Bite force, electromyography, and mandible mobility during the 6-month period after surgical treatment for isolated fractures of the zygomatico-orbital complex

Role of finite element analysis for selection of single point fixation in zygomaticomaxillary complex fracture

BACKGROUND

One-point fixation was superior to the two and three-points fixation in minimally displaced zygomaticomaxillary complex (ZMC) fracture regarding the cost, invasiveness, scaring, number of wounds, and operation time. Accordingly, this study aimed to predict which one-point fixation is the most stable in managing minimally displaced ZMC fracture.

MATERIAL & METHODS

This study simulated the different one-point fixation approaches on three ZMC models after fracture reduction and application of all forces exerted on the fractured area. The findings were represented as stress impact on the ZMC fracture and plating system as well as the inter-fragments micro-motion.

RESULTS

The von misses stresses of plates for the zygomaticofrontal, infra-orbital rim, and zygomaticomaxillary buttress model were (66.508, 1.285, and1.16 MPa) respectively. While the screws' von misses for the infraorbital rim, zygomaticofrontal, and zygomaticomaxillary buttress models were (13.8, 4.05, and 1.60 MPa) respectively. Whereas, the maximum principles stress at zygomaticofrontal, zygomaticomaxillary buttress, and infraorbital rim models were (37.03, 37.01, and 34.46 MPa) respectively. In addition, the inter-fragment micro-motion for zygomaticomaxillary buttress, infraorbital rim, and zygomaticofrontal models were (0.26, 0.25, and 0.15 mm) respectively.

CONCLUSION

One-point fixation at zygomaticomaxillary buttress is the preferred point because it is exposed to low stresses, and the inter-fragment micro-motion is within the approved limit with the elements in the same direction of fixation which indicates the rigid fixation. In addition, it is less palpable and scarless.

TRIAL REGISTRATION

clinical trial.gov (NCT05819372) at 19/04/2023.

To Assess the Effect of Trauma on the Temporomandibular Joint in Postoperative Cases of Zygomaticomaxillary Complex Fractures

Aim and Objectives

The study aims to assess the incidence and features of temporomandibular joint(TMJ) dysfunction in post-surgical treatment of unilateral zygomaticomaxillary complex(ZMC) fractures.The objectives are:To assess severity of TMJ dysfunction in postoperative cases of ZMC fractures.To create awareness of the same among clinicians.

Methods

Patients presenting with zygomaticomaxillary complex fractures were evaluated prospectively. Evaluation of TMJ dysfunction was done by different parameters via questionnaire, clinical and radiographic examination preoperatively and a follow-up period of 1 week, 3 months and 6 months. The parameters were, clicking of joint, pain on opening /closing, pain on biting, deviation of mandible, pain in the preauricular region, ringing sound and mouth opening. Statistical analysis was done by the Friedman test and Post Hoc analysis.

Results

On presentation, 69.1% patients diagnosed with ZMC fractures presented with symptoms related to TMJ dysfunction. Post-surgery 1 week majority findings persisted, with 21 patients complained of pain on opening or closing and 2 patients with a persistent opening click. These symptoms, however, decreased over the 3 month and 6 month follow up period. 5 patients presented with decreased mouth opening which was attributed to lack of adequate physiotherapy.

Conclusion

Patients presented with mild symptoms of TMJ dysfunction until 6 months post-surgery, however these symptoms weren't significant as the pain score assessed was found to decrease in the following post-operative periods. And the symptoms present were'nt exclusive to conclude a TMJ dysfunction. Early treatment and a close follow up are key to prevent progression of symptoms.

Evaluation of one-point fixation for zygomaticomaxillary complex fractures using a three-dimensional photogrammetric analysis

BACKGROUND

The goal of treatment for zygomaticomaxillary (ZM) complex (ZMC) fractures is to achieve stability and restore aesthetic appearance through three-dimensional reduction and rigid fixation. The purpose of this study was to evaluate the stability and aesthetic appearance outcomes of one-point fixation using a three-dimensional photogrammetric analysis.

METHODS

From March 2014 to December 2014, 34 patients with ZMC fractures were treated by one-point fixation in the ZM buttress using unsintered hydroxyapatite (u-HA)/poly-L-lactide (PLLA) plates. Differences in soft tissue inter-malar height between the fractured side and unfractured sides were evaluated using photogrammetric analysis with a three-dimensional camera (Morphius®) at the preoperative and 1 week, 1 and 3 months after surgery. The differences in bony inter-malar height between the fractured and unfractured sides were evaluated using computer tomography at the pre-operative and 6 months after surgery. The paired t-test was used to compare differences in malar height.

