Fundamental considerations on the morphophysiology and mor- phopathology of the (TMJ)

Ana-Maria Grumezescu Iancu1, Dragoº Totolici2, Lucian Ieremia3

1 Frankfurt am Main, Germany 2 Constanþa, 3 Târgu Mureº, Romania

Summary

The authors evidence the importance of being knowledgeable as regards the TMJ anatomy as well as its specific peculiarities are interpreted through the new intersystemic medical vision of contem- porary Gnathology. The nine essential features presented above open the perspective of assimilating morphophysiolo- gy and morphopathology knowledge on this articulation, which is a unique item in its capacity as the posterior anatomic determinant of functional occlusion.

Keywords: tmj morphophysiology and pathology, posterior anatomical determinant, functional occlusion..

without discal-condylar implications - Note I - (Ieremia et al., 1987, 1999, 2000). Most often, the appearance of 1. The need of getting acquainted dyshomeostasis of this complex ensemble with the TMJ anatomy will directly or indirectly generate baneful consequences on other biosystems of the human organism as well. Due to its poly- One of the most significant conquests morphic symptomatology, usually charac- of contemporary Gnathology is the integra- terizing a syndrome, and to an intracapsular tion of all dental braches within the frame of or extracapsular pathology produced by pre- Biology under the name of Dental Medicine. disposing, initiating or perpetual multi- Following the emergence and applica- causal etiological risk factors (that can mix tion of multiple technical means of macro- up and reciprocally condition themselves scopic, microscopic and radiological clini- through different intimate mechanisms), the cal examination of TMJ, of refining the orofacial structures are equally affected, complex means of epidemiological investi- against the aggravating background of over- gation – analyzed by the help of anamnestic lapping certain systemic diseases (Pullinger and objective indices, processed by comput- et al, 2000). Such craniomandibular dys- er programs – a new methodology was set function is the consequence of imbalance, up. It allowed extremely relevant results, by having three basic origins: using an intersystemic medical reasoning, - postural, through the functional dis- which was able to assess the functional or turbance of the muscles which connect the dysfunctional status of the stomatognathic mandible to the , the vertebral column system, also termed orofacial (OFS), with or and the shoulder girdle;

38 OHDMBSC - Vol. IV - No. 4 - December, 2005

- lingual, through the dyspraxia of etiology by explaining the pathology of infantile deglutition; morbid entities of the TMJ, still represent - dental, through malocclusion with nowadays a controversial subject. It deviations in teeth gearing, due to traumatic demands knowledge of the complex anato- occlusion (TO). my of this articulation, which actively takes The correlation between posture and part in achieving the essential functions of the mandible is observed through the recip- the stomatognathic ensemble, that R. rocal influence transmitted. For instance, Slavicek (1996) considers being a “cyber- when the mandible is imbalanced because of netic supersystem”. the tongue or teeth, it will systematically Not last, in our opinion, adequate trigger posture alterations, converting into a importance should be given to the occlusal source of individualized pathology. Equally, function (OF), which represents the physio- the posture acting on the mandibular logical condition of dental arches confronta- can generate biomechanical changes, tion during the functioning of the stomatog- accompanied by TMJ pain. nathic system, through mandibular chocking Such significant observations derive and guidance. Two significant capabilities from the concept of muscular, articular are distinguished: masticatory and postural. and facial integration, which states that the An optimal interarch gearing through three-dimensional equilibrium of the stable, symmetrical and multiple occlusal mandible as against the skull and face can- stops will influence an adjusting modeling not be considered functional unless the ele- of the articular tubercle and of the ments that make up the OFS (TMJ, the mus- mandibuar condyle head, thus achieving cles and aponeurotic network) do not cause consistency between the condylar slope, the any damage to the organism. incisive slope and the skeletal frame. This concept named “of chains”, elab- This favorable correlation will allow orated by Fonder and May (cited by F. the dental arches to withstand as much as Serviere, 1989) and sustained by G. Struyf- possible the numerous parafunctional Denys (1982) has three important corollar- aggressions (bruxism, vicious habits), lying ies: at the boundary between physiologic and - the functional imbalance of a muscu- pathologic. lar organ, characterized by spasm or According to M. Watanabe et al. hypotonia will cause, by contiguity, a (2001), B. Kazuyoshi et al. (2001), such similar reaction in the neighboring statement can be considered as pertaining to muscles, of the same dynamic system; the physiologic, by taking part in the main- - an articular dysfunction generates tenance of psychological balance of the another remote dysfunction, in respect individual in the OFS homeostasis. to the convergence of main constraints If the intensity of parafunctional mani- induced by an initial lesion; festations is important and repetitive, it - aponeuroses constitute a systemic becomes a pathological risk factor complex of tensions, at the level of (Amemory, 1999; Alamaudi, 2001; Molina which imbalances produced by con- et al., 2001; Sari et al., 2001; Koyano et al., straints, trauma and inflammatory 2003), causing structural alterations (patho- pathology reverberate. logical dental abrasions, teeth drifting, Regardless of all the above-mentioned myalgia, arthropathies) on the ground of aspects, the assessment of temporomandibu- remodeling the hard components of the TMJ lar disorders in literature, the systematiza- with regressive, progressive or combined tion of pathology and the identification of specificity (Kurita et al., 2000, 2001;

