The Effect of Sleep Duration on Salivary Growth Hormone and Dental Occlusion in Relation to Height Status among Kindergarten Children

Background Sleep means relaxation and rest, it is an essential biological process that is required on a daily basis for all humans regardless of sex, age or ethnic origin, sleep deprivation is becoming most common in today's society compared to a few decades ago, short sleep duration adversely impacts human health. The purpose of this study was to assess the effect of sleep duration on preschool children growth and their dental occlusion. Material and Methods The sample composed of 150 children of 5 years old who were selected from different kindergartens in Baghdad. The children were divided into two groups according to sleep duration per day. For salivary Human Growth Hormone (HGH) identification, the unstimulated salivary sample was collected from 80 children under standardized condition then analyzed for assessment of HGH level. The occlusal assessment was carried out with the teeth in centric occlusion then height for age Z-score was calculated. Results The results reported that the mean value of salivary HGH was lower among children with 7-9 sleeping hr. /day than children with 10-12 sleeping hr. /day with statistically highly significant difference (Pless than 0.01). Concerning each gender the same highly significant difference finding was recorded (Pless than 0.01). The relation between salivary HGH concentration and sleeping hr. /day showed strong highly significant relation in positive direction for preschool children with 7-9 sleeping hr. /day, for preschool children with 10-12 sleeping hr. /day, and for total sample. The findings showed that 35.8% of preschool children with 7-9 sleeping hr. /day had a distal step, followed by 12.6% and 1.3% preschool children had flash terminal plane and mesial step respectively, while 33.8% of preschool children with 10-12 sleeping hr. /day had a mesial step, followed by 10.6% and 5.3% preschool children had flash terminal plane and distal step respectively. The results reported that the mean value of HAZ was highly significantly lower among children with 7-9 sleeping hr. /day than children with 10-12 sleeping hr. /day (Pless than 0.01). Concerning each gender the same finding was recorded with statistically highly significant difference (Pless than 0.01). For preschool children with 7-9 sleeping hr. /day, the relation between HAZ and sleeping hr. /day was weak non-significant in positive direction. For preschool children with 10-12 sleeping hr. /day, the relation between HAZ and sleeping hr. /day was weak non- significant in negative direction. For total preschool children, the relation between HAZ and sleeping hr. /day was highly significant in positive direction. The results also showed that the percentage of HAZ above average (above 1 SD), with average (0 SD) and below Average (below -1 SD) were 13.3%, 50.7% and 17.3 respectively, with 13.3% and 5.3% children were suffer from stunting and sever stunting (below -2 SD and -3 SD of the reference CDC population) respectively among preschool children with7-9 sleeping hr. /day, while the percentage of HAZ above average (above 1 SD), with average (0 SD) and below average (below -1 SD) were 41.3%, 56% and 2.7% respectively, with no children were suffer from stunting or sever stunting among preschool children with 10-12 sleeping hr. /day. Conclusions The findings of the present study showed that the sleep duration per day might affect children growth and their dental occlusion.