Im not sure what the OMAS scale is but I am a head and neck review radiographer, I run a clinic weekly to monitor and assist in the the side effects of our head and neck patients. I would be happy to offer my assistance. We currently prescribe a product called gelclair which helps to reduce the effects of mucocitis and have been using it for sometiem and seeing its effectiveness. We did previously use MUguard but I understand that this product has been discontinued in the uk but widely used in the U.S

Hi

Oral complications of cancer treatment arise in various forms and degrees of severity, depending on the individual and the cancer treatment. Chemotherapy often impairs the function of bone marrow, suppressing the formation of white blood cells, red blood cells, and platelets (myelosuppression). Some cancer treatments are described as stomatotoxic because they have toxic effects on the oral tissues. Following are lists of side effects common to both chemotherapy and radiation therapy, and complications specific to each type of treatment. You will need to consider the possibility of these complications each time you evaluate a patient with cancer.

Oral complications common to both chemotherapy and radiation

Oral mucositis: inflammation and ulceration of the mucous membranes; can increase the risk for pain, oral and systemic infection, and nutritional compromise.

Infection: viral, bacterial, and fungal; results from myelosuppression, xerostomia, and/or damage to the mucosa from chemotherapy or radiotherapy.

Xerostomia/salivary gland dysfunction: dryness of the mouth due to thickened, reduced, or absent salivary flow; increases the risk of infection and compromises speaking, chewing, and swallowing. Medications other than chemotherapy can also cause salivary gland dysfunction. Persistent dry mouth increases the risk for dental caries.

Functional disabilities: impaired ability to eat, taste, swallow, and speak because of mucositis, dry mouth, trismus, and infection.

Taste alterations: changes in taste perception of foods, ranging from unpleasant to tasteless.

Nutritional compromise: poor nutrition from eating difficulties caused by mucositis, dry mouth, dysphagia, and loss of taste.

Abnormal dental development: altered tooth development, craniofacial growth, or skeletal development in children secondary to radiotherapy and/or high doses of chemotherapy before age 9.

Other complications of chemotherapy

Neurotoxicity: persistent, deep aching and burning pain that mimics a toothache, but for which no dental or mucosal source can be found. This complication is a side effect of certain classes of drugs, such as the vinca alkaloids.

Bleeding: oral bleeding from the decreased platelets and clotting factors associated with the effects of therapy on bone marrow. 

Other complications of radiation therapy

Radiation caries: lifelong risk of rampant dental decay that may begin within 3 months of completing radiation treatment if changes in either the quality or quantity of saliva persist.

Trismus/tissue fibrosis: loss of elasticity of masticatory muscles that restricts normal ability to open the mouth.

Osteonecrosis: blood vessel compromise and necrosis of bone exposed to high-dose radiation therapy; results in decreased ability to heal if traumatized.

http://www.nidcr.nih.gov/oralhealth/Topics/CancerTreatment/OralComplicationsCancerOral.htm