39 OHDMBSC - Vol. IV - No. 4 - December, 2005

Ieremia et al., 2004 a, b, c). tion of this pathology is required, by the cor- According to H. A. Israel et al. (1999), rect assessment of evolutional stages of the K. Yamada et al. (2001), the excessive TMJ craniomandibular painful dysfunctional syn- involvement in bruxism, generated by max- drome (CMPDS). illary clenching and interarch constriction, Consequent to this estimation, the mon- brings about changes in the structure of the itoring of individuals epidemiologically articular cartilage, with the specific bio- investigated, the choice and application of chemical consequences of intracapsular adequate therapy with individualized and pathology of degenerative nature. prophylactic character, followed by the con- This conclusion was borne out by N. firmation of treatment efficacy by the help Stegena et al. (2000) and by other of computerized medical programs, are per- researchers as well (Lyons, 2001; formed. Piotrowski et al., 2001). Although bruxism and certain vicious oral habits are reckoned 2. Specific peculiarities of the TMJ as possible causes responsible for excessive dental wear, abfraction and TMJ dysfunc- Willing to contribute to applying mod- tion, unfortunately no cause has yet been ern methodology of contemporary established. Gnathology through investigations, in order It seems though that personal dissatis- to trace out this pathology in human com- faction, psychological stress and even diffi- munities (quite frequent at all ages and cult social conditions can be considered risk sexes) we will demonstrate what the nine factors that generate stomatognathic ensem- unique features of the TMJ consist of as ble dyshomeostasis, with discal-condylar compared to the rest of the articulations in dysfunctional implications at the TMJ level the human body. (Macfarlane et al., 2002; Johansson et al., Such clinical functional morphology 2004). data, interspersed with notions of physiolo- Quite recently, the most plausible gy, physiopathology and macroscopic bio- hypothesis is that of excessive pathological mechanics, colligated with light and elec- dental abrasion, of extended partial unre- tron microscopy and histochemical analy- stored edentation or iatrogenically restored, ses, have opened new prospects towards on the priority background of psychogenic unraveling intimate mechanisms of normal factors. This can reduce the adaptive capac- or pathological biological processes. ity of the TMJ and associated tissues, main- It is well known that the TMJ, as a pos- ly favorizing the evolution of nocturnal terior anatomical determinant of occlusion bruxism, generating tissular complications (Figure 1), contributes, through its anatomi- of the hard and soft articular components cal and biomechanical peculiarities to carry- (Ieremia et al., 2001, 2002), and leading to ing out OFS essential functions through the diagnosis difficulties (Grumezescu et al., subsequent significant components: the 2004). articular surfaces, the disc, the capsula and As TMJ dysfunction is the main cause its own intraarticular and extraarticluar liga- of nonodontogenic algia of the OFS territo- ments and the dynamizing muscular com- ry and includes many morbid entities affect- plex. ing the masticatory muscles, TMJ and other This articulation is permanently associated structures, according to De exposed to the biological process of model- Boever at al. (2000 a, b), L. Ieremia et al. ing under the action of morphological and (2000), Alex. Rotaru et al. (2001), the need functional variations at the level of other of detecting the clinical forms of manifesta- components of the stomatognathic system.

