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The European Journal of Orthodontics Advance Access originally published online on November 4, 2005
The European Journal of Orthodontics 2006 28(2):112-119; doi:10.1093/ejo/cji080
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© The Author 2005. Published by Oxford University Press on behalf of the European Orthodontics Society. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org.

Masticatory performance in children and adolescents with Class I and II malocclusions

Andrés Toro*, Peter H. Buschang**, Gaylord Throckmorton** and Samuel Roldán*

Departments of Orthodontics, * Instituto de Ciencias de la Salud, CES, Medellín, Colombia and ** Baylor College of Dentistry, The Texas A&M University System Health Science Center, Dallas, Texas, USA

Address for correspondence Dr Samuel Roldán, Calle 4 sur # 43AA-26, Cons. 306, Unidad Médica Torreplaza, Medellín, Colombia. E-mail: sroldan{at}epm.net.co


   Summary
Top
 Summary
Introduction
 Subjects and method
 Results
 Discussion
 Conclusions
 References
 
It is not fully understood whether masticatory performance is compromised in individuals with the more common forms of malocclusion (i.e. Class I and Class II). The aim of this prospective investigation was to establish the relationships between masticatory performance, malocclusion (type and severity), age, body size and gender, in children and adolescents. A total of 335 individuals were examined at the average ages of 6, 9, 12 and 15 years. Each subject's occlusal status was described by Angle classification and by the Peer Assessment Ratio (PAR) index. Masticatory performance was quantified by the median particle size (MPS) and the broadness of particle distribution using artificial food.

Masticatory performance improved significantly with age. The 6-year-old children were less able to break down the food particles (MPS 4.20 mm2) than the 15 year olds (MPS 3.24 mm2). Analysis of covariance showed that age differences in performance are related to an increase in body size. There were statistically significant differences in masticatory performance between children with normal occlusion and those with a Class I malocclusion; no differences were found between normal occlusion and Class II malocclusion. Gender differences did not explain the variation in masticatory performance.

It is concluded that occlusal indices are not reliable predictors of masticatory performance. Traditional descriptors of malocclusion type and severity apparently cannot explain most of the variation in masticatory performance in children and adolescents.


   Introduction
Top
 Summary
 Introduction
Subjects and method
 Results
 Discussion
 Conclusions
 References
 
Mastication is a complex, non-random, process characterized by the comminution and break down of food into smaller particles to facilitate digestion. Because smaller food particles provide a larger surface area for enzymatic function, both food breakdown (Kay and Shiene, 1979Go) and gastric emptying (Pera et al., 2002Go) are facilitated. The relationship between malocclusion and masticatory function is important because there is no agreement on whether malocclusion is a physiological or a pathological condition (Tang and Wei, 1993Go; Richmond et al., 1995Go; World Health Organization, 1995Go). Occlusal factors explain much of the variation in masticatory performance among healthy subjects. Adult masticatory performance is known to diminish with the loss of post-canine teeth (Akeel et al., 1992Go; Van der Bilt et al., 1993Go). Individuals with severe types of malocclusion are less efficient at breaking down food than those with normal occlusion (Shiere and Manly, 1952Go; Omar et al., 1987Go; Henrikson et al., 1998Go; Van den Braber et al., 2001Go; English et al., 2002Go).

Although a number of studies have examined the relationship between masticatory performance and malocclusion in children, they have been limited in several respects. Some of these investigations used natural foods whose mechanical properties are difficult to standardize over a large number of subjects (Shiere and Manly, 1952Go). Others have used small numbers of sieves to measure the distribution of the size of chewed particles (Shiere and Manly, 1952Go; Helkimo et al., 1977Go; Edlund and Lamm, 1980Go; Henrikson et al., 1998Go). A small number of sieves limits discrimination of different levels of masticatory performance (Julien et al., 1996Go; Buschang et al., 1997Go). Finally, previous studies have compared different Angle classification of malocclusion, but have not carefully controlled for the severity of the malocclusion within each Class. This has led to conflicting results when comparing masticatory performance among different malocclusion groups (Shiere and Manly, 1952Go; Henrikson et al., 1998Go; English et al., 2002Go). Although the relationship between the severity of malocclusion and masticatory performance has been investigated in adults (Omar et al., 1987Go), there are no comparable studies in children.

