All that feel-good stuff doesn't come cheap, however—it's not unheard of for patient to spend $20,000 for a full-scale "smile restoration." Still, Lowenberg and Lituchy consider their fees to be substantially lower than those of their peers. Besides, they've been known to waive a bill here and there.

Television star Julianna Margulies is one such beneficiary of Lowenberg's largesse. In her pre-fame days nine years ago, when she was waitressing in New York, Lowenberg was more than willing to help her through a rough patch. "At the time, I was so broke I couldn't afford X-rays," the "ER" star recalls. "Marc was kind, sweet and very gentle. He gave me free X-rays until I could eventually pay him back, years later. "I consider Marc to be the Picasso of dentistry," adds Margulies, who still flies in from L.A. for office visits and has contributed her boyfriend, "Men Behaving Badly" star Ron Eldard, to Lowenberg's client roster. "He looks at teeth the way a painter looks at a canvas."

Not bad for a man who kicked off this illustrious career merely filling cavities, even if it was for old-school rock gods like Keith Richards, Bryan Ferry and Iggy Pop.

But at times, Lowenberg's obsession with gorgeous smiles has led him into some pretty murky waters. His first wife, for instance, whom he met while attending dental school, is probably still reeling from her years with him.