40 OHDMBSC - Vol. IV - No. 4 - December, 2005

Thus, when the adjusting solicitation stage mobility: rotation in the inferior stage exceeds the TMJ possibilities, discal-condy- and translation in the superior stage (Uram- lar dysfunctions may surface, generating Þuculescu, 2001). Such combined dynamics irreversible lesions in the hard articular induced certain specialists to regard them as components. Siamese articulations, because the move- The maintenance of the individual ments of both disco-condylar ensembles are functional constants in permanent change in symmetrical and compensatory, the biological balance, their conscious regula- mandible occupying an important place in tion demand of the dentist, apart from taking the craniofacial bony massif, having com- into consideration all morphology and mor- plex functionality. phopathology knowledge of this articula- tion, an outstanding capacity of analysis, 3. It is the only mobile articulation of correlation and synthesis, unlike with the the skull, ensuring the connection between technical professions – industry, electronics its base and the mandible. – where precise parameters are used (Costa, 1987). 4. TMJ is suspended from the skull by According to my PhD supervisor, the the temporal and masseter muscles, being specific features of the TMJ are: attached to the hyoid bone superiorly and to the air-digestive tract and to the occipital 1. It is a pluriaxial synovial diarthrosis bone and cervical rachis posteriorly. of ginglymo-arthrodial character ensuring condylar dynamics through combined 5. It is a unique articulation in the movements of rotation and translation, organism, since it has its own muscular being very solicited in numerous functions insertion on the disc. On its anteromedial indispensable to life, such as: part, the superior fascicle of the lateral  mastication; pterygoid muscle attaches directly or indi-  deglutition; rectly and on the anterior and lateral part,  phonation; the temporal and masseter fibers are  breathing. attached (Ieremia et al., 1981, 1987). The Various functions are conditioned not main role of the disc is to turn the two incon- only by mandibular kinematics, guided by gruent articular surfaces (of the temporal the masticatory muscles contraction, but bone and mandibular condyle) into congru- also through the synergic participation of ent surfaces, thus contributing to the protec- other muscular organs of the cervico- tion of the TMJ as against the occlusal cephalic extremity, which take part equally forces (Isberg Annika, 2001). in voluntary or reflex actions (Ueda et al., 2002; Shiau et al., 2003), with the result that 6. By contrast to other synovial articu- mandibular balance is subject to occlusal lations, the contact surfaces of the osseous and muscular stability. components of the TMJ are not covered by hyaline cartilage, but by dense fibrous con- 2. As it is a double articulation, of nective tissue, resistant to biomechanical condylar type, with a superior supradiscal stress (especially shearing), being less sus- compartment (disco-temporal) and an inferi- ceptible to aging and possessing greater or infradiscal compartment (condylo-dis- healing capacity (Mãrcãuþeanu Corina, cal), having two separated synovias, the 1998). The TMJ is protected thanks to the TMJ can be considered the most evolved spatial disposition of the proteoglicans-col- articulation of the organism. It has a two- lagen network and to its capacity of retain-

