Role of distraction osteogenesis and flip genioplasty to correct sleep apnea and aesthetics in long standing TMJ ankylosis – A case report

Abstract

Introduction and importance

Temporomandibular joint (TMJ) ankylosis triad includes TMJ ankylosis, micrognathia, and obstructive sleep apnea (OSA) which is common in long-standing cases of TMJ ankylosis. Unilateral long-standing cases of TMJ ankylosis also result in a severe discrepancy in the midline of the chin.

Case presentation

A young adult female presented with restricted mouth opening and daylight sleepiness. Her AHI was mild and there was excessive facial disfigurement. Right-side TMJ ankylosis was diagnosed with compromised posterior airway space and Ramal height was also short on the affected side. Chin has severely deviated to the affected side.

Clinical discussion

Treatment protocols for TMJ ankylosis are different for different case scenarios. A proper protocol derivation is a must looking into the clinical and radiographical examination of the patient. As mentioned in previous literature, anti-Kaban's protocol has been shown to provide good results. A genioplasty improves the chin midline deviation.

Conclusion

A careful assessment and a proper treatment plan should be selected for the management and early relief of the symptoms of the patient. Thorough knowledge and update should be available to the operating surgeon to choose the correct treatment plan for the management of a triad patient.

Highlights

• •Temporomandibular joint ankylosis and its management
• •Unilateral TMJ ankylosis and facial discrepancy
• •Drawing of protocol for TMJ ankylosis
• •Horizontally pedicled flip genioplasty for chin midline correction
• •Kaban's and Anti-Kaban's protocol for TMJ ankylosis

1. Introduction

Temporomandibular joint (TMJ) ankylosis is one of the causes of restricted mouth opening [1]. It also affects the growth pattern and development of the mandible and face. This affects a patient's mental and social well-being, especially in females. When TMJ ankylosis occurs in a young population, it causes a TMJ triad. It includes TMJ ankylosis, micrognathia, and obstructive sleep apnea (OSA) [2]. Increasing the posterior airway space along with the release of TMJ ankylosis should be the aim of the treatment of a triad patient. In females, improvement of facial aesthetics should also be considered while drawing up a treatment plan. The article here is formulated according to the SCARE 2020 guidelines checklist [3].

2. Presentation of case

A 25-year-old female reported to the Department of Oral and Maxillofacial Surgery in November 2020. She reports a chief complaint of restricted mouth opening since childhood. The patient also reported gasping and snoring at night. She also had daylight sleepiness, morning headache, and tiredness. The patient was unable to provide an accurate history of trauma or infection of the jaw or face in childhood. There is no family history relevant to the present illness. Also, due to poverty and neglect of the female child, she had no previous treatment consideration for the chief complaint.

On extra-oral examination, no mouth opening was noted. Anatomic differentiation of the right TMJ could not be done on palpation. Facial asymmetry was noted, with the chin deviating towards the right side. A convex profile was recorded, and flattening of the face on the right side was noted (Fig. 1). A deep antegonial notch was palpable on the right side. An orthopantomogram (OPG) was advised as a primary radiographic investigation (Fig. 2). Radiographic examination and cephalometric analysis for orthognathic surgery (COGS) revealed shortening of the right ramus height with distortion of the right TMJ anatomy. Hence, TMJ ankylosis with retrognathic mandible, prognathic maxilla, and a compromised airway with a decreased cervico-mental angle was diagnosed. The apnea-hypopnea index (AHI) was mild.

Fig. 1.

Right profile showing a convex profile of the patient.

Fig. 2.

Preoperative orthopantomogram showing distorted anatomy of right TMJ with deep antegonial notch on the right side.

The patient was scheduled for a two-step surgical procedure. In the first stage of surgery, a linear internal distractor was placed and fixed with screws after osteotomy at the angle region of the affected site. This stage was performed by the second author. Later, after 3 days, the distractor was activated, and a 1 mm distraction was done daily till the desired length was obtained. Distractor was in-situ for 90 postoperative days. In the second stage of the surgery, the ankylotic mass was removed. Alkayat-Bramley's approach was selected because it gives better access to the ankylotic mass [4]. Temporalis fascia-muscle flap was used as an interposition material. Now, the distraction device was removed. Adequate mouth opening was achieved. A horizontally pedicled flip genioplasty was done to correct the chin midline. This stage was performed by the third author.

