Longitudinal clinical study on the effect of slow maxillary expansion with removable appliances

The aim of this clinical study was to evaluate the longitudinal changes in dental arches in patients treated with a slow maxillary expansion appliance in primary dentition or early mixed dentitionMethodsThe sample consisted of 19 children (13 girls and 6 boys) with a narrowing of the maxillary arch. The mean ages at the start, at the end of expansion, and at the final follow-up (1 year 7 months after the retention) were 7 years 10 months, 8 years 10 months and 12 years 4 months, respectively. The mean expansion period was 1 year and the mean retention period after the expansion was 1 year 11 months. The control group consisted of 28 Japanese persons with untreated normal occlusion.ResultsThe results were as follows. (1) At the end of the expansion, the maxillary dental arch width increased remarkably, and there was no significant difference in comparison with the control group. (2) At the follow-up after the retention, although the maxillary intercanine width was significantly smaller than the control group, the maxillary intermolar width stabilized during retention and there was no significant difference in comparison with the control group. (3) The mandibular intermolar width gradually increased during the maxillary expansion.ConclusionThis clinical study demonstrated that this type of treatment using a slow maxillary expansion appliance in primary dentition or early mixed dentition is effective and stable in the long term for the maxillary molar regions. Furthermore, it was suggested that the lateral development of the mandibular dental arch could be promoted by expanding the maxillary dental arch width.     

Dental crowding in primary dentition and its relationship to arch and crown dimensions among preschool children of Davangere

The purpose of the present study was to evaluate dental crowding in the deciduous dentition and its relationship to the crown and the arch dimensions among preschool children of Davangere. Stratified randomized selection of one hundred, 3-4 year old healthy children with all primary teeth erupted was done and divided into two groups. One group had children with anterior crowding in both the arches while the other had spacing. Alginate impressions of the upper and lower arches were made and the study casts were obtained. The tooth and arch dimensions were determined. Mesiodistal dimensions of all the teeth were significantly larger in the crowded arch group. However, the buccolingual dimensions of the maxillary right central incisor, mandibular lateral incisors and the maxillary molars and the crown shape ratio of maxillary lateral incisors, mandibular canines and mandibular right second molar was statistically different. No significant correlation was found between the arch width and the presence of crowding of deciduous dentition. The arch depth of the spaced dentition was greater when compared to the crowded ones. The arch perimeter of the crowded arches was significantly less than the spaced arches.     

A longitudinal study on growth and development of dental arches of primary, mixed and permanent dentitions

In dental clinic for children, criteria for growth and developmental changes related to increases in the width and length of the dental arch at the primary, mixed, and permanent dentition stages are essential. This study was carried out to measure the width and the length of normal dental arch and to make detailed observations of growth and developmental processes in the dental arch at each dentition stage. Materials were serial study casts of the maxilla and the mandible taken every 2 month from 127 children (74 boys and 54 girls). The casts were made from 6 months after birth until the age of 15. Measurements of the width of the dental arch were made between bilateral teeth of the same tooth type, both deciduous and permanent. The length of the dental arch was measured on the basis of the perpendicular distance from the contact point of mesial surfaces of central incisors to a line between bilateral teeth of the same tooth type. Measured values were categorized according to either chronological age or tooth age on the basis of the eruption of the central permanent incisors. The indices of the dental arch with relation to the width and the length at each dentition stage were calculated for the sake of partial and total observations of alterations in dental arch form. The results were as follows: 1) In terms of chronological age, until 1 year before the eruption of permanent replacements, the width of the dental arch gradually decreased in both the maxilla and the mandible in the regions of the deciduous central and lateral incisors. Increasing slightly from about the age of 6 years and the period of mixed dentition, the width of the dental arch remained stable until the permanent dentition stage. From the primary dentition stage, the width of the dental arch in the region of the maxillary and mandibular canines and first and second molars gradually increased. Therefore it remained stable until the eruption of permanent dentition. The width in the region of the permanent maxillary and mandibular first molars gradually increased and attained a stable condition at about 12 years of age. In males, the width in the area of the maxillary secondary molars decreased slightly and tended to decrease in the mandible. In females, on the other hand, the width showed a tendency to increase with advancing ages. With the exception of the second permanent molars, the width between the distance of bilateral teeth were consistently larger in males than in females.(ABSTRACT TRUNCATED AT 400 WORDS)     