Masticatory performance improves with chronological age, body size, bite force, and an increased area of occlusal contact and near contact areas (Julien et al., 1996Go; Hatch et al., 2000Go). However, not all of these factors are independent. As individuals age, they increase in body size, muscle mass and their ability to generate bite forces. As shown by Julien et al. (1996)Go, it is important to control for body size when evaluating group differences in masticatory performance. Masticatory performance also improves with an increased area of occlusal contact and near contact (Yurkstas and Manly, 1949Go; Bourdiol and Mioche, 2000Go; Owens et al., 2002Go). Therefore, masticatory performance should not be expected to improve at a constant rate in growing children, particularly during the change from the primary to the permanent dentition (Shiere and Manly, 1952Go).

The purpose of this study was to evaluate masticatory performance among children and adolescents with untreated normal occlusion and malocclusion. To overcome the limitations of previous studies, an artificial food (CutterSil®, Heraeus Kulzer, Germany) was used and a seven-sieve quantitation method employed to correlate performance with age, gender, type of malocclusion and the severity of malocclusion, while controlling for the confounding effects of body size.


   Subjects and method
Top
 Summary
 Introduction
 Subjects and method
Results
 Discussion
 Conclusions
 References
 
A total of 2 344 school children were screened for this study. All the children, who represented middle-class Colombians, attended two private schools in different areas of Medellin, Colombia. The sample was self-selected on the basis of willingness to participate and was subdivided on the following criteria:

  1. Boys and girls.
  2. Ages between 5.5–6.5 (age group 6), 8.5–9.5 (age group 9), 11.5–12.5 (age group 12), and 14.5–15.5 (age group 15) years.
  3. The children in age group 6 did not have the first molars occluding (i.e. they were either in the primary dentition or their first molars had not reached the occlusal plane).
  4. Normal occlusion (i.e. Class I molar relationship with less than 3 mm of crowding, less than a 3 mm overjet and an overbite less than one-third coverage of the lower incisors), Class I malocclusion (i.e. Class I molar relationship with more than 3 mm of crowding, more than 3 mm of overjet and an overbite more than one-third coverage of the lower incisors), and Class II malocclusion (i.e. at least one half cusp Class II molar relationship).

The sample had no congenitally missing teeth, was free of signs or symptoms of temporomandibular dysfunction, had no history of previous orthodontic treatment, and had no tooth with more than two-thirds of its occlusal surface restored.

Based on the selection and rejection criteria, a total of 335 children and adolescents (224 males and 111 females) were included in the study (Table 1). Informed consent was obtained from all of the subjects and their parents.


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  		Table 1 Sample distribution according to age, gender and type of occlusion.

 

Peer Assessment Rating (PAR) index

Alginate impressions (New Stetic, Medellin, Colombia) were taken from all the subjects, and stone models (Whip Mix, Louisville, Kentucky, USA) were produced. The PAR index was computed for each subject using dental casts. The PAR index was based on the sum of 11 weighted components of malocclusion including posterior right, posterior left and anterior tooth displacement (maxillary and mandibular), right and left buccal occlusion, overjet, overbite, and midline discrepancy (Richmond et al., 1992Go).


Anthropometric assessments

Standing and sitting height were measured to the nearest 1.0 mm using a stadiometer. Body weight was measured using a calibrated electronic scale to the nearest 0.1 kg. Body Mass Index (BMI) was computed from the height and weight measurements as [weight (kg)/height2(cm)]. The following anthropometric measurements (Figure 1a,b) were carried out as described by Sánchez and Rodríguez (1987)Go and Lohman et al. (1988)Go. In addition the following were measured:

  1. Cephalic index: (Pa–Pa/Gl–Oc).
  2. Arm circumference.
  3. Subscapular and tricipital skinfolds.


Figure 1
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  		Figure 1  Anthropometric measurements. (a) 1. Bizygomatic width: zygoma– zygoma (Zy–Zy); 2. bigonial width: gonion–gonion (Go–Go); 3. biparietal width: parietal–parietal (Pa–Pa). (b) 4. face height: nasion–gnathion (Na–Gn); 5. total face height: gnathion–triquion (Gn–Tr).

