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The effect of orthognathic surgery on the temporomandibular joint and oral function: a systematic review

The effect of orthognathic surgery on the temporomandibular joint and oral function: a systematic review



International Journal of Oral & Maxillofacial Surgery, 2017-05-01, Volume 46, Issue 5, Pages 554-563, Copyright © 2017 International Association of Oral and Maxillofacial Surgeons


Abstract

The objective of this systematic review was to examine the effect of orthognathic surgery (OS) on the temporomandibular joint and oral function. Electronic databases were systematically searched for studies published until October 2015. Articles were assessed against predefined inclusion criteria. The included papers were divided into four groups based on the type of OS performed. The following items were recorded: quality of evidence using the Oxford Centre for Evidence-Based medicine (CEBM) criteria, number of patients, presence/absence of controls, mean age at treatment, follow-up time, clinical examination findings, bite force, use of the Helkimo Index and Research Diagnostic Criteria for Temporomandibular Disorders, imaging findings, and patient questionnaire results. A total of 4669 articles were identified; 76 relevant articles were included in the review. These studies assessed a total 3399 patients and 380 controls, with a mean age of 25.4 years. The great variety of OS techniques, examination techniques, diagnostic criteria, and imaging techniques used in the articles studied, as well as the quality of the study designs, made it difficult to compare studies and to draw conclusions. However, looking at the different aspects studied in general, it can be stated that OS seems to have little or no harmful effect on the TMJ and oral function (level of evidence: levels II, III, and IV).

Orthognathic surgery (OS) is a well-known surgical intervention to change and/or correct the facial-related structures. OS can roughly be divided into three categories: maxillary surgery, mandibular surgery, and combined double-jaw surgery. The most discussed surgical strategies are the bilateral sagittal split osteotomy (BSSO), vertical ramus osteotomy (VRO), mandibular midline distraction (MMD), surgically assisted rapid maxillary expansion (SARME), Le Fort I osteotomy (LFI), and bimaxillary osteotomy (BIMAX).

The main indications for OS are to improve function (including malocclusion, mastication, speech, respiratory function, sleep apnoea, and ocular function), minimize the treatment time, and obtain stability following orthodontic treatment, which includes the prevention of relapse. Another indication for OS is to improve aesthetics, e.g. in cases of congenital dentofacial discrepancies, acquired dentofacial discrepancies, and growth disturbances, and to obtain harmony and balance in facial appearance.

OS is considered a low risk and successful procedure. Successful outcomes in terms of oral function can be measured in many different ways, for example through the absence or presence of joint noises, mandibular movements, maximum mouth opening, pain on palpation, bite force, or patient satisfaction (on facial appearance and chewing ability). Qualifying and quantifying oral function is complex and there are few standardized procedures. Therefore, it would be interesting to identify the different outcomes of measuring oral function described and the effect of OS on the temporomandibular joint (TMJ) as reported in the literature. Prospective and long-term studies on the effects of OS on the TMJ, masticatory muscles, and function are still lacking. The aim of this study was to systematically review the scientific literature addressing the effect of OS on the TMJ and oral function.

Materials and methods

Search strategy

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used in this review.

An electronic search was conducted in seven databases: Embase, MEDLINE Ovid, Cochrane Central Register of Controlled Trials, Web of Science, PubMed (the subset as supplied by publishers), CINAHL (EBSCOhost), and Google Scholar. The search strategy combined terms for OS or mandibular or maxillary osteotomy with terms for TMJ or oral function. For the Embase, MEDLINE, and CINAHL searches, thesaurus terms were used alongside words in the title and/or abstract; in the other databases, only words in the title and/or abstract were used. The databases were searched from inception until October 2015. The search was limited to human studies, but no limitations on language were applied.

The full search strategies are given in Appendix A . The reference lists of all relevant articles were screened for additional relevant sources.

Data collection and analysis

Two of the review authors (EtV and AtV) screened the titles and abstracts (when available) of all reports independently. For all studies that appeared to meet the inclusion criteria, or when data in the title and/or abstract were insufficient, the full-text version was obtained to allow a definitive decision to be made. Both authors read the full-text articles and each author made an independent decision as to whether the studies met the inclusion criteria. Any disagreement was resolved by discussion; when no agreement could be reached, an additional researcher was involved (MK) until consensus was reached.

