La voie d’abord sous-angulo-mandibulaire haute (voie de Risdon modifiée) pour le traitement des fractures sous-condyliennes de la mandibule

The "low preauricular" transmasseteric anteroparotid (TMAP) technique as a standard way to treat extracapsular condylar fractures

Condylar fracture treatment is a debated topic among maxillofacial surgeons. Various surgical techniques are used today, each one with advantages and disadvantages. The aim of this study is to present and evaluate our technique adopted for treatment of any type of extracapsular condylar fractures. Between 2020 and 2022, 16 condylar fractures were treated. In two patients with bilateral condylar fractures, the present technique was compared to the mini-retromandibular approach. All the patients were checked for clinical and radiological outcomes, facial nerve injury, scar visibility and presence of salivary complications. Dental occlusion was always restored, and facial nerve damage or salivary disorders were not observed. The skin incision, limited to the caudal two-thirds of the auricle, made the scar almost invisible and greatly improved the surgical field in the condylar neck area, facilitating the treatment. The proposed technique provides easier internal fixation for both neck and base condylar fractures with good cosmetic results, ensuring better protection of the facial nerve and parotid gland. The surgical technique described has not shown disadvantages in terms of operational difficulty, results, and complications. This novel surgical technique could represent a new choice in the treatment of extracapsular condylar fractures, although further studies are needed to support this new proposal.

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.

Modified high-submandibular appraoch for open reduction and internal fixation of condylar fracture: case series report

OBJECTIVES

Recently a modified high-submandibular approach (HSMA) has been introduced for treatment of condylar fracture. This approach involves an incision line close to the mandibular angle and transmasseteric transection, leading to a low incidence of facial palsy and allowing good visualization of the condyle area, especially the condylar neck and subcondyle positions. This study reports several cases managed with this modified HSMA technique for treating condylar fractures.

MATERIALS AND METHODS

Six cases of condylar fractures treated with modified HSMA technique were reviewed.

RESULTS

Three unilateral subcondylar fracture, 1 bilateral subcondylar fracture, 1 unilateral condylar neck fracture, 1 unlateral simultaneous condylar neck and subcondylar fracture cases were reviewed. All the cases were successfully treated without any major complication.

CONCLUSION

Reduction, fixation, and osteosynthesis of condylar fractures via the modified HSMA technique enabled effective and stable treatment outcomes. Therefore, the described approach can be used especially for subcondylar and condylar neck fractures with minimal complications.

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.

Wound of the Parotid Duct Following a Subcondylar Fracture

Salivary gland and duct complications following surgical approaches to condylar fractures are well known, particularly in approaches requiring parotid tissue dissection. We report a rare case of a parotid duct wound caused by the fracture itself and due to a lateral displacement of the condylar fragment. Four days after the surgical management of a trifocal mandibular fracture (head fracture on the left side, laterally displaced condylar base and angular fracture on the right side) the patient presented with a fluctuating subcutaneous swelling in the right cheek, evoking a sialocele. The sialography showed a massive leak of iodinated contrast medium just in front of the parotid hilum, joining the subcutaneous undermining made during the approach and confirmed the diagnosis of a parotid duct wound. A pressure dressing was applied to the right mandibular angle for 2 weeks, allowing for complete remission. In conclusion, this unusual clinical case illustrates the fact that the parotid duct may be endangered in the event of condylar base fractures, not only by the surgical approach but also by the fracture itself, especially when there is severe lateral displacement.

The high subangulomandibular approach for condylar fractures of the mandible

Introduction

The approaches to mandibular condyle fractures are described in the literature in an abbreviated manner. Their complications, especially facial nerve damage, have limited the surgical indication.

Presentation of case

Through this clinical case, we reported the way and the interest of using a twisted steel wire to increase the visibility of the fracture site and facilitate the reduction of even the highest localized fractures.

Discussion

The high subangulomandibular approach remains a safe approach, with less risk of facial nerve injury if the planes are respected and the facial nerve is avoided if encountered. Nevertheless, this approach is indicated in low condylar and some neck fractures.

Conclusion

Given the benefits of this approach compared to other techniques, we recommend its use.

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The high subangulomandibular approach has been proven to be superior to other approaches for mandibular condyle fractures.

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The majority of surgeons practice this route only for low condylar fractures and using 3D plates.

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With the help of traction of the ramus by a twisted steel wire, this route can be used for all subcondylar fractures, even the most difficult and highest.

