Background: Teeth requiring extraction before radiotherapy in head & neck cancer patients should be removed as long as possible before the initiation of radiation therapy. Conventionally, a minimum 2-week waiting primary healing period is recommended. Although the above 2-week period is ideal, it was not uncommon for the radiotherapist and cancer patient to feel an urgent need to process with radiotherapy despite the need for dental care. Therefore, alternative approaches for early radiotherapy, including conservative endodontic treatment and a 1-week waiting primary healing period after dental extraction at the time of radiotherapy, were considered and applied based on the experimental study Materials and Methods: Eighteen dogs were processed for histopathologic wound healing. The effect of the primary endodontic treatment and extraction before early radiotherapy was examined. Results: No specific complication, such as, post-extraction wound infection, radiation osteitis and osteoradionecrosis, were encountered despite the early radiotherapy. Conclusion: Based on the experimental study, a minimum 1-week waiting primary healing period for oral care before radiotherapy is suitable for the early radiotherapy in head and neck cancer patients.