Included studies had to describe the treatment of humans and had to be published in English. Articles focusing on topics other than treatment, on other conditions not specified as OS and involvement of the TMJ, on comorbidity, or on the treatment of craniofacial syndromes were excluded. Review articles, studies describing the same patients, abstracts or posters presented at meetings, and articles published before 1990 were also excluded.

The articles included in the review were divided into the following four groups based on the type of orthognathic intervention: BSSO, VRO, LFI, and BIMAX. Several papers reported more than one of these groups; these papers were included for all groups that were described separately.

The following items were recorded for all of the articles included: quality of evidence using the Oxford Centre for Evidence-Based Medicine (CEBM) criteria, number of patients, presence or absence of a control group, mean age at treatment, follow-up time, clinical examination (including mandibular movements, maximum mouth opening, and pain on palpation), use of the Helkimo Index, the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), imaging (including computed tomography (CT), cone beam computed tomography (CBCT), magnetic resonance imaging (MRI), panoramic radiography, tomography, lateral radiography, transcranial radiography, and anterior–posterior radiography), and patient questionnaire results.

Results

After de-duplication, 2442 references were retrieved. The titles and abstracts of the 2442 articles were screened. In the case where the abstract was missing and/or it was questionable whether the abstract met the above-mentioned criteria, the full-text article was retrieved so as to avoid excluding any article of possible relevance. A total of 2151 papers were excluded for various reasons. The remaining 291 articles were screened on reading the full-text. Another 215 articles were excluded. The full-text was not available for five papers. No additional relevant articles were identified through the reference list search. Therefore 76 articles were included in the review. The PRISMA flowchart showing the number of articles remaining at each stage of the sequence of identification, screening, and final inclusion is illustrated in Fig. 1 .

Data extraction flowchart, according to the PRISMA statement 3 (OS, orthognathic surgery).
Fig. 1
Data extraction flowchart, according to the PRISMA statement (OS, orthognathic surgery).

An overview of all included studies is given in Table 1 . These papers were divided into the following four groups based on the type of orthognathic intervention: BSSO, VRO, LFI, and BIMAX; the items mentioned above were recorded ( Tables 2–5 ).

Table 1
Overview of all included papers.
Author and year CEBM level of evidence Sample size ( n ) patients/controls
1 Alder et al. (1999) IV 21
2 Al-Gunaid et al. (2008) IV 31
3 Aoyama et al. (2005) IV 37
4 Athanasiou and Mavreas (1991) IV 24
5 Athanasiou and Melsen (1992) IV 36
6 Athanasiou and Yucel-Eroglu (1994) IV 82
7 Athanasiou et al. (1996) IV 43
8 Borstlap et al. (2004) IV 222
9 Borstlap et al. (2004) IV 222
10 Boutros et al. (2008) IV 7
11 Boyd et al. (1991) IV 22
12 Chen et al. (2013) IV 31
13 Choi et al. (2014) III 78/67
14 Cortez and Passeri (2007) IV 11
15 Cottrell et al. (1997) IV 22
16 Cutbirth et al. (1998) IV 100
17 de Paula et al. (2013) IV 50
18 Ellis III et al. (1996) III 24/24
19 Fang et al. (2009) IV 24
20 Farella et al. (2007) IV 14
21 Fernandez Sanroman et al. (1997) III 24/10
22 Flynn et al. (1990) IV 40
23 Ha et al. (2013) IV 22
24 Harada et al. (2000) III 25/20
25 Harada et al. (2003) IV 24
26 Harper (1990) IV 54
27 Harris et al. (1999) IV 21
28 Hashimoto et al. (2008) IV 16
29 Hu et al. (2000) IV 50
30 Hunt and Cunningham (1997) IV 42
31 Iwase et al. (1998) IV 23/10
32 Iwase et al. (2006) IV 27/27
33 Jung et al. (2009) IV 217
34 Kallela et al. (2005) IV 40
35 Katsumata et al. (2006) IV 85
36 Kawakami et al. (2009) IV 22
37 Kawamata et al. (1998) IV 5
38 Kerstens et al. (1990) IV 41
39 Kikuta et al. (1994) IV 30
40 Kim et al. (2009) IV 23
41 Kim et al. (2010) IV 26
42 Kim et al. (2011) IV 26
43 Kim et al. (2012) IV 43
44 Kim et al. (2013) IV 22
45 Kim et al. (2014) IV 33
46 Lai et al. (2002) IV 23
47 Lee and Park (2002) IV 30
48 Lee et al. (2008) IV 36
49 Nakata et al. (2007) IV 36/30
50 Nemeth et al. (2000) II 140
51 Nishimura et al. (1997) IV 46
52 Nishimura et al. (2004) III 15
53 Ohkura et al. (2001) III 57/40
54 Park et al. (2012) IV 22
55 Rebellato et al. (1999) IV 29
56 Rodrigues-Garcia et al. (1998) IV 124
57 Rustemeyer and Gregersen (2012) IV 50
58 Scheerlinck et al. (1994) IV 103
59 Smith et al. (1992) IV 22
60 Song et al. (1997) III 9/26
61 Stroster and Pangrazio-Kulbersh (1994) IV 53
62 Throckmorton et al. (1995) III 24/26
63 Ueki et al. (2001) IV 22/20
64 Ueki et al. (2007) IV 45
65 Ueki et al. (2007) III 50
66 Ueki et al. (2008) III 47
67 Ueki et al. (2008) III 68
68 Ueki et al. (2009) III 29
69 Ueki et al. (2009) IV 26
70 Ueki et al. (2014) IV 73
71 van Den Braber et al. (2004) III 11/12
72 van den Braber et al. (2006) III 12/12
73 Wang et al. (2009) III 14/30
74 Yang et al. (2005) IV 67
75 Zarrinkelk et al. (1996) III 15/26
76 Zimmer (1993) IV 21

