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.     

Occlusion and tooth/arch dimensions in the primary dentition of preschool Jordanian children

Summary. Objectives. To assess tooth and arch dimensions, occlusal relationships and the presence of spacing or crowding in primary dentition of Jordanian children. Study design. A list of 10 kindergartens was randomly selected in the governate of Irbid, Jordan. A total of 1048 children (2·5–6 years old) with complete primary dentitions were examined for occlusal relationships in three planes, and the presence of spacing or crowding. Of those, study casts were taken for 87 randomly selected 4–5‐year‐old children (39 girls, 48 boys). Measurements of tooth and arch dimensions were made using electronic digital sliding callipers. Results. In general, males had larger mesiodistal tooth width and larger arch dimensions. Bilateral mesial step molar relationship was found in 47·7% of children followed by bilateral flush terminal molar relationship in 37% and bilateral distal step in 3·7%. Asymmetric right/left molar relationship was found in 11·6% of children examined. Class I canine relationship was found in 57% of children, followed by Class II canines in 29% and Class III canines in 3·7%. Fifty per cent of children examined had Class I incisors, 24·7% had Class II Division 1, 13·5% had Class II Division 2 and 11·8% showed reversed overjet. Ideal overbite was seen in 44·3% of children, reduced overbite in 21·8%, increased overbite in 28·2% and 5·7% had anterior openbite. Buccal crossbite was seen in 7% of the sample. Generalized spacing was found in 61·8% and 61·1% of children in the upper and lower arches, respectively. Anthropoid spaces were found in 70% of the upper arches and in 51% of the lower arches. Conclusions. Males had larger tooth/arch dimension than that of females in the primary dentition stage. Mesial step molar relationship was found in 47·7% of the subjects followed by flush terminal molar relationship in 37%. The majority of children examined had spaced primary dentition.     

Digora数字影像系统测量分析正常乳牙列

目的检测Digora数字影像系统测量牙列的可行性.方法随机抽取31名正常乳牙列幼儿,分别以Digora系统及游标卡尺测量乳牙列并比较.结果Digora数字影像系统的测量值小于游标卡尺,具有高度统计学意义.结论Digora数字影像系统测量乳牙列具有可行性.     

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.     

The relationship between alveolar bone height and age in the primary dentition

Abstract The natural history of changes in attachment level in the primary dentition should be determined before considering diagnostic criteria for periodontal diseases in children. The present study was designed to describe longitudinal changes in the distance between the alveolar bone crest and the cementoenamel junction (ABC-CEJ) determined radiographically. Bite-wing radiographs were obtained from 33 children as part of a routine annual dental examination in a rural community. The ABC-CEJ distance of 1500 sites located at the mesial and distal aspects of primary molars and distal aspect of primary cuspids were measured. An analysis of variance model was used to assess the effect of age, sex, tooth, side of the mouth, jaw, site and patient on the ABC-CEJ measurements. The side of the mouth (left, right) and the site (mesial, distal) had no significant effect on the ABC-CEJ distance. ABC-CEJ distances in the upper jaw were greater than in the lower jaw, and different teeth exhibited different ABC-CEJ distances. Canines had the greatest distance and second molars the smallest. The most interesting relationship was between alveolar bone height and age. The overall ABC-CEJ distance seemed to increase with age; however, this was not a linear relationship but followed the pattern of facial growth, with two spurts separated by a period of minimal increase. The results indicate that different levels of ABC-CEJ distance might be considered as a cut-off value for radiographic diagnosis of alveolar bone loss at different ages, for different primary teeth and for different jaws.     

Dental arch dimensions in primary dentition of children aged three to five years in Chennai and Hyderabad.

OBJECTIVE: The purpose of this study was to assess the arch dimensions in primary dentition of 3-5 years old children in Chennai and Hyderabad. As no primary to the mixed dentition and determining the existence of sexual dimorphism. METHODS: Children were selected fro various schools of both Chennai and Hyderabad, with complte set of primary dentition. Study casts were made and measurements of arch dimensions were made using digital sliding calipers. The data obtained was subjected to statistical analysis. RESULTS: The mean values and standard deviations of the various arch dimensions are given in the tables. CONCLUSION: Generally boys exhibited a greater arch dimensions than girls in both groups. Some of the dimensions showed a statistically significant mean values.     

