Abstract
In the dental literature, the association between the occlusion and hypersensitive teeth is poorly explained. Quantified occlusal contact force and timing parameters have been largely ignored in studies assessing hypersensitive teeth. This chapter introduces a novel occlusal concept, frictional dental hypersensitivity (FDH), after systemically simplifying the existing and often confusing terminology used in the literature to describe the variant clinical presentations of the hypersensitive dentition. Clinical evidence from combining computerized occlusal analysis and electromyography is presented linking opposing posterior tooth friction and muscular hyperactivity to FDH. This chapter will outline how occlusion, many muscular TMD symptoms, and FDH are all interrelated. Both a pilot study and a 100 subject cold ice water swish follow-up study are presented and used a numerical visual analog scale (NS/VAS) to quantify cold response dental hypersensitivity resolution observed in occlusally symptomatic patients that underwent the immediate complete anterior guidance development coronoplasty (ICAGD). This computer-guided occlusal adjustment procedure eliminated pretreatment FDH symptomatology, further supporting that dental hypersensitivity often has an occlusally-based, frictional etiology. Additionally, consideration for the orthopedic influences that may directly affect the occlusion and neurology of the system are outlined, as well as the medical concept of tooth allodynia. Furthermore, trigeminal neurological influences are compared and contrasted to autonomic sympathetic inputs in relation to the influence that they each have upon the hypersensitive dentition. Lastly, the greater auricular diagnostic nerve block is discussed, as is the influence that this nerve may have upon the hypersensitive mandibular posterior dentition.
TopIntroduction
Dentin Hypersensitivity (DH) is classically described in the dental literature as a sharp, acute pain of short duration, arising from open dentinal tubules in vital teeth, which is diagnosed through a process of exclusion with a thorough dental screening, examination, and history (Porto, Andrade, & Montes, 2009). DH has been generally promoted to occur in the cervical regions of teeth, as in the abfractive process, or historically on the occlusal surface where occlusal microtrauma, erosion, abrasion, and/or attrition has exposed dentinal tubules. Just before the turn of the 21st century, references began to differentiate DH from what has come to be known as Cervical Dentin Hypersensitivity (CDH); the former is currently used to describe short, dull and lingering hypersensitivity pain, whilst the latter is used to describe the fast, sharp and rapidly conductive pain associated with the hypersensitive dentition (Pashley, 1993; Coleman & Kinderknecht, 2000). Both hypersensitivity descriptors may occur in patients with or without open dentinal tubules in the vital dentition, and both are diagnosed through a process of exclusion.
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To date, the dental profession still lacks objective and scientifically validated information to diagnose and treat all cases of Dental Hypersensitivity (DTLH), but as this novel chapter will demonstrate, strides are underway to further elucidate the true genesis of the hypersensitive dentition.
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Within this chapter the term Dental Hypersensitivity (abbreviated as DTLH), will be referring to all forms of tooth hypersensitivity pains, such that DTLH encompasses DH, CDH, and Frictional Dental Hypersensitivity (FDH), described below.
Designed for practical clinical usage, this chapter will offer sensible alternatives to the confusing and often inaccurate descriptors used to both diagnose and describe the hypersensitive dentition, as well as explore how occlusion is often linked to the sharp, short duration, rapidly conductive acute pain consistent with the clinical diagnosis of Frictional Dental Hypersensitivity (FDH) which can occur with or without exposed dentinal tubules. The included literature will detail how dental occlusion can be one of the primary causative factors in the development of hypersensitive dentitions, resultant from prolonged frictional interactions between opposing teeth in excursive function and how the same occlusal surface friction can lead to hyperactive muscles which may over time cause abfractive events, exposed dentin, and patent dentin tubules. The new term of Frictional Dental Hypersensitivity (FDH) will be presented which describes Dental Hypersensitivity (DTLH) of occlusal etiology irrespective of the presence or lack of exposed dentin. The conditions known as Traumatic Occlusion (synonymous with occlusal microtrauma and hyperocclusion) and Cervical Dentin Hypersensitivity (CDH) will also be defined, compared and contrasted to FDH, as well as to classical DH that involves exposed dentin. The myriad of scientific theories attempting to explain the causation of DH and CDH will also be reviewed, along with a discussion of the theories that potentially explain FDH events. A rational protocol for optimum treatment using occlusal adjustment to treat FDH and the clinical factors that can identify FDH patients whom could benefit from computer-guided occlusal treatment, are detailed as well. Additionally, references will be provided that demonstrate the profound influence that the status of the bilateral TMJ’s have upon the occlusion, as well as the influence that the autonomic nervous system can and does have upon the hypersensitive dentition.
Key Terms in this Chapter
MRI: A diagnostic technique that uses magnetic fields and radio frequency waves to temporarily tip hydrogen protons, which produce a detailed image of the body’s soft tissue and bones. In contrast to x-ray and CT hard tissue imaging, MRI imaging is especially useful for detailing soft tissues.
Sensitization: A heightened, or newfound hypersensitivity to noxious stimuli. Sensitization can develop from a normal, innocuous stimulation, following a nerve injury.
Tooth Flexion: A deviation or bend of a tooth that is restricted to the root portion of a tooth.
Dental Allodynia: A tooth allodynia has been described as pain, resultant from occlusal contact, or from cold stimulation.
Mechanoreception: An unconscious sensing, or a conscious perception of touch or mechanical displacement, arising from stimuli outside of the body.
