Daniele Manfredini

02:30 – 04:00 PM
Standardized Tool for the Assessment of Bruxism (STAB): The first multidimensional assessment system for bruxism

The definition of bruxism has evolved over the past few years, progressively going beyond the old belief that bruxism is synonymous of grinding the teeth while asleep (Lobbezoo et al., 2013; Lobbezoo et al., 2018). With the increase in knowledge concerning the sleep correlates and the muscle activities that may equally be present also during wakefulness(Manfredini et al., 2019; Manfredini et al., 2021), the bruxism construct has shifted from a pathology or disorder to a motor activity that may be a sign of underlying conditions and may even have possible physiological or protective relevance (Raphael et al., 2016; Manfredini et al., 2016).

In the 2018 consensus paper, sleep bruxism (SB) is defined as a masticatory muscle activity (MMA) during sleep that is characterized as rhythmic (phasic) or non-rhythmic (tonic) and is not a movement disorder or a sleep disorder in otherwise healthy individuals. Awake bruxism (AB) is defined as a masticatory muscle activity during wakefulness that is characterized by repetitive or sustained tooth contact and/or by bracing or trusting of the mandible and is not a movement disorder in otherwise healthy individuals (Lobbezoo et al., 2018).

Within these premises, while preparing the Standardized Tool for the Assessment of Bruxism (STAB), the need emerged for the identification of the best strategy to define the bruxism status, comorbidities, etiology, and consequences. As muscle activities, both sleep and awake bruxism require a thorough assessment that could be based on a combination of subject-based, clinically based, and instrumentally based information.

The rationale for creating the tool and the road map that led to the selection of items included in the STAB have been discussed in some recent publications (Manfredini et al., 2020; Manfredini et al., 2022). This lecture presents the STAB, with the list of items included in each specific axis and domain.

05:30 – 07:00 PM
Temporomandibular disorders and orthodontics
This lecture will provide an overview of the orthodontist’s role in the practice of temporomandibular disorders (TMDs).

Decades of clinical research have provided growing scientific evidence on the absence of relationship between features of dental occlusion or condylar position and TMDs. They also shed light on the need to focus on neurological and psychological issues for a proper management of patients with temporomandibular joint (TMJ) and jaw muscle pain.

Whilst this evidence is fully embraced by dentists with expertise in the orofacial pain field, it is still hard to swallow by some communities of orthodontists. Claims that there is purported “clinical evidence” in support of mandibular repositioning and orthodontic finalization, on anecdotic basis and inductive reasoning, is the best argument to confute any scientific reasoning. Invasive treatments in the form of irreversible occlusal changes and years-long treatment are thus still proposed, against any recommendations by the expert academies.
Some arguments to discourage orthodontic treatment to treat TMDs are simply based on oral physiology. For instance, teeth almost never really touch in maximum intercuspidation; movement guidance is important for an articulator, but never performed in real life; features of the interarch relationship are just a static frame; condylar position is asymmetric by definition; the condyle-fossa or condyle-disc relationship cannot be “corrected” only on one side, and this is bizarre if one considers that most patients have monolateral symptoms.

Thus, any occlusally-oriented etiological theory for TMDs needs for all sort of exceptions against physiology to be considered “true”.

Consequently, it not a surprise that the literature, which is indeed based on patients (i.e., clinical evidence!), dismantles such theories. For instance, how to explain TMD pain in patients with good occlusion? And what about the absence of symptoms in patients with bad-looking occlusion? And the many patients with asymptomatic osteoarthrosis? Only anecdotes can help an occlusal practitioner finding an explanation in front of these patients.

In short, orthodontics can be considered neutral, at best, for the TMJs. It cannot cure TMDs, but it is also unlikely that it may cause TMJ symptoms. Knowledge on the epidemiology of TMJ sounds is fundamental for understanding the latter statement.

So, what should an orthodontist do?

The answer is that an orthodontist should realize that TMD symptoms are mainly due to an emotional overload, which leads to muscle tension and, via host response, to the onset of signs and symptoms.

The orthodontist looking outside from the TMD patient’s mouth will easily see an individual with emotional distress, and without any occlusal or TMJ positional clue to explain symptoms, if compared with asymptomatic individuals. Depending on the symptoms, management strategies ranging from very simple behavioral advices for the control of awake bruxism to complex multimodal strategies for chronic orofacial pain are the required approaches.

Within the concept of overload, an oral appliance is just a crutch, not the cure or a diagnostic device. Thinking of it makes everything immediately fit with all the clinical knowledge that has been sustained by generations of orofacial pain practitioners.

Learning objectives:

• To gain an update on current evidence on temporomandibular disorders;
• To understand that orthodontics is neutral with respect to temporomandibular disorders;
• To provide ethical messages about the need to avoid occlusal overtreatments for TMD management.