Orthognathic treatment and temporomandibular disorders: a systematic review. Part 2. Signs and symptoms and meta-analyses

The Impact of Orthodontic Treatment on Masticatory Performance: A Literature Review

The aim of this narrative review was to evaluate the possible association between orthodontic therapy and improved masticatory function. A search strategy was conducted using the PubMed database for up to January 2020 using the keywords "mastication" and "orthodontics". Only human studies investigating mastication in orthodontics settings were selected. The search strategy resulted in 1,011 articles, out of which 57 were included in the final analysis. Investigations have generally agreed that masticatory and chewing functions improved post-orthodontic and orthognathic treatments. Studies also showed improvement in the quality of life of patients' post-orthodontic treatment. The articles examined reinforced that besides esthetic reasons, orthodontic therapy does improve the masticatory and chewing functions of individuals, ultimately enhancing their health-related quality of life.

Mandibular stability and condylar changes following orthognathic surgery in mandibular hypoplasia patients associated with preoperative condylar resorption

OBJECTIVES

To evaluate postoperative mandibular stability and condylar changes in patients with mandibular hypoplasia and preoperative condylar resorption (CR) undergoing orthognathic surgery.

MATERIALS AND METHODS

Fifty-four patients were included in this retrospective study. Computed tomography (CT) scans were acquired preoperatively (T0), 2-7 days immediate postoperatively (T1), and at least 1 year postoperatively (T2). Three-dimensional (3D) cephalometric analysis and measurements of condylar angle, volume, and position (joint spaces) were performed. A 2-mm mandibular relapse was deemed clinically acceptable. We also analyzed the correlations between relapse and postoperative CR and susceptible factors using a multivariate logistic regression model.

RESULTS

The results showed one year after the surgery, the average mandibular relapse was 1.0 mm (p < 0.05), and the average reduction of condylar volume was 152.4 mm³ (12.7%). Condyle-fossa relationships were improved immediately after the surgery, with a tendency of returning to their original state in the follow-up (p < 0.05). Anteroposterior advancement at point B (B-CP advancement) at T1 and superior joint space (SJS) at T0 were significantly correlated with mandibular relapse, and postoperative CR was mainly associated with vertical increasement at point B (B-AP increasement) at T1. The optimal cut-off values were as follows: 1.6 mm for SJS, 4.2 mm for B-CP advancement, and 1.8 mm for B-AP increasement. Concomitant advancement Genioplasty showed no significant correlation with relapse and postoperative CR.

CONCLUSIONS

While patients with mandibular hypoplasia and preoperative CR were vulnerable to further condylar resorption after mandibular advancement, the treatment outcomes were generally clinically acceptable. Postoperative relapse was associated with a larger than 4.2 mm of mandibular advancement measured at B-CP and a larger than 1.6 mm of superior joint space measured at SJS, and postoperative CR was associated with a larger than 1.8 mm of mandibular vertical increasement measured at B-AP.

CLINICAL RELEVANCE

The findings of this study suggested that the mandibular advancement might be limited to 5 mm for patients with preoperative CR. A concomitant advancement genioplasty might also be considered to achieve a better facial profile in these patients.

Orthognathic surgery in class II patients: a longitudinal study on quality of life, TMD, and psychological aspects

OBJECTIVES

To evaluate, longitudinally, the impacts of orthognathic surgery in patients with skeletal class II malocclusion on oral health-related quality of life (OHRQoL), temporomandibular disorders (TMD) and psychological symptoms.

MATERIALS AND METHODS

Forty-three patients with skeletal class II malocclusion who were submitted to orthognathic surgery were evaluated during their preoperative and postoperative periods. They answered the short version of the Oral Health Impact Profile (OHIP-14) and were also diagnosed according to Axes I and II of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The evolution of OHRQoL and TMD before and after surgery was verified, and the relationships among these variables were found through statistical analysis using Wilcoxon, McNemar, chi-square, and Mann-Whitney tests, with a 5% significance level.

RESULTS

The median of the overall OHIP-14 score and five domains decreased after orthognathic surgery (p < 0.05), the functional limitation domain increased (p = 0.014), and the physical disability domain did not show an association (p = 0.133). There were improvements in articular pain (p = 0.016), chronic pain (p = 0.019), and nonspecific physical symptoms excluding pain (p = 0.013). In addition, an association was found between poorer OHRQoL (overall scale and domains) and the Axis II variables of the RDC/TMD (p < 0.05).

CONCLUSION

Orthognathic surgery improved perceived OHRQoL, articular pain, and chronic pain. The conditions of Axis II of the RDC/TMD interfered with OHRQoL postoperatively.

CLINICAL RELEVANCE

Although orthognathic surgery improves QoL and some TMD conditions in skeletal class II patients, poorer postoperative outcomes are observed when psychological conditions are present.

