Epidemiology of Hoffmeister's genetically determined predisposition to disturbed development of the dentition in patients with true skeletal class III malocclusion.

ABSTRACT

AIM: The prevalence of symptoms of Hoffmeister's "genetically determined predisposition to disturbed development of the dentition" as studied in patients with true skeletal Class III malocclusion; results of the study were compared with those found in the scientific literature regarding samples from the normal population and from orthodontic patients. PATIENTS AND METHODS: The prevalence of 20 defined symptoms was evaluated in 120 patients with true skeletal Class III malocclusion. The patients were selected on the basis of a positive family history and on the presentation of typical characteristics of a skeletal Class III morphology in a lateral cephalogram. The mean age of the patients evaluated was 12.4 years. The patients' files, 1161 radiographs and plaster casts were analyzed. The prevalence of the individual symptoms was compared by means of the chi(2)-test (p < or = 0.05). RESULTS: 118 patients (98.3%) were found to have 292 symptoms of "genetically determined predisposition to disturbed development of the dentition". Increased distance between molar buds, atypical tooth bud position and atypical root shape were the symptoms recorded most frequently. With regard to the simultaneous existence of several symptoms, the combination of four such symptoms was most frequent (20.8%), followed by the combination of three symptoms (15.8%), and five symptoms (15.0%). Congenital hypodontia was found in 19.2% of the patients. CONCLUSION: It should be kept in mind for patients with true skeletal Class III malocclusion that this type of dysgnathia is most likely combined with other symptoms of disturbed development of the dentition. The higher prevalence of those symptoms found in patients with skeletal Class III malocclusion when compared with the normal population and other orthodontic patients renders orthodontic treatment of those patients more difficult and calls for comprehensive clinical and radiological examination prior to any treatment.