RESULTS

Six months after surgery, 34 patients achieved satisfactory bony stability and symmetric malar appearances. Comparisons of differences in soft-tissue inter-malar height revealed statistically significant differences between the pre-operative period and 1 week and 1 month after surgery (p < .01). There was no statistically significant difference between 1 and 3 months after surgery. Comparison of differences in bony inter-malar height revealed a statistically significant difference between before and 6 months after surgery (p < .01).

CONCLUSIONS

When we conducted a three-dimensional photogrammetric analysis, although it has restricted surgical indications, one-point fixation of the ZM buttress using an u-HA / PLLA plate yielded reliable, satisfactory, and safe clinical results in patients with ZMC fractures.

CLINICAL QUESTION / LEVEL OF EVIDENCE

Therapeutic, III.

Postoperative temporomandibular dysfunction in patients with fractures of the zygomatic complex: a prospective follow-up study

The aim of this prospective follow-up study was to clarify the incidence and characteristics of dysfunction of the temporomandibular joint (TMJ) in patients treated surgically for fractures of the zygomatic complex. Patients were evaluated on presentation and six months after injury to assess the function of the masticatory system using the Helkimo index, which incorporates two complementary subindices: the subjective symptomatic (anamnestic) index (A_i) and the objective clinical dysfunction index (D_i). Forty-five patients (12 women and 33 men, mean (range) age 44 (21-83)years) completed the study. Six patients developed subjective symptoms of dysfunction of the TMJ during follow-up, in four of whom they were severe. Clinical findings were noted in 38 patients but without significant association with subjective symptoms. Dysfunction of the TMJ is common six months after surgical treatment of a fracture of the zygomatic complex, and patients with such fractures should be evaluated for temporomandibular dysfunction during follow-up and referred for treatment when necessary.

Health-related quality of life of patients with zygomatic fracture

Background

The objective was to evaluate health-related quality of life (HRQoL) before and after surgical treatment of zygomatic complex fracture and assess patients’ perceptions of the aesthetic and functional outcomes of surgery.

Material and Methods

A prospective study of 79 adult patients before and after surgery for zygomatic complex fracture was conducted. HRQoL was measured using the generic 15-dimensional (15D) instrument, and patient satisfaction was assessed by an additional questionnaire.

Results

The mean preoperative 15D score for patients was lower than for general population that was matched for age and gender (p=0.011). The mean 15D score was lowest on the first postoperative day (p<0.001) when patients were worse off for 6 of the 15 dimensions of the HRQoL instrument and better off for three dimensions. However, patients achieved, and even exceeded, the mean 15D score of the general population during the first month following surgery. Infraorbital sensory loss at the end of the six-month follow-up appeared to be the single most important factor that plagued the patients.

Conclusions

HRQoL is significantly reduced after trauma but improves a few weeks after surgery. Infraorbital nerve sensory loss is a notable long-term factor that affects patients after zygomatic complex fracture.

Key words:Zygomatic fracture, maxillofacial trauma, health-related quality of life, disturbance of infraorbital nerve, facial sensation.

Impact of midface and upper face fracture on bite force, mandibular mobility, and electromyographic activity

This study evaluated the bite force, electromyographic activity, and mandibular mobility in patients undergoing surgery for facial fracture treatment that required a coronal approach. Ten men were divided into two groups: group I, coronal approach with pre-auricular extension (n=4, average age 34.5 years); group II, coronal approach (n=6, average age 24.8 years). The maximum bite force was measured using a dynamometer and mandibular mobility using a calliper. The electromyographic activity of the right masseter (RM), left masseter (LM), right temporal (RT), and left temporal (LT) muscles was evaluated using a Myosystem-Br1 apparatus. Patients were evaluated at 1, 2, 3, and 6 months after surgery. Data were analysed using the repeated measures test (SPSS 21.0; P≤0.05). Statistically significant differences were found for electromyographic activity at rest (group II: LM P=0.00), left laterality (group I: RT P=0.02; group II: RT P=0.04), and maximum voluntary contraction (group I: RM P=0.04 and RT P=0.04; group II: RM P=0.05, LM P=0.00, and LT P=0.01 and for maximum molar bite force in the right (group I, P=0.00; group II, P=0.01) and left (group II, P=0.01) molar regions. The subjects regained electromyographic activity, maximum bite force, and mandibular mobility throughout the period evaluated.

