Extraction of permanent first molars severely affected by MIH is a good treatment alternative. Favourable spontaneous space reduction and development of the permanent dentition positioning can be expected without any intervention in the majority of cases extracted prior to the eruption of the second molar.

Cephalometric radiographs and dental study casts were analyzed in a group of 23 seven-year-old cleft lip and palate patients, 16 with unilateral and 7 with bilateral cleft. The patients' primary surgical procedures had been completed except for closure of the cleft in the hard palate. For comparison, similar records from another group of patients, 18 with unilateral and 8 with bilateral cleft lip and palate, were studied. In these cases the cleft of the hard palate had been repaired in infancy, using a vomer flap procedure. The results indicated that midfacial growth and dental occlusion of the unilateral cleft sample was significantly better in patients whose closure of the hard palatal cleft had been delayed to the stage of mixed dentition than where repair had been performed with a vomer flap in infancy. No differences were found, however, between similar subgroups with bilateral cleft lip and palate.

Our results of bone grafting to the alveolar process during the mixed dentition were investigated in 55 consecutively treated patients (66 clefts). The amount of remaining bone and gingival retraction at the tooth mesial to the cleft after 3 and 12 months was measured and correlated with the following anatomical conditions present during surgery: width of the cleft, rotation of the adjacent incisor, stage of eruption of the tooth distal to the cleft. It was also considered if any deciduous lateral incisor or canine was extracted during surgery and if any flap dehiscence took place postoperatively. It was found that flap dehiscence resulted in significantly less bone at 3 months and at 1 year after surgery. Furthermore, extraction of a deciduous tooth was found to be significantly correlated to less bone 1 year after surgery, in which cases there were also persisting gingival retractions. The other factors had no significant influence on the outcome of surgery.

High loosening rates of the trapezium components of trapeziometacarpal total joint prostheses have been reported. The purpose of this study was to compare the primary press fit fixation of two different, uncemented cup designs (MOTEC and Elektra) with the primary fixation of a cemented polyethylene cup (DLC) in a pig bone model. We did a push out test to measure the maximal load strength of the implants and a low-pressure cyclic loading test combined with radiostereometric analysis to measure the micromotion of the implants. There was no significant difference in fixation strength between the two uncemented screw cup designs or between the two uncemented screw cups and the cemented polyethylene cup. However, we found that threading of the bone before insertion of the Electra screw cup weakens the primary fixation strength of the implant. The results indicate that focus should be on the insertion technique as well as on the cup design of uncemented trapezium cup implants. Further studies of trapezium implant migration in a clinical setting are needed.