Condyle modeling stability, craniofacial asymmetry and ACTN3 genotypes: Contribution to TMD prevalence in a cohort of dentofacial deformities

PLoS One. 2020 Jul 29;15(7):e0236425. doi: 10.1371/journal.pone.0236425. eCollection 2020.

Abstract

Craniofacial asymmetry, mandibular condylar modeling and temporomandibular joint disorders are common comorbidities of skeletally disproportionate malocclusions, but etiology of occurrence together is poorly understood. We compared asymmetry, condyle modeling stability and temporomandibular health in a cohort of 128 patients having orthodontics and orthognathic surgery to correct dentofacial deformity malocclusions. We also compared ACTN3 and ENPP1 genotypes for association to clinical conditions. Pre-surgical posterior-anterior cephalometric and panometric radiographic analyses; jaw pain and function questionnaire and clinical examination of TMD; and SNP-genotype analysis from saliva samples were compared to assess interrelationships. Almost half had asymmetries in need of surgical correction, which could be subdivided into four distinct morphological patterns. Asymmetric condyle modeling between sides was significantly greater in craniofacial asymmetry, but most commonly had an unanticipated pattern. Often, longer or larger condyles occurred on the shorter mandibular ramus side. Subjects with longer ramus but dimensionally smaller condyles were more likely to have self-reported TMD symptoms (p = 0.023) and significantly greater clinical diagnosis of TMD (p = 0 .000001), with masticatory myalgia most prominent. Genotyping found two significant genotype associations for ACTN3 rs1671064 (Q523R missense) p = 0.02; rs678397 (intronic SNP) p = 0.04 and one significant allele association rs1815739 (R577X nonsense) p = 0.00. Skeletal asymmetry, unusual condyle modeling and TMD are common and interrelated components of many dentofacial deformities. Imbalanced musculoskeletal functional adaptations and genetic or epigenetic influences contribute to the etiology, and require further investigation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actinin / genetics*
  • Adult
  • Chin / diagnostic imaging
  • Dentofacial Deformities / diagnostic imaging
  • Dentofacial Deformities / genetics*
  • Dentofacial Deformities / pathology
  • Dentofacial Deformities / surgery
  • Face / diagnostic imaging
  • Female
  • Genetic Association Studies
  • Genetic Predisposition to Disease*
  • Humans
  • Jaw / diagnostic imaging
  • Male
  • Malocclusion / diagnostic imaging
  • Malocclusion / genetics
  • Malocclusion / pathology
  • Malocclusion / surgery
  • Mandibular Condyle / diagnostic imaging
  • Mandibular Condyle / pathology
  • Mandibular Condyle / surgery
  • Models, Dental
  • Orthognathic Surgical Procedures
  • Phosphoric Diester Hydrolases / genetics*
  • Polymorphism, Single Nucleotide / genetics
  • Pyrophosphatases / genetics*
  • Temporomandibular Joint Disorders / diagnostic imaging
  • Temporomandibular Joint Disorders / genetics*
  • Temporomandibular Joint Disorders / pathology
  • Temporomandibular Joint Disorders / surgery

Substances

  • ACTN3 protein, human
  • Actinin
  • Phosphoric Diester Hydrolases
  • ectonucleotide pyrophosphatase phosphodiesterase 1
  • Pyrophosphatases