Absence of association between a preferred chewing side and its area of functional occlusal contact in the human dentition.

Preference for a particular chewing side may be influenced by several factors, one of which could be the functional contact area on each side of the dentition. In this study, interocclusal wax records were made for each of the 30 subjects. A digital image of the transilluminated wax record was analysed to group 'grey' values into categories of wax thickness. The total area for tight and intermediate tooth contacts was calculated for both the left- and right-hand sides of each subject. The chewing-side preference was recorded. No correlation was found between the area of occlusal contact on one side and the preference for chewing on that side. Occlusal contact area does not appear to be a determinant of chewing-side preference.     

Relationship between chewing side preference and handedness and lateral asymmetry of peripheral factors

Objective

To determine whether chewing side preference is related to handedness and lateral asymmetry of occlusal characteristics, muscular force and temporomandibular disorders (TMD) in a dentate population.

Design

One hundred and seventeen dentate adults participated in this cross-sectional study. Static and dynamic occlusal characteristics were determined at the maximal intercuspal position and at the lateral excursions by scanning interocclusal records and analysing them using image software. Unilateral maximum bite force and finger-thumb grip force were measured by means of a gnathodynamometer. TMD were assessed according to the Research Diagnostic Criteria for TMD. Chewing side preference and masticatory laterality were determined by observing the jaw's movement while each subject chewed silicone. Asymmetry or side difference of the variables was calculated. Correlation between side difference variables and masticatory laterality was studied using Spearman correlation coefficient.

Results

Fifty-nine subjects chewed on the right, 15 on the left and 43 chewed on both sides. There was no relationship between preferred chewing side and handedness, lateral asymmetry of TMD or side difference in finger-thumb grip force. Significant and positive correlations were observed between masticatory laterality and side differences in bite force and side differences in occlusal contact area at intercuspal position (P < 0.01).

Conclusions

Chewing side preference in a dentate population is related to lateral asymmetry of bite force and asymmetry of occlusal contact area at the intercuspal position but not to handedness.     

Molar bite force and its correlation with signs of temporomandibular dysfunction in mixed and permanent dentition

The aim of the study was to evaluate molar bite force (BF) magnitude and its correlation to the signs of temporomandibular dysfunction (TMD), gender, weight, height and age in 101 students ranging in age from 6 to 18 years (32 boys/21 girls with mixed dentition and 23 boys/25 girls with permanent dentition). TMD clinical signs were evaluated using the Craniomandibular Index (CMI), and two subscales, the Dysfunction Index (DI) and the Palpation Index (PI). BF was determined with a pressurized tube connected to a sensor (MPX5700-Motorola SPS). anova, Tukey's test, and Pearson's and Spearman's coefficients were evaluated. BF was higher in the permanent dentition (P < 0.05). There was no difference in BF between genders within the groups, but boys with permanent dentition had higher values than children with mixed dentition (P < 0.05). The girls with permanent dentition presented negative correlation in BF with PI and CMI (P < 0.05). BF was positively correlated with weight, height and age in the permanent dentition group (P < 0.05). It was concluded that BF increased from mixed to permanent dentition, with an assumed enhancing influence of body variables and ageing. The TMD signs in older girls were correlated to decreasing BF, suggesting an influence of muscle tenderness preventing subjects from exerting maximum BF.     

Relationships between occlusal or free-smooth and approximal caries in mixed dentition

This cross-sectional study aimed to examine the relationships between free-smooth or occlusal surfaces and approximal caries in 104 schoolchildren between 6 and 8 years of age. Caries diagnosis was clinically and radiographically assessed, and white spot lesions, evident caries lesions or restorations, as well as radiolucence in enamel were considered to be caries. In the studied subjects, the correlations were analyzed in the 1st primary molars (Ds), the 2nd primary molars (Es), the 1st permanent molars (6s), and all molars. The data were statistically analyzed by chi-square test. Significant correlations between occlusal surface caries and approximal surface lesions were observed in Ds and Es teeth and in all molars, but not for 1st permanent molars. For free-smooth surface, these correlations were significant only for Es and all molars. Sensitivity and specificity for occlusal surface as an indicator of approximal caries in the same tooth type ranged from 73% to 83% and 51% to 58%, respectively. Similarly, for free-smooth surface the values varied from 22% to 60% and 57% to 90%, respectively. Sensitivity and specificity for occlusal surface caries in identifying subjects with approximal caries were 78% and 70%, respectively; for free-smooth surface, the corresponding values were 59% and 65%, respectively. The results suggest that visually detected caries lesions are indicative of approximal caries. Thus, if a certain risk limit is defined and the corresponding number of caries lesions in different surfaces is reached, the risk is above the threshold and could be a practical guideline on the need for radiography in this age group of patients with "moderate caries experience".     

