Planning for combined TMJ arthroplasty and orthognathic surgery

Methods of Definitive Correction of Mandibular Deformity in Hemimandibular Hyperplasia Based on Radiological, Anatomical, and Topographical Measurements-Proposition of Author's Own Protocol

In order to fully evaluate and establish the degree of bone overgrowth, various radiological studies are essential in the careful planning of the amount of surgical excision. In the presented paper, the authors use self-designed anatomo-topographical reference points for planning the surgeries. Routine panoramic radiographs and low-dose computed tomography based on anatomical landmarks help in measuring the proportions of mandibular bone overgrowth with the following preoperative anatomical landmarks: (Go-Go), (Go(Right)-Gn), (Go(Left)-Gn), and (Me−Gn). Measurements taken at selected points and landmarks (gonion-gnathion/gnathion-menton) are easy to conduct. In the authors’ proposal, the main key factor is total chin correction, which is necessary in cases of severe overgrowth; when F0 > C and Go-Gn>, there is >7 mm of vertical bone overgrowth, and the mandibular canal is positioned <5 mm from the inferior mandibular border—MIB. Larger overgrowths (>7 mm) have a greater outcome on the final symmetry than smaller overgrowths. As no guidelines are known, the authors present their own proposal.

Protocol for fully digital and customized management of concomitant temporomandibular joint replacement and orthognathic surgery

End-stage temporomandibular joint (TMJ) disease is caused by a multitude of pathological processes that impair TMJ anatomy and function. In many cases, end-stage TMJ disease and dentofacial skeletal deformities coexist. The optimal treatment for such conditions is total alloplastic joint replacement and orthognathic surgery. Such procedures have historically been conducted in two separate stages. Furthermore, while technological improvements resulting from the widespread adoption of virtual reality initially led to significant improvements in the field of orthognathic planning, the adoption of virtual design techniques to optimize TMJ reconstruction was a later achievement. Therefore, planning for TMJ replacement and orthognathic surgery did not develop in parallel, leading to various combinations of planning for orthognathic surgery and TMJ replacement with the aim of performing both procedures simultaneously in one stage. Nowadays, improvements in virtual planning and three-dimensional printing have allowed these procedures to be conducted in the same surgical step based on fully digital planning and entirely customized surgery. This paper introduces a fully digital protocol for the treatment of end-stage TMJ disease and associated acquired dentofacial deformities, in which all surgical steps are customized and the whole surgery is performed in succession using automated procedures, thanks to the combined use of virtual surgical planning, surgical guides, custom-designed TMJ prostheses, and patient-fitted osteosynthesis devices.

Anatomical and Clinical Implications in Neocondyle Stability After a Condylectomy

: A condylectomy of the mandibular condyle is considered to be the treatment of choice in most cases of condylar head hyperactivity. The aim of the procedure is to remove the growth center of the mandible which is responsible for the mandibular enlargement and asymmetry. This surgical procedure has an impact on the condyle shape and position, but the restoration of mandibular movement and a stable joint position (namely, the proper alignment of the newly shaped condylar head within the condyle fossa) should also be considered important surgical outcomes. In this article, the authors present their own experience in performing condylectomies with an arthroplasty procedure and a special forced suturing technique (FST) in terms of achieving early, accurate mandibular movement and maintaining a stable condyle position in early and late outcomes.

MATERIALS AND METHODS

A modified high condylectomy with arthroplasty and FST results had been studied in anatomical, radiological, and clinical model.

RESULTS

Early findings after FST are promising. A slight improvement in lateral jaw movement was noted after condylectomy with arthroplasty (P < 0.05) both in early and late follow-up. Incisal opening, mandibular protrusion, and lateral movement were sustained. A stable condyle position within the fossa was achieved in each case of condylectomy with arthroplasty (P < 0.05).

CONCLUSIONS

The FST condylectomy and reattachment of the lateral pterygoid muscle in a new, wider position provided an improvement in lateral jaw movement as well as in incisal opening and mandibular protrusion in early follow-up examination compared to the presurgical values. It seems that the FST enabled a better new condylar head position in the glenoid fossa and improved early functional mandibular movement.