Maxillary arch dimensions after palatal surgery at different ages on beagle dogs

Changes of maxillary arch dimensions were studied longitudinally until maturity, after palatal surgery was performed on 37 beagle dogs at different ages. The dogs were divided into three experimental groups, a sham group, and a control group. At the age of 6, 16, or 25 weeks in the experimental groups, we created a soft-tissue cleft in the medial region of the palate, made relaxation incisions, and elevated and closed the mucoperiosteum in the midline, thus leaving two areas of denuded bone adjacent to the dentition. We made dental casts regularly until the age of 37 weeks, and studied maxillary arch dimensions. Surgery performed before or during the transition of teeth did not change maxillary arch dimensions in the deciduous dentition, but after the transition, the increase in arch width in the pre-molar region was reduced. Surgery performed after completion of the permanent dentition did not change maxillary arch dimensions. Delay of palatal surgery until the transition of teeth was completed favored normal development of the maxillary dental arch.     

Dental arch dimensions in the mixed dentition: a study of Brazilian children from 9 to 12 years of age

Objective

This study evaluated dental arch dimensional changes of Brazilian children.

Material and methods

Dental casts were taken from 66 children (29 males; 37 females) with normal occlusion selected among 1,687 students from public and private schools aged 9, 10, 11 and 12 years, according to the following criteria: Class I canine and molar relationships; well-aligned upper and lower dental arches; mixed dentition; good facial symmetry; no previous orthodontic treatment. Dental arch dimensions were taken by one examiner using the Korkhaus’ compass and a digital pachymeter. ANOVA test was applied to compare the arch dimensions at the different ages and the t-test was used to compare the arch dimensions of male and female subjects. Arch forms were compared by means of chi-square tests.

Results

Only the maxillary anterior segment length showed a statistically significant increase from 10 to 12 years of age. Males had a significantly larger maxillary depth than females at the age range evaluated. The predominant dental arch form found was elliptical.

Conclusion

In the studied age range, anterior maxillary length increased from 10 to 12 years of age, males had larger maxillary depth than females and the predominant arch form was elliptical.     

Comparison of dental arch measurements in the primary dentition between contemporary and historic samples.

The purpose of this study was to investigate secular changes that may have occurred in dental arch dimensions by comparing a sample of contemporary North American white children (born between 1992 and 1995) in the primary dentition to those children found in an earlier study of North American white children (born between 1946 and 1948). The sample of contemporary children has been followed prospectively since birth and was assessed at 4(1/2) to 5 years of age. Data for the historic sample were obtained from 5-year-old children who were enrolled in the Iowa Growth Study. The 2 samples were similar in terms of geographic location, racial and ethnic backgrounds, and socioeconomic status. To further enhance the comparison and to match the 2 groups, the 2 samples were restricted to white children with a normal overjet (<4 mm) and normal anteroposterior molar relationship, no anterior open bite, and no crossbite. In addition, individuals were excluded if any permanent teeth were erupted. Measurements of maxillary and mandibular arch lengths and intercanine and intermolar arch widths were made, with measurements of overjet and overbite. The results indicated that maxillary and mandibular arch lengths in both sexes were significantly shorter in the contemporary sample; all arch widths were significantly smaller in contemporary boys, but not in girls. These findings suggest that average arch dimensions may be smaller in contemporary children than in past generations. Further research is needed to determine whether smaller arch dimensions are associated with more crowding in the primary, mixed, and permanent dentitions.     

Indicators of mandibular dental crowding in the mixed dentition

PURPOSE: Dental crowding occurring in the anterior part of the mandible in the early mixed dentition has been a subject of increasing concern for child patients, their parents, and the pediatric dentist. The aim of this study was to evaluate indicators of crowding found at the primary dentition, which may lead to the future manifestation of crowding at the anterior part of the mandibular arch in the early mixed dentition. METHODS: Skeletal and dental morphological characteristics at the stage of primary dentition were compared between two groups, using dental casts and cephalograms of 23 subjects. These two groups had been formed by evaluating the degree of crowding at 9 years of age (12 normal and 11 crowded cases). RESULTS: The size of several teeth in the crowding group was significantly greater than that found in the normal group. For the cephalometric measurements, a statistically significant difference was found only in the cranial base dimension (S-SE). The stepwise discriminant analysis showed that the mesiodistal size of the maxillary primary canine, the maxillary and mandibular dental arch lengths, and the posterior cranial base length (S-Ba) were effective discriminators in separating the two groups. CONCLUSIONS: It is concluded that larger primary tooth size is the chief indicator in the development of dental crowding. However, the maxillary and mandibular dental arch lengths and the cranial base dimensions, especially that of the posterior cranial base length in the primary dentition, should also be considered as indicators when attempting to predict dental crowding in the early mixed dentition.     