The relationship between caries in the primary dentition at 5 years of age and permanent dentition at 10 years of age - a longitudinal study

OBJECTIVES: To explore a possible relationship between the caries experience and pattern in the primary dentition at 5 years of age and the permanent dentition at 10 years of age. Further, to examine the possibility of predicting children in a caries-risk group at 5 years verified at 10 years of age. MATERIALS AND METHODS: A sample of 186 children (90 males) were clinically examined as 5-year-olds and re-examined as 10-year-olds by calibrated dentists. A five-graded diagnostic system including enamel caries was used. Bitewing radiographs were taken. A true risk group of children at 10 years were defined as those with at least one dentin or filled lesion on the mesial surface of 6-year molars, and/or on incisors, and/or total DMFS (decayed, missing, and filled surfaces) more than 1 SD above the mean. The prediction was measured in terms of OR (odds ratio), sensitivity/specificity, and receiver operating characteristic curves. RESULTS: Statistically significant correlations (r=0.5) were found between the caries experience in the two dentitions as well as between the primary second molars at baseline and the permanent teeth at 10 years. 'Primary second molars' and 'all primary molars' were the most powerful predictors for allocation into the risk group (24% of the sample). The highest achieved sum of sensitivity and specificity, 148%, was attained at a cut-off point above two carious surfaces in enamel and/or dentin in primary second molars. CONCLUSIONS: Statistically significant relationship in disease between the dentitions was found. More than two surfaces with caries experience in primary second molars are suggested as a clinically useful predictor at 5 years of age for being at high risk at age 10.     

Secular changes in tooth size and dental arch dimensions in the mixed dentition

Secular changes in the mixed dentition were studied. Permanent tooth size and dental arch dimensions were examined in Norwegian children born in the 1960s and 1980s, Swedish children born in the 1960s and 1980s, Norwegian Sami children born in the 1980s, and a sample of Norwegian skulls dating from the 14th to the 19th century. The Norwegian Sami children were nomadic in the summertime. A sample of pigs was studied before and after a maceration process to determine what dimensional changes might occur in such a process. A shrinkage of 0.3%-1.7% was found. This information was used when the skulls were compared with the modern groups. Lateral dental arch lengths were shorter in the children born in the 1960s compared with the children born in the 1980s. This was a result of the higher prevalence of caries in the second deciduous molars in the 1960s groups. Children who had lost a deciduous canine prematurely were found to have smaller dental arch perimeters. When compared with other data, this was blamed on a pre-existing crowding. Permanent tooth size was smaller in the skulls compared with the modern groups. Improved nutrition is considered to be the main reason for the difference. Relative dental arch space differed in the group born in the 1960s from that in the other groups, indicating a greater prevalence of crowding in the former. Relative dental arch space in the skulls and in the group born in the 1980s was similar. A more traditional way of living, as practised by the Sami group in this thesis, was not favorable for relative dental arch space. The transverse intermaxillary relation in boys changed from the 1960s to the 1980s, which indicated that the 1980s group ran a greater risk of developing a posterior cross-bite. Before the same conclusion could be made in the girls, the mesial drift of the first permanent molars had to be corrected for, because of a higher prevalence of caries in the 1960s group. The sex-pooled analysis of the skulls and the contemporary groups revealed that the risk for developing a posterior cross-bite in the 1980s group was greater than in the skulls. The skulls had smaller arch depths than the modern groups.     

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。     

Infant orthopedics has no effect on maxillary arch dimensions in the deciduous dentition of children with complete unilateral cleft lip and palate (Dutchcleft).

