A man found dead in his home in Maryborough last year suffered extensive facial fractures caused by "substantial force", an expert witness has told a Children's Court.
Two boys are charged with the murder of 45-year-old John Bourke, whose body was discovered in his Derby Street home on July 15 last year.
Victorian Institute of Forensic Medicine radiologist Dr Chris O'Donnell told a committal hearing that Mr Bourke sustained serious injury which would have required "substantial force to cause that degree of facial bone disruption".
"This is clearly not a trivial injury to the facial bones because of the extent and the deformity," Dr O'Donnell said.
Dr O'Donnell said there were significant fractures to the lower jaw bone, the front of the face and the cheek bone, which indicated at least three instances of substantial force.
The court heard Mr Bourke had a genetic condition called osteogenesis imperfecta, or brittle bone disease.
Dr O'Donnell said people with this condition would sustain fractures more easily and less force would be required to cause fractures.
Everyday activity could result in fractures for people with OI, he said, but it depended on the severity of their condition.
Dr O'Donnell said a person's inactivity could increase the risk of fracture.
The forensic radiologist told the court he identified numerous fractures in Mr Bourke's bones through his examination of imaging, including fractures that were recent, healing and healed.
A number of the fractures were acute, or recent, Dr O'Donnell said, with no evidence of healing.
He said the fractures in the face showed no evidence of healing and fractures to two vertebrae in the thoracic spine were also recent.
A recent fracture had occurred around a metal pin in the thigh bone where there had previously been surgical intervention, Dr O'Donnell said, and almost every rib had been fractured, with the condition of various injuries ranging from healed to healing to acute.
He said there was evidence Mr Bourke had suffered multiple fractures in the past.
The committal will continue later this year.
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