Table 2
Type of surgery: bilateral sagittal split osteotomy (BSSO).
Total articles scored for this item Outcome
Total number of patients 1932 52
Mean age of patients, years 26.3 46
Mean follow-up time, months 24.7 44
Clinical examination
Mandibular movements 12 5 smaller 7 no change
Maximum mouth opening 20 5 smaller 15 no change
Palpation 7 0 more pain 2 less pain 5 no change
Bite force 13 9 increase 1 decrease 3 no change
Helkimo index/RDC/TMD 4 2 improvement 1 worsening 1 no change
Imaging
(CB)CT 11 7 change 4 no change
MRI 7 2 change 5 no change
Panoramic radiography 3 3 change
Tomography 2 2 change
Lateral radiography 4 1 change 2 no change 1 NM
Transcranial radiography 1 1 change
Questionnaires 3 3 improvement
CBCT, cone beam computed tomography; CT, computed tomography; MRI, magnetic resonance imaging; NM, not mentioned; RDC/TMD, Research Diagnostic Criteria for Temporomandibular Disorders.

Table 3
Type of surgery: vertical ramus osteotomy (VRO).
Total articles scored for this item Outcome
Total number of patients 520 17
Mean age of patients, years 23.4 12
Mean follow-up time, months 16.9 16
Clinical examination
Mandibular movements 6 2 smaller 3 no change 1 NM
Maximum mouth opening 8 3 smaller 5 no change
Palpation 5 1 more pain 2 no change 2 NM
Bite force 2 2 increase
Helkimo index/RDC/TMD 3 2 improvement 1 worsening
Imaging
(CB)CT 4 4 change
MRI 4 4 change
Tomography 2 1 change 1 no change
Lateral radiography 4 4 change
Transcranial radiography
Anterior–posterior
Questionnaires
CBCT, cone beam computed tomography; CT, computed tomography; MRI, magnetic resonance imaging; NM, not mentioned; RDC/TMD, Research Diagnostic Criteria for Temporomandibular Disorders.

Table 4
Type of surgery: Le Fort I osteotomy (LFI).
Total articles scored for this item Outcome
Total number of patients 130 9
Mean age of patients, years 23.9 3
Mean follow-up time, months 10.5 10
Clinical examination
Mandibular movements 5 4 no change 1 NM
Maximum mouth opening 5 4 no change 1 NM
Palpation 3 2 less pain 1 NM
Bite force 2 2 increase
Helkimo index/RDC/TMD 3 1 improvement 1 worsening 1 no change
Imaging
(CB)CT 2 1 change 1 no change
MRI 1 1 no change
Panoramic radiography 1 1 no change
Tomography 2 2 no change
Lateral radiography
Transcranial radiography 1 1 no change
Fluoroscopic imaging 1 1 no change
Questionnaires 3 3 improvement
CBCT, cone beam computed tomography; CT, computed tomography; MRI, magnetic resonance imaging; NM, not mentioned; RDC/TMD, Research Diagnostic Criteria for Temporomandibular Disorders.