OBJECTIVE: Evaluation of the effect of infant orthopedics on maxillary arch dimensions in the deciduous dentition in patients with unilateral cleft lip and palate. DESIGN: Prospective two-arm randomized controlled clinical trial with three participating cleft palate centers. SETTING: Cleft palate centers of the Radboud University Nijmegen Medical Center, Academic Center of Dentistry Amsterdam, and University Medical Center Rotterdam, the Netherlands. PATIENTS: Children with complete unilateral cleft lip and palate (n = 54) were included. INTERVENTIONS: Patients were randomly divided into two groups. Half of the patients (IO+) had a presurgical orthopedic plate until surgical closure of the soft palate at the age of 52 weeks; the other half (IO-) did not undergo presurgical orthopedics. MEAN OUTCOME MEASURES: Maxillary arch dimensions were assessed on dental casts at 4 and 6 years of age with measurements for arch width, arch depth, arch length, arch form, and the vertical position of the lesser segment. Contact and collapse were assessed also. RESULTS: There were no clinically significant differences found between IO+ and IO- for any of the variables. CONCLUSIONS: Infant orthopedics had no observable effect on the maxillary arch dimensions or on the contact and collapse scores in the deciduous dentition at the ages of 4 and 6 years. Considering the Dutchcleft results to date, there is no need to perform infant orthopedics for unilateral cleft lip and palate patients.     

The diastemas in deciduous dentition: the relationship to the tooth size and the dental arches dimensions.

Tooth size and different arch parameters were studied for influence in the presence or absence of diastemas in the primary dentition. The size of teeth scarcely influences the presence or absence of diastemas, but the dental arch dimensions are closely connected with diastemas.     

Effect of an intraoral retrusion plate on maxillary arch dimensions in complete bilateral cleft lip and palate patients.

OBJECTIVE: The aim of this study was to analyze maxillary arch dimensions in patients with complete bilateral cleft lip and palate treated with an intraoral retrusion plate prior to lip closure. PATIENTS: The effects of the intraoral retrusion plate were evaluated on serially obtained maxillary casts of 14 patients with complete bilateral cleft lip and palate. RESULTS: The Student's t test for dependent observations showed a significant decrease in distance between the premaxilla and the cleft lateral segments during active treatment. This decrease correlated with an increase in deviation of the premaxilla in relation to the vomer. For each millimeter decrease in distance between the premaxilla and the cleft lateral segments, an average increase in deviation of 4.0 degrees was found. Left and right cleft widths decreased significantly, premaxillary width increased significantly, and transverse dimensions did not change significantly. CONCLUSION: From this study it can be concluded that active presurgical treatment with an intraoral retrusion plate induces a significant decrease in distance between the premaxilla and the lateral segments. This decrease is frequently accompanied by an increase in deviation of the premaxilla relative to the vomer.     

Association between breastfeeding duration,non-nutritive sucking habits and dental arch dimensions in deciduous dentition: a cross-sectional study

Background

This cross-sectional retrospective study was conducted to determine association between breastfeeding duration, non-nutritive sucking habits, dental arch transverse diameters, posterior crossbite and anterior open bite in deciduous dentition.

Methods

415 children (228 males and 187 females), 4 to 6 years old, from a mixed Indian population were clinically examined. Based on written questionnaire answered by parents, children were divided into two groups: group 1 (breastfed for <6 months (n = 158)) and group 2 (breastfed for ≥6 months (n = 257)). The associations were analysed using chi-square test (P < 0.05 taken as statistically significant). Odds ratio (OR) was calculated to determine the strength of associations tested. Multivariate logistic regression analysis was done for obtaining independent predictors of posterior crossbite and maxillary and mandibular IMD (Inter-molar distance) and ICD (Inter-canine distance).

Results

Non-nutritive sucking (NNS) was present in 15.18% children (20.3% in group 1 as compared to 12.1% in group 2 (P = 0.024)). The average ICD and IMD in maxilla and average IMD in mandible were significantly higher among group 2 as compared to group 1 (P < 0.01). In mandible, average ICD did not differ significantly between the two groups (P = 0.342). The distribution of anterior open bite did not differ significantly between the two groups (P = 0.865). The distribution of posterior crossbite was significantly different between the two groups (P = 0.001). OR assessment (OR = 1.852) revealed that group 1 had almost twofold higher prevalence of NNS habits than group 2. Multivariate logistic regression analysis revealed that the first group had independently fourfold increased risk of developing crossbite compared to the second group (OR = 4.3). Multivariate linear regression analysis also revealed that age and breastfeeding duration were the most significant determinants of ICD and IMD.

