Journal of Oral Rehabilitation. 1991, Volume 18, pages 483-489

Orofacial functions in patients with congenital andacquired maxillary defects: a fluoroscopic study

E. YONTCHEV, S. KARLSSON, A. LITH*, S.A. A L M Q V I S T t ,P . L l N D B L A D t a ^ ^ B . E N G S T R O M § Department of Prosthetic Dentistry.

* Department of Oral Radiology, f Department of Logopaedics and Phoniatrics. ^Department of

Linguistics and ^Department of Audiovisual Recording, University of Goteborg, Goteborg, Sweden

SummaryBy means of videofluoroscopic recordings, chewing, swallowing and speech weremonitored in nine patients with congenital and acquired maxillary defects. All of themwere rehabilitated with a maxillary obturator prosthesis. The defective region wasseldom used for chewing. No leakage between the obturator and surrounding tissuewas observed, either for sohds or for hquids. All of the prosthetic reconstructionswere surprisingly stable during function. In the phonetic analysis, speech productionwas judged to be restored almost to normal. Videofluoroscopy may be valuable as acomplement to other functional diagnostic procedures, and for the evaluation andimprovement of rehabilitation with an obturator prosthesis.

IntroductionA pervading defect of the maxilla and/or the soft palate may create significantfunctional and social problems for the subject. Oral motor functions such as chewing,swallowing and speech could be partially or totally impaired, depending on theextension and location of the defect. The location, size and form of the defect and itsrelationship with the teeth, surrounding tissues and organs often determine the designof the prosthetic reconstruction and the final outcome of the total rehabilitation. Manycancer patients have been irradiated, with subsequent impairment of the salivarysecretion rate and increased risk of caries. In edentulous patients, the quantity andquality of the saliva are also very important variables for the orofacial functions andthe retention of the obturator prostheses.

Swallowing solids and liquids can be difficult when the integrity of the maxilla and/orsoft palate has been affected. Despite optimal prosthetic rehabilitation, leakage willoccasionally occur, with subsequent problems for the patient. When this is the case,it will become very difficult to diagnose the location of the deficit. Reports onfluorographic recording of oral functions in patients with maxillofacial defects arevirtually absent from the literature. However, cineradiography and videofluoroscopyhave previously been used to study oral motor functions such as chewing and speechproduction (Lifschiz, 1963; Wictorin, Lundberg & Hedegard, 1971; Karlsson, 1979;Anapol, 1988; Karlsson et al., 1989).

The main aim of the present study was to investigate oral motor function in terms

Correspondence: Dr Stig Karlsson, Faculty of Odontology, University of Goteborg, Box 33070,S-40033 Goteborg, Sweden.

483

484 E. Yontchev et aL

of chewing, swallowing and speech in a group of patients with maxillary defects. Afurther aim was to assess the leakage of solids and liquids in relation to the location,size and form of the defect and dislodgement of the prosthesis during function.

The design of the study was approved by the Ethics Committee of the Universityof Goteborg.

Materiai and methodsThe patients who participated in this study were selected from the Section of Maxillo-facial Prosthetics at the Maxillofacial Centre, Faculty of Odontology, University ofGoteborg. The following principles were applied:

(i) the patient was to have either a palatal cleft or a defect after partial maxillectomy;(ii) at least one patient from every class according to the classification of maxillary

defects (Aramany, 1978) was to be included;(iii) the patient was to have adapted to the obturator prosthesis for at least 1 year,

and to have no problems related to the prosthesis;(iv) the patient was to have given his or her informed consent to participate in the

study.Ten patients (five men and five women) of mean age 72-3 years (range 44—92

years) were selected according to the above-mentioned principles. Nine of themagreed to participate in the study. Two of the participants belonged to class I, threebelonged to class II, one to class III, two to class IV and one edentulous patient had atotal palatal cleft. In one patient from class I and one from class III the soft palate wasalso affected. One patient from class II also had the mandible resected on the same side.

Videofluoroscopic masticatory recordingsIn order to obtain firm and well-contrasting measuring indicators, the obturatorprostheses were fitted with indicators made of lead pellets 2 x 2 mm in size. They wereembedded in the acrylic in the frontal, left and right vestibular regions, and in theobturator part of the prosthesis. The videofluoroscopic device consisted of an imageintensifier interfaced to a videotape recorder (Siemens Super Rotalix, RBV 17 SNOptilux, Vidican camera). Recordings were made in two projections, lateral andfrontal. During recording, the test subject was placed between the focus and the inputscreen, seated in a chair with an adjustable headrest and earplugs for positioning ofthe head. The position of the head in the image field was checked fluoroscopically ona monitor from the investigator's position. Each subject was given two kinds of testfood: cubes of meat and bread of different sizes, both containing 20—30% bariumcontrast medium. The subject had a free choice of bolus size and chewing side. Inorder to investigate the fit between the obturator and the surrounding tissues duringswallowing, a contrasting liquid was used.

