It is theorized that CD8+ immune cells become overactive by stimulation from drugs or drug metabolites. CD8+ T cells then mediate keratinocyte cell death through release of a number of molecules, including perforin, granzyme B, and granulysin. Other agents, including tumor necrosis factor alpha and Fas ligand, also appear to be involved in TEN pathogenesis. Diagnosis
The diagnosis of TEN is based on both clinical and histologic findings. Early TEN can resemble non-specific drug reactions, so clinicians should maintain a high index of suspicion for TEN. The presence of oral, ocular, and/or genital mucositis is helpful diagnostically, as these findings are present in nearly all patients with TEN. The Nikolsky sign (a separation of the papillary dermis from the basal layer upon gentle lateral pressure) and the Asboe-Hansen sign (a lateral extension of bullae with pressure) are also helpful diagnostic signs found in patients with TEN.Given the significant morbidity and mortality from TEN, as well as improvement in outcome from prompt treatment, there is significant interest in the discovery of serum biomarkers for early diagnosis of TEN. Serum granulysin and serum high-mobility group protein B1 (HMGB1) are among a few of the markers being investigated which have shown promise in early research. Histology
Definitive diagnosis of TEN often requires biopsy confirmation. Histologically, early TEN shows scattered necrotic keratinocytes. In more advanced TEN, full thickness epidermal necrosis is visualized, with a subepidermal split, and scant inflammatory infiltrate in the papillary dermis. Epidermal necrosis found on histology is a sensitive but nonspecific finding for TEN.
Macrognathism is an abnormally large or protruding jaw. The opposite condition is called micrognathia. Causes
Heredity
Pituitary gigantism
Pagets disease of bone
Acromegaly
Fetal alcohol syndrome
Leontiasis ossea
Cleidocranial dysplasia

Treatment
Treatment is surgical. Osteotomy may be done in case of maxillary macrognathia. Mandibular macrognathia is generally managed by resection of a portion of the mandible. == References ==