Intraoral occlusal telemetry. Part II. Registration of tooth contacts in chewing and swallowing

Fixed partial dentures and operative dentistry

Intraoral tooth

occlusal

contacts

telemetry.

in chewing

Part II. Registration and

of

swallowing

Jan H. N. Pameijer, D.M.D.,* Irving Glickman, D.M.D.,** and Fred W. Roeber, B.S.*** Tufts University, School of Dental Medicine, Boston, Mass.

A

n intraoral electronic telemetry system which utilizes miniaturized multifrequency radio transmitters for studying occlusion has been described in Part I.* This sensitive system records precise information concerning the frequency, duration, and location of the tooth contacts of natural teeth during chewing and swallowing. AS many as six different functional and parafunctional contacts can be registered in different locations on the same tooth by this equipment. This article describes the types of recordings produced by the system during chewing and swallowing. EXPERIMENTAL

METHOD

The intraoral transmitting device consists of an oscillator, battery, and a multilayered Beryllium-copper switch combined in a unit small enough to fit into a pontic that is replacing a single molar tooth. Depending upon the number of layers, the switch can activate the oscillator at three or six different frequencies. The switch is closed only when it is contacted by a small gold inlay inserted in the lingual CUSP of the opposing tooth. Signals are picked up by an antenna and fed to receivers which are connected to a six channel oscil1ograph.l Swallowing is indicated by a sensor around the patient’s neck. The sensor produces a characteristic pattern on the o’scillograph which correlates swallowing with tooth contacts. A telegrapher’s key connected to the oscillograph is used as an event marker to register chewing strokes and swallowing. This report is from an investigation supported by the Research and Development Command? Office of the Surgeon General, Department of the Army, under Contract No. DA-49193-MD-2614. *Assistant Clinical Professor in Periodontology. **Research Professor of Oral Pathology, Professor of Periodontology. ***.4pplird

Physicist,

Raytheon

Co., Wayland,

and Chairman

of the Department

Mass. SURANO

151

152

Pameijer,

Glickman,

1. Pros. Dent.

and Roebcr

l+cbruary,

1968

Fig. 1. The switch is embedded in the molar pontic. (A) The switch is aligned anteroposteriorly. (B) The switch is aligned buccolingually. The battery and oscillator are also contained within the pontic. Table Tooth Tooth

I contacts contacts

in chewing Switch

and swallowing alignment

in intraoral

telemetry

Location of tooth contact

Anteroposteriorly

“Habitual” occlusion 0.75 mm. anterior from habitual 0.75 mm. posterior from habitual

Buccolingually

“Habitual” occlusion 0.75 mm. left lateral from habitual 0.75 mm. right lateral from habitual

Single contacts

Anteroposteriorly Gliding

recorded

contacts Buccolingually

occlusion occlusion occlusion occlusion

Protrusive glide Retrusive glide Right lateral glide Left lateral ,glide

Six subjects have been studied by this method. To demonstrate the parameters established by tooth contacts in chewing and swallowing, an analysis of the recordings (using a three signal switch) made of a man with a full complement of teeth except for one mandibular molar are presented. Transmitting devices were built into two interchangeable fixed partial dentures. In one, the switch was positioned antero(centric) occlusion” posteriorly so that it recorded tooth contacts in the “habitual” *In this article the term “habitual occlusion” will be used for purposes of communication without implying any significance in the physiology of occlusion. Habitual occlusion is the maximum intercuspated occlusion with the mandible out of centric relation.

Volume Numhel~

19 ?

Intraoral

occlusal

telemetry

153

Fig. 2. Typical recordings of tooth contacts with the switch aligned anteroposteriorly indicate: Channel 1, tooth contacts anterior to “habitual” occlusion; channel 2, tooth contacts in “habitual” occlusion; channel 3, tooth contacts posterior to “habitual” occlusion; channel 4, recording of tooth contacts while swallowing; and channel 5, the event marker registered by telegrapher’s key. The timer is shown on the bottom line.

