Transitional joint effusion in the mandibular prognathic surgery patient: intraoral vertical ramus osteotomy versus sagittal split ramus osteotomy

Changes in strain energy density in the temporomandibular joint disk after sagittal split ramus osteotomy using a computed tomography-based finite element model

PURPOSE

We evaluated the changes in the strain energy density (SED) in the temporomandibular joint (TMJ) disk after sagittal split ramus osteotomy (SSRO) at three time points. A finite element model (FEM) based on real patient-based computed tomography (CT) data was used to examine the effect of SSRO on the TMJ.

METHODS

Measurements of the condylar position and angulation in CT images and FEM analyses were performed for 17 patients scheduled to undergo SSROs at the following time points: before surgery, immediately after surgery, and 1 year after surgery. SED on the entire disk was calculated at each of the three time points using FEM. Furthermore, the relationship between individual SED values and the corresponding condylar position was also evaluated.

RESULTS

No significant change was observed in the condylar position at the three time points. The FEM analysis showed that SED was the highest and lowest immediately after and 1 year after surgery, respectively. A possible SED distribution imbalance between the left and right joints was improved 1 year after SSRO. Concerning the effect of fossa morphometry and condylar position, wide and deep glenoid fossae and a more posterior condylar position tended to show lower SED.

CONCLUSION

SED in the articular disk temporarily increased after surgery and significantly decreased 1 year after surgery compared with that before surgery. SSRO generally improved the imbalance between the left and right joints. Thus, SSRO, which improves maxillofacial morphology, may also improve components of temporomandibular disorders.

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

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).

Avoiding condylar displacement after intraoral vertical ramus osteotomy

The intraoral vertical osteotomy is a versatile and simple technique usually applied to correct mandibular prognathism. Its greatest advantages include ease of performance and minimum neurosensory disturbances, whereas maxillomandibular fixation is pointed as its major disadvantage. Another important concern about this technique is condylar displacement, which may lead to temporomandibular dysfunction. Technical notes to avoid condylar luxation are discussed after 15 years of experience using this osteotomy as the technique of choice to correct mandibular prognathism. Three similar cases are presented, where 1 condyle was displaced from the glenoid fossa, resulting in mandibular deviation during function in patients requiring small mandibular setback.