Orthognatic Surgery With Reconstruction of the Temporomandibular Joint

Abstract

Orthognathic surgery with reconstruction of the temporomandibular joint (TMJ) addresses conditions where dentofacial deformity (DFD) is present along with damage to the temporomandibular joint. A stable TMJ without signs of pathology is a basic prerequisite for successful orthognathic surgery. If pathology is present, it is necessary to first address the condition of the TMJ (through conservative, mini-invasive and surgical methods). Only after the condition of the TMJ is stabilized is it possible to surgically address DFD. Orthognathic surgery in conjunction with TJR is performed in a single operation, where precise planning of these surgical procedures is vital for their successful execution.

1. Introduction

Orthognathic surgery with reconstruction of the temporomandibular joint (TMJ) addresses conditions where dentofacial deformity (DFD) is present along with damage to the temporomandibular joint. Basically, these are conditions where [1, 2]:

1. DFD is the result of condylar pathology

2. there is primarily DFD, but with developing TMD.

The aim of treating these conditions is:

1. to achieve good facial esthetics and satisfactory occlusion, airway and breathing capabilities

2. to reduce or eliminate pain and restore full functionality of the temporomandibular joint

This goal is achieved through standard orthognathic surgical techniques (sagittal osteotomy, LeFort I osteotomy, genioplasty), together with the use of TMJ reconstruction techniques in a single surgical procedure. Patients may also choose two-stage surgery (TMJ reconstruction and subsequent orthognathic surgery), however performing both procedures in a single operation reduces the impact of general anesthesia, reduces the overall duration of surgery and the patient need only recover once, which is an indisputable benefit. Nonetheless, performing both procedures at the same time requires flawless preparation and planning [3, 4, 5, 6, 7].

In general, a stable TMJ is required for a stable orthognathic outcome. If the TMJ is pathologically altered, then correcting facial asymmetry while ignoring the pathological condition of the TMJ can lead to a recurrence of facial asymmetry, malocclusion, and exacerbation of joint problems [1].

2. TMJ indication for joint reconstruction

Patients with TMJ pathology and concomitant DFD may show typical TMJ symptoms (limited jaw movement, presence of TMJ pain, occlusal disturbance). Nevertheless, a second group of patients exhibit clinically asymptomatic TMJ, where the impact on DFD is only revealed by imaging methods [1, 3]. In these patients, the condition of the TMJ represents a potential risk to the long-term stability of the outcome of orthognathic surgery in the event of progressing TMJ pathology. The question is whether to choose preventive TMJ reconstruction in these patients or to address the condition of the joint by other methods [3]. This problem is especially evident in the diagnosis of idiopathic condylar resorption (ICR), where some authors prefer stabilizing the joint (bite guards, drug therapy, TMJ open surgery) or performing preventive TMJ reconstruction [8, 9, 10].

2.1 Indications for joint reconstruction during orthognathic surgery include

1. conditions where joint function is limited due to a change in condylar quality (severe osteoarthritis, end-stage internal derangement, severe septic TMJ arthritis, avascular necrosis, systemic connective tissue and autoimmune diseases, synovial chondromatosis, primary condylar tumors such as osteoma, osteochondroma, diffuse tenosynovial giant cell tumor)

2. reduced condyle height due to pathological TMJ processes (idiopathic condylar resorption, inflammatory arthritis, severe osteoarthritis, severe septic TMJ arthritis, systemic connective tissue and autoimmune diseases)

3. absence of the condyle (congenital and developmental defects affecting TMJ structures, conditions after condylar resection for traumatic impairment or resection of TMJ tumors)

4. TMJ ankylosis

5. conditions following previous unsatisfactory surgeries

A clear contraindication for TMJ reconstruction to address DFD (and in general) are patients with disco-condylar complex disorders (clinically manifested by acoustic phenomena, locking, limited jaw movement) and patients with chronic pain who have no obvious joint pathology (e.g., myofascial pain) [2].

3. Options for TMJ reconstruction in patients with dentofacial deformities

TMJ reconstruction can generally be achieved by using two basic methods:

1. Use of autogenous materials (costochondral graft, sternoclavicular graft, fibular graft, chondro-osseous graft harvested from iliac crest)

2. Use of allogeneic materials (where the most common materials are titanium, a cobalt chromium alloy and polyethylene)

Autogenous materials are popular for TMJ reconstruction in pediatric patients (especially costochondral graft) due to their growth capacity. However, the unpredictability of growth is a problem (excessive growth or no growth), as well as unpredictable bone graft stability and donor site morbidity. The use of allogenous materials is not suitable for TMJ reconstruction with concurrent orthognathic surgery [11, 12, 13].