Sympathetically Induced Dystonia of Occlusion (SIDO): The autonomic nervous system causing an abnormal tonicity in the muscles of mastication, emanating from the sympathetic nervous system pathways.
BioEMG III: A proprietary descriptive term designating the BioResearch EMG hardware, which is used to quantify muscular activity. Surface electrodes are used to measure muscular output, which is subsequently introduced into proprietary software that processes the data, and displays real-time muscular activity in quantified microvoltages. The BioEMG III technology can be simultaneously linked to the T-Scan digital occlusal analysis technology, to record both tooth forces, timing sequences, and muscle activity levels in 0.003-second-long increments.
Friction: Micro-deformation of the surface atoms as they absorb the kinetic energy of movement across the surfaces.
Neural Occlusion Screening (NOS): A diagnostic protocol that has been developed for practical clinical use, to derive a list of differential diagnoses from digitally derived and objective biomechanical, orthopedic, growth and development, myogenous, occlusal, temporal, and neurological measurements.
Frictional Dental Hypersensitivity (FDH): A nociceptive response to tooth torsion and flexion induced from excessive occlusal surface frictional engagements of posterior teeth during mandibular excursions. FDH is a process which presents clinically as a sharp, acute, transient pain consistent with symptoms of cervical dentinal hypersensitivity. FDH is likely due to a combination of both trigeminal and autonomic sympathetic inputs. FDH does not always involve exposed dentin and patent dentinal tubules.
Joint-Based Occlusion: The biomechanical fact that the ultimate foundation for the occlusion is the condition of the soft and hard tissue components of both temporomandibular joints.
Erosion: The flow of liquids across intact tooth structure, over time diminishes these same tooth surfaces.
Mechanoreceptors: Sensory nerve end organs which respond to mechanical stimuli, such as pressure, vibration, tension, and friction.
Biocorrosion: Endogenous and exogenous acidic and proteolytic chemical degradation of enamel and dentin, as well as the piezoelectric electrochemical action on the collagen in dentin.
Dental Hypersensitivity (DTLH): A term that encompasses all forms of tooth hypersensitivity pains, including DH, CDH, and frictional dental hypersensitivity (FDH).
Lactic Acid: A water-soluble byproduct of anaerobic glucose metabolism produced during muscle contraction. Excess levels of lactic acid can lead to myalgic symptoms in muscular TMD patients.
Piper Syndrome: A non-specific, often intractable orofacial pain, due to excessive sympathetic nervous system dysregulation, which can induce a chronic vasoconstriction of orofacial tissues. Often appearing after a relatively innocuous dental procedure or following a macrotraumatic injury, Piper Syndrome is likely an offshoot of Complex Regional Pain Syndrome Type 1 (CRPS-1) of the head and neck.
Midcourse Corrections: Excursive kinks in the center of force (COF) trajectory, visible within the 2D ForceView window indicating there are excessive frictional collisions in opposing teeth during a right or left excursive movement. These aberrations are not necessarily solely due to the teeth not discluding well during the movements. They may be partially caused by orthopedic influences from the TMJs, upon the mandibular excursive movements. Midcourse corrections are an important parameter to address and straighten, when performing the ICAGD occlusal adjustment therapy.
Autonomic Sympathetic Nerves: That branch of the autonomic nervous system responsible for control of unconscious functions such as accelerating heart rate, constriction of blood vessels, and raising blood pressure.
Disclusion Time: A measurable T-Scan excursive movement occlusal parameter that computes the elapsed time required for teeth to disengage from static intercuspation at the commencement of a mandibular excursion, until all posterior teeth bilaterally completely disengage, and only the anterior teeth remain in contact.
Allodynia: (Ancient Greek ????? állos “other” and ?d??? odúne “pain”) refers to central pain sensitization (increased response of neurons) following normally non-painful, often repetitive, stimulation. Allodynia can lead to the triggering of a pain response from stimuli which do not normally provoke pain, such as from the intake of cold fluids in the oral cavity.
CBCT: A diagnostic technique particularly suited for hard tissues that uses divergent x-rays and computed tomography, to produce three-dimensional images of hard tissues. CBCT is especially useful for identifying bodily tissues containing calcium ions.
Joint Vibration Analysis (JVA): A diagnostic screening technology that uses vibration detection and quantification, to objectively screen the orthopedic status and condition of the bilateral temporomandibular joints. The implementation of the hardware and software components helps clinicians arrive at a tentative, Piper classification for each temporomandibular joint.
Cervical Dentinal Hypersensitivity (CDH): CDH is a sharp, fast and rapidly conductive pain response, involving resistive alveolar bone support, when the primary etiologic factor is occlusal contact overload. CDH appears from stress, endogenous or exogenous biocorrosion, or “incidental tooth trauma”. CDH may, or may or involve, exposed dentinal tubules.
Dentin(al) Hypersensitivity (DH): A sharp, acute pain of short duration arising from open dentinal tubules in response to a normally innocuous stimulus, which is diagnosed through a process of exclusion with a thorough dental screening, examination, and history. DH clinically presents as a dull and well localized pain, which is often difficult to distinguish from transient inflammatory pulpal pain. Alternatively, Pulpal pain is described as a prolonged, dull, and aching pain, that is poorly localized and persists long after the removal of the stimulus. DH etiology involves exposed dentinal tubules in vital teeth.