Temporomandibular Joint Pathology and Its Indication in Clinical Orthodontics Temporomandibular Joint Pathology and Its Indication in Clinical Orthodontics

Temporomandibular joint (TMJ) pathology has been an area of study in dentistry


Factors at the cellular level
Cellular factors can be defined as factors that exert their activity at the extracellular level, includinggrowthfactors,cytokines,extracellularmatrix(ECM)andothertypesofproteins. Growthfactorsandcytokinesserveaslocalmediatorsinresponsetomechanicalandinflammatorystimuli,whileECMserveasintercellularstructuralsupport [14].

Factors at the molecular level
Molecularfactorscanbedefinedasfactorsthatoperatewithinthecellbymeansofgenetic andotherintracellularfactors.Suchfactorscanbecategorizedintotranscriptionfactors,novel genes specific for condylar growth and other intracellular proteins. Transcription factors control genetic expression, while intracellular proteins control signal transduction and cell cyclingpathways.

Stepwise versus single-step mandibular advancement
There has been extensive literature for the comparison of two approaches of mandibular advancement: stepwise versus single-step advancement. Currently, stepwise advancement has been determined as being the preferable therapy.
Oneofthereasonssupportingstepwiseadvancementistheimprovementinskeletaleffect, mostnotablythesagittaljawrelationshipwiththemaxilla,assumingamoreforwardpositionedmandibleduetomoregrowththansingle-stepadvancement [21,95].Thisimprovement may be attributed to work completed by Petrovic et al. who found that the forward repositioning of the mandible periodically increases the rate and amount of growth in the condylar cartilage [96].VanLamandRabiealsofoundthatstepwisetreatmentwascorrelated withsignificantlygreaternewboneformation [21].
One modality of stepwise advancement in orthodontic treatment is the Herbst appliance; duetotheadvantagesofstepwisetreatment,ithasbeenrecommendedtobeincludedinan