Prosthodontics

Preprosthetic therapy utilizing a temporaryocclusal acrylic splint: A case reportTomislav Badel, DMD, MSDVSonja Kraljeviç, DMD, MSD, PhDVJosip Panduriç, DMD, MSD,Miljenko Marotti, DMD, MSD, PhD^

This case report describes the complex occlusal rehabilitation of a patient with signs and symptoms ottemporomandibular disorders with utilization of an occlusal acrylic splint as a means ct initial treatment torneuromuscular reprogramming and repositioning ot the condyle within the mandibular tossa fcr occiusaistability, thus allowing adaptation to a new ccclusai vertical dimension. (Quintessence Int200435-401^05)

Key words: occlusal treatment, occlusal vertical dimension, stabilization splint, temporomandibuiar disorder

Indication and planning of occiusai treatment shouldtake into account the multiple roles of occlusion in

the mutual relations of craniomandibular systemstructures, A specific aspect of the treatment is the ex-istence of mutual relationships among temporo-mandibular disorders (TMD), excessive tooth wear,and compromised occlusion.'

The following are indications for occlusal treat-ment: frequent fractures of tooth and restorative appli-ances; parafunctional movements; decreased occlusalvertical dimension (OVD); tooth trauma; periodon-tium or soft tissues of the mouth and alveolar ridges;unacceptable or defective occlusal contacts; disruptedesthetics; and the existence

'Assistant, Depariment ot Prostho dort íes. Scfiool of Dentai Medicine,University ot Zagreb. Zagreb, Croatia,

^Professor, Department ot Prosthodontics, School o( Dental Medicine.

University of Zagreb, ZagreC, Croatia.

^Professor, Department of Radiology, Clinical Hospital "Sestre milosrdnice,"Univeisit/ of Zagreb, Zagreb, Croatia.

Reprint requests: Dr Tomislav Badel, Departrrent of Prosthodontics,School of Dentai Medicine, University of Zagreb, Gunfluliçeva 5, tOOOOZagreb, Croatia. E-mail: tomisiau.badeiehi.liinet.hr

Tooth wear is considered pathologic when compari-son is made with tooth wear typical for the patient'sage and when prosthodontic treatment is essential be-cause of impaired chewing function, phonetics, facialprofile, and TMD symptoms.^ The loss of posteriorteeth, extent of tooth wear, as well as interocclusal dis-tance have a significant effect on the funcfional condi-tion of c rani o mandihular structures and facial dishar-mony. Consequently, it is necessary to carry out OVDevaluation and assessment of its influence on the oc-currence of the decompensatory conditions.

Leib̂ * and Dyiina^ recommended that suspectedchanges in OVD should be corrected over a test-timeperiod by wearing an acrylic occlusal splint. This oc-clusal splint therapy is essential for patients who pre-sent more severe forms of occlusal disorder and/orwith TMD symptoms. Through this initial occlusaltreatment, the mandible can be reprogrammed, myo-genic and arthrogenous pain can be eliminated, thecentric and eccentric occlusal concept of occlusioncan be tested, and optimal occlusal relations attained,which can then be incorporated in the definiteprosthodontic treatment.

No report on splints or prosthodontic treatmentwould be complete without understanding the role ofcentric relation (CR) in the healthy stomatognathicsystem.' Dawson' defined CR as "the relationship of

Quintessence IniernaTionai 401

Badel et al •

Fig 1 Preoperative view of patient showing old and wornmandibular fixed prosthesis. Note closed vertioai dimension andexcessive ove rb i te.

fhe mandible to the maxilla when fhe properly alignedcondyle/disc assemblies are in fhe most superior posi-tions against fhe eminence irrespeetive of tooth posi-tion or vertical dimension." Centrie relation is the opti-mal arrangement of joinf, dise, and masficatorymuscles. The mandibular position where the condylesare in CR and teeth are maximally intercuspidated iscalled cenfrie relate occlusion (CRO).''