Revisiting the sub-mandibular approach with a modified incision

Angle of mandible has been long plagued throughout the history for being one of the most common places of facial bone fracture and also related complications if not treated properly. Hereby, two cases of fracture of angle of mandible those were surgically treated with an aim to modify existing extra-oral approaches specifically for treating the mandibular angle fractures for the purpose of open reduction and internal fixation so as to have a good access combined with an aesthetic and inconspicuous scar postoperatively are described. Also, an attempt is made to add one more type of incision to many existing ones so that future surgeons can choose over which best suits their procedure and as an addition to the ever-increasing literature. There is no doubt that meticulous surgical procedure and experience is needed to identify the structures, to stay in the plane of desire and work in comparatively bloodless field. Hence this approach can be bit challenging for newer surgeons. Nonetheless, the result after the closure of the field is quite rewarding.

Previously Reported Approach Now Used for Temporomandibular Joint Replacement

Over time, different techniques have been described to obtain broad access to the temporomandibular joint (TMJ), in order to allow good visibility, minimizing post-operative complications at the same time. Most of these techniques have been very useful to perform joint replacement using custom made prostheses, varying in its extension, aesthetics and functional results. The aim of this study was to present the authors' experience using the Blair approach modified by Fernández in 2015, to replace failed TMJ prostheses, when distortion of the surgical reference points has occurred.

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.

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.

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

PURPOSE

The purpose of this anatomic study was to compare the retraction force necessary to expose the mandibular neck in the Risdon and the high cervical anteroparotid transmasseteric (HAT) approaches.

METHODS

An anatomic study was performed on 18 formalin-embalmed cadavers. We performed a Risdon approach on the left side, and an HAT approach on the right side in all the cases. The subjects were placed in a normative frame and the force necessary to maintain a satisfactory exposure of the condyle was measured with a system of cables, pulleys, and mechanical dynamometer. The statistical comparison between the two sides was carried out using the Wilcoxon signed-rank test for paired series.

RESULTS

In all the cases, the region of interest was exposed as in the operating room. In the Risdon approach, the mean force was 32 Newtons (4-47). In the HAT approach, the mean force was 19 Newtons (4-33). The difference was statistically significant (p < 0.001). The age, gender, and duration of conservation had no influence on the retraction force.

CONCLUSION

In the HAT approach, the retraction of the soft tissues was significantly lower than in the Risdon approach. This study gave an additional explanation to the remarkable safety of the HAT approach. Our results were in favor of the generalization of this technique.

Relationship between facial nerve damage and transbuccal trocar placement: an anatomical cohort study

The surgical treatment of ramus and mandibular angle fractures is typically performed by intraoral and transbuccal approaches. As these approaches may result in nerve damage, this anatomical study was performed to establish the relationship between the transbuccal trocar position and the likelihood of inducing facial nerve damage. Twenty dissections of the parotid regions were performed after a simulation of surgical approaches aimed at addressing mandibular condylar and angle fractures. Two trocar tubes, ramic and angular, were inserted and left in position throughout the dissection. This procedure allowed the qualitative relationship between the various tube positions and facial nerve damage to be analyzed. The potential risk of contact between the ramic trocar and the facial nerve branches was 90%, while the angular trocar was in contact in 45% of cases. There was no contact with the trunk, cervicofacial division, or temporofacial division of the facial nerve. The contacts occurred at the level of secondary division branches, particularly pronounced for superior and inferior buccal branches, despite the absence of macroscopically visible trauma. Based on these findings, it is proposed that trocars should be used in procedures aimed at addressing subcondylar or angle fractures of the mandible.

Epidemiology and treatment outcome of surgically treated mandibular condyle fractures. A five years retrospective study

Surgical management of mandibular condyle fractures is still controversial. Although it provides better outcome than closed treatment questions still remain about the surgical approach and the osteosynthesis devices to be used. Between 2005 and 2010, we managed 168 mandibular condyle fractures with open treatment. Two surgical approaches were used in this study, a pre-auricular and a high submandibular approach (one or the other or as a combined approach). Internal fixation was performed using TCP(®) plates (Medartis, Basel, Switzerland) or with two lag screws (15 and 17 mm). Delta plates were used in 15 cases (8.9%). We report the epidemiology of these fractures and the outcomes of the surgical treatment. We assessed the complications related to the surgical procedure and those related to the osteosynthesis material. The facial nerve related complication rate was very low and the osteosynthesis materials used proved to be strong enough to realize a stable fixation. The two approaches used in this study appeared to be safe with good aesthetic results. Most of the surgical procedure failures occurred in high subcondylar fractures especially when bilateral.

