Patients who underwent tooth extraction with continued oral bisphosphonate therapy showed delayed healing of the extraction socket as the cumulative administration period prolonged, but BRONJ did not develop.

: We report a case of synchronous squamous cell carcinoma of the mandibular gingiva and primary malignant lymphoma of the neck. A 51-year-old man was referred to our hospital for further evaluation of an intractable gingival ulcer. Physical examination at initial presentation showed an ulcerative lesion of the left mandibular molar gingiva with an irregular border and induration, which was diagnosed as squamous cell carcinoma on a biopsy. An imaging study showed mandibular invasion of squamous cell carcinoma and metastases to the left cervical lymph nodes. Marginal resection of the mandible and left neck dissection were performed with the patient under general anesthesia. There was no histopathological evidence of cervical lymph node metastasis. However, postoperative physical and radiographic findings at 2 months showed two swollen lymph nodes in the right side of the neck, suggesting early metastases to the contralateral cervical lymph nodes. Right neck dissection was performed with the patient under general anesthesia, and the histopathological diagnosis was malignant lymphoma （marginal zone B-cell lymphoma） . The final diagnosis was synchronous squamous cell carcinoma of the mandibular gingiva and primary malignant lymphoma of the neck. The patient was strictly followed up with no additional treatment because of the low malignancy of marginal zone B-cell lymphoma. There has been no evidence of recurrence or metastasis during the 6 years 9 months after the operation.

Aims: Methamphetamine (meth) is a powerful, highly addictive stimulant that affects the central nervous system, and its side effects may result in severe selfmutilation. This report describes a case of a meth user with severe oral injury that demonstrates the necessity for prompt treatment when severe tongue biting occurs. Methods and results: A 43-year-old meth-using man with severe tongue biting was left untreated for more than 24 hours, resulting in extensive ischemic changes in the tongue and eventual extensive tissue necrosis. After debridement and deep suture repair in several layers, the wound healed. However, tongue dysfunction and a speech disorder remained because of tongue shortening. Conclusion:Meth may induce or aggravate severe oral self-mutilation. Tongue biting with severe tissue damage may occur as oral self-mutilation in meth users; however, among self-mutilation behaviors, tongue biting is especially difficult to prevent. A withdrawal from meth and a behavioral approach may be necessary for fundamental prevention, but it is often difficult in high dependence users.When severe tongue biting occurs, prompt suture reconstruction must be performed before ischemic change occurs to prevent tissue necrosis. K E Y W O R D Smethamphetamine, self-mutilation, tissue necrosis, tongue biting INTRODUCTIONMethamphetamine (meth) is a widely abused psychostimulant. It is pharmacologically classified as an indirectly acting sympathomimetic 1,2 and may affect excitatory synaptic transmission via activation of the dopamine and serotonin receptor systems in the hippocampus. 3 Meth is considered more neurotoxic than amphetamine, which has a chemical structure similar to meth, due to its cationic lipophilicity allowing transport to the brain across the blood-brain barrier. 4 Meth, in the form of dextro-meth hydrochloride, is also used for medical purposes and has been approved© 2021 Special Care Dentistry Association and Wiley Periodicals LLC for the treatment of attention deficit hyperactivity disorder, extreme obesity, and narcolepsy. 5 Meth, however, is often used recreationally and is most commonly smoked, but also snorted, injected, swallowed, or inserted rectally, 6 with harmful side effects. 7 Acute adverse effects of meth include subjective effects (e.g., anxiety, paranoia, and hallucination) and physiological effects (e.g., hypertension, hyperthermia, tachycardia, tachypnea, and anorexia). 8 Chronic use of meth may result in neurologic and psychiatric symptoms, including amnesia, confusion, depression, psychosis, violence, and suicidal ideation, which are caused by dopamine