Allogeneic prostheses can be partial or total.

Partial replacement (typically a prosthetic replacement of the mandibular condyle, which is inserted into the joint fossa) is again not a suitable for DFD. The long-term use of these prostheses is associated with an increased risk of fossa resorption due to direct contact of the head of the prosthesis with the bone fossa [13].

The ideal solution for TMJ reconstruction with DFD is total joint replacement (TJR).

Total joint replacement consists of [14, 15]:

1. fossa replacement (the prosthesis is manufactured from UHMWPE - ultra-high molecular weight polyethylene)

2. condylar replacement. The actual head of the prosthesis is made of chromium-cobalt alloy and the fixative part of the prosthesis is made of titanium. Chromium-cobalt alloy has the ability to bind with titanium, it is strong, with a highly polishable and biocompatible surface. It has excellent properties like the surface of the head of the physiological joint in relation to the polyethylene fossa and represents the orthopedic standard for total TMJ endoprostheses.

Total prostheses are available in two versions- stock prostheses and patient-fitted prostheses [15, 16].

Stock prostheses are usually manufactured in several sizes, with the ideal size of prosthesis components selected during surgery [16]. If these prostheses are used in orthognathic surgery, it must be kept in mind that this is an altogether compromise solution. Stock prostheses have the same shape and mandibular advancement is usually only achieved as a result of the inappropriate distal inclination of the prosthesis, or by moving the prosthesis behind the posterior branch of the mandible. An ideal result can only be achieved by using patient-fitted prostheses, whose shape is designed to concurrently allow the planned repositioning of the lower jaw (Figure 1). Another advantage of patient-fitted prostheses is their improved fit and osseointegration, thus resulting in less friction and micromovement, better stability and potentially longer mean durability [17, 18]. When the zygomatic arch and glenoid fossa were absent, the fossa component was custom-fitted to the base of the skull and lateral temporal bone morphology [11] (Figures 2 and 3).

Figure 1.

TMJ prosthesis design enabling mandibular advancement.

Figure 2.

22 years old man with HFM (absence of joint structures and absence of zygomatic arch).

Figure 3.

22 years old man with HFM (planned reconstruction of joints structures and zygomatic arch).

Relative contraindications of alloplastic total TMJ replacement are [19, 20]:

1. uncontrolled systemic disease

2. active infection at the surgical site

3. allergy to the implant/prosthesis material.

Today, the previously unequivocal refusal to use TJR in pediatric patients with a growing skeleton [14] is changing, as it is no longer considered an unsuitable indication [21, 22]. Growth activity of the mandible is observed when employing TJR even in growing skeletons [21]. The use of TJR of the TMJ in children is possible in the following indications [21]:

1. High inflammatory TMJ arthritis unresponsive to other modalities of treatment

2. Recurrent fibrosis and/or bony ankylosis unresponsive to other modalities of treatment

3. Failed tissue grafts (bone and soft tissue)

4. Loss of vertical mandibular height and/or occlusal relationship because of bony resorption, trauma, developmental abnormalities, or pathological lesions.

It must be realized that TJR is joint replacement that is not equivalent to the physiological joint. TJR does not allow the same movement as the physiological joint. The components of the prosthesis mainly allow rotational movement, while the physiological joint allows rotation, as well as translational movement. Joint replacements only exhibit slight translation (pseudo-translation), which causes deviations in mouth opening in unilateral TJR (movement deviates to the side of the TJR). Some authors report improved translational movement when performing lateral pterygoid muscle reattachment [23, 24].

4. Orthodontic preparation of the patient

The initial consultation between the doctor and patient is important for successful treatment. The purpose of the consultation is to consider the options of surgical treatment, but also to acquaint the patient with the limits and complications of treatment. The patient is acquainted with the reasons why TMJ reconstruction is planned. It is important to know the patient’s expectations and the reasons why they decided to address their DFD. Of course, it is essential to temper any unrealistic expectations the patient may have (both in terms of correcting the DFD and eliminating TMJ problems).

