Source-bound perceptual persistence in chronic orofacial symptoms: a hypothesis framework

3.1 Organizing framework: a source-bound maintenance loop

Building on the maintenance domains identified in the previous review, the present synthesis organizes the relevant literature into four explanatory process steps: signal availability, symptom/percept credibility, active orofacial resampling, and source stabilization.

The four process steps were derived from four explanatory questions that follow from the source-bound problem addressed in this review. The first question is why sensory or pain-related evidence remains available to perception; this defines signal availability. The second question is why available evidence acquires the status of meaningful bodily evidence rather than being treated as harmless background sensation; this defines symptom/percept credibility. The third question is how a suspected source that is accessible through orofacial action can be repeatedly tested and thereby regenerated as sensory evidence; this defines active orofacial resampling. The fourth question is how attribution, treatment history, body memory, reassurance seeking, and clinical interactions may stabilize the source over time; this defines source stabilization.

The steps are therefore distinguished by the explanatory question from which they are derived. They may overlap in practice because attention, salience, and action-readiness can contribute to each of them. They are therefore not proposed as independent mechanisms with sharp boundaries. However, they are also not simply four descriptions of persistent attention. Persistent attention describes continued focus on a symptom or bodily site. The present framework asks a more specific source-bound question: how available sensory evidence becomes credible, is repeatedly regenerated through orofacial action, and becomes stabilized around a suspected source that remains clinically actionable. The construct that captures this convergence is source dominance. Signal availability, symptom/percept credibility, active orofacial resampling, and source stabilization are therefore treated as supporting process steps that specify how a suspected orofacial source may become and remain dominant. Together, they form a proposed maintenance loop through which the source may continue to organize perception, action, treatment seeking, clinical reasoning, and expectations of recovery.

To reduce ambiguity, Table 1 defines the core terms used in the framework, specifies their role in the proposed maintenance loop, and lists candidate indicators for future empirical work. Terms were retained only when they carried a distinct conceptual or operational function. The four process steps are informed by distinct but converging literatures; their integration into a recurrent source-bound maintenance loop is the central hypothesis advanced by this review. Table 2 (Ref. [4, 5, 8, 9, 11, 12, 13, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36]); Table 3 (Ref. [1, 4, 5, 6, 13, 21, 31, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48]); Table 4 (Ref. [15, 16, 17, 18, 19, 20, 24, 27, 36, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64]); Table 5 (Ref. [1, 3, 5, 6, 19, 20, 21, 22, 24, 31, 39, 40, 45, 47, 52, 62, 63, 64, 65, 66, 67, 68, 69]) summarize the representative literatures informing each step.

3.2 Signal availability: pain-system mechanisms

Table 2 summarizes representative literature informing the first process step: signal availability. This step asks how an orofacial experience remains available to perception when current peripheral findings no longer adequately explain its intensity, duration, spread, recurrence, or clinical impact. Signal availability may follow an identifiable trigger, but it may also arise without a clear precipitating event. In this framework, ongoing tissue damage, active inflammation, dental disease, or a clear nerve lesion represent possible routes by which sensory evidence remains available, but are not the only routes. Sensory evidence may also arise through residual oral input, increased somatosensory or nociceptive gain, altered descending modulation, impaired inhibition, internally generated input, or inferred sensory evidence when current peripheral support is minimal. In pain-dominant presentations, signal availability may further be supported by peripheral and central sensitization mechanisms, including activity-dependent increases in trigeminal nociceptive excitability.

Many oral signals are continuously present during ordinary function yet normally remain in the background because they are predictable, self-generated, and clinically irrelevant. The key question is why some signals remain perceptually available. A predictive-processing vocabulary may describe one part of this process: small oral differences may be assigned increased precision or salience, making them more likely to be treated as informative. This vocabulary is used here heuristically to describe signal weighting, uncertainty, salience, and action-readiness.

Signal weighting also depends on context. Minor tooth contact, mucosal sensation, pressure, muscular input, joint sensation, or trigeminal input may remain foregrounded when uncertainty, threat, previous treatment failure, failed reassurance, or loss of confidence makes such input clinically meaningful. Under these conditions, the decisive factor is not only the magnitude of the signal, but also the state of the perceptual system receiving and interpreting it.

Signal availability therefore helps explain why an experience can continue to recur, fluctuate, or remain intrusive. It is a necessary but incomplete step in the proposed loop. Available sensory or pain-related evidence must also become credible as bodily evidence and remain linked to a suspected orofacial source. That transition is addressed in the next section.

