A 5 year old Japanese girl who had previously been diagnosed with LS was referred to the orthodontic clinic in the Fukuoka Dental College Medical and Dental Hospital in Fukuoka, Japan, because she had posterior crossbite. She is the second child with healthy parents who have no family history of genetic disorders. The diagnosis of LS was based on clinical findings. At birth, she had knee joint dislocations, equinovarus foot deformities, and a cleft of the soft palate only with no extension to the hard palate, alveolus, or lip (type 1 of Veau’s classification []). Operations for dislocations and equinovarus deformities were respectively performed at the ages of 4 and 9 months. Furlow’s palatoplasty was performed for the soft palate repair when she was 1.7 years old. She had not undergone any orthodontic treatment including presurgical orthodontics. The Enjoji scale [], recorded at the age of four, revealed delays of social behavior and emotional and language development.\nShe underwent orthodontic examinations, including general, facial and intraoral examinations, lateral and frontal cephalometric analyses, and a study model examination for orthodontic diagnosis. On general examination, her height and weight were 112.3 cm and 15.1 kg, respectively. These were below the reference for the 75th and 10th percentile in her age and sex group, respectively. The hand–wrist radiograph was used to examine her skeletal maturity (Fig. a). The patient's skeletal age was matched at 5.3 years by the TW2 RUS method applied to the Japanese population, whereas the Greulich–Pyle Atlas method estimated the corresponding age at 5.5 years []. Based on these methods, her skeletal age almost matched her chronological age of 5.6 years. She had long cylindrically shaped fingers (Fig. b). Dysmorphic facial features were noted, including hypertelorism, a prominent forehead, depressed nasal bridge, and a flattened midface. Her facial profile was straight. Her chin point deviated toward the right side from the facial midline (Fig. ).\nIntraoral examination revealed the complete primary dentition with an overjet of 2.0 mm, an overbite of 2.0 mm, and mesial step-type terminal planes on both sides. There were no spaces around the fused tooth with the left deciduous central and lateral incisors in the upper dentition, while the lower dentition exhibited anterior crowding and mesial rotation of the first deciduous molars on both sides. On the right side, posterior crossbite was observed resulting from a functional lateral shift of the mandible owing to the premature contacts between the maxillary and mandibular right primary molars. In centric relation prior to the mandibular shifting, the mandibular dental midline was nearly consistent with the facial midline. In centric occlusion, the maxillary and mandibular dental midlines deviated 1.5 mm to the left and 2.0 mm to the right relative to the facial midline, respectively. As a result, the upper and lower dental midline discrepancy was 3.5 mm (Fig. ).\nOn study models examination, the arch widths between the primary canines, and the first and second molars were measured to compare them with the standard values obtained from Japanese children with normal primary occlusions (Fig. and Table ) []. In the case of the primary canine, all the distances of the bilateral tips and the bilateral palatal or lingual cervical lines were measured. In the cases of the primary molars, the distances between the bilateral buccal grooves of the first and second molars were also measured. On the maxillary and mandibular dentitions, all the arch width measurements were significantly smaller than one standard deviation (SD) below the Japanese norms matched for the patient’s age.\nThe panoramic radiograph showed that the maxillary left lateral incisor was congenitally missing. The tooth germ of the maxillary left second molar was not present. The tooth crown of the unerupted, maxillary right central incisor was rotated and was close to that of the maxillary right lateral incisor. The fused tooth with the left deciduous central and lateral incisors showed the union of tooth crowns by the dentin and two roots with independent root canals (Fig. ).\nFigure shows the lateral and frontal cephalogram of the patient. Cephalograms were taken in a standard manner with a magnification ratio of 1.1. Figure a, b shows the conventional cephalometric analyses. The results are given in Table . These indicated the posteriorly positioned maxilla and mandible (SNA, SNB, and facial angle), skeletal Class III jaw relationship (ANB), steep mandibular plane (FMA) with the large Gonial angle, and growth tendency of the mandible (Y-axis) toward the postero-inferior direction. Inclination of the maxillary primary incisors was within the normal range (U1 to SN), while the mandibular primary incisor inclined more lingually than the norm (L1 to Mandible) [].