Changes in the temporomandibular joint clicking and pain disorders after orthognathic surgery: Comparison of orthodontics-first approach and surgery-first approach

The purposes of this study were to investigate the influence of the orthodontics-first approach (OFA) and surgery-first approach (SFA) on changes in the signs and symptoms of temporomandibular joint disorders (TMDs) and to compare pre- and postoperative orthodontic treatment duration and total treatment duration between the two approaches. This retrospective study recruited 182 adult patients with malocclusions treated with OFA and SFA and recorded variables such as age, gender, skeletal classification, and signs and symptoms of TMD (clicking and pain disorders) before the start of the surgical-orthodontic treatment and after surgery. Changes in the signs and symptoms of TMD and treatment duration were evaluated within each approach and compared between two approaches. A binary logistic regression was performed to assess the influence of the variables on the postoperative signs and symptoms of TMD. There were no significant postoperative changes in temporomandibular joint (TMJ) pain for OFA and SFA, whereas a significant reduction was found in TMJ clicking after surgery for both approaches. According to binary logistic regression, the type of surgical-orthodontic treatment (OFA or SFA) was not a significant risk factor for postoperative TMJ clicking and pain, and the risk of postoperative TMJ clicking and pain was significant only when TMJ clicking (OR = 10.774, p < 0.001) and pain (OR = 26.876, p = 0.008) existed before the start of the entire treatment, respectively. With regard to the treatment duration, SFA (21.1 ± 10.3 months) exhibited significantly shorter total treatment duration than OFA (34.4 ± 11.9 months) (p < 0.001). The results of this study suggest that surgical-orthodontic treatment using SFA can be a feasible option of treatment for dentofacial deformities based on the equivalent effect on TMD and shorter overall treatment period compared to conventional surgical-orthodontic treatment using OFA.

Correlation between oral health-related quality of life and clinical dysfunction index in patients with temporomandibular joint osteoarthritis

We evaluated the correlation between oral health-related quality of life (OHRQoL) and the Helkimo clinical dysfunction index (HDI) in patients with temporomandibular joint osteoarthritis (TMJ OA). Clinical data and scores for the Chinese version of the 14-item Oral Health Impact Profile (OHIP-C14) were recorded and analyzed for 541 patients with TMJ OA. Each patient was assigned an HDI score of 1 to 25, which was used to classify severity into three categories. OHRQoL was assessed by using OHIP-C14 score, which ranged from 0 to 56. Both HDI score and severity were significantly correlated with total OHIP-C14 score (P < 0.001 for both comparisons). The scores for all HDI domains except function impairment (P = 0.205) were significantly correlated with OHIP-C14 score. The scores for all seven OHIP-C14 domains were significantly correlated with HDI score and severity. Several correlations between OHIP-C14 domains and HDI domain scores were significant. HDI score and severity were correlated with OHIP-C14 score in TMJ OA patients. As compared with function-related domains, pain-related HDI domains were more strongly inversely related to OHRQoL.(J Oral Sci 58, 483-490, 2016).

Complications associated with orthognathic surgery

While most patients undergo orthognathic surgery for aesthetic purposes, aesthetic improvements are most often followed by postoperative functional complications. Therefore, patients must carefully decide whether their purpose of undergoing orthognathic surgery lies on the aesthetic side or the functional side. There is a wide variety of complications associated with orthognathic surgery. There should be a clear distinction between malpractice and complications. Complications can be resolved without any serious problems if the cause is detected early and adequate treatment provided. Oral and maxillofacial surgeons must have a full understanding of the types, causes, and treatment of complications, and should deliver this information to patients who develop these complications.

Clinical predictive factors for temporomandibular disorders following combined orthodontic and orthognathic surgical treatment in patients with Class III malocclusion

OBJECTIVE

The aim of this study was to identify clinical factors predisposing to the development or worsening of temporomandibular disorders (TMDs) following orthodontic surgical treatment for Class III malocclusion.

METHODS

A retrospective cohort study was performed on 88 patients with Class III malocclusion having undergone a combined orthodontic and orthognathic surgical treatment. Temporomandibular joint and masticatory muscle examinations were available prior to treatment and one year post-operatively. Multivariate logistic regression was used to predict the development of post-operative TMDs, and linear regression was used to predict the worsening of TMDs using Helkimo indices.

RESULTS

Patients with Class III malocclusion presenting with pre-treatment anamnestic TMJ clicking (OR = 5.8; p = 0.03) and undergoing bimaxillary osteotomy procedures (OR = 18.6; p = 0.04) were more at risk for the development of TMDs.

DISCUSSION

TMDs must be evaluated, monitored, and managed with caution in patients with Class III malocclusion presenting with pre-treatment joint clicking and who are planned for bimaxillary osteotomies.