Dylina' recommends that splint therapy utilize CRas fhe physiologic treatment position. Centric relationis an invaluable position in restorative dentistry whenthere are no posterior oeclusal contacts remaining atthe desired OVD.' Patients who have TMD and re-quire prosthetic rehabilitation need special attention.As an irreversible and permatient procedure, prostho-dontie reconstruction can only follow in the patientwith no TMD symptoms.^-'"

TMD has its efiologic basis in disturbed adaptationof craniomandibular structures and excessive use ofcompensatory mechanisms." The mosf frequentlymentioned factors are: macrotrauma; microtrauma;and dental, occlusal, anatomic, psychologic, and be-havioral factors.'^''' The concept of occlusion as anefiologic facfor in TMD may have httle reliable scien-tific evidence. Wassell" and PuUinger ef aP^ have sug-gested that occlusion disorders are most frequently ofsecondary importance for fhe occurrence of dysfunc-tion (ie, they intensify symptoms caused by other etio-logie factors).

The present case describes fhe inifial and definitiveprosthodonfic occlusal treatment of a patient wifhTMD signs and symptoms, who has a functionally wornout and unsuifable prosthetic reconstruction. The cur-rent report shows the need for complex occlusal reha-bilitation, with the goal of achieving a sfahle occlusionutilizing an optimal horizontal and vertical dimension.

Fig 2 Changed facial profiie of the patient in Fig 1. Note reducedlower third of Ihe lace with deranged position, volume, and mutualcontact of lips.

CASE REPORT

A 59-year-old man was referred by his general practi-tioner to the Clinic at the School of Dental Medicinein Zagreb. He complained of bilateral pain and crepi-tation in the area of the temporomandibular joint(TMJ) and pain in the masticatory muscles whilechewing and when in the "wide-open mouth" posi-tion. The patient had experieneed the symptoms,which were more marked in the left TMJ, for morethan 20 years. The patient reported that clicking hadbeen the dominant symptom in the TMJs. He con-nected fhe occurrence of symptoms with extensiveprosthetic restoration in the maxilla and mandible car-ried out over several occasions during the previous 20years. He had noticed lowering of the vertical overlapof fhe frontal feeth after restorative treatments, whichwas exaeerbated by tooth wear.

Clinical examination and diagnosis

The patient presented wifh a 10-year-old, f 6-unit fkedpartial denture (FPD) in the maxilla, an 8-year-old,seven-unit FPD in the mandible, and a 5-year-oldmandibular removable partial denture (RPD). Therewas marked abrasion to the veneers on the mandibu-lar FPD and artifieial acrylic teeth of the mandibularRPD (Fig 1). As a resuU of the decreased OVD, the fa-cial profile was changed and the lower third of theface markedly reduced (Fig 2). Active movementswere measured: opening of 37 mm; right laferotrusionof 9 mm; left laterotrusion of 10 mm; and protrusionof 2 mm. Passive opening (passive sfretching)amounted fo 6 mm. The following static occlusal fac-tors were noted: angle Class II/I and depth of fhe ver-tical overlap of the maxillary central incisor over fhelabial surface of the mandibular incisor (overbite),amounting fo 7 mm.

402 Voiume 35, Number 5, 2004

• Bade l et al •

Dtagnosis of the patient was performed according toRDC-̂ TMD criteria,'«' Manual examinafion techniqueswere used in the diagnostics'' and magnefic resonanceimaging (MRl) of the TMJs in the position of maximalintercuspation (MI) and maximally open mouth(Magnetom Harmony, Siemens; field force of 1 Tesla),The appearance of the left TMJ by means of MRI (Tlmeigted image. Spin Echo technique SE 700/40 mil-liseconds) showed degenerative changes with subcbon-dral sclerosation in the area of the articular eminence.Subluxation witb mild anterior movement could beseen in the closed mouth position (Fig 3),

According to the diagnostic system of Dworkin andLeResche,'« the following three diagnoses were deter-mined: group I - myofacial pain with limited opening;and group III for left and ri¿it TMJs (osteoarthrifis).

