JAPAN: Old fashioned toothbrushes are losing favor with consumers who prefer electric models that feature increasingly advanced functions, such as generating sonic waves and heads that vibrate at high speed. Despite the higher price tag, the rapidly aging population and growing concerns about oral hygiene are helping to boost sales. Sonic toothbrushes offer users a sense that their teeth have been thoroughly cleaned in a short period of time, which helps enhance their popularity. However, exper...