Intraoperative Hemorrhage and Postoperative Sequelae after Intraoral Vertical Ramus Osteotomy to Treat Mandibular Prognathism

Objective. To investigate the factors affecting intraoperative hemorrhage and postoperative sequelae after orthognathic surgery. Materials and Methods. Eighty patients with mandibular prognathism underwent surgical mandibular setback with intraoral vertical ramus osteotomy (IVRO). The correlation between the blood loss volume and postoperative VAS with the gender, age, and operating time was assessed using the t-test and Spearman rank correlation coefficient. The correlation between the magnitude of mandibular setback with the presence of TMJ clicking symptoms and lip sensation was also assessed. Results. The mean operating time and blood loss volume for men and women were 249.52 min and 229.39 min, and 104.03 mL and 86.12 mL, respectively. The mean VAS in men and women was 3.21 and 2.93, and 1.79 and 1.32 on the first and second postoperative days. There is no gender difference in the operating time, blood loss, VAS, TMJ symptoms, and lip numbness. The magnitude of mandibular setback was not correlated with immediate and long-term postoperative lip numbness. Conclusion. There are no gender differences in the intraoperative hemorrhage and postoperative sequelae (pain, lip numbness, and TMJ symptoms). In addition, neither symptom was significantly correlated with the amount of mandibular setback.

TMJ response to mandibular advancement surgery: an overview of risk factors

Objective

In order to understand the conflicting information on temporomandibular joint (TMJ) pathophysiologic responses after mandibular advancement surgery, an overview of the literature was proposed with a focus on certain risk factors.

Methods

A literature search was carried out in the Cochrane, PubMed, Scopus and Web of Science databases in the period from January 1980 through March 2013. Various combinations of keywords related to TMJ changes [disc displacement, arthralgia, condylar resorption (CR)] and aspects of surgical intervention (fixation technique, amount of advancement) were used. A hand search of these papers was also carried out to identify additional articles.

Results

A total of 148 articles were considered for this overview and, although methodological troubles were common, this review identified relevant findings which the practitioner can take into consideration during treatment planning: 1- Surgery was unable to influence TMJ with preexisting displaced disc and crepitus; 2- Clicking and arthralgia were not predictable after surgery, although there was greater likelihood of improvement rather than deterioration; 3- The amount of mandibular advancement and counterclockwise rotation, and the rigidity of the fixation technique seemed to influence TMJ position and health; 4- The risk of CR increased, especially in identified high-risk cases.

Conclusions

Young adult females with mandibular retrognathism and increased mandibular plane angle are susceptible to painful TMJ, and are subject to less improvement after surgery and prone to CR. Furthermore, thorough evidenced-based studies are required to understand the response of the TMJ after mandibular advancement surgery.

The effect of temporomandibular disorders on condition-specific quality of life in patients with dentofacial deformities

OBJECTIVE

This study investigated the effect of temporomandibular disorders on quality of life (QOL) of patients with dentofacial deformities.

STUDY DESIGN

A case-control study was performed involving 3 age- and gender-matched groups: 38 preoperative participants, 38 postoperative participants, and 39 control participants. Temporomandibular joints were assessed using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD axis I), and QOL was assessed using the Orthognathic Quality of Life Questionnaire (OQLQ) and the Short-Form Health Survey (SF-36).

RESULTS

Significantly lower OQLQ scores were found in postoperative patients with one or more RDC/TMD findings; the domains in which these occurred were mental health, dentofacial esthetics, and awareness of dentofacial esthetics for patients with myofascial pain; social aspects and awareness of dentofacial esthetics for patients with disk displacement with reduction; and all domains for patients with arthritis (all P < .05).

CONCLUSIONS

Despite the variable effect of orthognathic treatment on TMDs, the presence of TMDs in patients after treatment can have a negative effect on their QOL.

Craniomandibular disorders and mandibular reference position in orthodontic treatment

The aim of this paper is to bring into focus the literature on the choice of the mandibular reference position in orthodontic treatment; of a particular reference to this paper is intercuspal position, centric relation position, or therapeutic position. To give a comprehensive account of the literature review on craniomandibular disorders (CMD), we have relied on books and articles using both Google Scholar and PubMed. Selection criteria included a combination of Mesh and type of article. Article classification was made by two authors, using the following structure outline: prevalence of craniomandibular disorders, its etiology and pathophysiology, occlusion and craniomandibular disorders, orthodontic treatment and CMD, and the mandibular reference position in orthodontics. An important conclusion that emerged from the present literature review is that CMD do not seem to be directly related to orthodontic treatment, and their appearance cannot be predicted or prevented by any means. Therefore, orthodontists must adopt a mandibular reference suitable to their patients and which best respects the balance existing in the stomatognathic system.

[Relations between orthognathic surgery and temporomandibular disorders: a systematic review]

A painful and dysfunctional temporomandibular joint can be associated with a musculoskeletal anomaly. The multifactorial character of the etiology is now recognized. Among the etiologies, the role of orthognathic surgery is still debated. The analysis of the literature from 2000 to 2011 reveals for most authors a decrease in the frequency and intensity of signs and symptoms after surgery, especially pain and clicking. Risk factors may influence post-surgical results. Studies on patient risk factors such as age, sex, type of dysmorphia are inconclusive. Surgical techniques and the procedure used may have an influence on the development of post-surgical clinical signs and symptoms of temporomandibular disorders.