By "splinters" I meant material consistent with the wood of the paintbrush.
From Foreign Faction: Who Really Kidnapped JonBenet? by James Kolar:
"The site of the damaged tissue was excised and prepared for a pathology slide. Later examination would reveal the presence of 'cellulose material' in the membrane of the hymeneal opening that was consistent with the wood of the paintbrush used as a handle in the cord of the garrote."
Cellulose material may not necessarily be wood from the paintbrush.
This is an assumption that has been made without the backing of any forensic evidence.
It could have just as easily been cellulose from toilet paper.
Not quite sure where I heard about the healing of the bruising, but here is what Dr. McCann had to say about the bruising, which I believe I already posted in response to one of tovarisch's questions:
From The Bonita Papers:
"There was a three dimensional thickening from inside to outside on the inferior hymeneal rim with a bruise apparent on the external surface of the hymen and a narrowing of the hymeneal rim from the edge of the hymen to where it attaches to the muscular portion of the vaginal openings. At the narrowing area, there appeared to be very little if any hymen present. There was also exposure of the vaginal rugae, a structure of the vagina which is normally covered by an intact hymen. The hymeneal orifice measured one centimeter which is abnormal or unusual for this particular age group and is further evidence of prior sexual abuse with a more recent injury as shown by the bruised area on the inferior hymeneal rim. A generalized increase in redness of the tissues of the vestibule was apparent, and small red flecks of blood were visible around the perineum and the external surface of the genitalia"
The Bonita Papers are not actually evidence in the case.
I believe they are actually a rough draft of notes from someone who was intending to write a book.
As for McCann, he has written many papers on physical injuries and sexual assault. Here is one.
http://pediatrics.aappublications.org/content/119/5/e1094.abstract
It says, in part:
"RESULTS. The injuries that were sustained by the 113 prepubertal girls consisted of 21 accidental or noninflicted injuries, 73 secondary to abuse, and 19 “unknown cause” injuries. All 126 pubertal adolescents were sexual assault victims. The hymenal injuries healed at various rates and except for the deeper lacerations left no evidence of the previous trauma. Abrasions and “mild” submucosal hemorrhages disappeared within 3 to 4 days, whereas “marked” hemorrhages persisted for 11 to 15 days. Only petechiae and blood blisters proved to be “markers” for determining the approximate age of an injury. Petechiae resolved within 48 hours in the prepubertal girls and 72 hours in the adolescents. A blood blister was detected at 34 days in an adolescent. As lacerations healed, their observed depth became shallower and their configuration smoothed out. Of the girls who sustained “superficial,” “intermediate,” or “deep” lacerations, 15 of 18 prepubertal girls had smooth and continuous appearing hymenal rims, whereas 24 of 41 adolescents' hymens had a normal, “scalloped” appearance and 30 of 34 had no disruption of continuity on healing. The final “width” of a hymenal rim was dependent on the initial depth of the laceration. No scar tissue formation was observed in either group of girls. "
While this is consistent with some sexual contact either just prior or at the time of her death, the AR says there is some hyperemia (skin redenning) but no blood blister or petechiae to enable determination of the age of previous injury.
McCann's findings seem to contradict the assumption that any prior sexual assault would leave scarring or thickening.
I don't believe the word "chronic inflammation" mentioned in the AR should lead people to believe this refers to ongoing or persistent sexual assault prior to the night of her death.
JonBenet was know to suffer from frequent vulvovaginitis,
https://pedclerk.bsd.uchicago.edu/page/vulvovaginitis-prepubertal-child
(Note one of the causes is a 'foreign body' in the form of toilet paper.)