Measurements of bolus position and leakageThe videofluoroscopic recording was analysed by means of a videotape recorder(Panasonic's VHS, NVG-12 Vtr) and a 28-inch TV monitor. The analyses consistedof the positioning of the bolus, prosthetic displacement and leakage during chewingof the two test foods. An additional analysis was made of leakage during swallowingof a Uquid.

The position of the bolus was recorded in the lateral (profile) and frontal projectionswith the two test foods. For this analysis, the dental arch was divided into sections:

Fluoroscopic study of orofacial functions 485

A (anterior, i.e. incisors and canines), P (premolars) and M (molars) (Fig. 1). In thefrontal projection, the dentition was also divided into sections: A (anterior and twolateral sections), L (left) and R (right) (Fig. 2). All chewing cycles for both test foodswere analysed. The bolus position was determined by two observers simultaneously.

The bolus was described as being situated in more than one region when it was notpossible to assign at least half of it to one region. Bolus position was analysed in termsof the percentage location in the different regions. The relationship between themaxillary defect and the position of the bolus, as well as leakage, was also determmed.

Fig. 1. Regions used for tracing of bolus position in the frontal projection: anterior (A), left (L) andright (R) regions.

Fig. 2. Regions used for tracing of bolus position in the lateral projection: anterior (A), premolar (P)and molar (M) regions.

486 E. Yontchev et al.

Anticipated leakage of food or liquid during a chewing sequence was noted aspositive, and the reverse situation was noted as negative. Displacement of the prosthesiswas analysed by estimating the movement of the embedded lead indicators. Theextent of the displacement was recorded as none, or minute (0—2mm), moderate(2—8mm) or severe (>8mm).

Phoniatric recordingsThe movement of the soft tissues of the velum and nasopharynx in relation tothe prosthesis during speech was examined using propylidone contrast medium(Dionusil® 0-5 g m P ' , Glaxo), introduced via the nasal cavity. The patients read a listof words and sentences dictated by one of the authors. Since some of the patientssuffered from impaired hearing, the words and sentences were also presented writtenin large capital letters. The list consisted of four nonsense words (e.g. ma-ma-ma),two single words (e.g. 'Hoppa', in English = 'jump') and 15 sentences. The sentenceswere selected so as to give a wide variation of combinations of sounds in the initial,medial and final position. The hypothesis was that (s) and sounds requiring high intra-oral pressure, namely stops and fricatives, i.e. (p), (t), (f), would be most difficult forthe patients to produce. The sentences therefore consisted of several combinations ofthese sounds with different vowels, and also of nasals and fricatives other than (s) incombination with vowels. The X-ray and video equipment described earlier was used,complemented by a dynamic AKG microphone for recordings of the speech signal. APanasonic FIO video camera with a VEL mixer recorded the facial movements of thepatient during speech. The radiographic projections used were the same as those

Fig. 3. Position of liquid (a) at the beginning and (b) at the end of swallowing. Note the liquid, theobturator part and the embedded indicator (arrows) of the prosthesis. This patient had a defect ofthe hard and soft palate.

Fluoroscopic study of orofacial functions 487

described previously. Due to technical problems with the video equipment, the speechsignal for two of the patients was not recorded during the examination. Thus onlyseven patients were included in the study of speech production.

Three of the authors (S.A.A., P.L., A.L.) co-operated in the analysis of thearticulation movement of the soft tissues of the velum and nasopharynx, and analysedthe recordings of the sounds. (S.A.A. is a trained phoniatrician, and P.L. is a trainedphonetitian).

Radiation dose measurementDuring positioning of the patient and recording for 60s in each position, the absorbeddoses were 3-7 mSv in the frontal projection and 5-0 mSv in the lateral projection. Thisgives a total dose equivalent to 0-15 mSv for the whole recording procedure (Karlsson

et al., 1989).

Results

Bolus position

The reeordings in the lateral projection during chewing of meat and bread revealedthat the premolar and molar regions were used to almost the same extent, 70% of themasticatory cycles (Table 1). The anterior region only appeared to be used during theinitial phases of a masticatory sequence, and the mean percentage engagement was30% for both meat and bread. In the frontal projection, both sides, left and right,were utilized equally.