An initial consultation at the authors’ workplace is always held in the presence of orthodontist, orthognathic surgeon and TMJ surgeon. Orthodontic-surgical treatment of maxillary anomalies is a team effort, in which the specific approach in all phases is the result of joint decision-making and mutual consultation by individual experts.

Only after the patient has fully understood and consented to the procedure does planning the surgery begin.

The initial interview includes photo documentation of the patient, an X-ray and cone beam CT. Stone models of the upper and lower dental arch are also required to assess occlusal conditions.

In principle, the same rules apply for orthodontic preparation as when preparing patients for orthognathic surgery. Orthodontic pre-treatment is performed using fixed devices on the upper and lower arches. The main goals of orthodontic preoperative treatment are: decompensation of the defect and the creation of regular dental arches without the constriction, and rotation of the front teeth. Postoperative intercuspidation should create conditions for a stable overbite of the incisors, i.e., a suitable incisal overjet and bite depth, with normoocclusion of the canines. For lateral teeth, intercuspidation without a crossbite should be achieved postoperatively. The width of the dental arches must be proportional to each other, the shape of the arches must allow good postoperative intercuspidation [25].

In case of transverse narrowing of the upper jaw, orthodontic preparation includes expansion of the upper jaw depending on the patient’s age, i.e., ossification of the sutura palatina (non-surgically in growing patients with a Hyrax palatal expander, or surgically in adult patients using the SARME method - surgically assisted rapid maxillary expansion).

If the patient has a biplanar occlusal plane of the upper jaw, it is important to maintain this and prepare the patient segmentally. Segments are typically formed by osteotomy between the Central incisors into segments 17–11 and 21–27 or between the lateral incisors and canines, whereby the dental arch is divided into three segments second molar to canine, incisors, canine to second molar [26, 27, 28].

In patients with congenital defects (e.g., hemifacial microsomia) or in patients who developed ankylosis in childhood, there is often severe hypoplasia of the affected branch and body of the lower jaw. In these cases, it is appropriate to use distraction osteogenesis to extend the ramus and body of the lower jaw. This technique has the advantages of providing superior amount of bone lengthening and allows simultaneos expansion of surrounding soft tissues. This elongated bone will then facilitate the movement of the jaw to the appropriate position, significantly improving the resulting esthetic effect.

Preoperative preparation includes the removal of retained teeth and introduction of dental implants. Knowledge of the patient’s general condition is also required to prepare the patient for a procedure that takes several hours. Similarly, it is important to monitor levels of vitamin D and provide supplements, where necessary (low levels are associated with the risk of impaired healing of bone fragments).

The purpose of orthodontic preparation is to create ideal dental arches suitable for stable occlusion after repositioning one or both jaws. The length of orthodontic preparation depends on how complicated the condition of the dental arches is [29, 30, 31].

Depending on the condition of the dental arches, it is possible to prepare a patient for surgery in 4 ways [30]:

1. Surgery first: this approach proceeds with orthognathic surgery without preoperative orthodontic preparation and is followed by regular postoperative dental alignment.

2. Surgery early: the patient’s wish for an immediate esthetic change. In this treatment concept, the presence of severe crowding in need of extractions and complex 3D dental compensations due to facial asymmetry, including dental midline deviation, requires at least partial orthodontic preparation. As soon as severe crowding has been managed with extractions and a good amount of the required space closure is achieved, surgery is performed. In the case of severe 3D compensations and/or dental midline deviations, surgery proceeds once transverse compensations are resolved.

3. Surgery late: corresponds to the conventional approach for orthognathic surgery, i.e., the traditional sequence of preoperative orthodontics, surgery, and postoperative orthodontics.

4. Surgery only: Conceptually, a ‘surgery only’ protocol proceeds directly with surgery, without any previous or subsequent orthodontic treatment.

4.1 Planning orthognathic surgery

The actual planning of orthognathic surgery only begins after the completion of orthodontic preparation, when passive arches are deployed with orthodontic appliances. Planning consists of virtual surgical planning (VSP). The same CT is used for VSP as for planning joint replacement. A 3D virtual patient model is generated using a 3D planning program. This requires the aforementioned CT, as well as intraoral scans of dental arches, 3D photos and a clinical analysis of the patient. This virtual model then makes it possible to plan individual osteotomies and jaw repositioning [29, 32].