41 OHDMBSC - Vol. IV - No. 4 - December, 2005 ing extracellular water through buffer effect 8. TMJ size is generally directly pro- osmotic forces (Burlui et al., 2000). portional to skeleton dimensions and the dimensions of its components tend to be 7. In rest posture of both TMJs, articu- reciprocally adapted. lar pressure is reduced, but it increases dur- ing mandibular dynamics and dental arch 9. The alteration of one TMJ will constriction. This pressure varies individu- inevitably have consequences on the other ally and is of greater value in women as TMJ articulation and on the occlusion. compared to men. Articular movements are Reversely, an occlusal anomaly can generate limited by interdental contacts while closing temporomandibular disorders if the adapting the mouth while the occlusal relations con- possibilities of the articular components, dition the pressure transmitted to the articu- through remodeling, are exceeded lar components (Grumezescu Ana-Maria, (Schifman et al., 2001; Celic et al., 2002; 2001). According to R. Ciancaglini et al. Horga, 2003; Totolici et al., 2004; Ieremia et (2002), the dentist is compelled to analyze al., 2004 a, b, c). the distribution of contacts in maximal inter- cuspidation in patients with TMJ disorders, In note II we will describe macroscopi- in order to detect the premature contacts cally and microscopically the anatomofunc- which are be removed through occlusal tional components of the TMJ, with refer- adjustment, as they represent sources of ence to certain biomechanical aspects of the constraint for the articular components. hard articulary structures.

1. Figure 1. Skull, right view 20. condyle 2. coronal suture (According to McMinn and R. T. Hutchinds, 1989) 21. mental protuber- 3. ance 4. 22. mental foramen 5. nasion 23. styloid process 6. nasal bone 24. tympanic part of 7. frontal process of the the maxilla 25. mastoid process 8. anterior lacrimal 26. external acoustic crest meatus 9. lacrimal fossa 27. 10. posterior lacrimal of the temporal bone crest 28. squamous suture 11. lacrimal bone 29. zygomatic arch 12. orbital part of the 30. greater wing of ethmoid 31. the 13. frontozygomatic pterion suture 32. inferior line of 14. zygomatic bone the temporal bone 15. maxilla 33. superior line of 16. anterior nasal the temporal bone spine 34. 17. mandible 35. external occipital 18. mandibular ramus protuberance 19. coronoid process

