Restoration of occlusal and proximal contacts by a single molar crown improves the smoothness of the masticatory movement

Watamoto, Takao; Egusa, Hiroshi; Mizumori, Takahiro; Yashiro, Kohtaro; Takada, Kenji; Yatani, Hirofumi

doi:10.1016/j.jdent.2008.08.005

Cited by 14 publications

(20 citation statements)

References 36 publications

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“…Such graphical representations of jerk‐cost may help clinical practitioners to visualize and better understand changes of smoothness in their patients’ mandibular movements during chewing. Previous studies reported evaluations of movement smoothness in mastication calculated jerk‐cost using normalized units of time and 3D pathway length (4–9); these methods were used to avoid introducing calculation errors through multiple differentiations. This normalization, however, prohibited the accurate measurement of the momentary jerk and jerk‐cost associated with discrete masticatory phases.…”

Section: Discussionmentioning

confidence: 99%

“…If the patient exhibits a high jerk‐cost during occlusal adjustment procedures for new dental restorations and prosthetic appliances, the dentist must suspect that there is a premature occlusal contact, incorrect centric relation or other malocclusion, maladaptation to the prosthesis, or some combination of these problems. A previous study indicated that a functional interference caused by occlusal and proximal contacts by a single molar crown could be detected by jerk‐cost (6). Because the TPA incorporated in this system is also suitable for the measurement of shock and vibration as well as changes in position and inclination that occur in a specific part of the human body, future applications of this system may also prove promising in assessment of the movements of other parts of the body.…”

Section: Discussionmentioning

confidence: 99%

“…Mathematical analysis software converted voltage data from the sensor into units of acceleration, which was then differentiated over time for each of the X, Y, and Z‐direction series ¶ . The three‐dimensional jerk‐cost was then obtained based on the following equations (5, 6): …”

Section: Methodsmentioning

confidence: 99%

“…A previous study reported the utility of jerk‐cost measurements in the evaluation of masticatory movement and indicated a strong correlation between occlusal integrity and jerk‐cost (4). Other studies have shown that the jerk‐cost of the jaw movement during chewing is improved by the placement of prosthetic restorations (5, 6) and orthodontic treatments (7–9). It is expected, therefore, that the jerk‐cost as a measure of jaw movement smoothness may be used to evaluate the masticatory function of patients with tooth loss and malocclusion.…”

Section: Introductionmentioning

confidence: 99%

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Measurement of jerk-cost using a triaxial piezoelectric accelerometer for the evaluation of jaw movement smoothness

Minami

Nemoto

Nakamura

et al. 2010

Journal of Oral Rehabilitation

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Jerk-cost as a measure of jaw movement smoothness has been used to evaluate the masticatory function of patients with tooth loss and malocclusion. Jerk-cost measuring systems have thus far been unable to determine the jerk-cost of each chewing phase over time. The purposes of this study were (i) to develop a new method for measuring momentary jerk-cost of the jaw movement using a small triaxial piezoelectric accelerometer and (ii) to test the hypothesis that the lowest smoothness is seen during jaw-opening phase. The accelerometer was attached to the skin of the mentum of each subject. Vertical jaw displacement, acceleration, the jerk, and the time differential of jerk-cost during gum chewing were analysed as a function of time in five normal dentate subjects (n = 5). The system revealed intra-class correlation coefficients of intra-examiner, inter-examiner, and test-retest consistency of substantially high values (0.80-0.88). In all subjects, the highest jerk-cost was observed in the opening phase of each chewing cycle when the gum was parting from the teeth; the lowest jerk-cost was observed in the intercuspal phase throughout the chewing cycle, thus confirming the hypothesis. Significant differences were observed between the opening, closing, and intercuspal chewing phases (N = 5, P = 0.007). The smoothness measurement system used in this study evaluated the momentary smoothness of each chewing phase in the masticatory cycle. The system may serve as a diagnostic tool to evaluate the smoothness of the jaw movement in general dental practice.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Measurement of jerk-cost using a triaxial piezoelectric accelerometer for the evaluation of jaw movement smoothness

