The relationship between molar bite force and incisor inclination: A prospective cross-sectional study

Fujita

Clinical & Exp Dental Res

et al. 2020

The position of the dentition is considered to be determined by a combination of forces exerted by the perioral muscles and tongue. We hypothesized that mandibular anterior crowding may be related to abnormalities in the development of oral function. To determine the relationship between oral function and mandibular anterior crowding in early mixed dentition. A total of 61 children (30 boys, 31 girls) with early mixed dentition were included in this study. Height, body weight, maximum occlusal force, lip-closing strength, and maximum tongue pressure were measured in all participants, and their dental casts and lateral cephalograms were evaluated. Little's irregularity index (LII), evaluated by dental casts, was used as an indicator of mandibular anterior crowding. Maximum occlusal force and lip-closing strength were not significantly correlated with the LII, although they were positively correlated with maximum tongue pressure, mandibular intercanine perimeter distance, and upper central incisor (U1)-to-NL angle (p < .05). Maximum tongue pressure was negatively correlated with LII (p < .05). Maximum tongue pressure and LII were significantly positively correlated with the mandibular intercanine perimeter distance and U1/NL angle, and negatively correlated with the interincisal angle (p < .05 for all). Crowding of the mandibular anterior teeth was directly correlated with tongue pressure function and indirectly correlated with maximum occlusal force and lip-closing strength.

Section: Discussionsupporting

confidence: 93%

Relationship between oral function and mandibular anterior crowding in early mixed dentition

Fujita

Clinical & Exp Dental Res

et al. 2020

“… 6 Others found a significant correlation between the number of teeth in contact and the molar biting force. 16 – 20 , 23 , 26 Alabdullah et al 27 also reported a positive correlation between the molar biting force and the axial inclination of upper and lower incisors. They found that the higher the number of proclined incisors, the more the molar biting force.…”

Section: Limitationsmentioning

confidence: 92%

“…They found that the higher the number of proclined incisors, the more the molar biting force. 27 Transverse craniofacial relationships and crossbite also had a reported association with the biting force. 10 , 11 However, such factors, which might have a contributing effect on the health status of the permanent first molars, were not assessed in the current study.…”

Section: Limitationsmentioning

confidence: 99%

First molar health status in different craniofacial relationships

Linjawi

2016

CCIDE

ObjectiveTo investigate the association between the health status of permanent first molars and different craniofacial relationships among adolescents.Study designThis is a retrospective study on patients’ records aged 11–15 years. Sex, skeletal relationship, vertical growth pattern, malocclusion, overjet, and overbite were assessed. The health status of permanent first molars was recorded from the orthopantomograms and intraoral photographs as “sound” and “not sound”. Chi-square, Mann–Whitney U and Kruskal–Wallis tests, and Pearson’s correlation coefficient were used to analyze and correlate the assessed variables. Significance level was set at P<0.05.ResultsA total of 210 records were evaluated; 81 were male, 68 had Class I and 91 had Class II skeletal relationships. More than half of the subjects had normal (n=67) to moderate deep bite (n=72); normal (n=91), moderately increased (n=54), to severely increased (n=50) overjet; and Class I (n=106) and Class II division 1 (n=75) malocclusion. Significant differences were found in the health status of the permanent first molars with respect to sex (P=0.034), vertical growth pattern (P=0.01), and overbite (P=0.047). Strong correlations were only found between the health status of the permanent first molars and the following variables: sex (P=0.036) and vertical growth pattern (P=0.004). Significant correlation was further found between the upper left first molar health status and sex (P=0.019) and the lower right first molar health status and the vertical growth pattern (P=0.001). No significant association was found with the anteroposterior craniofacial relationships (P>0.05).ConclusionSex difference and vertical growth patterns were found to be potential predictors of the health status of the permanent first molars. No significant association was found with the anteroposterior craniofacial relationships.

“…Moreover, M.M. Alabdullah et al [1] found a direct linear relationship between the force of chewing muscles and the angular characteristics of the incisors.…”

Section: Introductionmentioning

confidence: 98%

Determination of individual teleroentgenographic characteristics of the lower medial incisors position in Ukrainian young men and young women with orthognathic bite

et al. 2018

Ethnic, sexual and age features of the incisors positions point to the need for the development of techniques that allow to determine their individual characteristics, since commonly accepted standards recommended for optimal positioning of incisors can only be used as indicative. The purpose of the study – by studying teleroentgenographic indices and conducting direct stepwise regression analysis in young men and young women of Ukraine with orthognathic bite, to develop and analyze the mathematical models of individual characteristics of the position of the lower medial incisors. With the Veraviewepocs 3D device, Morita (Japan) in 38 young men (17 to 21 years of age) and 55 young women (aged from 16 to 20 years) with occlusion close to orthognathic bite and balanced faces received side teleroentgenograms. Cephalometric analysis was performed using OnyxCeph3TM software. Cephalometric points and measurements were performed according to the recommendations of A.M. Schwarz, J. McNamara, W.B. Downs, R.A. Holdway, P.F. Schmuth, C.C. Steiner and C.H. Tweed. According to the above methods, in the licensed package “Statistica 6.0” using direct straight line regression analysis, the teleroentgenographic characteristics of the position of the lower medial incisors (distance 1l_NB, distance 1l_APog, angle 1l_DOP, IMPA angle, Mand1_NB angle, FMIA angle and Mand1_MeIm angle) were performed. In young men with orthognathic bite of 7 possible models of teleroentgenographic characteristics of the lower medial incisors, 5 were constructed with determination coefficient R2 from 0.694 to 0.849, and in young women, all 7 possible models with determination coefficient R2 from 0.595 to 0.794. In young men most often the regression equations included - the angle ANB and facial vertical index GL_SN_S (by 11.5%); lower face height ANS_ME, face angle NBA_PTGN and distance S_E (by 7.7%). In young women most often the regression equations included – the angle of N_POG (16.7%); Wits indicator (13.9%); inclination angle I (8.3%); H-angle, maxillo-mandibular angle MM and angle of facial axis NBA_PTGN (by 5.6%). Thus, in the work with the help of the method of stepwise regression with inclusion, among Ukrainians of juvenile age, on the basis of features teleroentgenographic indicators, the analysis of reliable models of individual teleroentgenographic characteristics of the position of the lower medial incisors was developed and carried out.