Monday Mourning

Replacing the mandibular fragments of 38427, Bergeron moved back to 38428, picked up the skull, and aimed his penlight.

“There was something on this one…” Bergeron’s voice trailed off.

“What?”

Bergeron swapped the skull for the jaw, and aimed his beam at the lower dentition.

“Yes.”

Abandoning the scope, I joined him.

“What?”

“This should clarify the uncertainty on your dates.”

Bergeron handed me the skull and penlight.

21

“TIP THE CRANIUM, THEN MOVE THE LIGHT BACK AND FORTH over the molars.”

I did as Bergeron instructed.

“Do you see a glossiness in the folds of the enamel?”

I didn’t.

“Angle the beam.”

Bergeron was right. The shine was subtle but present, way down in the grooves.

“What is it?”

“If I’m not mistaken, the molars have been treated with a pit and fissure sealant.”"

"When I looked up, Bergeron was gangling his way to the scope. The man was definitely not poetry in motion.

“Sealant is a thin coating of plastic resin that’s applied to the chewing surface of a bicuspid or molar.

It’s painted on as a liquid, and in roughly a minute it hardens to form a protective shield.”

“What’s the purpose?”

“To prevent occlusal caries. Tooth decay.”

Bergeron slipped the lower jaw of LSJML-38428 under the lens, peered through the eyepieces, and adjusted focus.

“Oui, madame. That’s a sealant.”

Hope did a little moth-flutter in my chest.

“When did these sealants come into use?”

“The first commercially available sealants were marketed to dentists in the early 1970s.

They’ve been in widespread use since the eighties.” Bergeron spoke without looking up.

The moth exploded into a hummingbird.

The girl in the leather shroud couldn’t have died in the fifties! By elimination, that jumped her to the late eighties!

I tried to keep my voice calm.

“How common are these sealants?”

“Unfortunately for forensic purposes, very. Most pediatric dentists recommend application once the permanent molars erupt. School-based programs have been under way in a majority of American states for at least twenty years.

Canada’s a bit behind in that, but sealants have been very popular here since the mid-eighties.”

Bergeron clicked off the fiber-optic light.

“Didn’t help this young lady much.” He thrust his chin at Dr. Energy’s girl. “She’s got more decay than that one over there.”

“So she was seeing a dentist at one point, then quit caring for her teeth.”

“Typical pattern for runaways.