OBJECTIVE: To investigate the relationship between oral muscle pressure and malocclusion in the mixed dentition.
METHODS: Maximum tongue, lip and cheek pressure was measured using the Iowa Oral Performance Instrument (IOPI) in 3 patient cohorts: patients with (1) posterior crossbite, (2) class II relationship and (3) a control group of patients without malocclusion. Linear models were used to compare the mean differences in muscle pressure between groups, with correction for age and gender. The imbalance between lips and tongue and between lips and cheeks was calculated by the Delta z-scores of each group.
RESULTS: A total of 146 participants were included, 46 (mean age 8.71±0.85), 41 (mean age 11.74±1.17) and 35 (mean age 10.71±1.92) in groups 1, 2 and 3 respectively. Patients with malocclusion showed significantly higher lip and lower cheek pressure and imbalance favouring the lips over the tongue compared to controls. Class II,1 patients showed significantly higher tongue pressure than Class II,2. No differences were found in muscle pressure or imbalance between crossbite and Class II nor between crossbite types.
CONCLUSIONS: These findings suggest that oral muscle pressure may be associated with malocclusion. This highlights the importance of functional diagnosis and its implications on the prevention and treatment of malocclusion, as well as on orthodontic stability.

The aim of the present study was to develop and design software-based \"virtual patient\" for learning functional diagnosis with clinical reasoning of respiratory dysfunction based on need analysis and perception of faculty and student on utility in the undergraduate physiotherapy curriculum. The objective of the study was to design a framework of a respiratory case scenario that includes personal details, history taking, physical examination, differential diagnosis, investigations, functional impairment, and diagnosis, design a prototype of the virtual patient case scenario using software in a virtual environment created in oculus quest, obtain faculty and student feedback, and analyze the feedback. The result of the study obtained on feedback analysis suggests that the virtual patient case scenario (prototype) contains the relevant information in an organized and sequenced manner. The virtual patient case scenario on the virtual reality platform will be helpful as a teaching and learning modality. The study concluded that the present virtual simulated case scenario (prototype) with more cases helps to develop functional diagnosis and clinical reasoning skills as a part of the undergraduate physiotherapy curriculum.