and at 0.75 mm. anterior and posterior to “habitual” occlusion. In the other, the switch was positioned buccolingually in order to record contacts in the central fossa in “habitual” occlusion, and at 0.75 mm. buccal and lingual to “habitual” occlusion (Fig. 1). Tooth contacts were studied under the following conditions: (1) opening and closing mandibular movements following instruction by the investigator; (2) opening and closing mandibular movements assisted by the investigator; and (3) eating a hamburger, uninstructed and unassisted, The recordings made under instruction and with assistance were used as parameters for studying tooth contacts during mastication. They also provided a means of verifying the reliability and reproducibility of the telemetric recordings. OBSERVATIONS The type of patterns developed by single and gliding tooth contacts recorded during chewing and swallowing are shown in Table I. A typical recording is shown in Fig. 2. Tooth contacts anterior to “habitual” occlusion, in “habitual” occlusion, and posterior to “habitual” occlusion appear on channels I, 2, and 3, respectively. Swallowing is indicated on channel 4. Chewing cycles and swallowing are indicated by the telegrapher’s key on channel 5. The

154

Pameijer,

Glickman,

.I. Pros. February,

and Koebcj

Dent. 1968

record of each tooth contact appears as a signal on channel 1, 2, or 9. The signal consists of two vertical lines interconnected by a horizontal line. The duration of the contact is indicated by the distance between these vertical lines. RECORDINGS

WITH

INSTRUCTED

AND

ASSISTED

MAND!tMJLAR

MOVEMENTS

Switch aligned allteropostcriorl2The subject was instructed to tap his teeth together several times in his most comfortable position (“habitual” occlusion). The switch was aligned so that contact in this position occurred between the gold inlay in the maxillary tooth and the middle section of the switch located in the rnandibular pontic (Fig. 3, C’ Guiding the mandible into repeated tooth contacts in a retruded position produced signals on the channel that indicated tooth contacts made posteriorly to “habitual” occlusion (Fig. 3) . When the subject held this position before bringing his teeth together in maximum intercuspation, a signal was recorded on channel S occlusion (Fig. 3, a) followed by ;I indicating tooth contact posteriorly to “habitual” skgnal on channel 2 indicating tooth contact in habitual occlusion (Fig. 3, b). This was typical of the signals recorded from an anterior glide produced hy a defkctir,e occlusal contact in the pathway of a closure in centric relation.

Fig. 3. Recordings made with the switch aligned anteroposterioriy. ‘Tooth contacts made posteriorly to “habitual” occlusion are shown on channel 3. A prolonged contact is shown at a, followed by contacts in “habitual” occlusion shown on channel 2. A long contact in “habitual” occlusion is shown at b. Repeated contacts in “habitual” occlusion are shown at c. The sequence of signals shown by a and b is typical for an anterior glide from a deflective occlusal contact in centric relation to “habitual” occlusion.

Fig. 4. Recordings made with the switch aligned buccolingually. Tooth contact in the “habitual” closure is shown in channel I at a, ri, and d; contact on the working side is shown in channel 3 at c, and a contact on the balancing side is shown in channel 2 at e.

Fig. 5. A recording made when the subject was eating a hamburger, while the switch was aligned anteroposteriorly. Repeated contacts during mastication are shown on channel 2 in the “habitual” position, and anterior to it on channel 1. The only contact in a position posterior to “habitual” occlusion (channel 3) occurs during one of the swallows, s, on channel 4.

156

Panwijer,

Glickman,,

and Roeber

Fig. 6. A recording made at a higher paper speed than that in Fig. 5, while the subject was eating a hamburger. The switch was aligned anteroposteriorly. Numerous tooth contacts were registered anterior to “habitual” occlusion (channel I, 0’). There is a glide from “habitual” occlusion (channel 2, h) to the anterior position (channel 2. u). There is also a prolonged contact in “habitual” occlusion (channel 2, h’) accompanying a swallow shown at channel 4, 5.

Fig. 7. A recording made while the subject was swallowing a holus of hamburger. There is a long contact ( 1.7 seconds) in “habitual” occlusion associated with a swaHow shown at channel 4, s. The duration of the swallow is computed from the I second timer (bottom line).