Initial splint treatment

A stabilization splint is a conservative form of initialtreatment of TMD and correction of disrupted OVD,The occlusal contacts and function of the mandibleare temporarily changed by means of an occlusalsplint, Tbe object is to achieve equal contacts of theposterior teeth and to ensure a CR of the mandible bymeans of CRO against tbe splint. During the initialnonspecific treatment, a neurologic release should beachieved by means of the splint, Occlusal splints alterthe occlusion reversibly, and increased OVD reducesmasticatory muscle activity and decreases symptoms

Splint impressions are taken in irreversible hydro-colloid (Xantalgin Select, Heraeus Kulzer) and work-ing casts in hard plaster (Vel-Mix Stone, Kerr), Themaxillary model is mounted in a semiadjustable artic-ulator (SAM 2P, SAM Prazisionstechnilt) by means ofa facebow (Axioquick, SAM Präzisionstechnik), TheCR of the mandible is registered bimanually with a CRwax record (Beauty Pink, Moyoco), and teeth impres-sions are secured by means of aluminum wax(Aluwax, Dental Products), The vertical dimension ismeastired extraorally by a gauge in tbe midline of theface between two points (subnasally and on tbechin).^" The base of tbe stabilization splint is done bymeans of vacuum-sbaped tbermoforming foils(Erkodur, Erkodent) over the maxillary working cast.The occlusal surfaces of the splint are fabricated fromautopolymerizing acrylic resin (ProBase Cold,Ivoclar)."

Through wearing the stabilization splint, an im-proved functional condition was achieved (ie, disap-pearance of TMD signs [arthralgia, myalgia, and TMJcrepitafion]). The patient tolerated the reposifioning ofthe condyle within the mandibular fossa and feft com-fortable with the splint at an increased OVD (Fig 4).

Fig 3 Sagittal MRI ot the left TMJ with closed moutn, with sublux-ational position ot the condyle. Note degenerative changes wittisubcnondral sclerosation (arrowheads). 1 = condyle; 2 = articulareminence; 3 = articular disc; 4 = e!<ternal auditory meatus.

After 6 weeks of wearing the splint, a reduction insublitxation was determined by MRI, and improve-ment in the position of the condyle within themandibular fossa (Fig 5),

Definite treatment

Definitive prosthodontic treatment (Fig 6a} was madepossible by tbe successful initial treatment with thesplint, A 16-unit FPD was fabricated in the maxilla,and a seven-unit FPD was placed for the anteriormandible supporting a distal extension RPD (Fig 6b),

CONCLUSION

The stabilization splint is the basic means of conserva-tive and reversible initial prosthodontic treatment forpatients with decreased OVD, and also for TMD. Inthe present case, a harmonious relationship of the pa-tient's facial profile was achieved by correction of tbeOVD (Fig 7),

The stabilization splint allows neuromuscular re-programming and repositioning of the condyle in theCR position within the mandibidar fossa, occlusal sta-bility, and adaptation of the craniomandibular struc-titres by increasing vertical dimension and eliminatingsigns and symptoms of TMD, The attained occlusal re-lations are tested over the period of 4 to 6 weeks ofwearing the splint.

The advantages of MRI as a noninvasive radiologiemethod in presenting the bony and soft tissues of the

Quintessence International 403

• Badei et ai

Fig 4 Craniomandibular reiations with appiied stabiiization splint

Fig 5 (rigt!t) Sagittal MRI ot the left TMJ with closed mouth andapplied splinl after 6 weeks wearing, showing a reduction in sub-iuxation, 1 = condyie: 2 = articuiar eminence: 3 - artioular disc: 4= external auditory meatus.

Fig 6a Craniomandibuiar relations after definitive prosthodonticrehabilitation. Note increased verticai dimension as evidenced bynormal overbite.

Fig 6b Panoramic radiography of linal fixed partial dentures.

Fig 7 Improved profile of the patient after definitive prosthodon-tic rehabilitation.

404 Volume 35, Number 5, 2004

Badei et al

TM]s are significant. The MRI is used in the diagnos-tics and monitoring of the effects of the initial treat-ment, which is compared with case history data andclinical findings.