 

Median particle size and broadness of the distribution

Due to the inherent variability and errors associated with the evaluation of natural food breakdown, CutterSil® (a condensation silicone impression material) has become the standard test food used to evaluate masticatory performance (Omar et al., 1987Go; Akeel et al., 1992Go; Van der Bilt et al., 1993Go; Julien et al., 1996Go; Buschang et al., 1997Go; Henrikson et al., 1998Go; Van den Braber et al., 2001Go; English et al., 2002Go; Owens et al., 2002Go). CutterSil® does not swell or dissolve in saliva, does not break along predetermined fracture lines, is not sticky, and is of standard consistency. The Cuttersil® was mixed according to the manufacturer's instructions and formed into tablets in a Plexiglas template. After hardening for 15 minutes, the tablets (5 mm thick and 20 mm in diameter) were removed from the template and allowed to set for at least one hour. The hardness of each tablet was between 474 and 512 load grams (62 to 65 in durometer units) and was measured using a model 306L type A durometer (PTC Instruments, Los Angeles, California, USA) and cut into quarters (Albert et al., 2003Go). Each subject placed the three-quarter-sized tablet onto their tongue, posterior to their incisors, and instructed to chew naturally for a total of 20 chews. The investigator counted the number of chews and timed each subject's chewing sequence. The subjects expectorated the sample into a plastic filter and rinsed with water until all the particles were removed from the mouth. Rinsings were also collected in the filter. The procedure was repeated five times until approximately 10 g of CutterSil® had been chewed and expectorated into the filter. The subjects were instructed to rest for 40 seconds between trials to avoid any fatigue. Chewing cycle duration (CCD) was calculated as the total duration of the five trials (excluding rest periods) divided by 100 (5 x 20 cycles).

The chewed sample was transferred to filter paper and dried in an oven for one hour at 80°C (Albert et al., 2003Go). The sample was then separated using seven sieves with mesh sizes of 5.6, 4.0, 2.8, 2.0, 0.85, 0.425, and 0.25 mm, stacked on a mechanical shaker and vibrated for two minutes. Once the sample was separated, the content of each sieve was weighed to the nearest 0.01 g. Cumulative weight percentages (defined by the amount of the sample that could pass through each successive sieve) were calculated for each individual. From these percentages, the median particle size (MPS) and broadness of particle distribution (BPD) were estimated using the Rosin–Rammler equation (Rosin and Rammler, 1933Go; Olthoff et al., 1984Go: Slagter et al., 1992Go):

Formula
where Qw is the weight percentage of particles with a diameter smaller than x (the maximum sieve aperture). The median particle size (x50) is the aperture of a theoretical sieve through which 50 per cent of the weight can pass, and b a unit-less measure that describes the broadness of the particles distribution. Increasing values of b correspond to cumulative weight percentage curves with steeper slopes and thus to distributions of particle sizes that are less broad (Figure 2).


Figure 2
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  		Figure 2  Three-quarter CutterSil® tablets prior to chewing (a) and the chewed particles (b).

 

Statistical analysis

The skewness and kurtosis statistics showed that the distributions of all variables, except BPD and the two skinfolds, were normally distributed. The non-normally distributed measurements were normalized using log transformation. To determine possible covariates needed for subsequent analyses, Pearson's product moment correlations were undertaken to evaluate the associations between masticatory performance and anthropometric measurements. Partial correlations were then carried out to determine whether the relationships between performance and the anthropometric measurements could be explained by an increase in body size. Analyses of variance and covariance were used to evaluate the effects of age, gender, PAR index, body size and interaction effects. Due to an interaction of age and classification of malocclusion, separate analyses were performed comparing subjects with Class I and Class II malocclusions against those with normal occlusion.


   Results
Top
 Summary
 Introduction
 Subjects and method
 Results
Discussion
 Conclusions
 References
 
Prior to correction for body height, the anthropometric measurements showed low but statistically significant negative correlations with MPS, BPD and CCD (Table 2a). Height showed the strongest relationship with the performance measurements. Tricipital skinfold thickness and the cephalic index were not significantly correlated with MPS, BPD or CCD. BMI and subscapular skinfold thickness were not related to CCD. After controlling for height, none of the correlations between masticatory performance and anthropometric measurements were statistically significant (Table 2b).