[Modified Risdon approach for non-traumatic ramus surgery]

INTRODUCTION

The Risdon modified approach, for mandibular surgery, is well adapted to treatment of low subcondylar fractures. According to our experience, this approach with a low rate of complications should also be considered for non-traumatic ramus surgery.

MATERIAL AND METHODS

Twenty Risdon modified approaches were used in 11 patients for non-traumatic indications (seven bilateral osteotomies, four unilateral osteotomies, one biopsy, one bone graft). One patient was operated twice with the same approach.

RESULTS

In all cases, the planned surgery could be performed using this approach. The only complication was a case of temporary paresis of the facial nerve's mandibular branch. The scar was always considered as quite acceptable.

DISCUSSION

As for traumatology, the Risdon modified approach is an improvement for ramus non-traumatic surgery. It has a very low rate of complications, especially for the facial nerve. The intraoral approach avoids scarring, but the resulting exposure is insufficient and requires using a transcutaneous device or endoscopy. In orthognathic surgery, the wide exposure of the lateral aspect of the ramus, the corpus, and the basilar edge, facilitates important mandibular advancement.

Classification of surgical approaches to the mandibular condyle

Published articles on surgical approaches to the mandibular condyle seem to be confusing. We present a classification system that describes and differentiates between surgical approaches to the mandibular condyle and is based on the relation to the facial nerve, height of the approach, and choice of skin incision.

Is the high submandibular transmasseteric approach to the mandibular condyle safe for the inferior buccal branch?

PURPOSE

There are basically 3 main approaches for extra-articular mandibular condyle fractures: low cervical, retromandibular and preauricular. These include a risk of facial palsy affecting the marginal mandibular branch. We use a high submandibular transmasseteric approach featuring masseter section 10-20 mm above the mandibular basilar edge. Our null hypothesis was that both the marginal mandibular and the inferior buccal branches are not more at risk than in other surgical approaches.

METHODS

This study was based on 20 parotidomasseteric dissections from 10 embalmed cadaveric heads. We used as reference the vertical line, passing through the mandibular angle, parallel to the preauricular line. We performed measurements of the marginal mandibular and inferior buccal branches' heights.

RESULTS

The inferior buccal branch had an average height of 16.8 mm and the highest standard deviation (7.2). Extremes were, respectively, 32 and 7 mm. The marginal mandibular branch had an average height of 3.2 mm with standard deviation equal to 3.0. Extremes were, respectively, 9 and -3 mm.

CONCLUSION

The high submandibular transmasseteric approach provides great exposure of facial nerve branches lying on the masseter muscle, if even encountered. Through masseteric incision performed between 10 and 20 mm above the basilar edge of the mandible, the marginal mandibular branch is safe from wound with an added safety margin of 4 mm. The surgeon using this approach is most likely to encounter the inferior buccal branch. It can then be avoided under visual control. This makes it a swift and safe approach to the mandibular condyle.

Clinical experience with osteosynthesis of subcondylar fractures of the mandible using TCP plates

AIM

To evaluate the clinical and radiological results obtained with a new kind of osteosynthesis device (Modus TCP) plates, Medartis, Basel, Switzerland), especially designed for low subcondylar fracture (LSCF) and high subcondylar fracture (HSCF) of the mandible in association with the high submandibular approach (HSMA).

METHOD

A prospective clinical and radiological study was carried out over a 41-month period. All adult patients suffering from a displaced LSCF or HSCF who consented to the surgical treatment were included in the study. All fractures were operated on using an HSMA and were stabilised using a 4- or 9-hole TCP((R)) plate. No intermaxillary fixation was used and a soft diet was started on the 1st postoperative day. Clinical examinations and control X-rays were carried out on the 10th postoperative day, in the 1st, the 3rd and, at least, in the 6th postoperative months.

MATERIAL

Sixty-four patients (12 females, 52 males - mean age: 28.3) with a total of 75 fractures (54 LSCF, 21 HSCF) were included in the study. Mean postoperative follow-up was 14 months.

RESULTS

In the 6th postoperative month, all fractures were consolidated in 79% of the cases in an anatomical position. A secondary displacement of the fracture occurred in 6.6% of the cases. Plate fracture was not observed. Dental occlusion remained unchanged in 94% of the patients. The mandibular movements (mouth opening, protrusion, lateral movements on the unfractured and fractured side) had normal mean values (49.5, 10.4, 12.8, 12.1mm, respectively). These movements were symmetrical in 95% of the patients. No patient complained about articular pain or noise. No facial nerve palsy was noticed, not even a transiently one. All patients but one found the scars acceptable.

CONCLUSION

TCP plates, in association with HSMA, were found to be an efficient osteosynthesis device for stabilising subcondylar fractures.