3.3 Symptom/percept credibility: percept-system mechanisms

Table 3 summarizes representative literature informing the second process step: symptom/percept credibility. This step asks how available sensory evidence becomes experienced as meaningful bodily evidence of an unresolved or clinically relevant problem.

The key transition is from sensory evidence to bodily evidence. A weak or ambiguous sensation may become clinically important when it is interpreted as evidence that a bodily source is abnormal or unresolved.

This transition is especially likely under conditions of uncertainty and unresolvedness. Such concern may arise when the patient cannot determine whether the sensation is harmless or pathological, when the sensation is interpreted as indicating possible damage or loss of function, when previous treatment has failed, when explanations conflict, or when reassurance leaves the bodily experience unchanged. Under these conditions, the perceptual system may treat the sensation as information about the state of the body.

Psychological and social factors enter this step by altering the perceived credibility and significance of sensory evidence. Anxiety, catastrophizing, depressive symptoms, loneliness, invalidation, loss of trust, or previous negative clinical encounters may increase vigilance, threat appraisal, and the need for explanation. They may therefore make an ambiguous oral signal more likely to be experienced as salient, credible, and difficult to dismiss. At the neural level, salience, monitoring, and action-readiness are likely to involve distributed interoceptive, prefrontal, and pain-modulatory networks. In the present framework, these networks are treated as candidate correlates of symptom/percept credibility rather than diagnostic biomarkers of source-bound persistence.

This may help explain why reassurance may fail. The clinician may be responding to negative findings, while the patient is responding to persistent bodily evidence. A normal radiograph, acceptable occlusion, or normal mucosal examination may reduce clinical suspicion, while the symptom can remain perceptually credible if the source continues to feel wrong.

3.4 Active orofacial resampling: orofacial sensorimotor mechanisms

Table 4 summarizes representative literature informing the third process step: active orofacial resampling. This step asks why a credible orofacial symptom is repeatedly tested through oral action and how such testing may regenerate sensory evidence from the suspected source.

The orofacial region is clinically important because many suspected sources are continuously accessible to action. Chewing, swallowing, clenching, speaking, jaw positioning, tongue exploration, and clinical testing can all become ways of evaluating whether the suspected source continues to feel abnormal.

Orofacial action does more than passively observe the suspected source; it changes the sensory state being evaluated. Oral functions depend on integrated tactile, proprioceptive, nociceptive, motor, gustatory, thermal, and affective feedback. Occlusion and jaw function also depend on sensorimotor adaptation and central modulation of periodontal, dental, and mucosal input. Repeated source-directed action may therefore regenerate an integrated sensory state in which contact, pressure, proprioception, discomfort, salience, and expectation are combined.

Source-directed testing is therefore clinically meaningful. Each orofacial action or clinical examination can produce additional sensory and perceptual information associated with the same source. When that source is already credible as the origin of the problem, new input may strengthen source attribution, increase monitoring, or renew the perceived need for explanation or correction. The patient is therefore not only thinking about the symptom or remembering it; the oral system repeatedly provides opportunities to resample the suspected source as a sensory and motor event.

This mechanism may be adaptive when ongoing pathology, injury, inflammation, overload, or functional limitation requires monitoring or protection. It becomes part of source-bound persistence when repeated sampling continues after the current peripheral explanation has become insufficient. In that situation, active orofacial behaviour may help maintain the symptom as perceptually real and continue to link it to the suspected source.

3.5 Source stabilization: clinical embedding mechanisms

Table 5 summarizes representative literature informing the fourth process step: source stabilization. This step asks how a repeatedly sampled orofacial experience becomes stabilized as a problem attributed to a specific oral source. Repeated sensory and clinical experiences occur within a clinical history. A dental procedure, extraction, occlusal adjustment, painful episode, failed treatment, invalidating consultation, or unresolved diagnosis can become the temporal anchor for the symptom. Subsequent sensations are then interpreted in relation to that history. The source becomes both a current sensory location and a clinically meaningful site of bodily concern.

This helps explain why a symptom may remain organized around a specific source. Source stabilization is supported by attribution, treatment history, body memory, metacognitive feelings of certainty or wrongness, and repeated attempts to obtain an explanation or correction. These processes shape how later sensations are noticed, interpreted, tested, and acted upon.

At this stage, local treatment may sometimes contribute to maintaining the loop. When no correctable local abnormality adequately explains the symptom burden, further procedures may keep the suspected source clinically active and repeatedly testable.

