Correlation between posterior teeth loss and temporomandibular joint disorder symptoms in adult patients

Introduction

A variety of clinical symptoms affecting the temporomandibular joint (TMJ), the muscles of mastication, or the related orofacial tissues are grouped under the name "temporomandibular disorders" (TMD). Specific symptoms, including headaches, neck pain, abnormal noises during jaw movements, pain or sensitivity in the chewing muscles or TMJ region, limited or incoherent movements, and an inappropriate relationship between jaw positions characterize it.¹ It is currently unclear what causes TMD.² TMD has been linked to several conditions, including bruxism, tooth grinding or clenching,³ osteoarthrosis, abnormal occlusion,⁴ tooth wear,⁵ non-working-side occlusal interferences,⁶ limited mandibular movements,⁷ partial loss of teeth,⁸ masseter muscle activity,⁹ osteoarthritis,¹⁰ and reduced maximum bite force.¹¹ The connection between TMD and posterior tooth loss is still up for debate and is a topic of constant discussion.

TMD is more common in people who lose their posterior teeth, particularly young women, with less missing posterior teeth in more quadrants.¹² However, TMD is not associated with malocclusion or the loss of five or more posterior teeth,¹³ and there is no relation between the number of lost teeth and TMD.¹⁴ There is inconsistency in the literature because some research found no relation between TMD and the number of absent posterior teeth.^15–17 Other authors, however, have claimed that losing molar support was associated with the presence and severity of osteoarthrosis^18–20 or with TMD.^21–24 The current study aimed to find a correlation between posterior teeth loss and symptoms of TMJ disorder in adult patients.

Methods

The present cross-sectional analytical study was carried out at Riyadh Elm University's prosthodontics department in Riyadh, Kingdom of Saudi Arabia. The Institutional Review Board of Riyadh Elm University in Riyadh, Kingdom of Saudi Arabia, gave its approval to the study (FPGRP/2021/574/527) in December 2021. The study was carried out between January and April of 2022. Participants had to be older than eighteen, have maxillary and mandibular front teeth, and have two or more posterior teeth (molars and premolars) missing for longer than six months, with the exception of the third molars. Subjects wearing removable partial dentures who had experienced traumatic tooth loss (e.g., a car accident, gunshot, maxillofacial surgery, etc.), those with a history of diagnosed and treated symptomatic TMD, and those currently diagnosed with fibromyalgia, trigeminal neuralgia, or on medication were excluded. Samples were chosen using convenience sampling. For the investigation, 50 samples in total that satisfied the inclusion requirements were chosen. Before the trial started, each participant gave their informed consent.

Since DC/TMD Axis-I and Axis-II protocols have a high dependability index value and are regarded as the gold standard, all relevant data pertaining to TMD was collected using them.²⁵ An international version of the clinical examination and a symptom questionnaire are part of the Axis-I protocol. Psychosocial state and pain-related impairment are assessed as part of the Axis II methodology. The decision tree and diagnostic criteria were used to make the diagnosis.²⁶

Results

The mean age of the subject was 41.5±6.3 years. The mean number of missing teeth, duration of missing teeth, and maximum unassisted opening of mouth were 3.4±1.3, 5±2.9, and 49.2±5.0, respectively.

The mean maximum mouth opening was higher with no headache (50.8±4.2) (p<0.05). On the other hand, the mean age (42.8±7.5) (p>0.05), number of missing teeth (3.8±1.4)(p>0.05), and duration of tooth loss (6.6±3.5)(p<0.05) were higher with the headache ( Table 1). Disc displacement with reduction is more likely to cause a headache (p<0.05) ( Table 2). The maximum mouth opening was higher with no pain (50.0±4.5) (p<0.05). On the other hand, the mean age (42.8±5.9) (p>0.05), number of missing teeth (4.4±1.5) (p>0.05), and duration of tooth loss (9.2±3.7) (p<0.05) were higher with pain ( Table 3). Displacement with reduction is more likely to cause pain (p<0.05) ( Table 4). The maximum mouth opening was higher with no clicking (51.8±2.4) (p<0.05). On the other hand, the mean age clicking (46.2±5.6) (p<0.05), number of missing teeth clicking (4.8±1.0) (p<0.05), and duration of tooth loss (8.4±2.5) were higher with clicking (p<0.05) ( Table 5). Disc displacement with reduction and reported TMJ click (p<0.05) is more likely to have clicking (p<0.05) ( Table 6).

A statistically significant positive correlation was found between age and the number of missing teeth (r=0.607) (p<0.05). Furthermore, a statistically significant negative correlation was found between age and maximum unassisted mouth opening (r=-0.402) (p<0.05); and the number of missing teeth and maximum unassisted mouth opening (r=-0.502) (p<0.05) ( Table 7). The mean number of missing teeth was statistically significantly higher in TMJ disorder (Disc displacement with reduction) (4.7 ± 1.0) (p<0.05) ( Table 8).