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  		Table 2a Pearson's product moment correlations between masticatory performance and anthropometric measurements.

 

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  		Table 2b Partial correlations between performance and the anthropometric measurements controlling for height.

 
Descriptive statistics for MPS, BPD, CCD and the PAR index are presented in Tables 3 and 4, respectively. Analyses of variance showed significant age, gender, and molar occlusion effects (Table 5a). The most important factor explaining variation in MPS and BPD was age (Figure 3). With increasing age, MPS, BPD and CCD decreased. Post hoc tests showed that MPS and BPD in the 6-year-old age group were significantly larger than in the other age groups. The post hoc tests also showed that there were no differences between the 9 and 12-year-old age groups, and that MPS and BPD of the 15-year-old age group were significantly smaller than for the other three age groups. They also demonstrated that the 6-year-old age group had a significantly longer chewing cycle duration than the other three age groups. The age effects on MPS were greatest between the 6–9 and the 12–15 age groups, regardless of occlusion (Figure 3). Children with normal occlusion had significantly smaller MPS and significantly wider distributions of particles than children with Class I malocclusions. In contrast, no significant differences in masticatory performance between children with normal and Class II malocclusions were found. A post hoc power analysis showed that the differences between normal and Class II malocclusion subjects could not be ruled out. While there were no gender differences in MPS or BPD, females had a significantly longer ({approx} 60 ms) chewing cycle duration than males.


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  		Table 3 Central tendencies (means and medians) and measurements of dispersion [standard deviation (SD) and interquartile ranges] for median particle size (MPS; mm2), broadness particle distribution (BPD) and chewing cycle duration (CCD; seconds).

 

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  		Table 4 Peer Assessment Rating index, means and standard deviations (SD) by malocclusion in the four age groups evaluated.

 

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  		Table 5a Analysis of variance evaluating the effects of age, molar occlusion (MO) and gender.

 

Figure 3
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  		Figure 3  Median particle size (MPS; mm) and standard error by malocclusion and age group.

 
Analyses of covariance evaluating the effects of height, PAR index and gender, showed that height explained significant amounts of variation for MPS and BPD, but not for CCD (Table 5b). After controlling for height, the age group effects identified in the analyses of variance were no longer statistically significant. The PAR index was related to MPS and BPD among children with normal and Class I malocclusions, but not in children with Class II malocclusions. Again, only masticatory cycle duration showed significant gender differences.


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  		Table 5b Analysis of covariance evaluating the effects of stature (Ht), Peer Assessment Rating (PAR) index and gender.

 

   Discussion
Top
 Summary
 Introduction
 Subjects and method
 Results
 Discussion
Conclusions
 References
 
Age is one of the most important sources of variation in masticatory performance. Using CutterSil® as the test food, Julien et al. (1996)Go also reported significant differences in masticatory performance between 6- to 8-year-old girls and young adult females. The differences they found in MPS between girls and females (1.1 mm) were slightly greater than those observed in the present study between the 6- and 15-year-olds (0.96 mm). This discrepancy could be due to the greater age range and sample composition in the study by Julien et al. (1996)Go. Henrikson et al. (1998)Go showed that masticatory performance was significantly better in 15-year-old than in 11-year-old girls.

The observed age differences in masticatory performance were strongly associated with increases in body size. Over the age span covered in this study, body size increased approximately 40 per cent, with presumed concomitant increase in muscle size and strength (Tanner, 1962Go; Marshall, 1978Go) and MPS decreased by 23 per cent. Maximum bite force is also known to increase with age (Kiliaridis et al., 1993Go; Shiau and Wang, 1993Go; Braun et al., 1996Go; Maki et al., 2001Go; Sonnesen et al., 2001Go). Increases in body size, muscle mass and bite force have been previously related to improved masticatory performance (Julien et al., 1996Go). In particular, the more dramatic improvements in performance observed between the 12- and 15-year-old age groups may be associated with the adolescent growth spurt, which is characterized by pronounced increases in body size and muscle mass (Tanner, 1962Go).