Table 5
Type of surgery: bimaxillary osteotomy (BIMAX).
Total articles scored for this item Outcome
Total number of patients 549 25
Mean age of patients, years 24.6 20
Mean follow-up time, months 11.7 23
Clinical examination
Mandibular movements 4 4 no change
Maximum mouth opening 8 6 no change 2 smaller
Palpation 3 2 less pain 1 no change
Bite force 4 4 increase
Helkimo index/RDC/TMD 3 2 improvement 1 no change
Imaging
(CB)CT 7 6 change 1 no change
MRI 4 3 change 1 no change
Panoramic radiography
Tomography 1 1 change
Lateral radiography 4 3 change 1 no change
Transcranial radiography 1 1 change
Fluoroscopic imaging 1 1 no change
Questionnaires 4 3 improvement 1 no change
CBCT, cone beam computed tomography; CT, computed tomography; MRI, magnetic resonance imaging; NM, not mentioned; RDC/TMD, Research Diagnostic Criteria for Temporomandibular Disorders.

Discussion

In almost all of the articles, the number of subjects studied was low. Combining the studies gave a total of 3399 patients and 380 controls. All control subjects in all groups were healthy subjects, with a complete dentition, little or no dental restoration, and a class I occlusion.

Clinical examination indexes mentioned in the articles included were the Helkimo index and the RDC/TMD Axis II ; none of the other articles specifically described the index used to classify the data.

Mandibular movement and maximum mouth opening

Mandibular movements and maximum mouth opening were scored by many articles, especially for the BSSO and VRO groups. An initial decrease in maximum mouth opening at 1–6 months post-surgery was described in almost all papers. The causes of this decrease in maximum mouth opening included intermaxillary fixation, jaw repositioning in combination with orthodontic treatment changing the position of the teeth, and the formation of scar tissue and/or inflammation. Approximately two-thirds to three-quarters of all patients in the BSSO and IVRO groups showed no difference in mandibular movements and maximum mouth opening after a follow-up period of 1–2 years. A small group showed a decrease in mandibular movements and mandibular opening. Although the differences were found to be significant, they amounted to only a few millimetres. A decrease in objective maximum mouth opening does not necessarily result in a subjective and/or objective limited mandibular mouth opening. No conclusions were drawn regarding the clinical relevance of this change, or the problems (if any) facing these patients in everyday life.

Pre-surgical and post-surgical mandibular movements and maximum mouth opening were about the same for the LFI and BIMAX groups after a follow-up period of 1–2 years.

Palpation

The majority of patients in the BSSO, VRO, LFI, and BIMAX groups showed a decrease in post-surgery pain on palpation. None of the studies described the amount of pressure applied or the specific palpation sites, except for those studies that used the Helkimo index or the RDC/TMD.

Bite force

Bite force was measured with different devices: Dental Prescale (Fuji Photo Film Co., Tokyo, Japan) and the associated analysis apparatus (Occluzer, Dental Occlusion Pressuregraph; Fuji Photo Film Co.), a bite force transducer with the ends covered with polypropylene tubing and opening the mouth to 15 mm, a bite fork with two force transducers, a custom-built bite force gauge with a transducer element, a T-scan system, and an occlusal force meter (MPM-300; Electric Light, Tokyo, Japan) and jaw force meter (MPM-2401; Nihon Kohden).

For almost all patients in the different surgical intervention groups, the maximum voluntary bite force showed a general decrease in occlusal force during the first few months after surgery, and then a gradual increase in bite force towards the level of the controls.

Imaging

Imaging studies described the differences in condylar joint space, condylar position, disc position pre- and postoperative, and condylar remodelling.

Computed tomography: CBCT and CT

A change in condylar position to a more superior and posterior position in the fossa was described for the VRO group and BSSO group when it was an advancement procedure. A more outward rotation of the condylar long axis was seen in the VRO group. In the case of setback, no change in condylar position was seen in the BSSO, BIMAX, and VRO groups. Furthermore, no changes were found in the LFI group. On the other hand, an initial change in condylar position was found for the LFI and BIMAX groups in four studies. An inferior and inward rotation of the condyle was found in the BSSO and BIMAX groups and a more outward rotation of the condyle was described in the VRO group. Remodelling, as defined by a newly formed bony layer in the posterior part of the condylar head, was reported for the VRO, BSSO, and BIMAX groups.