Clinical analysis of the patient involves a comprehensive examination of the patient’s face before surgery. Exact measurements are made (with special attention given to the Central position of the Chin) of the mutual relationship of the lips when relaxed, the bilateral symmetry of the mandible angles, symmetry of the contour of the lower jaw line, symmetry of Chin contours and possible deviations in the soft tissues of the face. Also noted are the movement of the lips when smiling, the exposure of incisors and a possible gummy smile, the relationship and position of the dental center of the upper and lower dental arch to the center of the face, the inclination of the occlusal plane and a comparison of its inclination to the bipupillary plane [26, 33].

The virtual 3D model not only makes it possible to assess the bone structure of the facial skeleton, but also creates an image of soft tissues, which is important to get an idea of esthetic outcome and facial changes in a patient with DFD [32]. The use of modern planning technologies brings better and more predictable results [33].

The resulting position of the upper and lower jaws will enable the virtual production of surgical splints, which will be printed on a 3D printer before the surgery and will allow the jaws to be moved to the planned position during the procedure [29].

Note: An intraoral scan is clearly preferred for a scan of the dental arches rather than scanning the dental arches from the model. An intraoral scan eliminates minor deviations in the impression and plaster model.

4.2 Planning and preparation of the TMJ prosthesis

As mentioned above, patient-fitted prostheses are always used for orthognathic surgery with TJR. These are prepared and produced in the following manner [15]:

1. CT scan protocol (from the middle of the forehead to the hyoid, dorsally to the anterior edge of the foramen magnum, in 0.5–0.75 mm sections, without head support - gantry tilt 0 degrees,)

2. Occlusion scan of the upper and lower dental arches

3. Orthognathic planning, preparation of a virtual splint

4. Submission of the CT, occlusion scan and virtual splint to the company producing the prosthesis

5. Virtual inspection of the placement of the splint, occlusion, comparison of the resulting position of the lower jaw with the lower jaw position during orthognathic planning

6. Planning resection lines, possible modifications around the socket and mandibular branch

7. Creation of a joint replacement model

After all steps have been approved, production of the prosthesis commences.

The entire process of creating a prosthesis takes several weeks to months.

Note 1: when planning mandibular advancement, it is important to realize the differences between sagittal osteotomy advancement and total replacement advancement. During sagittal osteotomy, the position of the distal fragment (part of the branch of the mandible with the muscular and articular process) remains in the same place. In contrast, in mandibular advancement with total joint replacement, the branch is completely shifted anteriorly. This shift can cause the coronoid process to come into contact with the posterior wall of the maxila (Figure 4), which will in turn result in reduced jaw mobility. This is resolved through a planned coronoidectomy.

Figure 4.

CT model with final position of lower jaw and contact of coronoid process with posterior part of maxila.

5. Algorithm for performing orthognathic surgery and TJR

It is important to remember that the surgical procedure combines both an intraoral and extraoral approach. The reconstruction of the temporomandibular joint uses extraoral approaches only, while orthognathic surgery is performed from an intraoral approach only. Due to the risk of infectious contamination of the prosthesis [2, 15, 20], it is vital to maintain strict separation of both approaches and, of course, use separate sets of instruments for both parts of the surgery. The authors also recommend separate sets of covering for the surgical field and thoroughly covering surgical wounds with sterile foils after completing individual steps of the procedure.

Basically, 2 types of surgical procedures are performed:

1. Bilateral TMJ reconstruction, with possible subsequent maxillary surgery

2. Unilateral TMJ reconstruction, split sagittal osteotomy (SSO) on the contralateral side, with possible subsequent maxillary surgery

Both types of surgery can be supplemented by intraorally performed genioplasty at the end of the procedure.

Note 1: If the fixative part of the condylar component of the prosthesis is longer and extends to at least the first molar (often in patients with hemifacial microsomia), the authors recommend waiting to perform genioplasty. This is to limit the contact between the intraoral environment and the prosthesis due to tissue preparation during genioplasty.

Note 2: Successful orthognathic surgery with TMJ reconstruction requires experience in performing both types of surgical procedures. At the authors’ workplace, these procedures are performed by 2 surgeons, an orthognathic surgeon and a TMJ surgeon, at the same time.