3.6 Integrated synthesis: from maintenance loop to source dominance

The four process steps describe interacting contributions to source-bound perceptual persistence. Their proposed integration forms a recurrent maintenance loop. The loop may continue after the effects of the local, neurogenic, or treatment-related trigger no longer adequately explain the current symptom burden. This clarifies what persists: not only pain, discomfort, burning, pressure, dysaesthesia, or occlusal awareness, but the organization of experience around a source.

Different orofacial conditions may enter the loop through different dominant pathways. Pain-dominant, dysaesthetic, and occlusal-percept presentations may differ in initiating mechanisms and sensory quality yet converge when a suspected orofacial source remains perceptually real and continues to organize recovery expectations.

Source dominance is the emergent organizing construct proposed by this framework. The four process steps specify how it may arise, be maintained, and feed back into attention, resampling, and treatment seeking.

Fig. 1 summarizes the proposed source-bound maintenance loop.

Fig. 1.Proposed source-bound maintenance loop. The four process steps interact around a suspected source and may give rise to source dominance. TMJ: temporomandibular joint.

4.1 Main implication: persistence as a source-bound maintenance loop

The central implication of this review is that chronic orofacial persistence may be conceptualized as source dominance operating within a source-bound maintenance loop. The relevant shift is from symptom presence alone to the way a symptom remains organized around a suspected source.

The framework integrates mechanisms described in predictive-processing, symptom-perception, nociplastic pain, pain-modulation, illness-representation, metacognitive, and clinical-embedding literatures. Its contribution lies in specifying how these mechanisms may converge in the orofacial situation, where a suspected source can remain concrete, accessible to repeated oral testing, and available for clinical intervention. A suspected orofacial source can therefore remain dominant even when the symptom burden is no longer adequately explained by current peripheral findings.

This source-bound organization gives persistent orofacial symptoms their clinical force. The experience remains perceptually real because it continues to be experienced as arising from a specific site. It remains accessible to repeated testing because the patient can repeatedly reproduce or probe it through orofacial actions. It remains clinically relevant because the suspected source can be examined, explained, protected, adjusted, restored, extracted, splinted, medicated, imaged, or otherwise treated.

Persistence therefore involves more than recurrence of pain, burning, pressure, discomfort, dysaesthesia, or occlusal awareness. It involves source dominance: the suspected orofacial source may influence what counts as evidence, what actions follow, what treatments remain conceivable, and what recovery is allowed to mean. This formulation preserves the bodily reality of the symptom while directing attention to the loop through which the source remains dominant across perception, behaviour, and care.

4.2 Operationalizing source dominance

Source dominance extends beyond localization or source attribution. Many acute and chronic symptoms are experienced as arising from a specific bodily site, and such source orientation is often adaptive because it can remain responsive to changes in the underlying condition. In source-bound perceptual persistence, by contrast, the suspected source continues to organize attention, behaviour, clinical action, and recovery expectations even when current findings no longer adequately explain the ongoing symptom burden.

Source dominance can be operationalized through observable indicators, although no validated scale for this construct currently exists. Candidate indicators include the time and attention occupied by the source; interpretation of ordinary or fluctuating sensations as evidence that the source remains abnormal; source-directed checking, repeated self-testing, protective behaviour, or avoidance of oral function; reassurance seeking; and continued pursuit of further assessment or correction despite insufficient explanatory findings.

Recovery expectations are especially informative. Source dominance would be expected to be greater when improvement is conceivable mainly as correction, removal, relaxation, or normalization of the source. It would be lower when improvement can also be understood as reduced monitoring, reduced checking, improved oral function, reduced threat, less interference, diminished treatment seeking, or restored confidence in oral function despite residual sensation.

Future studies could examine whether higher source dominance is associated with symptom persistence, disability, repeated treatment seeking, reduced response to reassurance, or poor outcome after further local intervention. Longitudinal or intervention studies could also test whether reductions in checking, threat interpretation, correction-focused recovery expectations, or source-related attentional occupation are associated with reduced source dominance even when residual sensation remains. Source dominance is therefore proposed as a candidate construct for measurement and hypothesis testing.

4.3 Perceptual source organization

In pain-dominant conditions, including painful TMD, PDAP, PIFP, BMS, chronic myogenous orofacial pain, and selected trigeminal neuropathic pain conditions, pain-system mechanisms may provide much of the sensory intensity, urgency, and disability [10, 27, 70]. Yet these experiences are also source-organized: pain is experienced as belonging to a tooth, socket, mucosa, muscle, joint, or trigeminal territory [27, 71]. In percept-dominant conditions such as OD, the dominant experience may be wrongness, salience, certainty, dysaesthesia, or the sense that a local source requires correction, with pain intensity playing a smaller role [20, 60].