The results also suggest that dental maturation may account for some of the differences observed between age groups, particularly for the younger groups. In a large cross-sectional study, Shiere and Manly (1952)Go showed that masticatory performance (based on number of chews required to achieve a standard degree of breakdown) for peanuts and carrots increased between 6 and 10 years of age, decreased from 10 to 11 years age, and then increased again through 14 years of age. Based on the selection criteria used for age group 6, eruption of the first molars could explain the greater improvement in performance observed between the 6 and 9 year olds than between the 9- and 12-year-old groups. In adults, the strongest crushing bite occurs at the first molars (Mansour and Reynick, 1975Go; Pruim et al., 1980Go). The smaller difference in masticatory performance between the 9- and 12-year-old groups may be related to the transitional nature of the mixed dentition.

While it is established that children with severe malocclusion do not break down foods as well as children with normal occlusion (Shiere and Manly, 1952Go), the relative differences between individuals with Class I and Class II malocclusions remain controversial. In the present study, 6–15-year-old individuals with normal occlusion had better masticatory performance than children and adolescents with Class I malocclusions, but not necessarily better than those with Class II malocclusions. Shiere and Manly (1952)Go, who reported no differences between children with normal occlusion and malocclusion (either Class I or Class II), used a less sensitive measure of masticatory performance and their sample sizes were smaller. In contrast to the present results, but using similar methods, English et al. (2002)Go evaluated patients 7 to 35 years of age prior to treatment and showed poorer than normal masticatory performance for Class II, but not for Class I subjects. There are three possible explanations for the different results obtained. First, there may have been differences in the severity of malocclusion among the studies. The patients evaluated by English et al. (2002)Go were seeking treatment and might be expected to have additional components of malocclusion for which treatment was required. The fact that the present Class II sample was not seeking treatment may be important because Henrikson et al. (1998)Go have previously shown that masticatory performance is better among Class II subjects not seeking treatment than Class II subjects seeking treatment, suggesting that untreated patients with more severe forms of malocclusion do not break down CutterSil® as well as those with less severe forms of malocclusion. Secondly, subjects with a Class I malocclusion were defined differently in the two studies. Whereas English et al. (2002)Go defined malocclusion based solely on Angle's classification, the Class I subjects in the present investigation were also required to have at least 3 mm or more of overjet and more than one-third lower incisor overbite. Finally, there were fewer subjects with Class II than Class I malocclusion, which makes it more difficult to establish differences statistically. Additional prospective studies are needed to fully understand differences in masticatory performance between different occlusal classes.

In this study the children and adolescents displayed lower mean PAR scores than previously reported for Class I and Class II subjects. Evaluating individuals 6.9–48 years of age seeking orthodontic treatment, Birkeland et al. (1997)Go reported PAR scores of 26.9 and 30.7 for Class I and Class II subjects, respectively. Pangrazio-Kulbersh et al. (1999)Go reported PAR scores of 15.5 and 16.3 in untreated children 9.8 years of age with Class I and II malocclusions. While the PAR scores in the current study increased with age, they were approximately 30 per cent lower than those reported by Pangrazio-Kulbersh et al. (1999)Go. This difference could be explained by the fact that in this sample the subjects were not seeking treatment because they had milder forms of malocclusion.

Finally, the results indicate that traditional descriptions of malocclusion are only weakly related to masticatory performance of individual patients. The differences in performance that have been reported between normal occlusion and malocclusion based on Angle's classification, although statistically significant, are proportionately small. In part this may be because the level of masticatory performance depends upon the intraoral selection and breakage of food particles (Van der Glas, et al., 1987), but the morphometric measurements in this study probably contribute only to the breakage process. These two processes were not separated in the analysis and it is possible that factors that contribute to the selection process play an important role in overall performance in children with malocclusions.

Occlusal indices measuring the severity of malocclusion are more objective, but also limited in their ability to assess masticatory performance. The PAR index was more closely related with performance than Angle's classification, but the relationship was too weak to be of clinical relevance. Of the five commonly used occlusal indexes evaluated by Omar et al. (1987), the Orthodontic Treatment Priority Index showed the highest correlation, but explained only 37 per cent of the variation in masticatory performance. Most occlusal indices have aesthetic and functional components that are not necessarily predictive of objective functional deficits. Based on the known association between masticatory performance and posterior occlusal contacts and near contact areas (Wilding, 1993Go; Julien et al., 1996Go; Bourdiol and Mioche, 2000; Hatch et al., 2000Go; Owens et al., 2002GoGo), bite registrations might provide a more reliable approach for quantifying the functional aspects of posterior occlusion.


