CATEGORY AUSTRALASIAN DENTIST 85 LINICAL (Fig. 16), disto-horizontal (Figs. 17), and disto-vertical mandibular movements while the protective vector involves a verticolateral mandibular movement (Darveniza 2001). The TMD patient illustrated in figure 17 with disto-horizontal mandibular movement claimed that “I can increase my tinnitus by 50% – just by moving my jaw – by pulling it backwards” (using the digastric muscles with concomitant pain in the left muscle). He mentioned that “tinnitus in his right ear – not distressing but in left ear – very distressing”, please note there was no distal or posterior vector during right jaw movement (Fig. 16). The patient has been treatment planned for bio-designed crowns 33/23 to create a protective vector (Darveniza 2001). Occluso-mandibular counselling It is imperative the TMD patient be informed how the collection of their four bites forms their occlusion. That is, how it has been created by the location, size and shape, of their teeth which, in turn, impacts on the movement of the lower jaw directing negative oro-facial forces towards the TMJ’s and facial musculature (Darveniza 2001). Occluso-mandibular counselling of TMD patients involves explaining the relationship between tooth contacts (occlusion) and their influence on directing mandibular movements that maybe harmful to the TMJs and musculature. This can be illustrated by providing a biodesigned temporary protective bite using a correctly angled thin metal instrument followed by an occluso-mandibular orientated explanation (Figs. 18, 19 and 20). Such explanation should detail how the temporary bite, now with a protective mandibular vector, re-directs the mandible during an excursive movement and instantly relieves/modifies TMJ pain and/ or muscle strain/pain, and momentarily ceases or softens many joint noises (Darveniza 2022). This starts with patient being shown their inherent unprotected occlusal scheme and the perceived effect on TMJ andmuscle pain, and joint noises. The patient was asked to pinpoint muscle or joint strain/ pain or joint noises during an unprotected mandibular movement. This was followed by an occluso-mandibular orientated explanation of how their jaw movements were damaging. The patient was informed that changing the shape of teeth can result in a bio-designed protective bite and jaw movement (Darveniza 2001). The patient was then informed that a temporary protective bite was going to be bio-designed in their mouth with the aid of a thin metal instrument (Figs. 18, 19 and 20). Correctly aligning a thin metal mixing spatula or Lecron between the canines creates a simulated canine restrictive ridge. The patient was directed to move laterally on the instrument placed over the upper canine and angled about 30 to 40 degrees vertically and 10 to 20 degrees medially depending on the lower tooth (Fig. 20). The patient was treatment planned for a zirconia veneer on 33 to build up a 1.5 mm cusp angled lingually, along with occlusal adjustment on the palatal of 22 and 23 teeth to create a protective left bite similar to the temporary protective bite. Similarly, a spatula was placed between the central incisors to create a simulated protrusive ramp to direct the mandible in protrusion. During these protective movements a noteworthy diminution or absence of TMJ or muscle strain/pain and joint noises momentarily occurs. Patients were made aware that the occlusal splint recommended for them would have these protective bites. Patients were further advised to refrain from parafunctioning on their inherently unprotected occlusion. Habit retraining Commonly observed harmful mandibular habitsobservedduringoccluso-mandibular analysis can result in hypermobile/ stretched TMJ ligaments (De Coster, Van den Berghe; et al. 2005,Shore 1970). These include cross-over in lateral, protrusive or latero-protrusive movements (Fig. 21) and extreme mouth opening (Fig. 22). Using Zeldows’s methodology the patient needs to be informed (step 1 ‘habit awareness’) that moving the lower jaw too far forward or sideways or open should be stopped (Zeldow1976).Thishabit results inexcessive TMJ ligament stretching and muscular fatigue which can contribute to TMD symptoms including joint noises occurring Fig. 20 This illustrates a wide cement spatula angled vertically and anteriorly to create a ‘temporary protective bite’ in left lateral occlusion simulating a median palatal ridge, of a maxillary canine, with a restrictive and guided protective long canine rise path (Darveniza 2001). This ‘temporary protective bite’ resulted in the pain in the left jaw movement disappearing when moving along the spatula with this bio-designed protective left lateral path. The pain immediately returned when the spatula was removed and the patient asked to move to the left resulting in a disto-horizontal mandibular movement of the left condyle penetrating posteriorly into the left TMJ. A zirconia veneer was recommended to build up a lingually angled cusp for the 33 tooth to bio-design a left protective bite, this involved adjusting the palatal surfaces of the 22 and 23 teeth. Fig. 19 This illustrates the lower midline is about 5-6 mm distal while in left lateral occlusion with a disto-horizontal lateral mandibular vector and destructive wedging of 32 between 22 and 23 resulting in an unprotected left lateral path with concomitant left TMJ and masseter pain (Darveniza 2001). Fig. 18 This illustrates a 50 year old patient with aligning upper and lower midlines and an impacted and infraerupted 33 canine tooth which is level with the lower central incisors and who has concomitant left TMJ/masseter pain. Ideally the lower canine cusp should have been 1.5 mm above the incisal plane to engage with the upper canine to develop a protective left lateral occlusion (Darveniza 2001).
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