Zygomaticomaxillary complex fractures are frequently encountered among midface fractures.
Anatomy: The maxilla and zygoma are composed of vertical and horizontal buttresses.
Examinations: For midface fractures, evaluations of head injury, visual function, cervical vertebrae, and ear and nose should be prioritized or performed in parallel. CT is the gold standard for imaging diagnosis of midface fractures.
Approaches: Midface fractures often require a skin incision.
Reduction: Reduction is categorized into closed reduction and open reduction.
Fixation: Fixation means reconstructing the buttress and making it immobile.
Pitfalls: Shortening of facial projection due to posterior deviation of the zygomatic body, changes in orbital volume due to rotation of the zygomatic body, and especially expansion of orbital volume due to external rotation of the zygomatic body are often overlooked.

View full abstract

In recent years, various surgical procedures have been reported for the open reduction and internal fixation （ORIF） of mandibular condyle fracture. In our department, the Risdon approach （RA） had been used for the ORIF of mandibular condyle fracture in the past, but since 2019, the high perimandibular approach （HPA） has been adopted. In this study, to clarify the differences between RA and HPA in mandibular condyle fracture, we compared the fracture site, operative time, postoperative facial nerve palsy, postoperative fixation, and amount of opening at discharge and at the end of opening training of these two techniques. Ninety cases and 105 sides with mandibular condyle fracture were diagnosed at our department during the ten years from 2013 to 2022. Twenty-two cases and 22 sides with ORIF were divided into the following two groups: RA group （11 cases and 11 sides） and HPA group （11 cases and 11 sides）, and then examined retrospectively. The operating time of the HA group （median time: 55 min） was significantly shorter than that of the RA group （median time: 89 min） （P＜0.01）. Postoperative facial paralysis was observed in 8 of 11 patients （72.7％） in the RA group only. No postoperative occlusal dysfunction or oral opening disorder was observed in either group. The results suggest that HPA is a useful technique that causes less postoperative paralysis in the mandibular marginal branch of the facial nerve and shorter operative time than RA.

View full abstract

Sodium hypochlorite （NaClO） solution is widely used clinically for root canal irrigation in endodontic therapies. We encountered a case where the extrusion of NaClO solution beyond the root canal during root canal treatment caused extensive hematoma in the face.
The patient was a woman in her 70s in whom pain and swelling were confirmed on the right side of her face immediately after root canal irrigation using NaClO solution during root canal treatment on her right maxillary canine. The dentist in charge explained to her that this was a reaction caused by medication extrusion. However, the patient was referred to our department as the facial hematoma and swelling were significant and she was concerned. She was diagnosed with facial hematoma caused by the extrusion of NaClO solution at the right maxillary canine, and anti-inflammatory treatment was performed. On day 20 after the appearance of symptoms, she visited our hospital for the last time as the hematoma and swelling had disappeared.
Root canal irrigation using NaClO solution is biologically hazardous, and severe symptoms may manifest. To prevent complications, it is essential to understand the anatomical position of the tooth to be treated, and use EDTA solution or low-concentration NaClO solution. In addition, when using NaClO solution, it is better to use well-designed irrigation equipment to prevent extrusion.

View full abstract

The hyoid bone is anatomically movable and protected by the mandible, cervical vertebrae, and clavicle. Therefore, hyoid bone fractures in conjunction with oral and maxillofacial trauma are extremely rare. We report the case of a 70-year-old man who sustained multiple injuries after falling down a flight of stairs. The patient received life-saving and stabilizing interventions at the Acute Care Surgery Center. Once the patient was stable enough for transfer, he was referred to our Department of Oral and Maxillofacial Surgery for definitive management of his oral and maxillofacial trauma. Head and neck CT confirmed maxillofacial fractures, including a hyoid bone fracture. The patient complained of difficulty swallowing, and a subsequent chest CT scan was suggestive of aspiration pneumonia. Thereafter, he received respiratory management at the Acute Care Surgery Center. The hyoid bone fracture was managed conservatively, while open reduction and internal fixation of the maxillofacial fractures were performed four days later. Swallowing function was continuously monitored by speech and language pathologists. Twenty days later, he successfully resumed regular diet intake and reintegrated into social activities. This case report describes the rare occurrence of maxillofacial fractures with difficulty swallowing owing to hyoid bone fracture.

View full abstract

Single fractures of the zygomatic bone are more commonly unilateral and less commonly bilateral. Furthermore, there are no reported cases of contralateral zygomatic bone fractures recurring at different timepoints. On the other hand, the most frequent cause of syncope is vasovagal syncope, which often recurs and reduces the patient’s quality of life.
We report a case of contralateral zygomatic bone fracture that occurred after an open reduction and internal fixation （ORIF） of a unilateral zygomatic bone fracture. A 55-year-old female patient had undergone an operation at our department of plastic surgery five years earlier due to a syncopal attack after consuming alcohol. She lost consciousness while walking, staggered, caught her foot on a curb, and fell, striking the right side of her face. She regained consciousness immediately and presented at a clinic. A zygomatic bone fracture was diagnosed, and she was referred to our hospital. She underwent an ORIF under general anesthesia. Seven years post-operatively, the patient is doing well without any infection of the wound.
To prevent reinjury after a fall, it is important to evaluate the risk factors of the syncopal attack that triggered the fall.

View full abstract

The treatment of facial fractures in pediatric patients should consider the degree of bone fragment deviation, occlusal status, tooth development, and patient’s age and level of cooperation with treatment. For pediatric mandibular fractures, closed reduction, such as with circummandibular wires, external fixation, and intermaxillary fixation with chin caps, has been widely used. However, if conservative treatment is insufficient to repair and fix the bone fragments, open reduction and internal fixation are the treatment options. In the present case, we treated a 9-month-old infant with mandibular midline fractures and bilateral mandibular condyles due to traffic trauma. Because the bone fragment of the symphysis had excessive deviation, an absorbable plate was used for open reduction and internal fixation. To increase the mechanical strength, closed reduction and fixation were achieved using circummandibular wires and a custom-made splint in the alveolar region. Nine months postoperatively, there was no obvious functional impairment in jaw movement, and the mandibular deciduous anterior tooth had erupted. We believe that osteosynthesis with circummandibular wires using a splint may be a treatment option, considering the damage to the tooth germ.

View full abstract