   Conclusions
Top
 Summary
 Introduction
 Subjects and method
 Results
 Discussion
 Conclusions
References
 

  1. Age and associated increases in body size are among the most important factors related to individual differences in masticatory performance.
  2. Age changes in masticatory performance are partially related to dental maturation.
  3. There are no gender differences in masticatory performance of 6- to 15-year-old children and adolescents.
  4. Children with Class I malocclusions do not break down foods as well as those with normal occlusion; children with severe Class I malocclusion cannot break down foods as well as those with less severe Class I malocclusion.


   Acknowledgement
 
This research was partially supported by Instituto colombiano para el desarrollo de la ciencia y la tecnología, Colciencias, Grant #1228–04–11856, Contrato: 177-2002.


   References
Top
 Summary
 Introduction
 Subjects and method
 Results
 Discussion
 Conclusions
 References
 

    Akeel R, Nilner M, Nilner K 1992 Masticatory efficiency in individuals with natural dentition. Sweden Dentistry Journal 16: 191–198

    Albert Jr T E, Buschang P H, Throckmorton G S 2003 Masticatory performance: a protocol for standardized production of an artificial test food. Journal of Oral Rehabilitation 30: 720–722[CrossRef][ISI][Medline]

    Birkeland K, Furevik J, Bøe O E, Wisth P J 1997 Evaluation of treatment and post-treatment changes by the PAR Index. European Journal of Orthodontics 19: 279–288[Abstract/Free Full Text]

    Bourdiol P, Mioche L 2000 Correlations between functional and occlusal tooth-surface areas and food texture during natural chewing sequences in humans. Archives of Oral Biology 45: 691–699[CrossRef][ISI][Medline]

    Braun S, Hnat W P, Freudenthaler J W, Marcotte M R, Honigle K, Johnson B E 1996 A study of maximum bite force during growth and development. Angle Orthodontist 66: 261–264[ISI][Medline]

    Buschang P H, Throckmorton G S, Travers K H, Johnson G 1997 The effects of bolus size and chewing rate on masticatory performance with artificial test foods. Journal of Oral Rehabilitation 24: 522–526[CrossRef][ISI][Medline]

    Edlund J, Lamm J 1980 Masticatory efficiency. Journal of Oral Rehabilitation 7: 123–130[ISI][Medline]

    English J D, Buschang P H, Throckmorton G S 2002 Does malocclusion affect masticatory performance? Angle Orthodontist 72: 21–27[ISI][Medline]

    Hatch J P, Shinkai S, Rugh J D, Paunovich E D 2000 Determinants of masticatory performance in dentate adults. Archives of Oral Biology 46: 641–648

    Helkimo E, Carlsson G E, Helkimo M 1977 Chewing efficiency and state of dentition. Acta Odontologica Scandinavica 36: 33–41

    Henrikson T, Ekberg E, Nilner M 1998 Masticatory efficiency and ability in relation to occlusion and mandibular dysfunction in girls. International Journal of Prosthodontics 11: 125–132[ISI][Medline]

    Julien K C, Buschang P H, Throckmorton G S, Dechow P C 1996 Normal masticatory performance in young adults and children. Archives of Oral Biology 41: 69–75[CrossRef][ISI][Medline]

    Kay R F, Shiene W S 1979 On the relationship between chiting particle size and digestibility in the primate Galago senegalensis. American Journal of Physical Anthropology 50: 301–308[CrossRef]

    Kiliaridis S, Kjellberg H, Wenneberg B, Engström C 1993 The relationship between maximal bite force, bite force endurance, and facial morphology during growth. Acta Odontologica Scandinavica 51: 323–331[ISI][Medline]

    Lohman T G, Roche A F, Martorell R 1988 Anthropometric standardization reference manual. Human Kinetics Books, Champaign, pp. 171

    Maki K, Nishioka A, Morimoto M, Naito M, Kimura M 2001 A study on the measurement of occlusal force and masticatory efficiency in school age Japanese children. International Journal of Paediatric Dentistry 11: 281–285