When the data for individual patients were analysed, a wide spectrum of bolusdistribution patterns was recorded (Table 2). Four of the patients did not use thedefective region at all during mastication. Three patients used the defective side dur-ing 20-30% of the masticatory cycles, and one patient positioned the bolus in thedefeetive region during 74% of the cycles. This patient was edentulous in both jaws,with hemimaxillectomy and resection of the soft palate performed 10 years earlier,followed by rehabilitation with a maxillary obturator prosthesis and a mandibularcomplete denture.

In general, there were no positional differences when mastication of meat andbread were compared.

Leakage and prosthesis dislodgementNo leakage of liquid, or meat or bread, could be observed during swallowing or mas-tication, even in patients with a very extensive defect (Fig. 3).

Table 1. Percentage distribution of bolus position in various tooth regions in lateral and frontalprojections

Lateral (%) Frontal (%)

Anterior Premolar Molar Right Left

Meat

27

Bread

36

Meat

69

Bread

77

Meat

68

Bread

51

Meat

49

Bread

54

Meat

47

Bread

52

488 E. Yontchev et al.

Table 2. Percentage distribution of bolus in intact, defective and combined regions

Patientno.

123456789

Total

Defective

Meat

30200

1900

740

42

21

region (%)

Bread

30430

2200

740

30

22

Intact

Meat

7180

10085

10010043

10047

81

region (%)

Bread

8010010078

10010035

10074

85

Both re|

Meat

15006

156

21260

10

^ions (%)

Bread

18470

162

4130210

20

The mobility of the obturator prosthesis was judged to be non-existent or minutefor most of the masticatory cycles. Moderate dislodgement was only observed oc-casionally. In patients with an extensive defect and a resected soft palate, a pumpphenomenon along the obturator border was sometimes observed at the end of amasticatory sequence.

Speech analysisAuditory analysis of the speech signal revealed normal or almost normal speech afterthe rehabilitation. However, three patients exhibited slight open nasality, and onehad stops with weak intra-oral pressure and an indistinct (s).

Analysis of the videotaped fluoroscopic recordings showed good activity of themovements of the velum of all patients, except for the patients with a total cleft. Themovements of the lateral pharyngeal walls were invisible, owing to the presence ofmetal material in the prostheses of three patients. In the remaining four patients, thelateral walls showed good or moderate activity during speech.

DiscussionIn the present group of patients with maxillo-mandibular defects, the distributionof the bolus in relation to the defect was of particular interest. Surprisingly enough,the defective region was totally avoided by only four of the patients. One of themwas edentulous and rehabilitated after hemimaxillectomy and ipsilateral hemiman-dibularectomy. This patient never used the defective side, but only used the anteriorregion. Another patient with similar defects, but with parts of the natural dentitionremaining, used the defective side to quite a large extent, about 35% of the masticatorycycles. The recorded differences between edentulous and dentate patients emphasizethe importance of preserving as much as possible of the natural dentition, even if itis mutilated.

Anticipated leakage during swallowing or chewing was not recorded during video-fluoroscopic monitoring. In the patients in whom the soft palate had been resected,adaptive changes in the swallowing pattern had occurred. In the initial stage, the

Fluoroscopic study of orofacial functions 489

tongue was positioned as low as possible with the hypopharynx wide open. After thispreparatory phase, the act of swallowing was performed very rapidly.

Rehabilitation with an obturator prosthesis restored speech production almost tonormal. However, in three of the patients a persistent slight open nasality was notedafter rehabilitation. A similar improvement in reduced nasal resonances after pros-thetic rehabilitation was reported by Tobey and Lincks (1989). In a study by Walter(1990), using nasal endoscopy, it was reported that 'closure patterns of the palato-pharyngeal isthmus varied according to whether the subjects were speaking, suckingor swallowing.' They advocated development of an obturator prosthesis to meet therequirements of speech production rather than of the function of swallowing. In thepresent study, both functions appear to have been restored almost to normal. Ouroverall impression is that these patients have adapted surprisingly well to their obturatorprostheses, exhibiting few and only minor problems.

The results of this study have demonstrated that videofluoroscopy serves as a valu-able complement to other diagnostic procedures for obtaining an overall picture oforal motor function. We believe that this method can be a helpful tool for the pros-thodontist in improving the function of the prosthesis. For studies of bolus position,leakage and intra-oral speech production patterns, videofluoroscopy appears to be theonly practicable method, and to be particularly valuable in the evaluation of obturatorprosthesis rehabilitation. The decision of whether and when to carry out videofluor-oscopic examination must be taken by the individual investigator, after weighing otherfactors relating to diagnosis against the radiation to which the patient is exposed.However, videofluoroscopy is fairly simple to perform, and no other method yields somuch information about oral motor function from a single recording.

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