The mandible, the largest bone in the human skull, holds the lower teeth in place and forms the lower jawline or arch. Sometimes, the mandible does not develop properly during childhood, leading to a narrow mandibular arch that can misalign teeth and restrict breathing. Signs of a narrow mandible include crowded lower teeth, inward-leaning teeth, improper tongue position, jaw misalignment, or breathing difficulties like mouth breathing or sleep apnea. Various procedures can be recommended to expand the mandibular arch, such as a lip bumper, screw-activated mandibular expander, surgically facilitated orthodontic therapy (SFOT), orthognathic surgery, or distraction osteogenesis. These advanced procedures often require an interdisciplinary team of orthodontists and oral surgeons to develop a personalized treatment plan. Treating a dental issue like a narrow mandible can simultaneously improve the airway and sleep quality, leading to an enhanced quality of life. Consult with your doctor to determine which procedure is appropriate for your unique situation.