Coronal Restorations and Temporomandibular Joint (TMJ) Dysfunction: A Survey Among General Practitioners of the Town of Abidjan

1. INTRODUCTION

The aim of dental restorations is to reconstitute the initial morphology of the teeth so as to allow them to again assume their various functions in the masticatory apparatus. They are an important component of daily practice and represent 40% of the procedures performed [1]. They involve the use of various entities such as composite materials with adhesive systems, amalgams, and glass-ionomer cements that should allow re-establishment of function and occlusion [2]. Occlusion must be controlled and the normal function needs to be reestablished by a proper fit [3]. When occlusion is not reestablished, dysfunc- tion can occur, particularly repeated fracture of obturations, occlusal trauma, enhanced looseness of the teeth, movement or dislocation of teeth, attrition of the hard dental tissues and of the restorations [3, 4]. Such dysfunction can also manifest as disorders of the masticatory muscles or of the Temporo mandibullary Joint (TMJ) [5]. Dental occlusion plays a major role in the functions of the masticatory apparatus [6, 7]. Indeed, it influences the mandibular posture at rest, the mandibular kinetics, mastication, swallowing, the loads applied to the TMJ, and the trajectories play a major role during Maximized Intercuspal Occlusion (MIO) [8]. As stated by Orthlieba et al. (2016) [9], the TMJ and dental occlusion are “linked, for better or for worse” even if a direct correlation between all TMJ and occlusion is still controversial.

In light of this, it struck us that it would be important to evaluate the level of knowledge and the approaches of general practitioners of the town of Abidjan in terms of the quality of occlusion control after restorative treatment in order to be able to make recommendations to prevent potential TMJ disorders.

2. METHODOLOGY

3. RESULTS

4. DISCUSSION

The repartition according to the type of practice, allowed us to show that the two sectors of practice were represented nearly equally, that is to say, 49.5% of the practitioners were in the private sector and 50.5% in the public sector, with a sex ratio of 1.68. Nearly all took part in continued training (89.7%). The sample was representative of all years of experience brackets and the most active categories were those that had more than 10 years of experience (48%). Similar results have been reported by other studies. Indeed, Kaboré et al. in 2015 [10] and Fall et al. [11] in 2018, in Burkina Faso, also reported the same trends in terms of the public sector and continued post-university training. However, these authors had a high level (40%) of young practitioners in their sample, that is to say, practitioners who had been in practice for less than 10 years. The work by Ndiaye et al. [12] in 2017 in Senegal and of Udoye et al. (2013) [13] in Nigeria also reported a predominance of males in the dental profession and a larger proportion in private practice.

The present study, although limited to the practitioners of the town of Abidjan, has allowed occlusion to be recognized as one of the foremost concerns of general practitioner dentists who perform restorative dentistry on a daily basis. Indeed, poorly suited restoration materials can impair occlusion and mandibular kinetics [14]. Conservative materials present great variability and they present different mechanical properties in terms of hardness [15], roughness [16] and elasticity modulus [17]. Additionally, some recently introduced conservative materials such as fiber reinforced composites [18] or CAD/CAM restoratives [19] present different hardness and flexural properties if compared with conventional conservative materials, thus leading to different possibilities of correlation with TMJ. For this reason, the knowledge about this topic has to be constantly updated.

When dysfunction manifest, the clinical signs most often reported by the practitioners were joint pain (76%) followed by cracking joint (64.4%) and muscle pain (69.9%). The etiological factors put forward were overhanging restorations for 49.4% of them. The objective of any occlusal restoration is to optimize masticatory function and to maintain dental health [20]. Occlusion is always involved to a certain degree in daily dental treatments [2]. By systematic screening, odontologists need to know how to recognize occlusion impairments, so as to at least avoid generating then by iatrogenic procedures [2]. Sudden occlusal changes can occur over the course of a restorative treatment with amalgam or composite resins that can lead to an overbite or an underbite [21]. When they are not tolerated, these changes in occlusion can lead to ineffective sensorimotor regulation [22, 23]. Occlusal surfaces, due to their shape, constitute the working part of a tooth. Occlusal and root morphologies affect the functional ergonomics [2]. Each tooth has an essential functional and stabilizing role. The occlusal morphology of human teeth comprises convex shapes, elevations that are cusp-shaped or that have free edges. The cusp shape constitutes the ergonomic response to the physiological requirements. The morphology has a direction and needs to be respected, restored, or reconstructed [24, 25]. When the occlusal alignment is perturbed, so are the abilities of the manducatory apparatus, which is harmful to the various structures [26, 27, 22]. Such one-off occlusal anomalies (one or two teeth), having appeared or worsened recently, can be corrected by a straightforward equilibration of the first intention with the aim of immediate optimization of occlusal functions [28, 29]. MAD can be clinically characterized by pain at the level of the TMJ and/or at the level of the masticatory muscles, as shown in this study. It can radiate to the eyes, the face, the shoulders, the neck, or the back. The patient may also state that they have headaches and otalgia [30]; which is also what practitioners have noted. Thus, while the symptoms of TMJ disorders can be unclear, they can be related to other pathologies [31-33]; whence the importance of a rigorous analysis that leads to a positive diagnosis. For the practitioners, the treatment of TMJ disorders amounted to selective grinding (70.1%) and wearing an occlusal mouthguard (65.5%) in advanced cases. Indeed, a mouthguard provides pain relief by muscle relaxation and by repositioning of the condyles [34, 28]. This study has reported that the vast majority of the practitioners always used articulation paper (94.3%) to evaluate the TMJ and 82.8% polished the amalgam restoration that they had carried out at a prior appointment. Physiologically, the TMJ constitutes a reference mandibular position whereby the relationship of the teeth is characterized by a maximum of interarcade contacts [24, 35]. It should be noted that the term “intercuspation” comprises the notion of displacement; it hence signifies, not the position, but the movement of the mandible resulting in the maximal intercuspidal position [36, 37]. The role of occlusion is, therefore, not trivial, and its regulation abides with definite rules. This is why in practice its control and its regulation need to be carried out with great thoroughness [38, 39]. When the skills of the practitioner are insufficient, the patient needs to be referred to a specialist, as indicated by more than half of the practitioners.

CONCLUSION

This study has shown that the general practitioners of the town of Abidjan have a good level of knowledge of the consequences of poorly carried out restorations? Such occlusion impairments typically produce improper muscle responses and lead to changes in pressure at the level of the temporomandibular joint. Hence, the need to follow the procedures for restoration so as not to generate them. Re-establishment of occlusal function, just like the sealing of coronal obturations, is indispensable for the longevity of restorations and thereby contributes to maintaining good-oro-dental health.

REFERENCES