42 OHDMBSC - Vol. IV - No. 4 - December, 2005

Reference Rev. Stomatologia Mureºeanã, 2001; II(1): 29-33. 16. Ieremia L, Grumezescu A-M , Horga Cl, Totolici D, Roman D: Reevaluation of certain opinions con- 1. Alamaudi N: Correlation between oral parafunc- cerning the etiopathogeny of craniomandibular dys- tion and temporomandibular disorders and emotional function. (in Romanian) Rev. Stomatologia status among Saudi children. J. Clin. Pediatr. Dent., Mureºeanã, 2002; III(1): 19-26. 2001; 26(1): 71-80. 17. Ieremia L, Glavce C, Biriº C, Totolici D: 2. Amemory Y: Influence of bruxism during sleep on Anthropometrical research on concerning the stomatognathic system. Kogubyo Gakkai Zasshi, consequences of dental arch changes on the hard com- 1999; 66(1): 76-87. ponents of the temporomandibular joint. (in 3. Burlui V, Morãraºu C: Gnathology. (in Romanian) Romanian). Note I and II. Oral presentation at the Ed. Apollonia, Iaºi, 2000. Centre of Anthropological Research of the “Francisc I 4. Celic R, Jerolimov V: Association of horizontal Rainer” Romanian Academy. Bucureºti, 12 May and vertical overlap with prevalence of temporo- 2004; a and b. mandibular disorders. J. of Oral Rehabil., 2002; 18. Ieremia L, Totolici D, Biriº C, Glavce C: 29(6): 588-593. Contribution to the analysis and interpretation of cer- 5. Ciancaglini R, Gherlone EF, Redaelli S, Redaelli tain craniofacial disharmonies and/or asymmetries G: The distribution of occlusal contacts in the inter- through craniostenosis or of other types of osseous cuspal position and temporomandibular disorders. J. pathology detected on skulls of the Centre of Oral Rehabil., 2002; 29(11): 1082-1090. Anthropological Research of the “Francisc I Rainer” 6. Costa E: Mandibular dysfunction syndrome. (in Romanian Academy. (in Romanian) Oral presentation Romanian) Ed. ªtiinþificã ºi Enciclopedicã, Bucureºti, at the Centre of Anthropological Research of the 1987. “Francisc I Rainer” Romanian Academy. Bucure?ti, 7. De Boever JA, Carlsson GE, Kliniberg IJ: Need 2004 c. for occlusal therapy and prosthodontic treatment in 19. Isberg A: Temporomandibular Joint the management of temporomandibular disorders. Dysfunction. A Practitioner’s Guide. Ed. Isis Medica Part I. Occlusal interferences and occlusal adjuste- Media, 2001. ment. J Oral Rehabil., 2000 a; 27: 367-370. 20. Israel H A, Diamond B, Saed-Nejad F, Ratcliffe 8. De Boever JA, Carlsson GE, Kliniberg IJ: Need A: The relationship between parafunctional masticato- for occlusal therapy and prosthodontic treatment in ry activity and arhtroscopically diagnosed temporo- the management of temporomandibular disorders. mandibular joint pathology. J. Oral Maxilofac. Surg., Part II. Tooth loss and prosthodontic treatment. J. 1999; 59(9): 1034-1039. Oral Rehabil., 2000 b; 27: 647-659. 21. Johansson A, Unell I., Carlskon G, Soderfeldt B, 9. Grumezescu A-M, Ieremia L: Reasons for draw- Halling A, Widar F: Association between social arid ing the attention of dental and general medicine physi- general health factors and symptoms, related to tem- cians on cranio-mandibular disorders, and the assess- poromandibular disorders and bruxism in a population ment of diagnosis difficulties. (in Romanian) Rev. de of 50-year-old subjects. Acta Odontol. Scand., 2004; Medicin? dentar?, University Press, Târgu-Mureº, 62(4): 231-237. 2004; 1(2-3): 82-87. 22. Kazuyoshi BM, Yoshihiro TM, Mayumi V, 10. Horga Cl V: Diagnosis of traumatic occlusion Glenn TC: A review of temporomandibular disorders and assment of complex noxious consequences on the diagnostic techniques. J. Prosthet. Dent., 2001; 86: orofacial system. (in Romanian) PhD thesis, 184-194. University of Medicine and Pharmacy, Târgu-Mureº, 23. Koyano K, Tsukiyama Y, Ichiki R: Local factors 2003. PhD supervisor: Prof Lucian Ieremia, DMD, associated with parafunction and prosthodontics. Int. PhD. J. Prosthodont, 2003; 16 Suppl. 82-83. Discussion pp 11. Ieremia L, Mocanu Bardac V, Cseh Z: Special 89-90. dental techniques in total prosthesis. (in Romanian) 24. Kurita IL, Ohtsuka A, Kobayashi H, Kurashina Ed. Medical?, Bucure?ti, 1981. K: Flattening of the articular eminence correlates with 12. Ieremia L, Dociu I: Occlusal function and dys- progressive internal derangement of the temporo- function. (in Romanian) Ed Medicalã, Bucureºti, mandibular joint. Dentomaxillofac Radiol, 2000; 2(5): 1987. 277-279. 13. Ieremia L, Chirilã Bãlaº M: 25. Kurita H, Ohtsuka A, Kobayashi H, Kurashina Gerontognathoprosthetics. Basic and applicative ele- K, Kopp S: Chewing ability as a parameter for evalu- ments. (in Romanian) Ed. University Press, Târgu- ating the disability of patients with temporomandibu- Mureº, 1999. lar disorders. J. of Rehabilitation, 2001; 28(5): 463- 14. Ieremia L, Bratu D, Negriu?iu M: Examination 465. methodology in dental prosthetics. (in Romanian) Ed. 26. Lyons K: Aetiology of abfraction lesions. N. Z. Signata, Timi?oara, 2000. Dent. J., 2001; 97(429): 91-98. 15. Mia L, Popºor D, Horga Cl, Biriº C, Suciu M., 27. Macfarlane TV, Kincev J, Ortington IV: The Fokt I: Up-to-dates regarding the clinic peculiarities association between psychological factors and orofa- of eccentric bruxism (nocturne), with noxious impli- cial pain: a community-based study. Eur. J. Pain, cations on the stomatognathic system. (in Romanian) 2002; 6(6): 427-434.