These formats may overlap in clinical practice. Pain, dysaesthesia, burning, pressure, occlusal wrongness, and related orofacial experiences are all forms of perceptual experience. They differ in phenomenological quality and dominant mechanisms, while all may become organized around a suspected orofacial source.

4.4 Why the orofacial region matters

The orofacial region provides a particularly clear setting for source-bound perceptual persistence because it combines multisensory integration, continuous sensorimotor sampling, and concrete clinical modifiability within a small and highly salient functional space. Symptoms in other bodily regions, including the spine, hip, knee, shoulder, or foot, may also become mechanically provoked, protected, investigated, and treated. The mouth makes this process especially visible because suspected sources can be sensed, tested, and modified through everyday oral function and dental or orofacial care.

Oral experience is intrinsically multisensory. Touch, proprioception, taste, temperature, pain, smell-related flavour perception, and motor feedback are integrated during eating, chewing, swallowing, speaking, clenching, and oral exploration. Neuroimaging findings suggest that oral multisensory processing involves crossmodal interactions in which somatosensory and motor regions are frequently implicated [15]. The orofacial sensorimotor system also includes teeth, mucosa, facial skin, masticatory muscles, temporomandibular joints, trigeminal pathways, and central circuits involved in pain, touch, taste, chewing, facial expression, speech, and swallowing [57]. Thus, a suspected source such as a tooth, bite, mucosal surface, muscle, joint, or trigeminal territory is more than a local anatomical site; it can function as a multisensory and sensorimotor perceptual object.

Taste and smell deserve specific mention because they contribute to oral and flavour experience. Taste-related symptoms are clinically relevant in BMS, where burning or dysaesthetic oral sensations may coexist with dysgeusia and xerostomia, although objective taste perception and saliva composition may be normal in some patients [72, 73, 74]. In the present framework, however, the main focus is on those orofacial sources that can remain repeatedly testable through oral behaviour or intervention: teeth, occlusion, mucosal surfaces, masticatory muscles, temporomandibular joints, and trigeminal territories. Chemosensory symptoms may increase oral salience and symptom burden, but, within the present framework, they are less directly accessible to repeated mechanical testing or source-directed local correction than these source-bound sensorimotor anchors.

This has direct relevance for persistence. When a patient checks a bite, explores a mucosal surface with the tongue, clenches, chews, or repeatedly tests jaw movement, the action may regenerate an integrated oral state involving contact, pressure, proprioception, motor feedback, affective salience, and expectation. This interpretation is consistent with evidence that oral functions are fundamentally multisensory, and that orofacial pain and sensorimotor behaviours reciprocally influence one another [15, 57]. The mouth may therefore make source-bound maintenance loops especially visible: the suspected source is continuously sensed, repeatedly self-tested, and often technically available for clinical correction.

4.5 Clinical meaning and psychological processes

Psychological and social processes influence how bodily evidence is weighted, interpreted, monitored, and acted upon [1, 5, 6]. Their clinical importance lies in how they may influence source dominance: whether the suspected source remains credible, urgent, and clinically relevant. Uncertainty, threat, previous treatment failure, invalidation, loss of control, catastrophizing, or failed reassurance may increase the perceived credibility and urgency of ambiguous or fluctuating sensations [21, 46]. A weak or ordinary signal may thereby come to feel like evidence that something remains wrong with a specific orofacial source.

This suggests a specific clinical role for psychological and behavioural intervention: reducing the processes that keep the suspected source dominant. Clinically, this may involve addressing uncertainty, reducing checking and reassurance loops, restoring confidence in oral function, and helping the patient tolerate residual or ambiguous sensations while weakening their interpretation as evidence of damage, failed adaptation, or failed treatment.

Existing intervention evidence should be interpreted cautiously. For persistent physical symptoms and bodily distress, psychological interventions appear to have small to moderate effects on symptom severity. Still, the evidence is heterogeneous and does not identify a single preferred technique or a source-dominance-specific treatment [75, 76]. In persistent orofacial pain, psychological care is best framed as multidisciplinary, formulation-guided management aimed at reducing disability, improving function, and modifying maladaptive responses to symptoms [77].