\nFigure c shows the facial depth measurements used in this study. The horizontal positions of the six landmarks in relation to a line perpendicular to the S–N line that passed through sella, were measured based on the method proposed by Ono []. The results of the facial depth measurements were shown in Table . The depths measured on Or, PTM, Pog, Me, and Ar were smaller than one SD below the Japanese norms matched for the patient’s age and sex, while the depth of the nasion was within the normal range []. For the posterior part of the mandible, the facial depths measured on Go were close to one SD below the norms. These indicated that the orbitale, the maxilla, and mandible were positioned posteriorly relative to the anterior cranial base.\nThe frontal cephalometric analysis was performed as shown in Fig. . The facial midline was drawn through the Crista Galli and perpendicular to the line that passed through the latero-orbitale (Lo) bilaterally. For each of the 14 landmarks used, the distance to the facial midline was measured on both sides. The facial widths were obtained based on the addition of the bilateral distances measured on each landmark []. Table shows the results of the facial width measurements. Compared with the Japanese norms matched for the patient’s age and sex, the cranial width measurements taken at MCB(p), Lo, OSM, OSL, and CN yielded values that exceeded the Japanese norms by one SD. The widths measured on the Mx, cMoU, and cMoL, were smaller than those of the Japanese norms, and indicated narrow maxillary basal arch and maxillary and mandibular dental arch widths.\nBased on the examinations performed, an orthodontic diagnosis of unilateral posterior crossbite due to a functional lateral shift of the mandible, a skeletal Class III jaw relationship, narrow maxillary and mandibular dental arches, mandibular anterior mild crowding, and congenital missing of the maxillary left lateral incisor and the maxillary left second molar was made. The proposed treatment plan included (1) the maxillary dental arch expansion to eliminate the premature contacts between the maxillary and mandibular right primary molars and to improve the lateral shift of the mandible, (2) observation of the jaw growth and occlusal development with potential options of the maxillary protraction and the mandibular dental arch expansion, and (3) a fixed appliance treatment for the permanent dentition. We initiated the treatment with the use of the removable expansion plate for the maxillary dental arch expansion. No obvious problems have been observed in treatment response of the patient so far.
Patient 4 is a 6-year-old boy, born to non-consanguineous parents at term by vaginal delivery with birth weight of 2.2 kg (−2 to −3 SD). He cried immediately after birth. He had one healthy elder brother. He was referred for evaluation with bilateral clubfeet, bilateral elbow and knee dislocations noted at birth. He achieved head holding at 5 months, roll over at 8 months, sitting at 9 months, standing at 13 months, walking with support at 15 months, and walking without support at 2 years.\nAt 6 years, his height was 110 cm and weight 22 kg (both normal for age). He had prominent forehead, mid face hypoplasia, telecanthus, downslanting palpebral fissures, and long philtrum (Fig. ). He had long cylindrical fingers with broad fingertips (Fig. ), and mild joint laxity. He also had bilateral elbow and knee dislocation and clubfeet (Fig. ). He had flexion deformity at bilateral elbow with pterygium over cubital fossa (Fig. ). Bilateral hip and wrist joints were normal. Skin, hair, and nails were normal.\nHe had normal cervical spine (Fig. ). Bilateral double ossification of calcaneum (Fig. ), bilateral elbow (Fig. and ) and knee dislocations (Fig. ), and bilateral metatarsus adductus (Fig. ) were noted. Radiographs of hip and thoracolumbar spine were unremarkable (Fig. ). Radiographs at 4 years, 5 years and 6 years of age revealed delayed carpal ossification (Fig. ) and showed abnormal distal phalanx of thumbs and small distal phalanges (Fig. ). Echocardiography was normal. His complete blood count, serum calcium, serum phosphorous, alkaline phosphatase, thyroid profile, and complete urine analysis were unremarkable.