Dental arches in submucous cleft palate: comparison of six-year-old boys with unoperated submucous cleft palate, with operated cleft of the soft palate, and without a cleft

OBJECTIVE: To evaluate the dental arch dimensions in 6-year-old boys with unoperated submucous cleft palate (SMCP), and to compare their dental arch dimensions with those of boys without clefts and boys with clefts of the soft palate (CP). MATERIAL AND METHODS: The sizes of dental arches in 97 boys were compared retrospectively from dental casts taken at a mean age of 6.4 years (range 5.2-8.4). The material included 34 boys without clefts, 30 with unoperated SMCP, and 33 with CP. In children with CP, palatal closure had been done by the pushback technique at a mean age of 1.5 years. RESULTS: The dental arch dimensions of the boys with SMCP were similar to those of boys without clefts, except for a decreased maxillary arch length. There was no difference in maxillary arch length between the boys with SMCP and those with CP. The boys with CP had smaller maxillary and mandibular dental arch widths than the boys without clefts and with SMCP. There were no differences in the number of boys with permanent incisors between the three groups. CONCLUSION: Six-year-old boys with unoperated SMCP have similar dental arch dimensions as boys without clefts, except for a decreased maxillary arch length.     

Dental arch dimensions in Class II division 1 malocclusions with mandibular deficiency

OBJECTIVE: To test the hypothesis that there is no difference in the dimensions of the upper and lower dental arches in Class II division 1 malocclusion with a mandibular deficiency compared to normal Class I occlusion dental arches. MATERIALS AND METHODS: Photocopies of the dental arches of 48 patients exhibiting Class II division 1 malocclusion with mandibular deficiency and of 51 individuals with normal occlusion were compared. Mandibular deficiency was diagnosed clinically. All 99 individuals were in the permanent dentition. The ages of the subjects ranged from 11 years 4 months to 20 years (mean age = 12 years 5 months). RESULTS: When compared to subjects with normal occlusion, the upper dental arches of the Class II division 1 patients presented reduced transverse dimensions and longer sagittal dimensions while the lower arches were less influenced. CONCLUSION: The hypothesis is rejected. Significant differences are present between the dimensions of the upper and lower dental arches in Class II division 1 malocclusion (with a mandibular deficiency and in the permanent dentition) compared to normal Class I occlusion dental arches.     

Dental arches in six-year-old children with operated and unoperated submucous cleft palate and isolated cleft palate

The sizes of dental arches in 129 children with cleft palate were evaluated retrospectively from dental casts taken at the mean age 6.2 years (range 5.2-7.5). The material included 61 children with submucous cleft palate (SMCP) and 68 children with isolated cleft palate (ICP). Twenty of the children with SMCP were not operated on, while 41 had had surgical treatment, either palatal repair (n = 16, mean age at operation: 1.6 years, range 0.8-3.9) or pharyngeal flap (VPP) surgery (n = 25, mean age at operation: 4.5 years, range 2.6-6.2). In children with ICP, one-stage hard-palate and soft-palate closure had been done at the mean age of 1.5 years (range 1.0-2.1). Decreased maxillary intermolar widths were seen in children with SMCP after VPP, and especially after palatal repair. The children with ICP had the smallest maxillary dental arch widths. No significant differences were observed in the maxillary arch length or mandibular intermolar arch dimensions in children with SMCP or ICP. Surgery is associated with decreased maxillary intermolar arch widths in children with SMCP. Children with ICP had smaller maxillary dental arch widths than children SMCP.     

Quantitative effects of a nickel-titanium palatal expander on skeletal and dental structures in the primary and mixed dentition: a preliminary study