Intraoral

occlusal

telemetry

157

Switch aligned buccolingually. The subject was instructed to tap his teeth together in his most comfortable position (“habitual” occlusion). This produced repeated recordings on channel 2 indicating tooth contacts in habitual occlusion (Fig. 4, a) . Then the patient was instructed to close, and move the mandible laterally to the right, keeping the teeth in contact. This produced a record indicating a contact of long duration in “habitual” occlusion (Fig. 4, b) followed by a signal indicating a contact on the working side (Fig. 4, c) as the teeth moved from “habitual” occlusion on to the linCgual incline of the maxillary buccal cusp. Left lateral movement from “habitual” occlusion (Fig. 4, e) produced contact on the buccal incline of the maxillary lingual cusp, usually designated as the contact on the balancing side (Fig. 4, e) . RECORDING

WHILE

EATING

A HAMBURGER,

UNINSTRUCTED

AND

UNASSISTED

Oscillograph recordings made when the subject was eating a hamburger and the switch was aligned anteroposteriorly are shown in Fig. 5. The recordings indicate occlusion, and anterior to it; but no tooth repeated tooth contacts in “habitual” contacts occurred posteriorly to “habitual” occlusion. Several swallows were occlusion, except in one recorded, and they occurred with the teeth in “habitual” instance in which there was a sliding contact from “habitual” occlusion to a posterior position (Fig. 5, h-f).

Fig. 8. A recording made while the subject was swallowing a bolus of hamburger. The switch is aligned buccolingually. Three swallows are shown on channel 4. In the first swallow, St, the teeth closed in “habitual” occlusion. In the second swallow, Sn, there is a glide from a tooth contact on the balancing side (channel 1, b) to “habitual” occlusion (channel 2, h). During the third swallow, S, there is a contact in “habitual” occlusion only.

158

Parneijer,

Glickman,

and Roebt,r

Kecordings made of a subject who was eatin,g a hamburger when the recordin? speed was increased is shown in Fig. 6. Single tooth contacts were demonstrated anteriorly to “habitual” occlusion (Fig. 6, a’) : gliding tooth contacts from the “habitual” occlusion to an anterior position (Fig. 6, h-a), and a singIt& contact of teeth in “habitual” occlusion (Fig. 6, II’,! during swallowing (Fig. 6, J). occlusion during A long (1.7 seconds’) single contact of teeth in “habitual” swallowing is illustrated in Fig. 7. The duration of the contact was cornputed by using the 1 second timer and the length of the horizontal marking (Fig. 7> h’). Eating a hamburger when the switch was placed buccolingually produced ‘1 consistent pattern of both single and gliding contacts in chewing with no regular pattern of tooth contacts in lateral excursions. Three swallows are shown in Fig. 8. occlusion (11); in the second In the first swallow (S,] ? the teeth were in “habitual” swallow, (S,! , the mandible glided from the balancing side contact (b) into “habitual” occlusion jh). In the third swallow, (S,\ , the teeth were in “habitual” OCelusion (1~). A working side contact ( w,I was also recorded in this sequence during cleansing by the patient between swallows. DISCUSSION Kecordings of tooth contacts in the natural dentition made during chewing and swallocving were obtained with a miniaturized intraoral telemetry system. This method permits the study of occlusion without artificial encumbrances. The fact that. the transmitting device fits in a pontic replacing a molar eliminates the need for an external apparatus, and avoids the risk of registering artificially induced neuromuscular responses. It is too early to attempt interpretation of the significance of the recordings in the physiology of occlusion. Normal and abnormal occlusal conditions are yet to be determined. Nevertheless, some of the more interesting findings are presented because they demonstrate the effectiveness and sensitivity of the telemetric systen1. Hy guided closure and by instruction it was possible to register tooth contacts in thr most retruded position of the mandible in relation to the maxillae. However. this position was used relatively infrequently in eating and swallowing. Most contacts during chewing occurred in “habitual” occlusion. The few tooth contacts during chewing posterior to “habitual” occlusion were recorded both during chewing and swallowing. In most instances, the teeth contacted in “habitual” occlusion during swallowing or a retrusive glide occurred from an anterior position into “habitual“ occlusion. Single contacts. and less frequently, lateral gliding contacts occurred during mastication. However? no repetitive pattern of tooth contacts was recorded during lateral excursions. SUMMARY Kecordings of tooth contacts produced by an intraoral telemetry system placed in the naturai teeth during chewing been presented and explained.

miniature electronic and swallowing have

Intraoral

occlusal

telemetry

159

Reference 1. Glickman, I., Pameijer, J. H. N., and Roeber, F.: Intraoral A Multifrequency Transmitter for Registering Tooth Contacts 19: 60, 1968. DRS. PAMEI JER AND GLICKMAN 136 HARRISON AVE. BOSTON, MASS. 02111 F. W. ROEBER: L2, RAYTHEON

COMPANY BOSTON POST ROAD WAYLAND, MASS. 01778

:

Occlusal Telemetry. Part I. in Occlusion. J. PROS. DENT.