Establishing Cephalometric Norms in Primary Dentition Using Comprehensive Craniofacial Growth Analysis - A Digital Cephalometric Study

ABSTRACT Objective: To establish cephalometric norms in primary dentition among males and females using novel customized Comprehensive Cephalometric Growth (CCG) Analysis. Material and Methods: The study was conducted on 67 subjects with a mean age of 5.5 yrs. Digital lateral cephalometric radiographs were obtained using Planmeca Pro One. The digital images were then transferred to Nemoceph software. Craniofacial Growth (CCG) Analysis was configured in the software with five sub-groups. This sub-grouping was done such that related components were grouped together and comprehensively; it would provide an assessment of every component of the craniofacial region that could be affected either by treatment maneuver or growth process. The same was used for the cephalometric analysis and to determine the cephalometric norms in the primary dentition. Results: Certain linear measurements were higher among males when compared to females. However, most measurements remained similar among males and females during this age group. The CCG analysis provided a comprehensive knowledge of the craniofacial parameters during the growth process. Conclusion: The cephalometric norms during primary dentition thus established using Comprehensive Craniofacial Growth analysis would provide the data for early diagnosis and treatment planning in interceptive orthodontic treatment procedures.

Influence of Gestational Age on Eruption of Primary Teeth in Indian Children - A Prospective Longitudinal Study

Context: Eruption of primary teeth is the most anticipated event in a child’s life. Genetics, gender, socio?economic status, gestational age are a few of the determinants of the primary teeth eruption. However, the effect of gestational age on the timing of primary teeth eruption among the Indian population has not been explored to date. Aim: The study was conducted to evaluate the influence of gestational age on time and sequence of eruption of primary teeth among children of Mysore. Settings and Design: A prospective longitudinal cohort study design was conducted at ‘Baby Oral Health Promotion Clinic’ at the Department of Paediatrics, JSS Hospital, Mysore. Methods and Material: 150 newborn babies were recruited by simple random sampling and followed up from birth to 36 months. Teeth present during each visit were recorded. Data were statistically analysed and interpreted. Statistical Analysis Used: Descriptive statistics, t?test for an independent sample, and Pearson’s Chi?squared test were applied. Results: The mandibular central incisor was the first tooth to erupt. Statistically insignificant early eruption in males was noted in both term and preterm children. When the chronological ages were compared, the preterm group showed a statistically significant delay in the eruption of all the teeth. However, when the age was adjusted for prematurity, only the central incisors and second molars showed a statistically significant delay. Conclusions: Gestational age has a strong significant association with the eruption of primary teeth and maybe one of the strong predictors for delayed eruption among children of Mysore.

Comparative evaluation of shear bond strength of nano‑hydroxyapatite incorporated glass ionomer cement and conventional glass ionomer cement on dense synthetic hydroxyapatite disk: An in vitro study.

Aim: The aim was to evaluate and compare the shear bond strength of nano‑hydroxyapatite (Nano‑HAp) incorporated and conventional glass ionomer cement (GIC). Materials and Methods: Nano‑HAp GIC was prepared by replacing 8 wt% of GIC powder with nano‑HAp powder. Twenty‑six HAp disks were used as substrate for bonding and divided into two equal groups. Before bonding the HAp disk was prepared by silicon carbide (no. 2500) followed by 10% polyacrylic acid conditioning. The standardized samples were prepared using split teflon mold on customized bonding jig so as to adhere testing materials to pretreated HAp disk. These samples were stored in distilled water for 24 h at 37°C before bond strength testing. Results: The descriptive statistical analysis and independent samples t‑test were used. The nano‑HAp incorporated and conventional GIC had the mean shear bond strength of 3.28 ± 0.89 MPa and 5.25 ± 0.88 MPa, respectively. Nano‑HAp incorporated GIC had lower shear bond strength with very high level of significance (P < 0.001). The nano‑HAp incorporated GIC showed mainly mixed type of failure whereas conventional GIC showed mainly a cohesive failure. Conclusion: The lower shear bond strength of nano‑HAp incorporate GIC revealed that the addition of nano‑HAp interfered with the bonding ability of GIC to the substrate interface, but the mixed type of failure in nano‑HAp incorporated GIC suggests that it increases the strength of the matrix. However, the role of nano‑size particles on the micro‑size particles of GIC for the bonding mechanism and the ratio and proportions of nano‑HAp to the GIC needs further elucidation.