The present study analysed the six-month effects of a nickel-titanium (NiTi) palatal expander on the dental and palatal structures of four primary (mean age 5.8 years) and nine mixed dentition children (mean age 8.7 years), with a posterior unilateral crossbite. Standardized dental and palatal landmarks were digitized using a three-dimensional (3D) electromagnetic instrument. Collected data were analysed with geometric-mathematical models. During a six-month interval, the natural growth and development of the dental arches and hard tissue palate was negligible, as assessed in seven control children (two in the primary dentition, mean age 4.4 years; five in the mixed dentition, mean age 7.7 years). In all children the crossbite was completely corrected. Indeed, dental expansion was always more than or corresponded to the palatal expansion. A smoothing of the size-independent (shape) palatal curvature in the transverse plane was observed. No differences in maximum palatal height were noted. Symmetrical derotation of the anchorage teeth in a distal direction occurred in almost all children. The inclination of the facial axis of the clinical crown (FACC) in the anatomical transverse plane of those teeth with differences between dental and palatal expansion always showed significant modifications (vestibular inclination up to 16.7 degrees). The clinical crown height of anchorage teeth remained nearly the same in all patients. No significant modifications in mandibular arch size were observed. The increase in maxillary arch width, especially in younger children, was probably due to a combination of different effects: opening of the midpalatal suture, tipping of the alveolar process, and molar tipping.     

The effects of early headgear treatment on dental arches and craniofacial morphology: a report of a 2 year randomized study

The aim of the present study was to determine the effects of early headgear treatment on dental arches and craniofacial morphology in children in the early mixed dentition. The total study group comprised 68 children of both sexes (40 boys and 28 girls) aged 7.6 years [standard deviation (SD) 0.3]. The children, who had a Class II tendency in occlusion and moderate crowding of the dental arches, were randomly divided into two groups of equal size, matched according to gender. In the headgear (HG) group, treatment was initiated immediately. The mean treatment time was 16 months. In the second group, which served as the control, only interceptive procedures were performed during the follow-up period. The records, which included dental casts and lateral cephalograms, were obtained after follow-up periods of 1 and 2 years. The lengths and the widths of the maxillary and mandibular dental arches were significantly increased in the HG group after the 2 year follow-up period. The mean increase in lower arch length and width was 2.4 mm (SD 1.7) and 2.2 mm (SD 1.2), respectively. On average, the space gain in the lower arch was half that of the upper arch. No significant changes were found in the arch dimensions of the control group. Maxillary growth restraint and labial tilting of the incisors were the most significant cephalometric findings in the HG group when compared with the controls. The use of headgear in the early mixed dentition is effective in the treatment of moderate crowding. It is noteworthy that significant space gain in the dimensions of the lower arch can be achieved by headgear application to the upper first molars.     

Prevalence of malocclusions in the early mixed dentition and orthodontic treatment need

Early interceptive treatment for the elimination of factors inhibiting dental arch development and mandibular and maxillary growth is applied varyingly by orthodontists, possibly because there is little scientific evidence that such interventions are of actual benefit. The aim of this study was to determine specific factors for treatment need in the early mixed dentition period in order to obtain basic data to support early intervention. The study was part of a larger survey of 8768 children aged between 6 and 17 years. From this sample, 1975 children aged between 6 and 8 years were used to estimate the prevalence of malocclusions using the Index of Orthodontic Treatment Need (IOTN) during the early mixed dentition period. The results showed that deep overbite and overjet, both more than 3.5 mm, were the most frequent discrepancies, affecting 46.2 and 37.5 per cent of patients, respectively. An anterior open bite was registered in 17.7 per cent, crossbite in 8.2 per cent, and a reverse overjet in 3.2 per cent. A tooth width to arch length discrepancy was recorded in 12 per cent of teeth in the upper arch and in 14.3 per cent in the lower arch. The proportion of children estimated using the Dental Health Component of the IOTN to have a great or very great treatment need (grades 4 and 5) was 26.2 per cent. The higher values of treatment need during the mixed dentition period may account for temporary changes in the dentition and for the discrepancy in overjet and overbite. These discrepancies will be compensated in part during mandibular growth and development of the dental arch. Nevertheless, the findings indicate the early development of progressive malocclusion symptoms which are evidenced in the IOTN and concur with the acronym 'MOCDO' hierarchy (missing, overjet, crossbite, displacement, overbite). This early formation of progressive symptoms inhibiting or disturbing mandibular or maxillary growth or the development of the normal dental arch, i.e. crossbite, reverse overjet and increased overjet with myofunctional disorders, should be treated at an early stage.     

