[Problems in orthodontic space closure after loss of first permanent molars].

Space closure after loss of first permanent molars represents a difficult treatment task. To arrive at a reasonable treatment result a great variety of factors has to be evaluated in each individual case. These are among others: patient's age, topography of toothless alveolar bone, specific periodontal conditions and general orthodontic problems. In case of several unfavourable prognosticated factors alternative treatment methods should be taken into consideration.