Conclusions

An increased prevalence of NNS in the first group suggests that NNS is a dominant variable in the association between breastfeeding duration and reduced intra-arch transverse diameters which leads to increased prevalence of posterior crossbites as seen in our study. Mandibular inter-canine width is however unaffected due to a lowered tongue posture seen in these children.     

Spacing in deciduous dentition of Polish children in relation to tooth size and dental arch dimensions

Aim

To assess the prevalence of primary and secondary spacing in the deciduous dentition and its correlation to tooth widths and dental arch dimensions.

Subjects and methods

Dental casts of 50 preschool children free from malocclusion, were analysed. The width of each space was measured as the smallest distance between the proximal surfaces of the neighbouring teeth, parallel to the occlusal plane. Crown width was measured as the greatest distance between the mesial and distal surfaces of the crown, parallel to the occlusal plane. Intercanine widths were measured between cusp tips of upper and lower canines. Intermolar widths were measured between the central fossae of the second molars. Arch lengths were measured from the midpoint between the central incisors to the midpoint between the distal surfaces of the deciduous second molars.

Results

The primary spaces were present in the upper dental arch in 90% children, on the average 2.09 mm in maxilla and 1.25 mm in mandible. Their widths were dependent on upper intercanine width. Secondary spacing was present in 92% children in the upper dental arch (mean 2.86 mm) and 90% in the lower (mean 3.08 mm). Lower secondary spacing was correlated to lower intercanine width and lower arch length. Total absence of interdental spacing was found in 4% children.

Conclusions

Interdental spacing of the deciduous dentition is present in 96% of Polish children. Children with wider intercanine widths have wider primary spaces in maxilla and wider secondary spaces in mandible.     

Dental arch dimensions in patients with unilateral cleft lip and palate

In this investigation, dental arch dimensions during different ages were studied in 72 children with unilateral cleft of the lip, alveolar process, and palate and were compared with those of normal children. All the children with clefts were treated surgically by surgeons of the Lancaster Cleft Palate Clinic. The dental arch dimensions were studied with the use of dental casts during the time of full deciduous dentition (3 to 4 years of age), mixed dentition (8 to 9 years of age), and permanent dentition (12 years of age). The major findings were: (1) all maxillary interdental widths and lengths were significantly smaller than the normal dimensions at all ages, except for intermolar width at age 12 years; and (2) the mandibular arch dimensions seemed to be related to changes in the maxillary arch; however, the influence of surgical procedures in the maxillary arch is not reflected severely in mandibular arch dental position.     

从生物力学角度探讨牙列完整和牙列缺损时的应力变化

目的:从生物力学角度对牙间的邻面接触关系的生理作用进行观察,探讨在咀嚼受力时牙冠组织的应力分布状况。方法:选用1具成人头颅颌骨标本,牙列完整,覆牙合、覆盖正常,咬合关系良好,牙之间接触关系紧密。标本经处理后,在每颗牙的牙冠区贴1mm×1mm箔式电阻应变片。在上下牙列正中咬合状态时垂直加载,加载力为20kg。用YJD-17型电阻应变仪,测量牙冠组织的应力值(GPa)。实验分为3组,即完整牙列组,第一磨牙缺失组,下颌右侧第一磨牙、侧切牙、中切牙缺失组。结果:完整牙列时测得应力值分别为:第二磨牙3.4641,第二前磨牙0.5132,尖牙1.0264,其余均为0。第一磨牙缺失时所测得应力值分别为:第二磨牙5.003,第二前磨牙1.4113,其余牙位与完整牙所测得数据相似。第一磨牙、侧切牙、中切牙缺失的牙列缺损时应力值分别为:第二磨牙5.2603,第二前磨牙1.6679,尖牙3.2075,第一前磨牙0。结论:完整牙列受力时,牙合力通过牙之间的接触区传递分散,牙冠的应力值很小。牙列缺损缺牙区邻近牙组织应力值明显增加。