Retraction force necessary to expose the mandibular neck in Risdon and high cervical anteroparotid transmasseteric approaches: an anatomic comparative study

Modified Preauricular Transparotid Approach for Treating Mandibular Condylar Fractures

AIM OF THE STUDY

We introduce a technical variant of the standard preauricular approach to treat intracapsular and condylar neck fractures: the modified preauricular transparotid approach (MPTA). The main modification, when compared with the conventional submandibular approach, is that the incision of the superficial musculoaponeurotic system is performed directly above the parotid gland, and the buccal branch of the facial nerve is dissected in a retrograde way within the parotid gland.

CASE SERIES

Between January 2019 and December 2020 at the Maxillofacial Departments of "Ospedale Maggiore" of Parma and "Policlinico San Martino" of Genoa 6 patients affected by intracapsular and condylar neck fractures underwent open reduction and internal with MPTA. Surgery was uneventful in all patients; no infections occurred in any of the cases; the mean procedure duration was 85 minutes, ranging from 75 to 115 minutes. At the 1-year follow-up, all patients had stable occlusion with a natural, well-balanced morphology of the face and adequate dynamic excursion of the mandible.

CONCLUSION

MPTA is particularly suited for intracapsular and condylar neck fractures. Morbidity is negligible in terms of damage to the facial nerve, vascular injuries, and esthetic deformity.

Postoperative Complications following Open Reduction and Rigid Internal Fixation of Mandibular Condylar Fracture Using the High Perimandibular Approach

The high perimandibular approach is a feasible surgical technique for treating mandibular condylar fractures with open reduction and internal fixation, followed by fewer complications. Temporary trismus is the only postoperative complication that may occur. This study evaluated postoperative complications following open reduction and rigid internal fixation (OR-IF) of mandibular condylar fractures using the high perimandibular approach. Twenty consecutive patients undergoing OR-IF were included in this study. They included 11 male and 9 female patients, of an average age of 58.5 years, all of whom responded to a follow-up call at least 12 months after the surgery. All patients were evaluated for range of mouth opening, postoperative complications, and radiological findings. A statistical analysis of the relationship between range of mouth opening and related clinical parameters at 6 months postoperative evaluation was conducted. The fracture of the condylar neck was associated with a limited range of mouth opening and longer operation time. However, longer operation time was not associated with a limited range of mouth opening. The high perimandibular approach with OR-IF in mandibular condylar fractures is a feasible and safe technique; however, prolonged surgery and mandibular condylar neck fractures could affect the postoperative range of mouth opening.

Analysis of the High Submandibular Approach: A Critical Reapprasail of a Transfacial Access to the Mandibular Skeleton

AIM

In 2006 following the development of dedicated osteosynthesis plates, Meyer and colleagues reported a successful clinical study of condylar fractures treated by a modified submandibular approach; it was called high submandibular approach or "Strasbourg approach." The aim of this study is to describe the high submandibular approach step by step.

CASE SERIES

Between January 2010 and December 2015 at the Maxillofacial Unit of the Hospital "Policlinico San Martino" 13 patients affected by subcondylar fracture underwent open reduction and internal with high submandibular approach. Surgery was uneventful in all patients; no infections occurred in any of the cases; the mean procedure duration was 89 minutes, ranging from 66 to 125 minutes. The mean hospital stay was 2.9 days, ranging from 2 to 6 days. At the 1-year follow-up, all patients had stable occlusion with a natural, well-balanced morphology of the face and adequate dynamic excursion of the mandible.

CONCLUSIONS

The morbidity is negligible in terms of damage to the facial nerve, vascular injuries, and aesthetic deformity. The authors think that further prospective clinical trials are necessary to assess and eventually develop this approach.

Preauricular anteroparotid transmasseteric approach of the mandibular condyle: The natural evolution after cervical dissections? An anatomical feasibility study

The purpose of this study was to evaluate the reliability and reproducibility of a novel approach for base and neck fractures of the mandible. An anatomical study was conducted on 22 given to Science subjects. A rhytidectomy-like approach was performed, followed by a transmasseteric anteroparotid dissection. Measures were taken of the incision length and bone exposure at every step. The identification of a ramus of the facial nerve during dissection was noted. The subjects were classified according to their facial adiposity. A correlation coefficient was measured between incision length and bone exposure as well as morphotype and bone exposure. Statistical analysis was carried out using the Pearson method for linear correlation, and Chi2 test for further analysis. Adequate condylar exposure was always achieved in the area of interest (i.e. in the main localization of base and neck fractures). There was no correlation between the length of the cranial cutaneous backcut and the bone exposure horizontally (p = 0.3296) or vertically (p = 0.8382). There was no correlation between the total length of the incision and the bone exposure horizontally (p = 0.5171) or vertically (p = 0.8404). There was a significant correlation between the subjects' facial adiposity and the bone exposure horizontally and vertically (p<0.005). This approach allowed adequate bone exposure to the mandible base and neck, with a possible 90° angulation of instruments for optimal bone fixation. The incidence of facial nerve rami identification during dissection was similar to other approaches. The scarring was hidden. These results allowed us to propose this approach in a clinical study.

