Temporomandibular joint ankylosis (TMJA) is a debilitating health condition that causes difficulty in mastication, speech and mouth opening, and it can be debilitating if left untreated [9]. Its management requires careful surgical intervention plans. In this study, we described the pattern of TMJA in one of the tertiary level hospitals in Ethiopia over a period of 9 years.
In the present study, ankylosis cases were more predominant in females (55.8%) than males (44.2%), with a sex ratio of female to male 1.26:1. This finding is in agreement with other reports from Sudan [2], Morocco [17], South Africa [8], Pakistan [18], and Nigeria [19]. In contrast, studies from Nigeria [5] and India [16] reported the predominance of TMJA cases among males than females.
TMJA had a wide age range distribution ranging from 4 to 65 years, with a mean age of 19.6 years. It was frequently seen in the 3rd and 4th decades of life. This finding is similar to a report from Morocco [17] in which peak age was the 3rd decade of life. On the contrary, a report from Indonesia [11] revealed that 2nd decade of life as a peak age.
The pathogenesis of TMJA can either be primary, when the pathological process directly affects the TMJ, as in the case of systemic diseases such as ankylosing spondylitis, rheumatoid disease, and psoriasis; or secondary, as in traumatic injury, which may cause intra-capsular condylar fractures and heamarthrosis [20, 21]. Trauma was identified as the most common cause of TMJA among our patients accounting for about 77.9% of the cases. This finding is consistent with reports from different parts of the world, such as Sudan [2], India [3], China [15], Indonesia [11], Turkey [14], and Pakistan [18] that reported trauma as the most common cause of TMJA. This could be because the majority of our patients were from rural areas where dental services in general and maxillofacial surgery services in particular are still in infancy. As a result, most of the patients with jaw fractures might have either remain undiagnosed or are managed unsatisfactorily.
TMJA cases could be presented as a bilateral or unilateral based on the number of joints affected. Most (72.6%) of our patients were presented with bilateral TMJA. This finding is coinciding with a report from Sudan [2], China [22] and India [23]. The high prevalence of bilateral TMJA might be due to trauma (falling) mechanism that could result in mandibular symphysis fracture which in turn produces a higher chance of osteogenic potential bone fragments in the condylar process. On the other hand, our finding is inconsistent with a report from Pakistan [18] that reported more cases of unilateral than bilateral TMJA. Among unilateral patients, most cases were seen on the right side than the left side, a finding consistent with reports from Sudan and Pakistan [2, 18]. However, a study from China reported a higher number of TMJA cases on the left side than the right side [22].
In the present study, the majority of TMJA cases were presented to our clinic after a significant delay, more than five years, from the onset of their symptoms. This finding is consistent with a report from Sudan [2]. The delay in the presentation of the patients might relate to the place of the residence of the patients where the majority of them live in rural areas that have limited access to early treatment. Furthermore, the lack of awareness and poor socio-economic status could potentially attribute to the higher number of TMJA [24].
TMJA is one of the complex health problems that could result in mandibular deformity, difficulty in mastication and swallowing of food, and speaking, and poor oral hygiene leading to dental caries and periodontal diseases [7]. In the present study, our TMJA patients were presented with mandibular deformity (23.0%), poor oral hygiene (23.6%), antegonal notch (19.2%), difficulty of mouth opening (8.3%), and deviation to affected side (7.7%). This finding is in line with reports from India [3], Morocco [17] and South Africa [8]. Thus, early detection and surgical intervention to release the ankylosed joint improves the patient’s quality of life.
The management of TMJA mainly relies on surgical procedures that aim at restoring joint function and prevent reankylosis [15]. Gap arthroplasty (GA), interpositional arthroplasty (IA), and reconstruction of the articulation (RA) after resection of the ankylotic mass with autogenous or alloplastic grafts are the three main surgical procedures that are currently used to treat TMJA cases [15]. In the present study, 57.9% of the patients were treated with GA, while the remaining 30.6% had IA. Our result showed no significant difference in the incidence of reankylosis between GA and IA. This finding is consistent with meta-analysis study that showed no significant difference in the incidence of reankylosis between the IA and the GA [15].