Jaw clenching effects in relation to two extreme occlusal features: patterns of diagnoses in a TMD patient population

Objective:

The aim of this investigation was to compare the pattern of temporomandibular disorder (TMD) diagnoses in clenching patients with different occlusal features, the null hypothesis being that no between-group differences exist.

Materials and methods:

Two groups of subjects receiving a jaw clenching diagnosis and having large overjet or anterior open bite (Group A; N?=?45, 75·5% females, mean age: 38·1±15·9 years) or normal occlusion (Group B; N?=?69, 71% females, mean age: 34·6±13·8 years) were recruited among a TMD patient population and were given Research Diagnostic Criteria for TMD (RDC/TMD) axis I diagnoses, namely, group I muscle disorders, group II disc displacements, and group III arthralgia/osteoarthritis/osteoarthrosis.

Major findings:

The distribution of RDC/TMD single and combined group diagnoses was significantly different between the two groups (P<0·05), with Group A subjects showing a higher prevalence of multiple diagnoses (60% versus 43·3%), as well as a higher prevalence of combined RDC/TMD axis I group II and III diagnoses (37·8% versus 20·2%). All TMD signs and symptoms were more frequent in the patients with large overjet or anterior open bite with respect to the patients with normal occlusion.

Conclusion:

In a TMD patient population, jaw clenching may have different consequences in subjects with large overjet or anterior open bite with respect to subjects featuring normal occlusion.