Phenotypic analysis of discordant monozygotic twins for pain-related temporomandibular joint disorder. Case report

• Autor(a) principal: Magri,Lais Valencise
• Data de Publicação: 2022
• Outros Autores: Melchior,Melissa de Oliveira, da-Silva,Graziela Valle, Gherardi-Donato,Edilaine Cristina Silva, Leite-Panissi,Christie Ramos Andrade
• Tipo de documento: Relatório
• Idioma: eng
• Título da fonte: BrJP (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2595-31922022000200178
• topic: Chronic pain; Facial pain; Monozygotic twin; Temporomandibular joint disorders; Central nervous system sensitization

ABSTRACT BACKGROUND AND OBJECTIVES: The design of research with monozygotic twins discordant for the disease has emerged as a powerful tool for the detection of phenotypic risk factors. The aim of this study is to report a clinical case of monozygotic twins discordant for pain-related temporomandibular joint disorder (TMD) from a cognitive-behavioral-emotional phenotypic analysis, from the comparison of clinical variables of pain, history of exposure to painful procedures in early childhood, and coping with pain. CASE REPORT: TMD-Twin presented a diagnosis of painful (myofascial pain with referral) and joint (disk displacement with reduction) TMD according to the criteria of the DC/TMD. Control-Twin did not show TMD, however she presented other chronic pains. TMD-Twin showed reduced pressure pain threshold, hyperalgesia in trigeminal and extra-trigeminal regions compared to the Control-Twin. TMD-Twin was more exposed to painful procedures and emotional events due to congenital heart problems. Both had central sensitization based on the Central Sensitization Inventory, although TMD-Twin had more catastrophic thoughts about pain. TMD-Twin presented an internal locus of control. CONCLUSION: Both monozygotic twins presented a chronic pain phenotype, although they were discordant with the TMD-related pain. The main differences were the lower pressure pain threshold and higher hyperalgesia locally presented by TMD-Twin. The internal locus of control indicates greater pain sensitivity, with better coping of the painful experience for the TMD-Twin. One possible explanation for this clinical condition can be that painful experiences in early childhood have shaped a phenotype of greater sensitivity with better coping and resilience to the painful condition.