CATEGORY AUSTRALASIAN DENTIST 99 LINICAL to protect the TMJ’s. When the upper and lower central incisors couple correctly a protective forward bite and corresponding mandibular movement protects the TMJ’s. If a patient has these above four protective bites it is called ‘Full Occlusal Protection’ (Darveniza 2001). Full counselling ‘Full counselling’ of TMD patients is defined by the author as targeting and modification of head, neck and occlusomandibular habits and improving sleep posture, and general body posture as required. This is achieved through the use of written handouts personally explained in detail during the examination, fitting of an occlusal splint and during splint and occlusal therapy sessions. Until now counselling TMD patients by clinicians and researchers has been desultory. Some clinicians have given token advice and some researchers provided ‘no counselling’ or no concomitant therapies when evaluating disc repositioning occlusal appliances (Kurita et al. 1998, Sato et al. 1995). It has been noted that splint wearing patients are often unaware of what to do or not to do with a splint or how to operate it or what occluso-mandibular habits should be avoided. As well, dentists and prosthodontists have not been extensively educated on what their role should be for instructing TMD patients on occlusion (Murphy 2006), intensive practice therapy to address bruxism (Ayer and Levin 1975) or habit changing (Zeldow 1976). A retrospective study by Alpern and Wharton on more than 1000 patients claimed that ‘stress-induced destructive habits’ appear to be a substantial contributor to TMD. They noted six habits and their protocol was to ‘teach’ every patient to avoid these habits as treatment was likely to fail without successful control of stress or destructive habits (Alpern and Wharton 1997) Full occlusal therapy In 2001, Darveniza reported on biodesigning occlusal schemes by modifying classic tooth anatomy to restorative anatomical shapes required to create ‘full occlusal protection’ and discussed the term hinge occlusion. An ideal ‘hinge occlusion occurs when reproducible hinging of the TMJs correlates with bilateral simultaneous contact (without incline contacts posteriorly) of the teeth in centric relation’ (Darveniza 2001). The author uses the term hinge occlusion or hinge bite to describe the existing occlusal scheme present when a patient makes first contact/contacts at the end of the hinging arc of closure in centric relation. ‘Full occlusal therapy’ can be defined as sequential treatment performed in three stages, as needed: Stage 1 a ‘Fully Protective Occlusal Splint’ with a minimum of four splint adjustments over a minimum three-month period (‘Formal Fully Protective Occlusal Splint Therapy’); Stage 2 with major and fine tune occlusal equilibration appointments; and Stage 3 bio-designing molar or anterior guidance with concurrent ‘Full Counselling’ targeting occluso-mandibular habits, sleep posture and optimum body posture (Darveniza 2001,Darveniza 2022,Darveniza 2022,Darveniza 2022 ). Occluso-mandibular analysis Occluso-mandibular analysis can be defined as the visual inspection of mandibular movement to determine the deflection, or vector, of the mandible generated from contiguous contacting teeth in hinge occlusion and the full range of excursive movements. This mandibular deflection against poorly, or ideally, positioned teeth is called an occlusomandibular vector and requires charting (Darveniza 2022 ). Contemporary functional occlusal analysis includes identifying tooth contacts in static occlusion and charting those contacts deemed as occlusal interferences. An occlusal interference can be defined by the author as that tooth contact occurring during mandibular movement that affects the smooth harmonious movement of the mandible with destructive mandibular vectors. Interferences result in themandible angling in an awkward manner, resulting in an unprotected occluso-mandibular vector, so that condylar forces are directed in a damaging manner towards the TMJ discs andmusculature. The condyle presses and distorts the disc assembly (bilaminar ligament, body of the disc and pterygoid muscle attachment) often resulting in minor disc displacement (joint noises) followed by disc derangement (reducing and non-reducing discs) with concomitant cranio-mandibular muscle strain and pain. The author has used ‘Full Occlusal Therapy’ as the starting point for conservative management of TMDs since 1981. Occluso-mandibular analysis and bio-designing lateral guidance/restriction for brachyfacial patients since 1988. For a dolichofacial patient with premolar and anterior open bites, the author first used Fig. 3 Schematic vertico-oblique view of the TMJ discs during ‘Full Occlusal Therapy’ illustrating a ‘Fully Protective Occlusal Splint’ with four splint adjustments, occlusal equilibration, and molar/anterior guidance in a time sequence. An aetiological hypothesis of a displaced disc re-centring during full occlusal therapy has been diagrammatically presented by: (1) decreasing parafunction, such as clenching, abolishes negative pressure (Nitzan 1994) on the superior portion of the disc (short pointed red arrows) which releases the crushed disc from the fossa by relieving the suction-cup effect (Sanders 1986); (2) relaxing the muscles of mastication, including the superior head of the lateral pterygoid muscle (long pointed red arrows), allows the elastic posterior ligament to gradually retract between splint adjustments or ‘rubber band recoil’ (Katzberg et al. 1980) the disc (rounded red arrows); and (3) when adhesions break (green broken springs) the disc can recentre aided by the elastic ligament.
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