the subjects. Signs of clinical dysfunction were found in 56% and were significantly commoner in girls than in boys (p less than 0.01). Since mild and moderate signs of mandibular dysfunction obviously make an early appearance, a routine dental examination should include a functional evaluation of the stomatognathic system, to identify patients who should be observed more closely.

Results of epidemiological examinations of the temporomandibular joint in adolescents and young adults

An epidemiological investigation of the temporomandibular joint in 800 persons was undertaken, including two groups of 400 persons aged 15-18 and 19-22 years. The numbers of boys and girls was about the same. Interview and clinical examination comprised morphological and functional features of the stomatognathic system. The TMJ examination carried out included mandibular movements, pain and sound symptoms. The results of the examinations were noted, counted by electronic methods and statistically analysed. From the material, two groups were selected: without TMJ symptoms (OTMJ group) and with TMJ disorders (TMJ group). TMJ disorders were evident in 67.62% of the examined persons and this was common to both age groups. In groups with TMJ disorders a significant incidence of girls was found. In groups with TMJ disorders the number of statistically significant pathological features in the stomatognathic system increased with age. TMJ disorders appeared in both age groups in various forms, separately or in combination, with different frequency. With reference to the number and kind of symptoms obtained on interview and/or on clinical examination, four degrees of intensity of TMJ disorders have been defined and their incidence discussed.