Mandibular movements in children with deciduous and mixed dentition and in young adults with permanent dentition-the association between movements and occlusal traits.

BACKGROUND: Cross-sectional studies of mandibular movements provide data on developmental trends of dentition and support planning of public health services. OBJECTIVE: The aim of this study was to measure mandibular movement capacities in children with deciduous and mixed dentition and in young adults with permanent dentition. The influence of age and gender on mandibular movements and the association between mandibular movements and occlusal traits were analysed. METHOD: The sample consisted of 1172 Estonians: group 1: children with deciduous dentition; group 2: children with mixed dentition; and group 3: young adults with permanent dentition. Maximum opening, mandibular laterotrusion, and protrusion were registered. RESULTS: Age was correlated with mandibular movements. Young adults had statistically significantly larger mandibular movements as compared to children with deciduous and mixed dentition, and children with mixed dentition had larger mandibular movements as compared to children with deciduous dentition. Young adult males had larger mandibular movements than females of the same age. Associations were found between mandibular movement capacities and some occlusal traits. Mandibular movement capacities were smaller in children with crossbite and open bite as compared with children without corresponding occlusal traits. Mandibular movement capacities were larger in children with deep bite and increased overjet as compared with those without corresponding occlusal traits. CONCLUSION: Mandibular movement capacities are age and gender dependent. Maximum mouth opening, mandibular laterotrusion, and protrusion are related, and mandibular movement and some occlusal traits are associated.

Occlusal traits of 4-5-year-old Estonians. Parents' perception of orthodontic treatment need and satisfaction with dental appearance.

This study aims to evaluate the prevalence of occlusal traits and to assess parents'/caregivers' satisfaction with child's dental appearance and perception of orthodontic treatment need in 4-5-year-old Estonians. Clinical records and plaster casts of 390 children (190 girls and 200 boys, mean age 4.7 years, range 4 - 5 years) were analyzed. Assessed occlusal traits included deciduous canine and second molar sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite, and scissor bite. Parents'/caregivers' opinions regarding their child's teeth were determined with a questionnaire. The most prevalent occlusal traits were symmetrical sagittal relationship in deciduous canines (78.2%) and molars (75.1%), Class I sagittal relationship in deciduous canines (69.7%) and midline diastema (67.7%). Asymmetrical sagittal canine relationship was registered in 21.8% deciduous canines and in 24.9% second deciduous molars. Parents'/caregivers' perceived orthodontic treatment need was related to Class III sagittal relationship in canines, increased overjet and overbite, negative overbite, and crossbite. Prevalence of most occlusal traits in Estonian children were in line with those reported in neighboring countries. Parents/caregivers were well able to observe occlusal traits that deviated from acceptable occlusion.

Occlusal traits, orthodontic treatment need and treatment complexity among untreated 17-21-year-olds in Estonia.

Objective: To analyze data on occlusal traits, orthodontic treatment need and treatment complexity in orthodontically untreated 17-21-year-old Estonians.Materials and methods: Clinical records and plaster casts of 390 untreated young adults (219 females and 171 males, mean age 18.5 years, range 17-21 years) were analyzed. Assessed occlusal traits included first molar and canine sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite and scissor bite. The Index of Complexity, Outcome and Need (ICON) was used to assess orthodontic treatment need and complexity. Participants' opinions regarding their teeth were determined with a questionnaire.Results: The most prevalent occlusal traits were Class I sagittal relationship in canines (76%) and molars (70%), crowding (51%), overbite ≥3.5 mm (48%), the end-to-end sagittal relationship in canines (48%) and overjet ≥3.5 mm (47%). Antero-posterior asymmetry was common both in canines (39%) and molars (37%). According to ICON, 36% of participants had orthodontic treatment need.Conclusions: Desire for orthodontic treatment was associated with crowding and increased overjet, and with no gender difference, participants' main expectation of treatment was an improvement in dentofacial aesthetics. Treatment needs determined with ICON was moderate and in line with the participants' desire for orthodontic treatment.

Occlusal traits and orthodontic treatment need in 7- to 10-year-olds in Estonia.

The aim of this study was to evaluate the distribution of occlusal traits and orthodontic treatment need and complexity in Estonian 7- to 10-year-old children. This data provides solid information for planning of orthodontic care. Data of 392 Estonian children (198 girls and 194 boys, mean age 9.0 years, range 7.1-10.4 years) was analysed in this cross-sectional study. Assessed traits included first molar and canine sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite, and scissor bite. Orthodontic treatment need and complexity were assessed using the Index of Complexity, Outcome, and Need. Parents' opinion regarding their child's teeth was determined using a questionnaire. The most prevalent occlusal traits were canine class I sagittal relationship (73.7%), midline diastema (73.0%), molar class I sagittal relationship (57.4%), and overbite ≥3.5 mm (51.8%). According to the Index of Complexity, Outcome, and Need, 64.3% of Estonian elementary school children were in need of orthodontic treatment. Treatment complexity was simple in 12.5%, mild in 38.8%, moderate in 22.7%, difficult in 14.0%, and very difficult in 12.0% of the children. Approximately 66.4% of the parents felt that their child needed orthodontic treatment. This study confirms earlier findings indicating that the most frequent sagittal relationship is class I in the first molars and class I in the canines. However, the sagittal relationship was asymmetric in more than half of the children. Correlation between objectively defined treatment need and parents' desire for treatment was high in Estonia.