Micrognathia with temporomandibular joint ankylosis and obstructive sleep apnea treated with mandibular distraction osteogenesis using skeletal anchorage: a case report

Surgical Innovation in Serial Reconstruction of Micrognathia Using Free Fibular Flap: Insights From a Study and Literature Review

BACKGROUND

Free fibular flap (FFF) is the main modality in the reconstruction of maxillofacial defects. Micrognathia is a condition where the mandible is smaller than it should be. Micrognathia is typically treated with mandibular distraction osteogenesis, bilateral sagittal split osteotomy, and conventional costochondral graft. In cases in which these procedures cannot be performed, FFF becomes a suitable alternative. Publications regarding the use of FFF in cases of micrognathia are currently still limited. In this case, we present the use of FFF in the reconstruction of a severely micrognathic mandible in an adult patient.

CASE PRESENTATION

A 28-year-old woman with micrognathia was referred to Dr. Ciptomangunkusumo Hospital for reconstruction. The patient had previously undergone temporomandibular joint (TMJ) reconstruction surgery with interpositional TMJ arthroplasty 10 years prior due to an ankylosing TMJ that prevented the opening of the jaw. The treatment for ankylosing TMJ was necessitated due to the patient's inability to open their mouth, resulting in significant challenges with alimentation, speech, and facial morphology. Here the authors reported mandibular lengthening reconstruction in the anteroposterior axis with FFF. A surgical osteotomy was performed on the posterior segment of the bilateral mandibular ramus, then the segmented fibula was inserted into the resulting defect. Flap refinement was also performed following FFF. Postsurgical evaluation revealed notable enhancements in the patient's esthetic appearance, occlusal function, and amelioration of obstructive sleep apnea symptoms.

CONCLUSIONS

FFF for mandibular reconstruction is feasible and effective in improving esthetic and functional outcomes in patients with micrognathia.

Triad of temporomandibular joint ankylosis, micrognathia, and obstructive sleep apnoea: a systematic review of surgical management

Complex functional issues arising from temporomandibular joint (TMJ) ankylosis are associated with abnormal mandibular growth secondary to the condylar-glenoid fossa and its surrounding structures. These include severe limited mouth opening, micrognathia, mandibular asymmetry, and obstructive sleep apnoea (OSA), which necessitate effective treatment to allow optimum functional rehabilitation. This article aims to present a comprehensive systematic review of the surgical strategy for patients who present with a triad of TMJ ankylosis, micrognathia and OSA via a literature search of PubMed, Google Scholar, and Scopus following PRISMA guidelines. The outcomes of interest were difference in maximum mouth opening, incidence of reankylosis, amount of mandibular advancement, posterior airway space, preoperative and postoperative apnoea/hypopnoea index, and arterial oxygen saturation, as well as changes in other cephalometric or polysomnographic variables. Thirty four studies involving 360 patients were included. Surgical interventions included distraction osteogenesis (DO), release of TMJ ankylosis and mandibular advancement, simultaneous arthroplasty and DO, pre-athroplasty DO, and post-arthroplasty DO. Most studies reported functional post-intervention mouth opening, with reankylosis reported in four. Mandibular advancement was between 6 mm and 34 mm. All studies reported improvement in the various polysomnographic variables measured. In conclusion, the systematic review was conducted based on a low level of literature evidence. Even though various surgical strategies were reported, effective case-specific management of TMJ ankylosis with micrognathia and OSA requires comprehensive assessment and careful consideration of surgical options that promote mandibular advancement and airway improvement.

Distraction osteogenesis promotes temporomandibular joint self-remodeling in the treatment of mandibular deviation caused by condylar ankylosis

Craniofacial deformity and malocclusion are primary concerns following temporomandibular joint ankylosis (TMJa) in growing patients, and they pose even greater challenges in adult patients. The treatment objectives always involve restoring proper jawbone structure, achieving stable occlusion, and attaining satisfactory joint mobility. This report presents a 4-year follow-up of an adult patient with TMJa-induced mandibular deviation, who underwent a combined treatment approach involving distraction osteogenesis (DO) and orthodontic-orthognathic surgery. Orthodontic treatment resulted in favorable occlusion and improved facial esthetics. A new condyle with a reconstructed glenoid fossa in a forward position was established after mandibular DO and the damaged TMJ experienced self-remodeling owing to functional improvement. Thus, this case demonstrates the efficacy of DO in promoting adaptive TMJ self-remodeling with long-term stability when treating mandibular deviation caused by condylar ankylosis in adult patients.

Distraction Osteogenesis as a reliable method in management of Obstructive Sleep Apnoea (OSA) secondary to TMJ Ankylosis: A Case Report

Obstructive sleep apnoea (OSA) is identified as repetitive and intermittent upper airway collapse or narrowing during sleep. Skeletal advancement through maxillomandibular surgery remains the most effective surgical treatment for OSA but is radical with certain relapse rate. Distraction Osteogenesis of mandible is a single-jaw surgical treatment alternative to bi-jaw surgeries having lesser complications. This case report describes successful management of a 46-year-old patient who reported with a chief complain of obstruction in breathing while sleeping since one year. Obstructive Sleep Apnoea (OSA) secondary to a retrognathic mandible was the final diagnosis, which was successfully treated by Distraction Osteogenesis (DO) of the mandible. The case showed enhancement in airway by 13mm and marked forward movement of Point-B (SNB increased by 6 degrees). The Epworth Sleepiness Scale value decreased from 19mm to 8 mm indicating substantial increase in the airway with stable results after 18 months of follow-up (elimination of symptoms and subsequent sound sleep). Distraction osteogenesis is an effective and reliable method to treat obstructive sleep apnoea secondary to retrognathic mandible.