Functional Evaluation of the Behavior of Masticatory Muscles in Zygomaticomaxillary Complex Fracture: A Prospective Study

AIMS

The purpose of this study is to functionally evaluate the behavior of the masticatory muscles (masseter and temporalis) following zygomaticomaxillary complex (ZMC) fractures by assessing bite force, electromyography (EMG), and mandibular movements.

MATERIALS AND METHODS

Group I consisted of 20 patients with unilateral ZMC fractures who were treated surgically with one-, two-, or three-point fixations at the frontozygomatic, infraorbital, or zygomaticomaxillary buttress region as per clinical and radiological assessments. Group II control group included 20 normal patients. The muscle activity was functionally evaluated before and after the surgery for a period of 6 months. The evaluation consisted of bite force measurement, EMG analysis of masseter and temporalis muscles, and measurements of mandibular movements.

RESULTS

There was an increase in bite force and EMG activity throughout the evaluated postoperative period, but at the end of 6 months, the values were still below the control levels for majority of the patients. Maximum mouth opening increased considerably after the surgery.

CONCLUSION

According to bite force and EMG, the masticatory musculature returned to near normal levels by the 3rd month after the surgery.

CLINICAL SIGNIFICANCE

Management of fractures of the zygoma by open reduction and fixation raises the question of the location of fixation points owing to the action of masseter and temporalis on the ZMC. This study supports the current clinical concept of minimized fixation in treating ZMC fractures.

Effect of surgical treatment of mandibular fracture: electromyographic analysis, bite force, and mandibular mobility

This study aimed to examine individuals undergoing surgery for the treatment of the fractured mandibular angle, using bite force, mandibular mobility, and electromyographic (EMG) analysis in many different clinical conditions, after 2 months postoperatively. Bite force was recorded with a digital dynamometer, model IDDK. The EMG activity (Myosystem-Br1) included the analysis of the masseter and temporal muscles. Mandibular mobility was measured using a digital pachymeter. The subjects were divided into 3 groups: G1, mandibular angle fracture (n = 7); G2, condylar process fracture (n = 5); and G3, control (n = 12). Data were tabulated and submitted to statistical analysis using the repeated-measure test carried out over time and the Student's t-test (P < 0.05), using the Statistical Package for the Social Sciences software, version 19 (SPSS Inc, Chicago, IL). G1 and G2 had an increase in bite force. In G1, there was a regular decrease in the EMG activity in the second postoperative month. G2 presented an irregular pattern in EMG data during the period tested. Regarding the mandibular mobility, both groups obtained amplitude of all mandibular movements with a high percentage, when compared with control. A good functional recovery was achieved by the individuals who had a mandible angle fracture or condylar process fracture, after 2 postoperative months.

Functional analysis of the stomatognathic system in individuals infected with human immunodeficiency virus

PURPOSE

To understand the effects of HIV type 1 on the function of the masticatory muscles.

METHODS

Sixty individuals were selected from both genders, aged between 22 and 57years (mean 36.77±9.33years), and divided into two groups: Group HIVG, 30 individuals with HIV subtype 1, and Group CG, 30 healthy individuals (control group). The individuals were submitted to assessments of their masticatory muscle activity, biting strength and thickness of the masticatory muscles by means of electromyography, maximal molar bite force and ultrasound imaging, respectively. The resultant data were statistically analyzed by t-tests (p<0.05).

RESULTS

The HIVG normalized EMG data from a mandibular rest position, protrusion, right and left laterality movement of the jaw showed that HIVG presented a relative increase in EMG activity compared to the CG. The HIVG had a lower masticatory cycle ability while chewing Parafilm M®, Raisins and Peanuts when compared to CG. During rest conditions, the ultrasound images showed a greater average muscular thickness in the right and left temporal region compared to CG. Upon maximal voluntary contraction, an increased average thickness was seen in the temporalis muscles and left sternocleidomastoid muscle when compared to the CG.

CONCLUSION

Based on the results of this research, it can be concluded that individuals with acquired immunodeficiency syndrome showed muscular changes related to the stomatognathic system, especially concerning EMG activity and muscle thickness.