The number of missing teeth showed OR=2.620 times higher risk of TMD (variable) as well as pain showed OR=6.089 times higher (p>0.05). Whereas, clicking was significantly associated and OR=13.8 times more likely to have TMD (variable) (p<0.05) ( Table 9). The pain was OR=6.021 times more likely associated with TMD (p>0.05). Whereas, clicking showed a significant association with the TMD (variable) (p<0.05) ( Table 10).

Discussion

The relationship between multiple posterior teeth missing and TMJ disorders always remains controversial. In addition, signs and symptoms like headache and muscular pain, TMJ sound, and restricted mouth opening may be some of the signs or symptoms associated with TMD disorders. Thus, the present study was planned to assess the correlation between posterior teeth loss and TMJ disorder symptoms in adult patients. The current study showed that patients with TMD (TMJ disc displacement with reduction) are more likely to have pain, headache, and TMJ clicking with statistically significant differences. A study by Aggarwal et al. is in agreement with the present study findings which showed that headaches occur more frequently in patients with TMD symptoms (27.4% vs 15.2%).²⁷ In line with the current investigation, another study by Derwich et al. found that TMJ reciprocal clicking is a common clinical sign of disc displacement with reduction and one of the most prevalent forms of TMJ internal derangements.²⁸

Furthermore, the present study showed that maximum mouth opening was greater with (no pain, no headache, and no TMJ clicking) with statistically significant differences. There are many previous reports relating to mouth opening and headaches. Schokker et al. found a close relationship between recurrent headaches and craniomandibular disorders, including the opening of the mouth.²⁹ Calixte et al. also reported less headaches with improved mouth-opening.³⁰ The degree of mouth opening and the quantity of auditory symptoms are associated with the severity of TMD, according to yet another study report by Kitsoulis et al.³¹ The present study showed that the number of missing teeth and the age increased as the maximum unassisted mouth opening decreased. This result is consistent with a study by Sawair et al. who showed that wide unassisted maximum mouth opening was associated with less risk of tooth loss and preservation of the third molar.³²

The present study found that the number of missing teeth was higher with disc displacement with a reduction with a statistically significant difference. According to a study by Tallents et al., the TMJ components become overloaded when posterior teeth are absent. The lack of posterior teeth has been hypothesized and experimentally demonstrated to cause mandibular overclosure, which would cause the condyles to shift from their typical centric position in the TMJ, resulting in joint dislocation.²⁴ Another study found that articular eminence in younger people and the onset of lesions on the load-bearing articular surfaces of the condyle were both influenced by loss of molar support.³³ Thus, it appears that most of the study reports are in accordance with the present study. The loss of posterior teeth is expected to bring similar changes in the TMJ joints. Missing posterior teeth appears to be responsible for the changes seen in the TMJ.³⁴

The evaluation in this study was conducted using the DC/TMD axis I and II, which is very pain-oriented, and (dis)function is not given much attention. Furthermore, the classification process, which is more subjective in nature, still heavily relies on palpation and operationalized pressure on the tissues of the masticatory muscles and the TMJs. Overdiagnosis (myofascial pain) and overtreatment while adhering to this classification are the outcomes. However, there was also evidence of the potential for underdiagnosis when using the RDC/TMD criteria. Therefore, it is necessary to implement a balance between these two. In the field of dentistry, the link between tooth loss and temporomandibular disorders is contentious because there may be more than one cause for these issues. Future research will need to evaluate factors like age, gender, and estrogen level. Additionally, evaluating research on secondary occlusion contact feature changes after posterior tooth loss, the effects of these secondary occlusion modifications, and the possible advantages of rectifying such occlusal abnormalities would be interesting.

Conclusions

Pain, headaches, clicking, and a reduction in maximum mouth opening are more common in TMD patients. There is a relation between TMJ disorders and clicking; and TMJ disorders and the number of tooth loss.

Author contributions

Conceptualization, B.H.A. and M.W.A.; methodology, B.H.A. and M.W.A; software, B.H.A. and M.W.A; validation, B.H.A. and M.W.A; formal analysis, B.H.A. and M.W.A; investigation, B.H.A. and M.W.A; resources, B.H.A. and M.W.A; data curation, B.H.A. and M.W.A; writing—original draft preparation, B.H.A. and M.W.A; writing—review and editing, B.H.A. and M.W.A; visualization, B.H.A. and M.W.A; supervision, B.H.A. and M.W.A; project administration, B.H.A. and M.W.A; funding acquisition, B.H.A. and M.W.A. All authors have read and agreed to the published version of the manuscript.

Ethics and consent statement

The study was approved by the Institutional Review Board of Riyadh Elm University, Riyadh, Kingdom of Saudi Arabia (FPGRP/2021/574/527) on 25 December 2021. Written and informed consent was obtained from all subjects involved in the study.