Distraction osteogenesis has been used in various departments since it was first reported in 1905. Patients with cleft lip and palate may experience undergrowth of the maxilla as a result of primary surgery, and if orthodontic treatment alone is not sufficient to improve the condition, surgical treatment is required. Also, in patients with cleft lip and palate, it is difficult to move the maxilla in a single stage, including the palatal mucosa that causes palate growth disorders, and the velopharyngeal function. Distraction osteogenesis is effective for moving bone fragments slowly against the resistance of the scar. We report a clinical study of patients with cleft lip and palate who underwent maxillary distraction osteogenesis.
　Twenty-nine patients with cleft lip and palate （33 cases） born between January 2012 and January 2024 who underwent distraction osteogenesis were enrolled. Cleft types were 10 bilateral cleft lip and palate（ BCLP）, 16 unilateral cleft lip and palate （UCLP）, and 3 cleft palate （CP）. Distraction osteogenesis procedures were maxillary anterior segmental distraction osteogenesis（ MASDO）, transverse maxillary distraction osteogenesis（ TMDO）, and Le Fort I distraction osteogenesis（LF1DO）. Classification by surgical procedures was 14 MASDO, 14 TMDO, and 5 LF1DO. The surgical classification by cleft type was as follows: 5 MASDO, 4 TMDO, and 3 LF1DO in BCLP; 9 MASDO, 9 TMDO, and 0 LF1DO in UCLP; and 0 MASDO, 1 TMDO, and 2 in CP. In 16 cases, normal occlusion was achieved through maxillary distraction osteogenesis and postoperative orthodontic treatment.
　Distraction osteogenesis has two aspects: it is similar to surgery for jaw deformities, and it is also a surgically assisted orthodontic procedure that can improve problems in orthodontic treatment, such as correcting discrepancies in the dentition. Although the number of cases of undergrowth of the maxilla has decreased due to improvements in primary surgical techniques, distraction osteogenesis is considered to be a useful technique for maxillary hypoplasia seen in patients with cleft lip and/or palate, where one-stage movement of the maxilla is difficult.

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Objective: At Tokushima University Hospital, the palatoplasty technique has been changed from the conventionally used pushback method to the Furlow or two-flap method since 2017. This study aimed to evaluate the effects of the change in palatoplasty technique on the occlusal relationship, the dimensions of cleft, and the velopharyngeal function in the deciduous dentition stage. Methods: Twenty-six patients with unilateral cleft lip and palate who underwent palatoplasty at Tokushima University Hospital between 2000 and 2020 were included. Of these, 15 patients who underwent palatoplasty using the pushback technique between 2000 and 2016 were classified as Group P, and 11 patients who underwent palatoplasty using the Furlow or two-flap technique between 2017 and 2020 were classified as Group F・T. The values of ANB angle, overjet, overbite, and 5-Year-Olds′ Index were used as indices of anteroposterior jaw relationship. Velopharyngeal function was assessed by measuring the distance from the posterior nasal spine to the upper pharyngeal wall, the thickness and length of the soft palate, and the depth of the pharynx using lateral cephalograms. Nasal air leakage was also assessed. Results: Group P was more likely to present with skeletal mandibular prognathism as the values of ANB angle and overjet were significantly smaller and the 5-Year-Olds′ Index tended to be larger than in Group F・T. In Group F・T, 10 out of 11 cases showed a positive overjet, whereas 14 out of 15 cases in Group P showed an anterior crossbite. Discussion: In this study, the pushback method was compared with the Furlow method and the two-flap method for palatoplasty in cleft palate patients. The results suggested that the Furlow method and the two-flap method promote postoperative maxillary growth and development, and are potentially not inferior in terms of velopharyngeal function.

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Presurgical orthopedic treatment for infants with cleft lip and palate aims to improve feeding disorders and reshape clefts. At Meikai University Hospital, palatal plates for presurgical orthopedic treatment are fully digitalized using CAD/CAM （computer-aided design/computer-aided manufacturing） technology. Although digitalization is convenient for patients and their guardians, the efficiency of plates on feeding function remains unclear. In this study, we investigated the relief thickness on clefts by digital technology, and examined the feeding function in infants with unilateral cleft lip, alveolus and palate.
　The subjects were five infants（ three boys and two girls: two with right clefts and three with left clefts） who visited our orthodontic clinic. STL data of the oral cavity was obtained from infants using an intraoral scanner. The different thickness of relief on the clefts was designed using CAD software, and the plates were fabricated by a 3D-printer. Total daily amount of feeding（ mL） was recorded in all cases.
　After the oral scanning, STL（ standard tessellation language） data provided excellent imaging accuracy of the nasal septum as well as the alveolar ridge. It provided high morphological reproduction of the palate, providing an accurate analysis for the irregular and asymmetric palate shape. The thickness of the fabricated palate was uniformly 2.0 mm, but there were different palate heights due to relieving clefts with different thickness. Of these, palates which had a palatal height of 8.0 mm after relief enabled more than 80 % of total daily feeding amount of a healthy infant in all five cases.
　These findings demonstrated that complete digitalization of the fabrication of the palatal plates provided an acceptable amount of feeding for infants with unilateral cleft lip, alveolus and palate. Digital technology can not only avoid the risk of vomiting and aspiration of the impression material, but also contribute to improving feeding function.

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