5.1 Bilateral TMJ reconstruction, with possible subsequent maxillary surgery

1. Endaural incision for exposure of the TMJ fossa and retromandibular (or subangular) incision for exposure of the mandibular ramus

2. Condylar resection and coronoid resection (if indicated)

3. Shift of the mandible to the planned position, intermediate splint, intermaxillary fixation

4. Placement of total joint prosthesis and fixation by screws on both sides

5. Pack fat graft around articulation area of prosthesis (harvest fat from abdomen)

6. Close extraoral incisions

7. Remove intermaxillary fixation, intermediate splint

8. Maxillary osteotomies and mobilization

9. Intranasal procedures, if indicated (turbinectomies, nasal septoplasty, etc.)

10. Placement of final splint, intermaxillary fixation

11. Fixation of maxillary osteotomies by mini-plates (bone grafting, if indicated)

12. Removal of intermaxillary fixation, final splint

13. Close intraoral incisions

5.2 Unilateral TMJ reconstruction, split sagittal osteotomy on the contralateral side, with possible subsequent maxillary surgery

1. Endaural incision for exposure of the TMJ fossa and retromandibular (or subangular) incision for exposure of the mandibular ramus

2. Condylar resection and coronoid resection (if indicated)

3. Contralateral mandibular ramus sagittal split osteotomy

4. Shift of the mandible to the planned position, intermediate splint, intermaxillary fixation

5. Placement of total joint prosthesis and fixation by screws on both sides

6. Pack fat graft around articulation area of prosthesis (harvest fat from abdomen)

7. Close extraoral incisions

8. Rigid fixation to contralateral mandibular ramus osteotomy

9. Removal of intermaxillary fixation, intermediate splint

10. Maxillary osteotomies and mobilization

11. Intranasal procedures, if indicated (turbinectomies, nasal septoplasty, etc.)

12. Placement of final splint, intermaxillary fixation

13. Fixation of maxillary osteotomies by mini-plates (bone grafting, if indicated)

14. Removal of intermaxillary fixation, final splint

15. Close intraoral incisions

Note 1: For mandibular advancement or CCW rotation of the mandible, it is advisable to thoroughly relax the masticatory muscles. TJR surgery usually involves stripping the masseter muscle and detaching the lateral pterygoid muscle through condylectomy. In the case of coronoidectomy, the ligament of the temporal muscle is detached. In case of more extensive mandibular repositioning, the authors recommend detaching the pterygomasseteric sling at the edge of the mandible and stripping the lower part of the medial pterygoid muscle from the inner surface of the mandibular ramus (within 1 cm above the edge of the mandible).

Note 2: There is a different algorithm for performing orthognathic surgery with TJR in patients with ankylosis. Unless performing surgery only or surgery first, then patients with ankylosis will first undergo an ankylosis resection. This allows the mobilization of the jaw and at the same time allows the start of orthodontic preparation. Only after this is completed is orthognathic surgery performed, together with TJR. Spacers are inserted into the resected ankylosis site (most often bone cement) to prevent reankylosis.

6. Postoperative regimen and care, follow-up system

The postoperative regimen fundamentally differs depending on the scope of the surgery.

If mandibular repositioning is performed using bilateral TJR without maxillary surgery, then the postoperative regimen consists of [13, 16]:

1. Early rehabilitation of mouth opening – from the 1st day after surgery (when the pressure dressing is removed). For the first two weeks the patient opens his/her mouth freely to the point of pain, from the 3rd week the mouth is opened with the help of the fingers or a dilator to achieve a minimum opening of 35 mm- interincisively. Gentle massages of the masticatory muscles (several times a day) are recommended.

2. Antibiotics are administered for a period of 10 days (the first 3 days intravenously, then orally)

3. Analgesics are administered according to pain

4. Anti-edematous therapy is advised for the first 3 days

In patients where TJR is performed concurrently with SSO or maxillary surgery, the postoperative regimen consists of [13, 16]:

1. Intermaxillary fixation with elastic bands for a period of 6 weeks. The patient is instructed how to change the elastic bands and changes them twice daily – the patient uses this time to thoroughly clean the oral cavity and to freely open his/her mouth to the point of pain for at least 5 minutes. Gentle massage of the masticatory muscles (several times a day) are recommended.