Minami

Nemoto

Nakamura

et al. 2010

Journal of Oral Rehabilitation

View full text Add to dashboard Cite

show abstract

“…A normalisation technique that generates a measure of jerk cost, which is independent of movement duration ( T ) and amplitude ( D ) (NJC = jerk cost × T 5 / D 2 ), has been proposed. Indices such as NJC, movement time, peak velocity and symmetry of the velocity profile have proved to be effective in explaining the degree of the skilfulness of the human limb and jaw motions .…”

Section: Methodsmentioning

confidence: 99%

Improvements in smoothness of chewing cycles in adults with mandibular prognathism after surgery: a longitudinal study

Yashiro

Takada

2013

J of Oral Rehabilitation

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Although adults with mandibular prognathism are known to show impaired smoothness of masticatory jaw movements, it remains uncertain whether/how the surgical-orthodontic treatment is effective to improve masticatory jaw movements. The aims of this study were (i) to verify whether the surgical-orthodontic treatment of patients with mandibular prognathism improve smoothness of the chewing jaw movements post-operatively and, if so, (ii) to examine whether the improved parameters show similar quantities as those of the control subjects. The chewing jaw movements for 13 patients with mandibular prognathism were recorded at pre- and post-treatment stages. The patient group was divided into two groups: Class III(closed) showed full occlusal contact at the habitual intercuspal position, whereas Class III(open) showed inability of occlusal contact between the upper and lower anterior teeth. The control group (CG) consisted of 52 subjects having acceptably good occlusion. The normalised jerk cost (NJC), movement duration and peak velocity in jaw closing were compared. For both Class III(open) and Class III(closed) groups, statistical comparisons revealed that the NJC and movement duration were decreased after the treatment, whereas the peak velocity was increased (all P < 0·01). For the Class III(open), these quantities at the post-treatment stage did not show any significant differences compared with those for the CG. It is concluded that the smoothness of chewing jaw movements for patient with mandibular prognathism were improved after treatment, and for the patients with anterior open bite at pre-treatment, the post-operatively achieved smoothness of jaw-closing movements did not differ from those of the CG.

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Dental Floss Selection and Its Impact on Evaluation of Interproximal Contacts in Licensure Exams

Teich

Joseph²,

Sartori

et al. 2014

Journal of Dental Education

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Ideal interproximal contacts between adjacent natural teeth or dental restorations are a critical factor for the health of the dental-alveolar complex. Interproximal contact tightness is a physiological entity affected by many patient-related and restorative parameters. This variation poses a challenge in deining the "clinically acceptable" contact area tightness (CAT) and therefore how students and clinicians should be trained to evaluate this parameter. The most widely used method to evaluate interproximal contacts is to pass dental loss between contact areas. Candidates for licensure exams are instructed to check contact areas with dental loss and are advised that this will be one of the crucial parameters to be evaluated in the overall restoration quality. The purpose of this study was to evaluate a standardized interproximal contact with six brands of dental loss. Thirty faculty members and thirty dental students at one U.S. dental school evaluated the tightness of a single interproximal contact on a typodont. The results showed that no difference was found between CAT evaluations by faculty and students, whereas signiicant differences were found between different loss brands. In light of the results, it is suggested that licensure boards should standardize the recommendation for which loss brand should be used in order to avoid inconsistencies in students' preparation.

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Restoration of occlusal and proximal contacts by a single molar crown improves the smoothness of the masticatory movement

Cited by 14 publications

References 36 publications

Measurement of jerk-cost using a triaxial piezoelectric accelerometer for the evaluation of jaw movement smoothness

Measurement of jerk-cost using a triaxial piezoelectric accelerometer for the evaluation of jaw movement smoothness

Improvements in smoothness of chewing cycles in adults with mandibular prognathism after surgery: a longitudinal study

Dental Floss Selection and Its Impact on Evaluation of Interproximal Contacts in Licensure Exams

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