Successful local anesthesia in dental treatment is the most important prerequisite for pain control of patients. However, unlike that in the maxilla, it is difficult to administer local anesthesia in the mandible, and the success rate of conventional inferior alveolar nerve block (IANB) is only 80–85%. It is attributed to various causes such as anatomical variations, extreme anxiety, and technical errors; thus, various alternatives have been devised to improve this. We will analyze the causes of failure in conventional IANB and examine various alternatives that can be applied in these cases.

Oral and maxillofacial infection is a common complication in patients undergoing chemotherapy. The treatment of oral diseases in such patients differs from that administered to healthy patients. This paper reports a case of acute osteomyelitis of odontogenic origin following a recent chemotherapy session. The patient's condition was life-threatening because of neutropenic fever and sepsis that developed during the inpatient supportive care. However, the patient showed prompt recovery within 40 days following the use of appropriate antibiotics and routine dressing, without the requirement for surgical treatment, except tooth extraction. As seen in this case, patients undergoing chemotherapy are more susceptible to rapid progression of infections in the oral and maxillofacial areas. Therefore, accurate diagnosis through prompt clinical and radiological examination, identification of the extent of infection, and assessment of the patient's immune system are crucial for favorable outcomes. It is also necessary to eliminate the source of infection through appropriate administration of antibiotics. In particular, a broad-spectrum antibiotic with anti-pneumococcal activity is essential. Proper antibiotic administration and wound dressing are essential for infection control. Furthermore, close consultation with a hemato-oncologist is necessary for effective infection management based on the professional evaluation of patients' immune mechanisms.

Williams-Beuren syndrome (WS) is a rare genetic disorder that results from microdeletion at chromosome 7, which harbors the elastin gene. Clinical findings include arteriopathy, aortic stenosis, hypertension, and laxities and contractures in different joints throughout the body. While many components of the temporomandibular joint (TMJ) normally contain elastin, there are few reports on TMJ manifestations of WS. This study reports a TMJ ankylosis case in a WS patient and shares insight on a possible link between development of TMJ ankylosis and elastin deficiency in WS patients. A WS patient presented with bilateral TMJ ankylosis and was successfully treated with TMJ gap arthroplasty. Hypermobility of TMJ and lack of elastin in retrodiscal tissue can induce anterior disc displacement without reduction. Due to lack of elastin, which has a significant role in the compensatory and reparatory mechanism of TMJ, WS patients might be prone to TMJ ankylosis.