Find Orphaned SharePoint Items using PowerShell script

The script below helps you find the orphaned items from SharePoint content databases

if ((Get-PSSnapin -Name Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue) -eq $null )
{Add-PSSnapin Microsoft.SharePoint.Powershell}

$CntDBs = Get-SPContentDatabase

ForEach ($CntDB in $CntDBs)
{   
      Write-Host "Detecting Orphans for " $CntDB.Name    $CntDB.Repair($false)
}

The above script will only list down the Orphaned items. You  can also repair these by changing

$CntDB.Repair($false) to $CntDB.Repair($true)

However before doing any such repair, you should be taking a back up of your DB.