Long-term clinical outcome of rapid maxillary expansion as the only treatment performed in Class I malocclusion

The purpose of this study was to investigate the long-term clinical responses of rapid maxillary expansion as the only treatment performed in Class I malocclusion using the Haas-type appliance. The longitudinal sample consisted of 90 sets of study models from 30 consecutive patients (12 males and 18 females) selected on the basis of the following inclusion criteria: all patients (1) had a Class I malocclusion with transverse maxillary/mandibular skeletal discrepancies, (2) were treated nonextraction in the early/ mid mixed dentition, (3) presented with mandibular dental arches with mild or no crowding, and (4) had no subsequent comprehensive orthodontic treatment implemented in either the maxilla or the mandible. The mean age was 8.2 years when treatment was initiated. Treatment outcomes were evaluated at pretreatment A1, short-term follow-up (one year after A1) A2, and long-term follow-up (four years after A2) A3. The changes in maxillary arch width and arch length were quantified and compared among assessment stages A1, A2, and A3 using the Student's t-test. The results demonstrated a highly significant increase in maxillary arch width in both the short- and long-term follow-ups. The arch width increased significantly during treatment and decreased slightly during the long-term follow-up. The long-term clinical response demonstrated the efficacy and stability of this type of treatment in achieving maxillary arch width. The follow-up examination during the early/mid/permanent dentition confirmed the validity of overtreatment.     

Sizes of dental arches and general body growth up to 6 years of age in children with isolated cleft palate

Development of the dental arches and height and weight at the ages of 3 yr and 6 yr were studied longitudinally in 60 children with isolated cleft palate (CP) and in 50 noncleft (NONC) children. Retrospective comparisons were also made in the CP group with arch size at the age of 0.2 yr and 1.8 yr. Anterior width at 0.2 yr of age was associated with canine width at the age of 3 yr (r = 0.70) and 6 yr (r = 0.60). Change in maxillary posterior width from 3 yr to 6 yr of age was related to the extension of the cleft, so that in the group with total cleft this dimension diminished. Measured in standard deviation scores (SDS), the means of maxillary width at canines and primary second molars in CP children varied from −1.0 to −2.0 and mandibular dimensions from -0.6 to -1.4. Discrepancy in arch depth diminished with age. Body size differed less from normal than the size of the dental arches. At 3 yr of age the height was −0.4 SDS in CP boys and −0.5 SDS in CP girls, but at 6 yr of age only −0.1 SDS in both boys and girls. Correlations between body size and the size of the dental arches were generally low (r < 0.20) both in CP and NONC children. The small size of the dental arches in CP children does not seem to be merely a reflection of the overall smaller size of CP children.     

Sizes of dental arches and general body growth up to 6 years of age in children with isolated cleft palate.

Development of the dental arches and height and weight at the ages of 3 yr and 6 yr were studied longitudinally in 60 children with isolated cleft palate (CP) and in 50 noncleft (NONC) children. Retrospective comparisons were also made in the CP group with arch size at the age of 0.2 yr and 1.8 yr. Anterior width at 0.2 yr of age was associated with canine width at the age of 3 yr (r = 0.70) and 6 yr (r = 0.60). Change in maxillary posterior width from 3 yr to 6 yr of age was related to the extension of the cleft, so that in the group with total cleft this dimension diminished. Measured in standard deviation scores (SDS), the means of maxillary width at canines and primary second molars in CP children varied from -1.0 to -2.0 and mandibular dimensions from -0.6 to -1.4. Discrepancy in arch depth diminished with age. Body size differed less from normal than the size of the dental arches. At 3 yr of age the height was -0.4 SDS in CP boys and -0.5 SDS in CP girls, but at 6 yr of age only -0.1 SDS in both boys and girls. Correlations between body size and the size of the dental arches were generally low (r less than 0.20) both in CP and NONC children. The small size of the dental arches in CP children does not seem to be merely a reflection of the overall smaller size of CP children.     

Short-term treatment effects of quad-helix on maxillomandibular expansion in patients with maxillary incisor crowding

The purpose of this study was to evaluate the effects of the maxillary arch expansion on maxillomandibular arch widths in patients treated with the quad-helix versus untreated controls. The treatment group consisted of 50 consecutive patients treated for maxillary incisor crowding with a quad-helix appliance in the early mixed dentition. Lateral cephalograms and dental casts taken at the start (T0) and end (T1) of the quad-helix treatment were obtained. The control group consisted of 50 untreated patients with the same type of malocclusion. Two consecutive lateral cephalograms and dental casts of each untreated patient were taken at about the same time as T0 and T1. All these study materials were analyzed for comparison between the two groups. The mean ages at T0 and T1 in the two groups were about the same. The maxillary first molars moved and tipped distally in the treatment group and mesially in the control group. The quad-helix treatment actually expanded the mandibular and maxillary arches concurrently. The more the maxillary arch widths were expanded and the less the maxillary first molars were inclined distally, the more the mandibular arch widths were expanded. The quad-helix activation caused lingual tipping and mesiobuccal rotation of the maxillary first molars. The mesiobuccal rotation of the maxillary first molars could turn molar occlusal relationships for the better from Class II to Class I. The quad-helix treatment gives rise to spontaneous expansion of the mandibular arch concurrent with maxillary expansion in the early mixed dentition patients with maxillary incisor crowding.     

