ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.1 > S21.15 > S21.159 S21.159 Open bite of unspecified front wall of thorax without penetration into thoracic cavity Non-Billable/Non-Specific Codes S21.159A..., initial encounterS21.159D..., subsequent encounterS21.159S..., sequela