Risk assessments in orthodontic patients developing white spot lesions.

AIM: To determine whether caries risk factors, including cariogenic bacterial levels and salivary function, can be used to identify orthodontic patients who develop white spot lesions (WSL). METHODS: This prospective case-control study comprised 50 patients 11-17 years of age, including 25 controls and 25 cases who developed new WSL during treatment. WSL, oral hygiene and fluorosis were evaluated from intraoral photographs. The biofilm was assessed with bacterial cultures and adenosine triphosphate (ATP) bioluminescence. Salivary analyses were performed to determine the pH of saliva and flow rates. A survey was used to assess snacking frequency, oral hygiene and fluoride utilization. RESULTS: There were no between-group pretreatment differences in WSL. Cases reported eating sugary foods significantly more often than the controls. There was a significant decline in oral hygiene during treatment, with no significant between-group difference. There also were no statistically significant between-group differences in the amount of saliva, buffer, ATP bioluminescence and bacterial levels. Both groups showed lower than normal buffer capacity and high bacterial levels. CONCLUSION: Cases had greater sugar intake between meals than controls. ATP bioluminescence, Streptococcus mutans levels with Saliva Check Mutans, and salivary factors do not identify patients who develop WSL.

Sex differences in jaw muscle duty factors during exercise in two environments: A pilot study.

It is unknown if females and males use jaw muscles similarly during exercise. This pilot study assessed jaw elevator muscle duty factors (DFs=time of muscle activity/total recording time) at repeated sessions to test if DFs are reliable and different between sexes during exercises in two environments. Ten female and seven male subjects recruited from university soccer teams provided informed consent. Surface electromyography was recorded from masseter and temporalis muscles during biting and leg-extension laboratory exercises. Average activities to produce 20N bite-forces for each muscle and subject determined thresholds (5-80%·T20N) for subject-specific DF calculations during exercises performed in laboratory and natural environments. Subjects self-recorded via portable electromyography equipment during in-field leg-extension and weight-lifting exercises. Effects of variables on DFs were assessed via ANOVA (α=0.05) and simple effects testing (Bonferroni-adjusted p⩽0.012). All subjects used jaw muscles during exercises in both environments. DFs between laboratory sessions were reliable (R=0.84). During laboratory exercises, male temporalis DFs were significantly higher than female DFs from both muscles (p⩽0.001). During in-field exercises females had higher DFs during weight-lifting while males had higher DFs during leg-extensions. In-field sex differences were significant at most thresholds and showed larger effect sizes for leg-extension compared to weight-lifting exercises.