Relationships between occlusal or free-smooth and approximal caries in mixed dentition

This cross-sectional study aimed to examine the relationships between free-smooth or occlusal surfaces and approximal caries in 104 schoolchildren between 6 and 8 years of age. Caries diagnosis was clinically and radiographically assessed, and white spot lesions, evident caries lesions or restorations, as well as radiolucence in enamel were considered to be caries. In the studied subjects, the correlations were analyzed in the 1st primary molars (Ds), the 2nd primary molars (Es), the 1st permanent molars (6s), and all molars. The data were statistically analyzed by chi-square test. Significant correlations between occlusal surface caries and approximal surface lesions were observed in Ds and Es teeth and in all molars, but not for 1st permanent molars. For free-smooth surface, these correlations were significant only for Es and all molars. Sensitivity and specificity for occlusal surface as an indicator of approximal caries in the same tooth type ranged from 73% to 83% and 51% to 58%, respectively. Similarly, for free-smooth surface the values varied from 22% to 60% and 57% to 90%, respectively. Sensitivity and specificity for occlusal surface caries in identifying subjects with approximal caries were 78% and 70%, respectively; for free-smooth surface, the corresponding values were 59% and 65%, respectively. The results suggest that visually detected caries lesions are indicative of approximal caries. Thus, if a certain risk limit is defined and the corresponding number of caries lesions in different surfaces is reached, the risk is above the threshold and could be a practical guideline on the need for radiography in this age group of patients with “moderate caries experience”.     

不完全性腭裂患者腭裂修复术后乳牙期与替牙期颅面形态变化的对比研究

目的研究不完全性腭裂患者修复术后乳牙期与替牙期的颅面形态差异。方法选择21例乳牙期和20例替牙期不完全性腭裂患者作为两个实验组，两组的性别比例匹配，进行X线头影测量对比分析。结果替牙期相比乳牙期颅底大小、上颌长、下颌大小及各面高均显著增长。上颌矢状向位置、下颌矢状向位置、颅底角下颌角、下颌平面角、上下颌垂直向关系以及面高之比均无显著变化。面突度显著减小。结论随年龄增长腭裂患者颅面部增大，但各部分之间的相互位置关系基本保持不变。     

The relationship between occlusal factors and bruxism in permanent and mixed dentition in Turkish children

The aim of this study was to investigate the relationship between occlusal factors (overjet, overbite, Angle's Classification of molars and cuspids, the relationship of the primary molars, openbite, lateral openbite, scissorbite and crossbite) and bruxism in permanent and mixed dentition in Turkish children. For this reason 182 children with mixed dentition and 212 children with permanent dentition were included in this study. Occlusal conditions were examined clinically and bruxism was assessed by using interview and questionnaires. Z Test was used to compare the results. It was found that in both dentitions some occlusal factors related with bruxism (overjet > 6 mm, overbite > 5 mm, negative overjet, openbite in permanent dentition; overjet > 6 mm, overbite > 5 mm, scissorbite, anterior-posterior multiple teeth crossbite, Angle Class I occlusion in mixed dentition.     

Treatment of sequelae in permanent dentition after severe trauma in primary dentition

Abstract – A case with a dilacerated upper right central and hypoplastic upper right lateral incisors covered with gingiva of a 10‐year‐old female, with a history of trauma at the age of 18 months, is presented. After clinical and radiographical evaluations, esthetic problem was solved with gingivectomy followed by composite restorations of the involved teeth.     

Localization of first permanent molars in lateral cephalometric and panoramic radiographs from early mixed dentition to early permanent dentition

Changes in position and mesiodistal angulations of maxillary and mandibular first permanent molars from early mixed dentition to early permanent dentition were measured on panoramic radiographs and compared with the values measured on lateral cephalometric radiographs. It was found that the maxillary and mandibular first permanent molars were uprighted gradually, drifted mesially and vertically, and that the changes in mesiodistal angulations were clearly on the panoramic radiographs in comparison with the cephalometric radiographs.     

