BANGOR — The Maine Supreme Judicial Court has rejected the appeal of a man who was convicted of manslaughter in the death of his 3-month-old son.

Dustin Brown of Bangor was 18 when he said his son, Xander, went limp during a feeding on Nov. 25, 2012.

He challenged the evidence that led to his conviction and 4½-year prison sentence.

The medical examiner determined that the infant died from a head injury, but the defense contended that the death was a “medical mystery.”

The judge who heard the case concluded that Brown caused the infant’s traumatic brain injury. The supreme court ruled Tuesday that the judge “found all the facts necessary” to support Brown’s conviction.