Combined or Staged Temporomandibular Joint and Orthognathic Surgery for Patients with Internal Derangement and Dentofacial Deformities

Patients with internal derangement of the temporomandibular joint and dentofacial deformities need appropriate evaluation for both conditions. Correct diagnosis of internal derangement is vital in determining the correct orthognathic surgery plan, and it is particularly important to differentiate between myofascial dysfunction and intra-articular joint problems. Depending on the stage of internal derangement, patients may need treatment for temporomandibular dysfunction symptomatically, staged, or concurrently with orthognathic surgery.

Facial asymmetry: a current review

The term "asymmetry" is used to make reference to dissimilarity between homologous elements, altering the balance between structures. Facial asymmetry is common in the overall population and is often presented subclinically. Nevertheless, on occasion, significant facial asymmetry results not only in functional, but also esthetic issues. Under these conditions, its etiology should be carefully investigated in order to achieve an adequate treatment plan. Facial asymmetry assessment comprises patient's first interview, extra- as well as intraoral clinical examination, and supplementary imaging examination. Subsequent asymmetry treatment depends on patient's age, the etiology of the condition and on the degree of disharmony, and might include from asymmetrical orthodontic mechanics to orthognathic surgery. Thus, the present study aims at addressing important aspects to be considered by the orthodontist reaching an accurate diagnosis and treatment plan of facial asymmetry, in addition to reporting treatment of some patients carriers of such challenging disharmony.

Computer-assisted surgical planning and simulation for unilateral condylar benign lesions causing facial asymmetry

OBJECTIVE

The purpose of this study was to investigate the best surgical sequence for the treatment of unilateral condylar benign lesions causing facial asymmetry by applying computer-assisted surgical planning and simulation.

STUDY DESIGN

Computed tomography (CT) data from 12 patients whose maxillary cant was corrected by maintaining the vertical position of the central incisors and equally intruding the long side of the maxilla and extruding the short side were analyzed by ProPlan CMF 1.4 software (Materialise Medical, Leuven, Belgium). Condylectomy and double jaw orthognathic surgery with 2 different surgical sequences were simulated: 1) maxillary LeFort I osteotomy first (MaxF), then condylectomy, followed by bilateral sagittal split ramus osteotomy (BSSO); and 2) mandible first (ManF), beginning with condylectomy, then BSSO, and lastly LeFort I osteotomy. The greatest space between the maxillary and mandibular first molar in the interim positions was measured virtually to compare the 2 surgical sequences.

RESULTS

The vertical distance between the upper and lower teeth of ManF patients was significantly smaller than that of MaxF patients (mean 2.99 mm, P < .001).

CONCLUSION

When occlusal cants are corrected by equally intruding one side and extruding the other side of the maxillary dentition, the interim position is more conducive to sequencing corrective surgery by performing condylectomy, then BSSO, followed by Le Fort I osteotomy.

Idiopathic intracranial hypertension eliminated by counterclockwise maxillomandibular advancement: a case report

INTRODUCTION

Obstructive sleep apnea (OSA) is a secondary cause of intracranial hypertension (IH). Decreased jugular venous drainage has been seen in patients with idiopathic IH.

CLINICAL PRESENTATION

A complex case of a 48-year-old female whose idiopathic IH was put into remission after counterclockwise maxillomandibular advancement (CC-MMA), despite persistence of her OSA.

CONCLUSION

This case highlights the relationship between OSA and IH and points to the significant morbidity that can result from mild OSA and from what are considered borderline intracranial pressures. This indicates the need for a high index of suspicion for actual underlying pathology that can be surgically corrected when patients manifest symptoms of a somatic syndrome. This is the first report in the medical literature of clinical elimination of IH by CC-MMA. The authors propose that this positive outcome was effected via mandibular advancement producing a decrease in jugular venous resistance, allowing improved absorption of cerebrospinal fluid.