The high sub-mandibular approach: Our experience about 496 procedures

INTRODUCTION

The potential drawbacks of surgical approaches to neck and base fractures of the mandibular condyle (visible scare, facial nerve injury) are still considered by many surgeons as a brake for open reduction and internal fixation. The aim of our study was to analyze the results in terms of access, scare quality and complications that could be noticed in a 12 years period of time with the use of the high sub-mandibular approach (HSMA) we first described in 2006 for the surgical treatment of neck and base fractures.

MATERIAL AND METHOD

All the files of patients operated on for condylar neck and base fractures approached by mean of a HSMA between January 2006 and December 2018 in our department and containing information concerning age, sex, type of fracture, kind of osteosynthesis material, operating time, name of the surgeon, postoperative complication linked to the approach, scare quality at 6 months follow-up at least were included. The skin incision and the dissection planes followed the original publication of Meyer et al. in 2006.

RESULTS

434 patients (sex ratio: 2.06, mean age: 32, 496 approaches) met the inclusion criteria. Following the AO classification, 21.2% of the fractures were classified as neck fractures and 78.8% as base fractures. 97.6% of all fractures were stabilized by mean of a 3D plate (TCP® plate, Medartis, Basel-CH), the remaining ones by mean of a combination of 1.2, 1.5 and 2.0 straight plates. Mean operating time was 40minutes per side. Patients were operated on by senior surgeons in 71.7% of the cases and by trainees under supervision for the others. Concerning the complications linked to the approach, we noticed 11 (2.2%) temporary (0 definitive) paresis of the facial nerve, 1 (0.2%) hematoma and 1 (0.2%) abscess that both needed revision. Scare was hypertrophic or considered as unaesthetic by the patient in 5 cases (1%).

DISCUSSION

The HSMA, if performed as initially described, is a safe and quick procedure compared to other cutaneous approaches. It gives access to all base fractures and to most of neck fractures. The very low rate of facial nerve complications is mainly explained by the plane by plane dissection making it very easy to avoid the facial nerve branches or to check them when encountered. The HSMA is particularly suited to the use of TCP plates as the upper holes of these plates, placed horizontally, are easy to reach from below. The HSMA is therefore still our preferred cutaneous approach to the condylar process.

Surgical approaches for condylar fractures related to facial nerve injury: deep versus superficial dissection

The aim of this study was to investigate the probability of facial nerve injury (FNI) in the treatment of condylar neck and subcondylar fractures (CN/SCFs) with percutaneous approaches and to identify factors predicting FNI. The data of 80 patients with 87 CN/SCFs were evaluated retrospectively. The primary outcome was FNI occurrence. The predictor variables were age, sex, aetiology, alcohol consumption, fracture site and pattern (dislocation or not), concomitant fractures, time interval to surgery, surgeon experience, plate type, and the dual classification of percutaneous approaches. The approaches were classified based on whether subcutaneous dissection traversed the marginal mandibular branch (MMB) deeply (deep group: submandibular and retroparotid approaches) or superficially (superficial group: transparotid, transmasseteric anteroparotid (TMAP), and high cervical-TMAP approaches). Twenty-two patients (27.5%) suffered FNI, of whom two in the deep group had permanent paralysis of the MMB. In the multivariate logistic regression model, deeply traversing surgery approaches (odds ratio 12.4, P=0.025) and the presence of a dislocated fracture (odds ratio 6.66, P=0.012) were associated with an increased risk of FNI. These results suggest that percutaneous approaches in the superficial group should be recommended for the treatment of CN/SCFs to reduce the risk of FNI.

Mandibular subcondylar fracture accessibility with transparotid approach by rhytidectomy and modified Risdon approach: An anatomical comparative study

PURPOSE

The purpose of our anatomical study was to compare the accessibility of the area at the level of the neck of the condyle and the condylar head by two different approaches: the modified Risdon approach and a transparotid approach by rhytidectomy (TPAR).

METHODS

An anatomical study was performed on 12 heads of cadavers preserved with a solution rich in glycerin and ethanol, but very low in formalin. A modified Risdon approach and a TPAR were each performed on a hemiface of the same head. The bone surface was rendered digitally accessible on an anatomical diagram using Image J software. The software was used to determine a concordance score between the area of accessibility and the area of interest necessary for osteosynthesis of a high subcondylar fracture. This score was presented as a numerical scale from 0 to 100. We measured the total number of pixels in our area of interest and assigned it a score of 100. We then compared the area of accessibility with the area of interest necessary for osteosynthesis of a high subcondylar fracture.

RESULTS

Using the modified Risdon approach, an average score of 55.88 (SD = 18.96) was found, or 55.88% of the accessible area of interest. Using TPAR, we found a score of 91.05 (SD = 7.95) or 91.05% of the accessible area of interest. This difference in score between the two techniques was significantly different (p < 0.001), taking into account intra-hemiface and intra-individual correlation.

CONCLUSION

TPAR seems to be more effective in treating high condylar process fractures of the mandible.