2. Antibiotics are administered for a period of 10 days (the first 3 days intravenously, then orally)

3. Analgesics are administered according to pain

4. Anti-edematous therapy is advised for the first 3 days

Patients at the authors’ workplace are typically hospitalized for several days after the surgery. In case of orthognathic surgery with TJR of the TMJ, hospitalization time is 3–7 days.

After surgery, each patient is scheduled for regular follow-up examinations at the authors’ workplace at 2 weeks, one month, three months, 6 and 12 months after the procedure, and then regularly once a year after that [13].

Note 1: The authors prefer individual rehabilitation that largely relies on the patient’s cooperation. The patient is instructed in methods for the rehabilitation of mouth opening and gentle muscle massages. If this rehabilitation is insufficient, a specialist, a physiotherapist, is brought in to help. The authors recommend specialized physiotherapy in case of complications – e.g., involvement of the facial nerve, trigeminal nerve [13].

Note 2: The risk of anterior dislocation of the prosthesis is increased due to the detachment of the ligaments of the masticatory muscles from the mandible (especially if a coronoidectomy was performed at the same time). It is appropriate to test the maximum range of motion of the mandible at the end of the surgery and to record whether or not dislocation occurs during maximal abduction [17]. If there is a risk of dislocation, temporary intermaxillary fixation with elastic bands is maintained (usually for the first postoperative week) [15].

7. Complications

We can divide complications into those associated with TJR and complications associated with orthognathic surgery.

Complications associated with TJR of the TMJ can be divided into perioperative and postoperative [15, 20, 34, 35, 36, 37].

Perioperative complications include:

1. Injuries to blood vessels and nerves. Vessels mainly include the temporal superficial vein and artery, the retromandibular vein and branches of the maxillary artery. Of the nerves, the facial nerve can be damaged most often (manifested by impaired facial expressions in the postoperative period). Another damaged nerve may be the trigeminal nerve (manifested in the postoperative period by chronic pain, hypoesthesia or anesthesia of the lower lip area).

2. Injuries to surrounding anatomical regions - most often the external auditory canal, more rarely the structures of the middle ear

3. Poor insertion, inadequate fixation of prosthesis components

Postoperative complications include:

1. Surgical site infections – this can occur early (within 3 weeks of surgery, manifesting as swelling, redness of the surgical site, increased pain) or with a delay (more than 3 weeks after surgery, manifesting as diffuse swelling and pain, without erythema, fever). Wolford [36] reports early infectious complications due to oral flora, and late complications due to skin flora. The risk of infection increases with the amount and type of resident skin bacteria, nutritional factors, systemic disease, and habits.

2. Complicated healing of surgical wounds, unaesthetic scars

3. Dislocation of the condylar components of the prosthesis (Figure 5). The most common is anterior dislocation, which occurs due to weakening of masticatory muscle tension, especially when the temporal muscle is detached during coronoidectomy. We also encounter posterior condylar dislocations, especially in major mandibular advancements, due to the traction of suprahyoid muscles. A fossa prosthesis designed with a posterior shield can prevent posterior dislocation

4. Loosening of prosthesis components, failure of prosthesis material

5. Allergic reaction to prosthesis material

6. Heterotopic bone ossification - development of heterotopic bone around the prosthesis leading to limited jaw function, pain

7. Chronic pain. This occurs as a result of nerve injuries during surgery, infection of prosthesis components, loosening of the prosthesis, formation of heterotopic bone around the TJR or the fixation of chronic pain already present before the surgery.

Figure 5.

Complication of TJR: luxation of prosthesis.

Complications associated with orthognathic surgery can again be divided into perioperative and postoperative [38, 39].

Perioperative complications include

1. Injuries to blood vessels-bleeding from the inferior alveolar artery, plexus pterygoideus, arteria palatina descendens, arteria maxillaris. The descending palatine artery is the most common source of mild to moderate bleeding during LeFort I osteotomy and subsequent delayed bleeding. Damage of the descending palatine artery may occur during medial wall osteotomy

2. Nerve injury - nervus alevolaris inferior, mental nerve, nervus palatinus major. Neurosensory alterations are normally perceived in the immediate postoperative period. They are the result of traction of the infraorbital nerve and direct trauma to the anterior, medial, and posterior superior alveolar nerves, as well as to the nasopalatine nerve and the descending palatal nerve

3. Bad split- unfavorable fracture

4. Inadequate mobilization of fragments

5. Tooth and periodontal damage in case of an inappropriate osteotomy line. An osteotomy closer than 5 mm to the dental apices poses the risk of root injuries.