43 OHDMBSC - Vol. IV - No. 4 - December, 2005

28. Mãrcãuþeanu C: Role of paraclinical investiga- 36. Serviere F: L’examen postural en occlusodontie tion in the diagnosis of temporomandibular dysfunc- quotidienne. Les Cahiers de prothese nr. 65, 1989. tion. (in Romanian) PhD thesis, University of 37. Slavicek R: Reflection sur soi-disant parafonc- Medicine and Pharmacy, Timiºoara, 1998. PhD super- tions. Rev. Orthop. Dento. Fac. 1996; 30: 75-88. visor Prof. Robert Nussbaum, PhD. 38. Stegenga B, Lobbezoo F: Bruxism and temporo- 29. Mc. Minn RMH, Hutchings RT: Colour Atlas of mandibular disorders. Ned. Tijdschr. Tandheelkd., Human Anatomy. Weert, The Netherlands, 1989.30. 2000; 107(7): 285-288. Molina OF, Dos Santos J, Msazzetto M, Nelson S, 39. Struyf-Denys G: Les chaînes musculaires et Nowlin T, Mainieri ET: Oral behavior in TMD and articulaires. Vol. I. Charleroy, S.B.O.R. T.M., edit. bruxism: a comparison study by severitiy of bruxism. 1982. Cranio, 2001; 19(2): 114-122. 40. Totolici D, Ieremia L: Applicative meaning of 31. Piotrowski BT, Gillette WB, Hancock EB: contemporary Gnathology in Orthodontics. (in Examining the prevalence and characteristics of Romanian) Rev de Medicinã Dentarã, University abfractionlike cervical lesions in a population of U.S. Press, Târgu-Mureº, 2004; 1(1): 1-9. J. Am. Dent. Assoc. 2001; 32(12): 1694-1701. 41. Uram-Þuculescu S: Occlusology notions (Ist 32. Pullinger A-G, Seligman DA: Quantification and part) Lecture for dental students. (in Romanian) Ed. validation of Predictive Values of Occlusal Force in LITO U.M.F. Timiºoara, 2001, Prof. Dorin Bratu, TMD Using a Multifactorial Analysis. J. Prosthet DMD, PhD. Dent, 2000; 83: 404 407. 42. Ueda HM., Kato M, Saifuddin M, Tabe H, 33. Rotaru A, Sîrbu C, Câmpean RS, Muntean L, Yamaguchi K, Tanne K: Difference in the fatigue of Rotaru H: Multidisciplinar approach of oral and cran- masticatory and neck muscle. J of Oral Rehabil., iofacial pain. (in Romanian) Ed „Atlas Closium”, 2002; 29(6): 575. Cluj- Napoca, 2001. 43. Watanabe M, Kehchi S, Tetsuji I: A role of occlu- 34. Sari S, Sonmez H: Investigation of the relation- sion in the etiology of’ T.M.D. Dentistry in Japan, ship between oral parafunctions and temporo- 2000; 36: 62-65. mandibular disorders. J. Oral Rehabil., 2002; 29(1): 44. Yamada K, Hanada K, Fukui T, Satov Y, Ochi K, 108-112. Hayashi T, Ito J: Condylar bony change and self 35. Schifman A, Gross MD: Diagnostic targeting of reported parafunctional habits in prosepective orthog- temporomandibular disorders. J. Oral Rehabil., 2001; natic surgery patients. Oral Surg. Oral Med. Oral 28(11): 1056-1063. Pathol.Oral Radiol. Endod., 2001; 92(3): 265-271.

Correspondence to: Dr. Ana-Maria Grumezescu-Iancu, DMD, Assist. Prof. at the Giessen University – Marburg, Germany. Home address: Sachsenhauser Landwehrweg 187, 60599 Frankfurt am Main, Germany. E-mail: [email protected]

44