Myths surrounding vertical dimension of occlusion in restorative dentistry: A scoping review

OBJECTIVE

This scoping review aims to clarify the concept of vertical dimension of occlusion (VDO) in prosthetic dentistry, addressing prevalent myths, and controversies regarding its clinical management and impact on the stomatognathic system.

METHODS

This paper critically examines common beliefs about VDO alteration and its effects on temporomandibular disorders (TMD) through an extensive literature review and an international survey. The survey included 862 general dentists and prosthodontists and explored their approaches to altering VDO and their perceptions of the clinical implications. The literature review provided a thorough analysis of existing research on VDO modification techniques, the adaptability of the stomatognathic system, and the relationship between VDO changes and TMD.

RESULTS

The survey revealed insights into dentists' perspectives on VDO, showing that while many practitioners test a new VDO due to concerns about patient adaptation, a significant majority observed that patients typically adjust well to a new VDO regardless of the technique used. The survey highlighted differing beliefs about the need for a gradual process and trial phase for VDO alteration, as well as the stability of modified VDO. Literature review suggests the stability and adaptability of VDO changes due to muscle adaptability and indicates no direct causal or curative link between VDO changes and TMD. Traditional methods for determining VDO in complete dentures may not be suitable for worn dentition, underscoring the need for tailored approaches.

CONCLUSION

This paper suggests that the traditional belief in the need for a prolonged trial phase for VDO alterations may be reconsidered in light of evidence supporting the adaptability of the stomatognathic system. Moreover, it emphasizes the importance of distinguishing between methods suitable for complete dentures and those for managing cases of worn dentition. The purported link between VDO alterations and TMD is also found to lack scientific evidence, highlighting the need for individualized patient care based on current evidence and clinical judgment.

Evaluation of the effect of T-Scan™ as an adjunct to stabilization splint in the treatment of temporomandibular joint disorders

OBJECTIVE

To assess the effectiveness of the stabilization splint (SS) combined with the T-Scan™ III system in the treatment of temporomandibular joint disorder (TMD) with myofascial pain.

METHODS

Forty-eight enrolled patients were randomly assigned to the SS group or T-Scan™-guided SS group. Mandibular Function Impairment Questionnaire (MFIQ), Maximum Comfortable Opening (MCO), Visual Analog Scale (VAS), and Patient Health Questionnaire-9 (PHQ-9) were used as the outcome variables.

RESULTS

The occlusal contacts of patients in the SS plus T-Scan™ group showed lower Occlusal Time (OT), Disocclusion Time (DT), and Asymmetry Index of Occlusal Force (AOF) after occlusal adjustment under the guidance of the T-Scan™. Importantly, the TMD symptoms were alleviated more obviously in SS plus T-Scan™ group, with better scores for MCO and MFIQ.

CONCLUSION

T-Scan™-guided occlusal adjustment of SS can obtain better OT, DT, and AOF, which furthers improvement of the therapeutic effects on TMD with myofascial pain.