6. Oronasal communication - mainly arises during the division of the maxilla into segments

Postoperative complications include

1. Bleeding (arteriovenous fistulae) can cause symptoms such as facial swelling, delayed bleeding, and development of a pulsatile sof mass

2. Neurosensory deficit- osteotomy induces changes in the maxillary teeth, buccal mucosa, palatal mucosa, and facial skin sensation. While skin sensation tends to recoer ovr time even after direct damage to sensory nerves, it may not completely recover to the condition that was present before surgery

3. Relapse

4. Delayed union or nonunion- of an osteotomy site may occur as a result of poor ealing of hard and soft tissues. The risk of nonunion is high when inadequate fixation is performed

5. Nasal septal malposition, which occurs after LeFort osteotomy and maxillary fixation. Septal malposition can occur during LeFort osteotomy and cause nasal deviation. The position of the septum must be checked, especially after extubation of the patient.

6. Inflammatory complications of the maxillary sinus

7. Release of osteosynthetic material

8. Infection Postoperative infections include cellulitis, abscess, maxillary sinusitis and osteomyelitis. Rates of postoperative infections are low thanks to aseptic techniques, antibiotics, and good blood supply into oral and maxillofacial area. Even when infections do occur, thex can be fully cured through early diagnosis and management.

8. Stability and assessment of the results of orthognathic surgery and TJR

If the quality or absence of joint structures does not ensure the stability of the result of orthognathic surgery, the combination with TJR guarantees a stable long-term result. The authors can confirm this from their own experience: 37 patients underwent orthognathic surgery concurrently with TJR (8 men, 29 women, average age 37, 1 years)- no relapse of DFD was recorded for at least one year after surgery (Figures 6–19).

Figure 6.

28 years old woman with rheumatoid arthritis.

Figure 7.

28 years old woman with rheumatoid arthritis- before surgery.

Figure 8.

28 years old woman with rheumatoid arthritis- frontal view.

Figure 9.

28 years old woman with rheumatoid arthritis- occlusion before surgery.

Figure 10.

28 years old woman with rheumatoid arthritis- occlusion before surgery, side view.

Figure 11.

CT scan with changes of TMJs.

Figure 12.

28 years old woman with rheumatoid arthritis- Virtual planning.

Figure 13.

28 years old woman with rheumatoid arthritis- Virtual planning, frontal view.

Figure 14.

28 years old woman with rheumatoid arthritis- X ray after orthognatic surgery and TJR of TMJs.

Figure 15.

28 years old woman with rheumatoid arthritis- after surgery- side view.

Figure 16.

28 years old woman with rheumatoid arthritis- after surgery.

Figure 17.

28 years old woman with rheumatoid arthritis- after surgery- frontal view.

Figure 18.

28 years old woman with rheumatoid arthritis- occlusion after surgery.

Figure 19.

28 years old woman with rheumatoid arthritis- occlusion after surgery, side view.

A number of authors have confirmed this fact in their studies [2, 11, 40, 41, 42] both in the stability of CCW rotation associated with TJR [40] and in the number of TMJ pathologies: autoimmune diseases with TMJ - rheumatoid arthritis and juvenile idiopathic arthritis [41], HFM [11], ICR [42].

9. Conclusion, summary

A stable TMJ without signs of pathology is a basic prerequisite for successful orthognathic surgery. If pathology is present, it is necessary to first address the condition of the TMJ (through conservative, mini-invasive and surgical methods). Only after the condition of the TMJ is stabilized is it possible to surgically address DFD.

In the indicated conditions (reduced joint function due to pathological changes of the condyle, reduction of condyle height due to pathological processes in the TMJ, absence of the condyle, TMJ ankylosis or previous unsatisfactory surgical therapy), it is necessary to replace joint structures. Allogeneic patient-fitted prostheses are ideally used for TMJ reconstruction, as the shape of these prostheses allows the lower jaw to be moved to the appropriate position.

Orthognathic surgery in conjunction with TJR is performed in a single operation, where precise planning of these surgical procedures is vital for their successful execution. The patient’s cooperation during postoperative care is also an integral part of successful orthognathic surgery with TJR.

Personal thanks

Authors thank to Medika Trade Praha for support.