[Allergies to dental metals. Titanium: a new allergen]

Oral allergies are underdiagnosed by dental health professionals. Patients with an oral allergy complain of various symptoms such as burning or tingling sensations, with or without oral dryness or loss of taste, or of more general symptoms such as headache, dyspepsia, asthenia, arthralgia, myalgia. The signs of oral allergy include erythema, labial oedema or purpuric patches on the palate, oral ulcers, gingivitis, geographical tongue, angular cheilitis, perioral eczematous eruption, or lichenoid reactions localized on the oral mucosa. There is an increase in the prevalence of oral allergies to metals used in dental materials. Allergy to gold included in dental prosthesis has been well documented since the years eighties. Recently, titanium, used in orthopedic devices and oral implants, considered as an inert material, can induce toxicity or allergic type I or IV reactions. These reactions to titanium could be responsible for unexplained successive failure cases of dental implants in some patients (named "cluster patients"). The risk of an allergy to titanium is increased in patients who are allergic to other metals. In these patients, an evaluation of allergy is recommended, in order to exclude any problem with titanium medical devices. We stress the importance of a multidisciplinary approach to take into account patients with an oral allergy, with participation of specialists from dental and dermatologic fields.

[Neurotropic metastasis of squamous cell carcinoma]

INTRODUCTION

Epidermoid skin carcinoma is the second most frequent skin cancer. It is rarely considered as aggressive. Other than its extension through the blood of lymph circulation, perineural invasion is also a significant form of tumoral invasion. We report a case of recurrent epidermoid skin carcinoma beginning with a neurological symptomatology.

OBSERVATION

A 77 year-old man with a history of right fronto-temporal epidermoid skin carcinoma turned up at our clinic with a ptosis of the right eyelid and hypoesthesia in the nerve VI area. He later developed pain in the arch of the eyebrow and diplopia. Five weeks later, two subcutaneous nodules appeared. Histology revealed a neuro-invasive epidermoid carcinoma explaining the clinical picture. Re-loading of the histological sections of the first injury confirmed the clearly differentiated invasive epidermoid carcinoma. However, renewed classified sections revealed neoplastic cells surrounding the nerve branches in the deep dermis.

DISCUSSION

Other than the extension through the blood or lymph circulation, epidermoid cutaneous cancers exhibit varying invasion of the nerve structures. Neurotropism is an aggressiveness marker. Only the pathologico-anatomic investigation enables an early diagnosis. In the case of recurrence, neurological symptomatology can precede skin injuries and make diagnosis difficult. The follow-up of the carriers of this type of tumor must include a neurological examination.

Micronuclei to detect in vivo chemotherapy damage in a p53 mutated solid tumour

Apoptosis induction and micronuclei formation were compared following cytotoxic treatments in two rat glioma differing in p53 integrity. In vitro, micronuclei emergence but not apoptosis was linked to the p53 mutated status. In vivo, micronuclei assays were more sensitive to evaluate DNA damage induced by chemotherapy in a p53-mutated solid tumour.