Relationship between occlusal findings and orofacial myofunctional status in primary and mixed dentition

Aim

The aim of this study was to provide basic representative data on the prevalence of malocclusions involving space deficiency in both primary and early mixed dentition and to examine the relationship between these malocclusions and orofacial dysfunctions. The results should be viewed from an orthodontic prevention and early treatment perspective.

Subjects and methods

Orthodontic findings in the maxilla and mandible as well as the myofunctional status of 766 children in primary dentition and 2,209 children in mixed dentition were examined clinically in a cross-sectional study. The following parameters from each jaw were subjected to orthodontic analysis: crowding in the anterior and posterior regions of the maxilla and mandible in primary and mixed dentitions, deviations from normal maxillary arch forms in the primary dentition, deviations from normal anterior maxillary arch width in mixed dentition and maxillary apical base morphology in mixed dentition. Static and dynamic orofacial dysfunctions were documented with reference to specific parameters and clinical tests.

Results

Crowding was observed in every tenth child in primary dentition (10.8%) and in every second child in mixed dentition (49.7%). Habitual open mouth posture, visceral swallowing, articulation disorders and oral habits were statistically significantly more frequent in children in primary dentition presenting a narrow maxillary arch. Reduced anterior maxillary arch width (compression) was statistically more frequent in children in early mixed dentitions with habitual open mouth posture. A narrow maxillary apical base correlated positively with all the orofacial dysfunctions analyzed.

Conclusions

Deviations from a regular arch form become apparent very early during dentition development and coexist with specific orofacial dysfunctions. They are thus important indicators for the early detection of functional abnormalities, causing deviations from normal dentition development. In children with orofacial dysfunctions the development of a narrow maxillary dental arch should be prevented by myofunctional therapy and by educating the parents. Interceptive orthodontic measures to treat a narrow maxillary arch in primary and early mixed dentition should also focus on eliminating functional disturbing factors, such as orofacial dysfunctions. Interdisciplinary cooperation with specialists in other fields of medicine, e.g. otorhinolaryngology and speech therapy, is essential to achieve this goal.     

Temporomandibular joint dysfunction and occlusion in the mixed and permanent dentition

The aim of this study was to investigate the relation between occlusal factors: Angle classification, overbite, overjet, openbite, anterior and posterior crossbite, scissors bite or buccal crossbite and lateral openbite--and the presence of mandibular dysfunction in a sample of 359 Turkish children with mixed and permanent dentition. Z Test was used to compare the results. It was found that, Class III malocclusion in the permanent dentition and openbite, overbite = 0, overjet = 0, anterior-posterior crossbite in the mixed dentition were related with TMD.     

Correlation between caries experience in primary and permanent dentition in birth-cohorts 1950–70

Abstract – Caries experience in the primary molars and canines at 8 yr of age and in the permanent dentition at 16 was correlated in every fourth birth-cohort between 1950 and 1970 in a Danish community. Correlations between 0.44 and 0.56 were found. Cross-tabulation of the data also revealed close association, but prediction of individual high caries risk children based solely on screening for caries experience in the primary dentition is hardly cost-effective.     

Peripheral,functional and postural asymmetries related to the preferred chewing side in adults with natural dentition

The aim of this cross‐sectional study was to determine the preferred chewing side and whether chewing side preference is related to peripheral, functional or postural lateral preferences. One hundred and forty‐six adults with natural dentition performed three masticatory assays, each consisting of five trials of chewing three pieces of silicon placed into a latex bag for 20 cycles, either freestyle or unilaterally on the right‐ or left‐hand side. Occlusal contact area in the intercuspal position, maximum bite force, masticatory performance and cycle duration were measured and the lateral asymmetry of these variables was calculated. Laterality tests were performed to determine handedness, footedness, earedness and eyedness as functional preferences, and hand‐clasping, arm‐folding and leg‐crossing as postural lateral preferences. The preferred chewing side was determined using three different methods: assessment of the first chewing cycle for each trial, calculation of the asymmetry index from all cycles and application of a visual analogue scale. Bivariate relationship and multiple linear regression analyses were performed. Among unilateral chewers, 77% of them preferred the right side for chewing. The factors most closely related to the preferred chewing side were asymmetry of bite force, asymmetry of masticatory performance and earedness, which explained up to 16% of the variance. Although several functional or postural lateral preferences seem to be related to the preferred chewing side, peripheral factors such as asymmetry of bite force and of masticatory performance are the most closely related to the preferred chewing side in adults with natural dentition.