Analysis of dental casts of 6-8- and 12-year-old Kenyan children

Dental plaster casts of 97 6-8-year-old and 173 12-year-old Maasai, Kikuyu, and Kalenjin children were studied. The Kikuyu are Bantu, while Maasai and Kalenjin are Nilo-Hamitic subjects. The variables measured were palatal depth (PD) and length (PL); maxillary and mandibular anterior arc circumferences (AC1) and (AC2), respectively; posterior arc circumferences (PC1) and (PC2), inter-canine (CC1), and (CC2); inter-molar (MM1) and (MM2) distances, and mandibular length (ML). The data were analysed using SPSS package. The mean values of all the variables were generally higher in the males compared with the females and significant sex differences in the means (P < 0.01) were found in AC1, PC1, PC2, CC1, CC2, MM1, and MM2 in the 12-year-old subjects. The means of all variables, except PL, ML, PC2, and CC2, increased from 6 to 12 years of age and significant differences in the means for age were found in ML, AC1, PC2, PD, MM1, MM2, and CC1. Mean maxillary inter-molar distance increased with age by 0.17-0.34 mm in the three groups. Mean values of mandibular variables were highest in the Kikuyu, while maxillary variables were highest in the Maasai. The Maasai casts showed a marked decrease in CC2, PC2, AC2, and ML compared with the Kikuyu and Kalenjin. Ethnic and sex differences in the dental arches may be masked by anterior tooth positions that are influenced by the dento-alveolar complex and soft tissues. Corresponding mandibular and maxillary variables were strongly correlated and anterior and posterior arc circumferences were correlated with inter-canine and intermolar distances. Details of the norms for dental arch dimensions and changes with age may allow for appropriate assessment of dental occlusion and treatment planning for Kenyan children.     

Effect of extraction in the late mixed dentition on the eruption of the first premolar in Macaca nemestrina

The effect of deciduous tooth extraction in the late mixed dentition on the eruption of succedaneous teeth was studied in ten Macaca nemestrina. Nineteen deciduous teeth were extracted: nine maxillary and ten mandibular left deciduous first molars. Regardless of sex, arch, chronologic or dental age, all first premolars on the experimental side erupted before those on the control side and this pattern was statistically significant. Extraction of deciduous molars in the late mixed dentition is seen to accelerate eruption of first premolars in Macaca nemestrina. This could be the result of eliminating the need for deciduous tooth root resorption during the normal process of eruption.     

Electromyographic analysis of masticatory and neck muscles in subjects with natural dentition, teeth-supported and implant-supported prostheses

Objectives: To compare the electromyographic (EMG) characteristics of masticatory and neck muscles in patients with natural dentition, teeth‐supported prostheses and implant‐supported prostheses. Materials and methods: Twenty‐five subjects aged 40–80 years were examined. Five patients had maxillary and mandibular implant‐supported fixed prostheses; five patients had mandibular implant‐supported fixed prosthesis and maxillary removable complete denture; seven patients had implant‐supported fixed prosthesis (one arch) and natural dentition or full‐arch tooth‐fixed prosthesis (one arch); and eight control subjects had natural dentition or single tooth‐fixed prostheses. Surface EMG of masseter, temporal and sternocleidomastoid muscles was performed during maximum teeth clenching and unilateral gum chewing. Interarch dental contacts were assessed with shim stocks. Results: All groups had similar interarch dental contacts (P>0.05). During clenching, patients with maxillary and mandibular implant‐supported fixed prostheses had unbalanced standardized masseter and temporalis anterior activities (74%), with significantly larger values found in the other patients and control subjects (all mean values larger than 86%, P=0.017). All patients chewed with significantly larger muscular potentials than control subjects (on average, 1434–2100 μV s vs. 980 μV s, P=0.04), and had altered muscular patterns (left side, P=0.021). The patients with one arch with natural dentition/tooth fixed prostheses had chewing muscular patterns similar to the control subjects. Conclusions: Clenching with the analyzed prostheses was performed with a relative increment of temporalis activity. Neuromuscular coordination during chewing was larger in patients who maintained their teeth or dental roots, independently from the number of dental contacts.