Hi Guest!
Great question. Unfortunately what we typically see with medical coverage of TMJ disorder treatment is that orthodontic treatment for TMJ disorders are considered non-covered.
As you mentioned, many medical coverage policies do state they will cover "removable intra-oral appliances" to treat TMJ disorders, as well other treatments such as trigger point injections.
For example, Aetna's medical policy titled "Temporomandibular Joint Disorders" states that "Orthodontic/bite adjustment services and orthodontic fixed appliances" is non-covered, found under the section IV B:
http://www.aetna.com/cpb/medical/data/1_99/0028.html"Aetna considers the following experimental and investigational for diagnosis and treatment of TMJ disorders:
28. Orthodontic/bite adjustment services and orthodontic fixed appliances"
Having said all of that - not all medical policies are created equal! There will be variance in what services are covered and not from policy to policy.
To answer your coding question - yes there should be both diagnosis (ICD-10) and procedure/equipment codes (CPT & HCPCS) included with the medical claim.
There are several diagnosis codes to choose from when it comes to TMJ disorders for your provider to choose from, such as:
M26.611 - Adhesions and ankylosis of right temporomandibular joint
M26.612 - Adhesions and ankylosis of left temporomandibular joint
M26.613 - Adhesions and ankylosis of bilateral temporomandibular joint
M26.621 - Arthralgia of right temporomandibular joint
M26.622 - Arthralgia of left temporomandibular joint
M26.623 - Arthralgia of bilateral temporomandibular joint
M26.631 - Articular disc disorder of right temporomandibular joint
M26.632 - Articular disc disorder of left temporomandibular joint
M26.633 - Articular disc disorder of bilateral temporomandibular joint
M26.641 Arthritis of right temporomandibular joint
M26.642 Arthritis of left temporomandibular joint
M26.643 Arthritis of bilateral temporomandibular joint
M26.651 Arthropathy of right temporomandibular joint
M26.652 Arthropathy of left temporomandibular joint
M26.653 Arthropathy of bilateral temporomandibular joint
M26.69 - Other specified disorders of temporomandibular joint
There are also symptom type codes, such as:
M79.11 - Myalgia of mastication muscle
R51.09 - Headache, unspecified
Now, as for the procedure/equipment code for braces: there actually is not a specific CPT or HCPCS code we are aware of to represent braces. So, practices may either use the "D" code (dental code) on the medical claim (many insurers these days will process "D" codes when they are medically necessary services), or can use the CPT code below and include a narrative report describing the procedure:
41899 - Unlisted procedure, dentoalveolar structures
Hope this helps!