147 Chart for recording findings from active movements, passive jaw opening, and endfeel
Jaw opening is usually measured between the incisal edges of the incisors (Hesse 1996) and to this is added the overbite (anterior vertical overlap). This is especially meaningful in patients with a “deep bite” (large vertical overlap). The amount of “normal” jaw opening averages 53-58 mm (Ingervall 1970. Agerberg 1974, Wood 1979). Even 6-year-olds have jaw openings of 43-45 mm (Landtwing 1978, Vanderas 1992). Although women in general have more mobile joints (Beighton et al. 1973, Carter and Wilkinson 1964, Hesse 1996), men are able to open their jaws wider by 3-5 mm. According to Agerberg (1974a-d), jaw opening is directly related to body size. It decreases significantly with age and measures only 45-53 mm in 70-year-olds (Agerberg and Österberg 1974, Lysell 1984, Mezitis et al. 1989).
In a selected group of patients with temporomandibular joint problems average jaw openings were 45 mm in men and 39 mm in women (Carlsson and Swardstrom 1971). Contrary to the general clinical impression, a correlation between the extent of active mandibular movement and overall joint mobility is either nonexistent (Westling and Helkimo 1992) or is present only weakly in isolated cases (Dijkstra et al. 1994, Hesse 1996).
While there is little disagreement on the definition of a physiological jaw opening, views vary on what constitutes a limitation of jaw opening: Because only 1.2% of all (not selected) adults have a jaw opening of less than 40 mm(Bit-laretal. 1991), Okeson (1998) accepts this measurement as the boundary, whereas Ingervall (1970) considers a value of 41-42 as a reasonable boundary for limitation of opening. Clinically, however, the many deliberations over establishment of a cut-off value are of no relevance, because a patient may have a measurement of 48 mm, for example, and still be significantly limited because the value was 62 mm before some past event. Regardless of the “scientific boundary” (40-42 mm) a limitation of jaw opening always exists when a patient’s mandibular mobility is objectively found to be less than it was at a previous examination.
There are significantly fewer statements in the literature on the physiological extent of lateral movements. Ingerval (1970) gives average values of 9.8-10.5 mm, Agerberg and Österberg (1974) report 8.7-8.8 mm, and Hesse (1996) reports 10.0-10.5 mm. There is no significant difference between males and females. The ratio of jaw opening distance to lateral movement in a healthy system is approximately 6: 1 (Dijkstra et al. 1998). Lateral movements of less than 8 mm are generally classified as restricted (Ingervall 1970. Okeson 1998).
Protrusive movements are neglected in the literature and in the clinics even more than lateral movements. Still, the extent of protrusion (i.e. condylar translation) provides important information on the mobility of the joints, and therefore reveals over how broad a surface the forces are distributed (stress = force per unit of area). The reports range from 8.8 mm (Bergholz 1985) and 9.1 mm (Hesse 1996). Likewise, there is no sex-related difference in the extent of protrusion. Children give somewhat higher protrusive measurements than adults until the age of 10 years when their measurements are basically the same as those made on adults (Ingervall 1970).
Protrusive movements of less than 7 mm are considered to be restricted, although they are not always signs of pathology that urgently calls for treatment. It is especially important to test patients for restriction of lateral and protrusive movements following temporomandibular joint surgery and orthodontic or orthognathic surgery.
The determination of active movements is followed by an investigation of passive movements. This is to be done only on patients with limited but painless jaw opening, because painful joints will not permit the procedures needed for differential diagnosis of a limitation.
148 Endfeel during passive jaw opening
At the end of an active movement every healthy joint can be moved farther through a certain amount of space. This can occur only through the application of external force and is therefore referred to as passive movement (Kimberly 1979). In the early days of manual functional analysis all the mandibular movements were followed by tests of further passive movement. However, as 10 years of clinical experience has shown, this provided no additional diagnostic or therapeutic information so that passive tests are now applied only to the jaw-opening movement.
The extent of passive jaw opening, also referred to by some authors (Hesse et al. 1990) as the “endfeel distance,” has been reported in one study (Westling and Helkimo 1992) as 1.2 mm and in another (Agerberg and Österberg 1974) as 2.1 mm. Still more specific measurements can be found in the work of Hesse (1996), who reports an endfeel distance in men of 3.0 ± 1.1 mm under a force of 44.6 ± 7.2 N and in women, 3.8 ± 1.4 mm under 37.1 ± 2.1 N. The extent of mandibular movement is influenced by the ligaments, capsule, intra-articular structures, muscles, fascia, and the skin (Evjenth and Hamberg 1985, Hesse 1996).
Limitation of jaw opening is always accompanied by shortening one of more of the above-mentioned structures (Schneider et al. 1988). Therefore, at the end of passive jaw opening the so-called endfeel is recorded (Fig. 156ff).
The endfeel is the feeling that the examiner detects at the end of a passive movement. It is always determined by the structures that are limiting the movement (Groot Landeweer and Bumann 1991). In healthy joints the endfeel is “hard ligamentary” and is not accompanied by pain (Cyriax 1979, Kaltenborn 1974, Janda 1974. Lewitt 1977, McCarroll et al. 1987, Hesse et al. 1990, Groot Landeweer and Bumann 1991, Bumann et al. 1993, Bumann and Groot Landeweer 1996b, Hesse 1996).
There are various classifications of the endfeel in the temporomandibular joint (Cyriax 1979, Evjenth and Hamberg 1985, Groot Landeweer and Bumann 1991, Hesse 1996). Clinically a distinction is made between physiological and structurally pathological endfeels (Figs. 148 and 161). Although there has been little inter-examiner agreement on the concept of the endfeel (Lobbezzoo-Scholte et al. 1994), Hesse (1996) could demonstrate a distinct correlation between the endfeel and the so-called “craniomandibular stiffness.” The evaluation of a combination of the extent of passive movement and the clinical endfeel is therefore a reliable parameter for the differential diagnosis of limitations of movement. Neither the endfeel nor the extent of passive movement helps to differentiate between myogenic and arthrogenic problems, as, for example, claimed by Fuhr and Reiber (1989).
149 Active jaw opening
incisors at the level of the incisal edge of an upper incisor in maximal occlusion. Active jaw opening can be measured directly or by measuring the incisal edge distance as shown here and adding to it the anterior vertical overlap (“overbite”).
Right: In the record of findings, green ink is used to enter the amount of pain-free movement and red Is used for painful movements.
150 Active movement of the mandible to the left
To measure lateral mandibular movements the upper midline is first projected onto the labial surface of a lower incisor. Then the patient executes a maximal lateral movement and the distance between the upper midline and the mark on the lower tooth is measured.
Right: The measurement is entered in the chart in the same way as the jaw-opening distance. The “normal” range is 10.5 ± 2.7 mm.
151 Active movement