In restorative dentistry, the main objective of initialtreatment with an occlusal splint is the correction ofthe vertical and horizontal dimensions that is accept-able to the patient. Conservative treatment with asplint is also useful in the treatment of TMD. Initialtreatment enables future definitive prosthodontictreatment with the physiologic relations achieved bythe splint.

REFERENCES

1. Dawson P. Evaluation, Diagnosis and Treatment of OcclusalProblems, ed 2. St Louis: Mosby. 1989:41-46.

2. Wassell RW, Steele JG. Consideration when planning oc-clusal rehabilitation: A review of the literature. Int Dent J1998:48:571-581.

3. Sato S. Hotta TH, Pedrazzi V. Removable occlusal overlaysplint in the management of tooth wear: A clinical report, JProsthet Dent 2000:83:392-395,

4. Leib AM. The occiusai bite splint-A noninvasive therapyfor occiusai habits and temporomandibuiar disorders.Compend Contin Educ Dent 1996:11:1081-1090.

5. Dylina TJ. A common-sense approach to splint therapy. JProsthet Dent 2001;86:539-545,

6. Keshvad A. Winstanley RB. An appraisal of the literature oncentric relation. Part III. J Oral Rehabil 2001:28:55-63.

7. Becker CM, Kaiser DA, Scbwalm C. Mandibuiar centricity:Centric relation. J Prosthet Dent 2000;83:158-160.

8. Weinherg LA. Definitive prosthodontic therapy for TMJ pa-tients. Part 1: Anterior and posterior condylar displacement.J Prosthet Dent I983;50:544-557

9. Türp JC, Stnib JR, Prosthetic rehabiiltatlon in patients wUhtemporomandibuiar disorders. J Prosthet Dent 1996;76:418-423.

10. Ekberg EC, Sabet ME, Petersson A, Nilner M. Occlusal ap-pliance therapy in a short-term perspective in patients viHthtemporomandibuiar disorders correlated to condyie posi-tion. Int I Prosthodont 1998;11:263-268.

U, Okeson JP, Management of Tem op roman dibular Disordersand Occlusion, ed 5. St Louis: Mosby, 2003:159,509-520,532-534,

12. DeBoever A, Carlsson GE. Etiology and differential diagno-sis. In: Zarb GA, Carisson GE, Sessle BJ (eds). Temporo-mandibuiar Joint and Masticatory Muscle Disorders, ed 2.Copenhagen' Munksgaard, 1994:171-187

13. Palla S. Myoarthropathien des Kausystems und orofazialeSchmerzen, ed 2. Zürich: ZZMK der Universität Zürich,1998:3-16.

14. Wassell RW, Do occlusal factors play a part in temporo-mandibuiar dysfunction? J Dent 1989:17:101-110,

15. Puliinger AG, Seligman DA, Gombein JA. A multiple logis-tic regression analysis of the risk and relative odds of tem-poromandibuiar disorders as a junctive of common occlusalfeatures. J Dent Res 1993;72:968-979.

16. Dworkin SF. LeResche L. Research diagnostic criteria fortemporomandibular disorders: Review, criteria, examina-tions and specifications, critique. J Craniomandib Disord1992;6:301-355.

17. Bumann A, Lotzmann U. Funktionsdiagnostik und Thera-pieprinzipien. In: Rateitscbak KH, Wolf HF (eds). Far-batlanten der Zahnmedizin, ed 1. Band 12. Stuttgart-NewYork: Thieme. 2000:53-140.

18. Nelson SJ. Principles of stabilization bite splint therapy.Dem Clin North Am 1993;39.403-421.

19. Widmalm SE. Use and abuse of bite spiints. CompendContin Educ Dent 1999:20:249-239.

20. Miralles R, Dodds C, Falazzi C, et al. Vertical dimension.Part 1: Comparison of clinical freeway space, J Cranioman-dib Pract 2001:19:230-236.

Ouinlessence Internaliortal 405