Simultaneous TMJ Ankylosis Release with Uniplanar Mandibular Distraction Osteogenesis for Correction of Facial Deformity and Obstructive Sleep Apnoea in Growing Patients: A Pilot Study

Aim

To evaluate the efficacy of simultaneous TMJ ankylosis (TMJA) release with uniplanar mandibular distraction in the management of facial deformity, improvement in function and obstructive sleep apnoea in growing patients.

Material and Methods

Ten patients in the age group of 5-15 years with unilateral/bilateral TMJA and mild to moderate OSA and short body length but ramus height within normal limits were treated with simultaneous ankylosis release and uniplanar mandibular distraction osteogenesis. Clinical, radiographic, and OSA parameters were evaluated and followed up for 1 year.

Results

Average mandibular body length increased by 16.6 mm, mouth opening by 26.9 mm, SNB angle by 9.53°, pharyngeal airway space by 6.29 mm, chin discrepancy corrected by 5.05 mm, apnoea-Hypopnoea index decreased by 15.9, N┴Pog by 12.27 mm, oxygen saturation (Spo2) by 4.1%, and oxygen desaturation index by 17.89%. All clinical, radiographic, and OSA parameters improved and were statistically significant except for mandibular plane angle and with minimal complications.

Conclusion

Simultaneous TMJA release with uniplanar mandibular Distraction osteogenesis may be recommended as the treatment of choice in growing patients with mild to moderate OSA and facial deformity, as it causes simultaneous correction of micrognathia, facial asymmetry, OSA and prevents the need for an additional surgery.

Pharmacological intervention of the FGF-PTH axis as a potential therapeutic for craniofacial ciliopathies

Ciliopathies represent a disease class characterized by a broad range of phenotypes including polycystic kidneys and skeletal anomalies. Ciliopathic skeletal phenotypes are among the most common and most difficult to treat due to a poor understanding of the pathological mechanisms leading to disease. Using an avian model (talpid2) for a human ciliopathy with both kidney and skeletal anomalies (Orofaciodigital syndrome 14), we identified disruptions in the FGF23-PTH axis that resulted in reduced calcium uptake in the developing mandible and subsequent micrognathia. While pharmacological intervention with the FDA-approved pan-FGFR inhibitor AZD4547 alone rescued expression of the FGF target Sprouty2, it did not significantly rescue micrognathia. In contrast, treatment with a cocktail of AZD4547 and Teriparatide acetate, a PTH agonist and FDA-approved treatment for osteoporosis, resulted in a molecular, cellular, and phenotypic rescue of ciliopathic micrognathia in talpid2 mutants. Together, these data provide novel insight into pathological molecular mechanisms associated with ciliopathic skeletal phenotypes and a potential therapeutic strategy for a pleiotropic disease class with limited to no treatment options.

Sequential treatment of unilateral temporo-mandibular joint ankylosis with distraction osteogenesis - a case report

Temporo-mandibular joint (TMJ) ankylosis is a common cause of acquired mandibular deformity in children and adults. It causes reduced mouth opening and limitation of functional movements resulting in mandibular growth impairment leading to mandibular retrognathism and facial asymmetry. The treatment of TMJ ankylosis is challenging, not only due to the complexities involved and the risk of relapse but also because it requires a high degree of patient cooperation. The treatment may be performed in 1 or 2 phases consisting of the initial release of ankylosis with or without condylar reconstruction, followed by a correction of mandibular hypoplasia and of facial asymmetry by orthognathic surgery. Distraction osteogenesis has been proposed to treat cases with severe deformity due to its inherent advantages of generating new bone and soft tissue. This case report describes the staged treatment of a patient with unilateral TMJ ankylosis. The patient presented with significant facial deformity due to mandibular retrognathism and facial asymmetry as a consequence of impaired growth. The treatment objectives included releasing ankylosis to establish mouth opening, addressing the dentofacial deformity and achieving a normal occlusion. The patient was treated with a combined surgical-orthodontic approach including distraction osteogenesis. The case was treated with a rigid external distractor and CBCT generated facial models were used to plan and execute adjunctive surgeries. The staged treatment approach resulted in a significant improvement of facial aesthetics.

Temporomandibular Joint Ankylosis Leading to Obstructive Sleep Apnea

Temporomandibular joint ankylosis in children commonly lead to difficulty in feeding, poor oral hygiene, retrognathic mandible and obstructive sleep apnea. Surgical release of the ankylosis has always been the standard treatment. The authors report a 12 year old boy with unilateral temporomandibular joint ankylosis and obstructive sleep apnea underwent surgical release of the ankylosis with successful gain in mouth opening. However, he continued to suffer from obstructive sleep apnea as confirmed by post-operative polysomnography. Orthognathic surgery for mandibular advancement is not favorable due to his young age and mandibular distraction osteogenesis was not a choice. A mandibular advancement device similar to orthodontic myofunctional appliance was the preferred choice in the post-operative period while waiting for definitive retrognathia surgical treatment after skeletal maturity. Surgical release of temporomandibular joint ankylosis corrects the oral problem but does not adequately address the narrow pharyngeal airway space. Assessment of pharyngeal airway with a high suspicion of obstructive sleep apnea is mandatory in the management of TMJ ankylosis.