    Mansour R M, Reynick R J 1975 In vivo occlusal forces and moments. I. Forces measured in terminal hinge position and associated moments. Journal of Dental Research 54: 114–120[Abstract/Free Full Text]

    Marshall W A 1978 Puberty in human growth. In: Falkner F, Tanner J M (eds.) Postnatal growth. Plenum Press, New York, pp. 141–181

    Olthoff L W, Van der Bilt A, Bosman F, Kleizen H H 1984 Distribution of particle sizes in food comminuted by human mastication. Archives of Oral Biology 29: 899–903[CrossRef][ISI][Medline]

    Omar S M, McEwen J D, Ogston S A 1987 A test for occlusal function. British Journal of Orthodontics 14: 85–90[Abstract]

    Owens S, Buschang P H, Throckmorton G, Palmer L, English J 2002 Masticatory performance and areas of occlusal contact and near contact in subjects with normal occlusion and malocclusion. American Journal of Orthodontics and Dentofacial Orthopedics 121: 602–609[CrossRef][ISI][Medline]

    Pangrazio-Kulbersh V, Kaczynski R, Shunock M 1999 Early treatment outcome assessed by the Peer Assessment Rating Index. American Journal of Orthodontics and Dentofacial Orthopedics 115: 544–550[CrossRef][ISI][Medline]

    Pera P, Bucca C, Borro P, Bernocco C, De Lillo A, Carrossa S 2002 Influence of mastication on gastric emptying. Journal of Dental Research 81: 179–181[Abstract/Free Full Text]

    Pruim G J, De Jongh H J, Ten Bosch J J 1980 Forces acting on the mandible during bilateral static bite at different bite force levels. Journal of Biomechanics 12: 755–763

    Richmond S et al. 1992 The development of the PAR Index (Peer Assessment Rating): reliability and validity. European Journal of Orthodontics 14: 125–139[Abstract/Free Full Text]

    Richmond S et al. 1995 Calibration of dentists in the use of oclusal indices. Community Dentistry of Oral Epidemiology 23: 173–176

    Rosin P, Rammler E 1933 Gesetzmassigkesten in der Kornzusammensetzing des zementes. Zement 31: 427–433

    Sánchez G, Rodríguez C 1987 Dimensiones antropométricas y controles de calidad. Instituto de Medicina Deportiva, La Habana, Cuba.

    Shiau Y Y, Wang J S 1993 The effects of dental condition on hand strength and maximum bite force. Cranio 11: 48–54[ISI][Medline]

    Shiere F R, Manly R S 1952 The effect of the changing dentition on masticatory function. Journal of Dental Research 31: 526–534[Abstract/Free Full Text]

    Slagter A P, Olthoff L W, Steen W H A, Bosman F 1992 Comminution of food by complete-denture wearers. Journal of Dental Research 71: 380–386[Abstract/Free Full Text]

    Sonnesen L, Bakke M, Solow B 2001 Bite force in pre-orthodontic children with unilateral crossbite. European Journal of Orthodontics 23: 741–749[Abstract/Free Full Text]

    Tang E, Wei S 1993 Recording and measuring malocclusion: a review of the literature. American Journal of Orthodontics and Dentofacial Orthopedics 103: 344–351[ISI][Medline]

    Tanner J M 1962 Growth at adolescence. Blackwell, Oxford

    Van den Braber W, Van der Glas H W, Van der Bilt A, Bosman F 2001 Chewing efficiency of pre-orthognathic surgery patients: selection and breakage of food particles. European Journal of Oral Sciences 109: 306–311[CrossRef][ISI][Medline]

    Van der Bilt A, Olthoff L W, Bosman F, Oosterhaven P 1993 The effect of missing postcanine teeth on chewing performance in man. Archives of Oral Biology 38: 423–429[CrossRef][ISI][Medline]

    Wilding R J C 1993 The association between chewing efficiency and occlusal contact area in man. Archives of Oral Biology 38: 589–596[CrossRef][ISI][Medline]

    World Health Organization 1995 Application of the international classification of diseases to dentistry and stomatology (ICD-DA). 3rd edn. World Health Organization, Geneva.

    Yurkstas A, Manly R S 1949 Measurement of occlusal contact area effective in mastication. American Journal of Orthodontics 35: 185–195[Medline]


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