For patients with a wide, complete, unilateral cleft lip and palate, pre-surgical maxillary orthodontic treatments have been used to reduce the alveolar gap before cheiloplasty. However, most of these treatments are complicated and laborious for patients and for medical professionals. Thus, we developed an original pre-surgical orthodontic device made with two separate acrylic resin plates connected with a spring-shaped β-titanium wire (β-TW). When the device was applied on the palate, each segment of the maxilla was automatically aligned for our target formation with the elastic force of β-titanium alloy. This study aimed to evaluate the efficacy of the new device and the size of the maxilla in comparison with the conventional Hotz procedures. A total of 47 patients with a wide unilateral cleft lip and palate were retrospectively evaluated; 33 patients were treated with our new device (β-TW plate group) and 14 were treated with a Hotz plate (HP group). We evaluated the alveolar gap reduction and the size of the maxilla between the two groups, obtaining intraoral maxillary impressions at birth, at 3 months and 1 year. The width of the alveolar gap in the β-TW plate group was significantly reduced compared with that in the HP group 1 month after the treatment (p < 0.001). The alveolar gap reduction continued until the age of 1 year (p = 0.02). By contrast, no significant difference in the maxillary size was observed between the two groups at any examination period. Our treatment protocol using the β-TW plate was not only easy and simple to apply but it was also cost-effective, with highly predictable outcomes. Moreover, it provided the ideal alveolar cleft reduction without detrimental collapse of the alveolar segments. Therefore, we consider our β-TW plate device to be useful for application in pre-surgical orthodontic treatments.