Magnetic resonance imaging (MRI)

For the BSSO group, no change was found in articular disc position or articular disc length on MRI. It is suggested that a double contour-like demarcation line on MRI might correspond to bone formation. Remodelling on the superior surface of the condylar head was seen in some joints on MRI. Joint effusion was found and resolved after 4 months.

In the VRO group, there were significant condylar position changes and horizontal changes in the condylar long axis on both sides. No changes occurred in joint discs that were normal preoperatively, and an improvement of anteriorly displaced discs to a more normal position in discs with anterior displacement with or without reduction preoperatively was seen. Remodelling on the superior surface of the condylar head was seen in some joints on MRI. Joint effusion was found and resolved after 4 months. No TMJ changes were found in the LFI group.

In the BIMAX group, a change was found in the direction and the moment arms of the masseter and medial pterygoid muscles. No change in articular disc position or articular disc length was found on MRI. Preoperative anterior disc displacement with reduction and without reduction did not change postoperatively. On the other hand, an improvement in anterior disc displacement with or without reduction for a short period post-surgery could be seen following BIMAX surgery.

Panoramic radiography

For the BSSO and LFI groups, three articles described a greater vertical change in the condyles, due to condylar resorption. For the BSSO group, remodelling was reported in 16% and resorption of the condylar head in 4%. The use of panoramic radiographs as a diagnostic tool was reported in one study. No articles reported on panoramic radiograph changes for the VRO and BIMAX groups.

Tomography

A condylar anterior or posterior displacement was seen in the BSSO group. In the VRO group, no major alterations were seen in the TMJ, but there was an increase in posterior and anterior spaces between the condyle and fossa. No changes in the TMJ were seen on tomography for the LFI group. A decrease in the superior and posterior regions was seen in the BIMAX group.

Lateral radiography

In the BSSO group, no significant effect on TMJ morphology and position was seen. In another article, a posterior displacement of the condyle was seen. In the VRO group, a more anterior–inferior displacement of the condyle was seen. Signs of condylar remodelling were seen. In the BIMAX group, obvious changes in condylar position were seen; the condyles tended to be located in a concentric position in relation to the glenoid fossa at 3 months after surgery. Although mentioned as a diagnostic tool to measure the position of the condyles, lateral radiographs were used only for cephalometric evaluation. No articles were found describing lateral radiographs in the LFI group.

Transcranial radiography

Changes in condylar position and condylar remodelling and resorption were seen in the BSSO and BIMAX groups. No changes were seen in the LFI group. No articles reported on transcranial radiographs in the VRO group.

Intraoperative fluoroscopy

Intraoperative fluoroscopy was used to evaluate the condylar position in OS. This method has the potential advantages of speed, simplicity, efficacy, and safety. No condyle was found to be displaced in the LFI and BIMAX groups on intraoperative fluoroscopy.

Questionnaires

For the BIMAX group, one article described questionnaires based on the Oral Health Impact Profile. This article concluded that orthognathic patients generally experience both functional and psychosocial benefits after surgical–orthodontic treatment. For the BSSO and LFI groups, the RDC/TMD Axis II was used in one article. The authors observed that the depression index, grade of non-specific physical symptoms, and chronic pain scale decreased after surgery, and the grade of non-specific physical symptoms including pain showed a significant decrease after surgery.

In conclusion, the great variety of OS techniques, examination techniques, diagnostic criteria, and imaging techniques used in the articles studied, as well as the quality of the study designs, makes it difficult to compare studies and to draw conclusions. Only one RCT was found. All articles scored low on methodological quality, and due to the heterogeneity in the articles and subsequent results, a meta-analysis of the data was not possible. The generally suboptimal quality of the literature highlights the need for better quality studies with clearly defined examination techniques and criteria to diagnose and evaluate the effect of OS on the TMJ. These will require better defined samples of subjects. Furthermore, more randomized controlled clinical trials with well-described OS are required. However, looking at the different aspects studied in general, it can be stated that OS seems to have little or no harmful effect on the TMJ and oral function.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Competing interests

There are no conflicts of interest in the materials or subject matter dealt with in the manuscript.

Ethical approval

Approval was obtained from the Medical Ethics Committee of Erasmus University Medical Centre Rotterdam.

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