A radiographic examination was done after 10 months to assess the surgery's outcome (Clavien-Dindo classification grade II). The cervico-mental angle was improved to the normal range (119°) [with COGS] (Fig. 3). The patient was satisfied with the surgical outcome. Sleep apnea was well addressed, as reported by the patient. Currently, she is undergoing orthodontic treatment for the correction of dentoalveolar malocclusion. Another surgical procedure is a must to correct the flattening of the face (Fig. 4).

Fig. 3.

Postoperative COGS analysis showing obtuse cervico-mental angle.

Fig. 4.

Comparison of pre- and postoperative front and lateral profile.

3. Discussion

TMJ ankylosis is a slow-processing pathology caused mostly by some trauma [1]. In infants, the cause of trauma to the TMJ is forceps delivery [5]. With age, the ankylotic mass increases in size. The mouth opening becomes more and more restricted. The anatomy of TMJ gets distorted. Adjacent bony structures like the zygomatic arch, the temporal compartment of TMJ, and the ramus also get affected. When TMJ ankylosis occurs in childhood, it is not the only pathology seen. With increasing age, the development and growth of the mandible are affected. Some other developmental deformities are also reported, such as mandibular retrognathism. This leads to OSA [2].

According to Sawhney's [6] classification, in this case, the TMJ ankylosis was type IV. According to He et al. [7], the classification was A4. Based on this the treatment was planned [8].

The treatment protocol for TMJ ankylosis has changed from only the removal of ankylotic mass to including DO [8]. A variety of interposition tissues has also been used and upgraded promptly. As per various authors, the temporalis muscle fascia flap shows the lowest recurrence rate of all the interposition grafts [9]. The condyle tends to grow forward and downward. Its growth is affected because of ankylosis, leading to more retrognathism of the mandible. This further compromises the posterior airway space [2].

In TMJ ankylosis cases, DO has become popular in the treatment of mandibular retrognathism. Distraction is preferred over costochondral graft, as the surgeon controls the callus formation and advancement of the mandible. Also, the DO corrects the soft tissue defect as it allows the soft tissue musculature to adjust to the new position [10].

Different surgical procedures formulation is reported in the literature for managing TMJ ankylosis [10]^, [11]^, [12]^, [13]^, [14]. The treatment plan of choice here was according to previous literature published in the year 2012 [14]. DO was carried out where the mandibular retrognathism was treated. Hence, the posterior airway space was increased. Then, the ankylotic mass was removed under the protocol for managing TMJ ankylosis [14]. Adequate mouth opening was achieved. To correct the facial asymmetry, horizontal flip pedicled genioplasty was done as mentioned in a previous literature [1].

On the postoperative evaluation of the patient, a satisfactory result was obtained in the mouth opening, obstructive sleep apnea, and facial aesthetics as well from both operator and patient perspective. The cervico-mental angle, which was earlier more acute than the normal range, is now also recorded as more obtuse, i.e., 119°. Hence, the outcome of this case supports the protocol proposed in the previous well-known literature [14]^, [15].

This treatment does not give fullness to the non-affected side. For this, the patient requires another surgery.

4. Conclusion

A triad of TMJ ankylosis, mandibular retrognathism, and obstructive sleep apnea is common in adult patients with long-standing ankylosis. A careful assessment and a proper treatment plan should be chosen for the management and early relief of the patient's symptoms. Thorough knowledge and updates should be available with the operating surgeon to help choose a correct treatment plan.

Patient consent

Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Ethical approval

Ethical approval was waived by the authors' institution.

Funding

Not applicable.

Guarantor

Dr Kalyani Bhate is the guarantor and takes responsibility of the data originality and conduct of study.

Research registration number

N/A.

Credit authorship contribution statement

• Dr. Murtaza Contractor - data collection, manuscript writing

• Dr. Kalyani Bhate - study concept or design, manuscript editing & reviewing

• Dr. Pushkar P. Waknis - data analysis, manuscript editing

• Dr. Sayali Awate - manuscript editing

• Dr. Sherwin Samuel- data analysis, manuscript writing.

Conflict of interest

None.