Within the present framework, interventions may reduce source dominance only insofar as they modify the maintaining processes that keep the suspected source credible. Depending on the individual formulation, treatment may target threat and uncertainty, catastrophic interpretation, reassurance seeking, correction-focused expectations, avoidance of oral function, clenching or guarding, repeated oral checking, trauma-related activation, emotionally charged symptom-related memories, or loss of confidence in normal oral use. The specific intervention may be cognitive-behavioural, acceptance-based, mindfulness-based, exposure-based, trauma-focused, relaxation-based, sensorimotor, body-oriented, or habit-focused, but its relevance depends on the maintaining process it addresses rather than on the treatment label itself. These implications are process-based hypotheses derived from the present framework and from formulation-guided approaches to persistent physical symptoms and persistent orofacial pain, rather than established source-dominance treatments [75, 76, 77].

The model also supports caution with repeated local intervention, including occlusal adjustment or restorative correction, when current peripheral findings no longer adequately explain the symptom burden. Local treatment remains appropriate when these findings sufficiently explain the burden. Otherwise, repeated occlusal or dental procedures could potentially reinforce source dominance by keeping the suspected source clinically active and by making recovery depend on further correction [62, 63]. In this situation, dental or occlusal care may contribute more usefully by establishing diagnostic stability, providing a non-blaming explanation, limiting repeated corrective procedures, and supporting confidence in oral function.

4.6 Therapeutic implications: source dominance as a candidate treatment target

The practical value of the framework lies in shifting attention from source certainty to source dominance. In many patients with chronic orofacial symptoms, the suspected source is already clear and strongly established. The therapeutic question is whether that source continues to govern attention, checking, treatment seeking, clinical decision-making, and recovery expectations.

When current peripheral findings are insufficient, care may be less effective if it remains organized around increasingly precise attempts to correct, disprove, or reassure patients about the suspected source. A more plausible therapeutic target may be the reduction of source dominance: weakening the extent to which the source controls monitoring, oral behaviour, treatment seeking, and the patient’s expectations of possible recovery. This suggests complementary therapeutic roles. The somatic clinician may establish diagnostic stability and explain source-bound perceptual persistence in a way that validates the patient’s experience. Psychological or behavioural treatment may become relevant when it targets the processes maintaining source dominance.

4.7 Limitations and conceptual safeguards

As a hypothesis-generating framework, source-bound perceptual persistence requires careful interpretation and has important limitations. The present framework is based on a theory-driven narrative review and conceptual synthesis. The literature was selected for conceptual and mechanistic relevance to the proposed process steps. The review provides no exhaustive coverage, formal risk-of-bias assessment, meta-analysis, or graded evidence for each claim. The proposed loop should therefore be read as an integrative hypothesis generated from converging literatures, with empirical validation required in future studies.

Several conceptual boundaries follow from this scope. Nociplastic pain is used as a concept mainly relevant to pain-dominant presentations, especially where altered nociceptive processing, hypersensitivity, or impaired modulation are prominent. Its relevance to percept-dominant conditions such as OD is more limited, because persistence in OD concerns an abnormal occlusal percept rather than pain amplification. Similarly, condition-specific vulnerability factors, including sex-related prevalence patterns, hormonal status, sleep disturbance, and systemic comorbidity, were not developed as separate domains, although they may influence pain-system sensitivity and symptom burden in specific conditions. This is especially relevant to BMS, where neuropathic, mucosal, systemic, hormonal, and psychosocial factors may contribute to symptom burden in ways not fully captured by the present source-bound framework.

The framework applies to cases in which ongoing symptom burden exceeds what current peripheral findings can explain. Appropriate diagnosis and treatment remain essential when active nociceptive, neurogenic, inflammatory, musculoskeletal, dental, mucosal, or structural pathology is present. Source-bound perceptual persistence is therefore best understood as a brain–body–clinical maintenance model for situations in which the current local explanation has become insufficient.

Psychological and social factors are included because they may influence how bodily sensations are interpreted, monitored, and acted upon, and thereby contribute to source dominance. They do not replace nociceptive, neuropathic, sensorimotor, or other bodily mechanisms.

Finally, predictive-processing and related terms are used cautiously. They provide useful vocabulary for expectation, salience, precision, updating, attenuation, and active sampling, but these terms are treated as heuristic tools rather than as a complete ontology of symptom persistence [31, 47, 48]. The value of the present framework lies in whether it generates empirically testable clinical and mechanistic hypotheses about how source-bound perceptual experiences persist, and how their dominance might be reduced.

Because this was a theory-driven narrative review, the possibility of confirmatory selection cannot be fully excluded. This risk was addressed by including literature that constrained the framework, differentiated mechanisms across conditions, or cautioned against overextended explanatory claims.