CATEGORY 102 AUSTRALASIAN DENTIST listening and responses given later, so that the patient continues to divulge aspects of their habits with judicious questioning. Questions involving habits outside the clinical setting requiring investigation include: the workplace, such as telephoneshoulder posture, hand-to-jaw posture (Fig. 8), and pen habits (Fig. 9); hobbies that involve eccentric jaw manipulation, like computer gaming and playing musical instruments (Figs. 10, 11 and 12); and sports activities that involve clenching, such as cycling and gymnasium activities including sit-ups and weightlifting. Identification of harmful habits should be immediately recorded and when appropriate discussed with the patient. Interceptive habit modification The dentist should consider discussing with the patient the habits observed or recorded during history taking and find an appropriate moment to alert or intercept the habit for modification. Prior to mentioning a specific habit, the patient needs to be informed that each individual habit does not create a TMJ disorder. However, multiple habits occurring during the day and often continuing into the night can contribute to an array of symptoms. Destructive habits will result in muscle fatigue followed by pain and continually stretching of TMJ ligaments can lead to a lax TMJ resulting in a mildly displaced disc in the form of clicking followed by disc derangement. A commonly observed facial habit includes lip scrunching or pursing (Fig. 13) and biting/pinching of the lower lipwith the incisors or canines (Fig. 14). These habits and others can easily be addressed with the patient seated during history taking and modified using Zeldow’s protocol (Zeldow 1976). This involves the patient being informed (step 1 ‘habit awareness’) that the habit of protruding the lower jaw forward and to the left side to bite/pinch their lower lip with the left canine needs to stop. Reasons and consequences should be outlined: this habit of protruding the jaw forward and to the left repetitively during the day then continuing nocturnally can result in the right TMJ ligaments becoming stretched. This in turn, can create an environment for possible disc displacement, and TMJ and muscle pain. The patient may have come with a parent or friend and a request should be made to this person to immediately inform the patient of this habit (step 2 ‘instant awareness’). The patient must now be given a good new habit (step 3 ‘new habit’) to help refrain from continuing their old destructive or non-beneficial habit. An appropriate new habit could be ‘gently moisten your lips with the tip of your tongue, allow your lips to gently touch while your teeth are apart without your lower jaw protruding’. This is the relaxed position for the lower jaw and TMJ’s. Acknowledgments I am grateful to Carl Warner, professional photographer, for all his audio-visual contributions in this paper. I would like to thank John Atkins, Honorary Research Fellow in philosophy from the University of Queensland, for the editorial help he afforded me in writing this paper. u Author details Darveniza Michael BDSc MDSc PhD FRACDS Prosthodontist, 42 Uralba Street, Lismore, New South Wales, Australia, 2480. Correspondence and bibliography: mdarvo@hotmail.com For a complete list of references email gapmagazines@gmail.com Fig. 13 The left view of this TMD patient illustrates an upper lip scrunching habit which resulted in extreme retrusion of the mandible, a retrusive vector, and overuse of the digastric muscles with pain. The right view illustrates a habit where the lower lip infolds with pressure behind the upper lip which protrudes the mandible in a non-functional manner. These chronic habits, along with other factors, resulted in disc displacement in the form of clicking joints, muscle neck and facial pains, and painful TMJ’s. The relevant patient instruction was to ‘desist from doing these habits’ and habit re-training involved creating a new habit of ‘licking the lips once and then placing the lips together with the teeth apart’. Fig. 11 The left view of this TMD patient playing the viola without a splint with the mandible pushed laterally to the right side with a disto-horizontal vector. This vector results in condylar movement posteriorly with a painful right TMJ. The right view illustrates the patient wearing a splint with a bio-designed right restrictive canine rise ridge to prevent the development of further pain. Fig. 14 The left view shows a moderately lingual tilted 33 canine tooth. The right view shows a lip biting habit with a 33 tooth in a similar position as in the left view. This habit created a right lateral mandibular movement with a resultant disto-horizontal vector directing the right condyle posteriorly into the right TMJ disc with pain. The relevant patient instruction was to ‘desist from doing this habit’ and habit re-training involved creating a new habit of ‘licking the lips once and then placing the lips together with the teeth apart’. Fig. 12 The left view in mid-protrusive path shows the lower midline 3 mm to the right which indicates a unilateral guided mid-protrusive path in a non-sagittal direction. The right view confirms that the mandible in final protrusive path guided unilaterally in an unprotected manner by 31 and 32 on the 21 tooth. It was noted that this harmful horizonto-lateral mandibular vector occurred immediately after playing the viola as the mandible was already pushed onto the right side and required only a small protrusion forward. The patient instruction was to emphasize that ‘edge to edge protrusion was not the default position for the lower jaw’ and a new habit was ‘lips together teeth apart’. LINICAL
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