Assessment of a New Medical Device (PirifixTM) for Positioning and Maintaining the Upper Dental Arch during Le Fort I Osteotomy.

INTRODUCTION: Several medical devices (MDs) are used to assist surgeons in positioning the upper dental arch (UDA) during Le Fort I osteotomies (LFIOs). Some only allow holding, others only positioning. This study aimed to assess the accuracy of a new MD (PirifixTM) coupling these two functions during LFIO on 3D-printed models. MATERIALS AND METHODS: DICOM data were selected from patients who underwent surgical planning for LFIO between 27 July 2020 and 1 December 2022. Their anatomy was reproduced after segmentation, planning, and stereolithography in two models. Each model was assigned to one of two surgical groups: the control group (positioning by occlusal splint) and the PirifixTM group. Each patient's model was planned with the objective of horizontalizing and recentering the UDA. After positioning, models were digitalized using Einscan Pro 2X and compared to the planned model with CloudCompare. The statistical analysis was performed using the Wilcoxon Mann-Whitney test. The result was considered significant if the p-value was less than 0.05. RESULTS: Twenty-one patients were selected. Forty-two anatomical models were 3D-printed. The mean difference compared to the planned and corrected positions was 0.69 mm for the control group and 0.84 mm for the PirifixTM group (p = 0.036). CONCLUSION: PirifixTM may be a new alternative to available MDs. Further investigations are needed to describe the relationship between the device and facial soft tissues.

Persistent myogenic temporomandibular disorders: Are navigation-guided botulinum toxin-A injections into the lateral pterygoid muscles effective?

BACKGROUND: Botulinum toxin has proven effective in treating persistent myogenous temporomandibular disorders (M-TMDs) unresponsive to conservative therapies. While the usual injection sites are the masseter and temporalis muscles, the deeper lateral pterygoid muscle (LPM) is often overlooked due to its difficulty of access and the risk of local complications. This study aims to evaluate the effectiveness of botulinum toxin-A injections (BTX-A) in the LPM with MR-guided navigation of patients with persistent M-TMDs. METHODS: This retrospective study enrolled 34 patients suffering from M-TMDs despite conservative therapies with a total of 51 injection sessions. All of them were treated by BTX-A injections in the LPM using MR-guided navigation, masseter and temporalis with clinical guidance. The effectiveness of the treatment was evaluated with measures of maximum pain-intensity scores of breakthrough and background pain, maximal interincisal mouth opening (MIO), and the presence of joint sounds. The assessment was conducted before injections, and subsequently, at 1 and 3 months postoperatively. Adverse events and perception of improvement with the treatment were also reported for each injection sessions. RESULTS: BTX-A injections in the LPM significantly improved pain scores intensity with a reduction of 65 % and 49 % respectively at the 1- and 3-month follow-ups, with peak effectiveness at 1 month. This study showed also a statistically significant improvement in mean MIO at 3 months post-injection and a decrease in joint sounds with persistence in 9,7 % of cases at 3-month follow-up compared to 41,2 % at baseline. No significant adverse events were observed. Patients treated with BTX-A injections in the LPM had a subjective complete improvement in their perception of treatment efficacy in 63 % of cases at the end of the follow-up period. CONCLUSIONS: This study reports clinical experience on the use of MR-guided navigation to perform accurate, reliable, and safe BTX-A injections in the LPM. Although our results appear to be encouraging regarding symptom improvement of patients suffering from persistent M-TMDs, this approach may not be feasible as a primary standard procedure for managing M-TMDs. Further research is necessary to explore potential reproducible, safe, and cost-effective alternatives to enhance the accessibility of the LPM in clinical practice.

Contribution of anatomical criteria to surgical approach for treatment of bilateral coronoid hyperplasia.

INTRODUCTION: Bilateral coronoid hyperplasia is a rare condition characterized by a progressive and painless limitation of mouth opening. The treatment consists of coronoidectomy by intraoral or coronal approach. There is no recommendation in the literature on the choice of the surgical approach according to the importance of the hypertrophy. The objective of our study is to search for predictive anatomical criteria of each approach. MATERIAL AND METHODS: These anatomical criteria were evaluated from 3D CT facial reconstructions of 4 male patients aged 4 to 30 years retrospectively after their surgery. A single intraoral approach was used for cases 1 and 2 (group A), a double approach for cases 3 and 4 (group B). Same measurements were performed on 10 male case controls (group C). We performed a descriptive analysis of our results due to an insufficient number of patients. RESULTS: The average width of the coronal processes was much greater in group B, when a double approach was necessary, than in groups A and C. In groups A and B, the average height of the coronoid notch is low compared to group C when there is a need for a coronal approach. The width/TZS ratio is increased in group B compared to group C. DISCUSSION: In our study, 3 criteria could be informative for the choice of the surgical approach: the width at the superior end of the coronoid process, the width/TZS ratio and the height of the coronoid notch but additional data are needed to confirm our therapeutic options.

Iatrogenic displacement of an impacted third maxillary molar in the parapharyngeal space: A case report.

Accidental iatrogenic displacement of third molars in peripheral soft tissues is a major intraoperative complication, but is considered rare. A young women reported discomfort during mandibular lateral movements since she underwent the extraction her impacted third molars under general anesthesia, 2 years before. The clinical examination was not specific except for a laterality limitation of the right mandibular movements. The germ of 28 appeared radiologically encapsulated in the peripheral muscle tissues in the left parapharyngeal space and showed no signs of ankylosis. After measurement of the benefit-risk balance the surgical extraction of the foreign body has been successfully carried out. After 6 weeks the patient was able to regain bilateral symmetrical mandibular laterality movements. It appeared that tooth 28 was interfering with the movements of the manducatory function, either by obstructing the mandibular path, and/or by irritating the pterygoid muscles or other peripheral tissues .

Characterization of Infraorbital Nerve Sequelae After Orbital Floor or Zygomaticomaxillary Complex Fractures.

INTRODUCTION: Neurological sequelae of infraorbital nerve (ION) lesion 6 months after orbital floor or zygomaticomaxillary complex (ZMC) fractures, associated with initial ION injury, were compared according to the treatment performed and the type of fracture. The topographic and symptomatic sequelae at 6 months were described. MATERIALS AND METHODS: Patients with orbital floor or ZMC fracture associated with initial ION injury, between November 2018 and April 2020 and clinically reassessed 6 months after trauma were included. Detailed neurological symptomatology was assessed by a questionnaire. RESULTS: A total of 81 patients were included. Forty-two patients (51.8%) showed persistent neurological signs, i.e., isolated hypoesthesia in 28 patients (66.7%), isolated pain in 10 patients (23.8%) and both in 5 patients (9.5%). The most affected area was the cheek (42.8%). Thirty-eight patients (46.9%) presented associated signs, which were intermittent in 78.9% of cases. A pronounced improvement happened for 65.1% of patients and 76.7% were not or only slightly hindered in their daily activities. There were significantly more neurologic symptoms at 6 months in the surgical group than in the observational group and more in the ZMC fracture group than in the orbital floor fracture group. DISCUSSION: Neurological symptomatology was more frequent in patients treated surgically. Our results suggest the interest of a surgical decompression when orbital or ZMC fracture is associated with nerve damage but more data are needed. Neurological injury requires a careful initial clinical evaluation and regular follow-up to help patients coping, painful symptoms may benefit from specialized care.