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Biomedical subjects

H Pancherz

Publications and source records attributed to H Pancherz.

86 records · Page 5Linked to original sources
PubMed1982

Vertical dentofacial changes during Herbst appliance treatment. A cephalometric investigation.

The effect of bite jumping with the Herbst appliance on the vertical dimensions of the dentofacial complex was analysed on profile roentgenograms. The material consisted of 42 Class II, Division 1 malocclusion cases with a deep anterior overbite. Twenty-two of the cases were successfully treated with the Herbst appliance for six months. The other 20 cases served as a control group. The Herbst appliance had a pronounced effect on vertical tooth position. The mandibular incisors and maxillary molars were intruded during treatment while the mandibular molars were allowed to erupt freely. As a result of the dental changes the overbite was reduced, lower facial height was increased as well as the angulation of the maxillary and mandibular occlusal planes. A small positive correlation existed between vertical bite opening at the start of treatment and the treatment changes of overbite, lower facial height and mandibular vertical tooth position. The appliance had a limited effect on vertical mandibular and maxillary jaw position, expressed by the angles ML/NSL and NL/NSL. In four patients, however, a marked posterior rotation of the entire maxillary complex was noted. The clinician should be aware of the vertical dentofacial changes occurring during Herbst appliance treatment and consider these changes when designing his treatment strategy and planning post-treatment retention.

Activator Appliances↗
PubMed1980

Activity of the temporal and masseter muscles in class II, division 1 malocclusions. An electromyographic investigation.

A quantitative analysis of EMG activity in the masticatory muscles was performed in homogeneous groups of boys with Class II, Division 1 malocclusion and normal occlusion. Integrated EMG recordings from the temporal and masseter muscles were analyzed during maximal biting in the intercuspal position (centric occlusion) and during the chewing of peanuts. The results of the investigation revealed the following: (1) During maximal biting in intercuspal position the boys with Class II malocclusion exhibited less EMG activity in the masseter and temporal muscles than the boys with normal occlusion. In the Class II boys the reduction in EMG activity was most apparent for the masseter muscle. (2) During chewing the Class II subjects showed less EMG activity in the masseter muscle than the normal occlusion subjects. For the temporal muscle, no differences were found between the two occlusion groups. (3) High positive correlations were found between the EMG activity during maximal biting and chewing for both muscles in the two occlusion groups. The impaired muscle activity found in the Class II cases may be attributed to a diverging dentofacial morphology and unstable occlusal contact conditions.

Child↗
PubMed1980

Temporal and masseter muscle activity in children and adults with normal occlusion. An electromyographic investigation.

Temporal and masseter muscle activity was investigated in male subjects with normal occlusion, 11 years (n = 23) and 25 years (n = 21) of age. Integrated EMG recordings were analysed quantitatively during maximal biting in intercuspal position and during chewing of peanuts. The results of the investigation revealed the following: 1. Masseter muscle activity was greater in the older than in the younger age group. 2. Temporal muscle activity was the same in both age groups. 3. Masseter muscle activity was increased in relation to temporal muscle activity in the older subjects. In the younger subjects the same activity was found in the two muscles. 4. For the temporal muscle the chewing activity was positively correlated to maximal biting activity in both age groups. For the masseter muscle a clear correlation between chewing and biting activity was found in the younger age group only. The difference in EMG activity found between children and adults may be attributed to age changes and/or an exercising effect of the masseter muscle occurring during maturation.

Adolescent↗
PubMed1979

Treatment of class II malocclusions by jumping the bite with the Herbst appliance. A cephalometric investigation.

The purpose of this study was to investigate the effect of continuous bite jumping with the Herbst appliance on the occlusion and craniofacial growth. The material consisted of twenty growing boys with Class II, Division 1 malocclusion. Ten of the boys were treated with the Herbst appliance for 6 months. The other ten boys served as a control group. Dental casts, profile roentgenograms, and TMJ radiographs were analyzed before and after 6 months of examination. The following treatment results were found: 1. Normal occlusal conditions occurred in all patients. 2. Maxillary growth may have been inhibited or redirected. The SNA angle was reduced slightly. 3. Mandibular growth was greater than average. The SNB angle increased. 4. Mandibular length increased, probably because of condylar growth stimulation. 5. Lower facial height increased. The mandibular plane angle, however, remained unchanged. 6. The convexity of the soft- and hard-tissue profile was somewhat reduced.

Cephalometry↗
PubMed1979

The mandibular plane angle in activator treatment.

The long-term results of activator treatment were investigated in 15 subjects with a small and 13 subject with a large pretreatment mandibular plane angle. The results of the investigation revealed the following: 1. Activator treatment resulted in a general improvement in the sagittal and vertical incisor relationship in both large and small angle cases. 2. Overjet relapse was more frequent and overbite relapse less frequent in large angle cases than in small angle cases. 3. During the period before treatment follow-up examination the frequency of patients with open bite increased in the large angle group and decreased in the small angle group. 4. The mandibular intercanine arch width was smaller and the frequency of crowding in the mandibular incisor segment was higher in the large angle group than in the small angle group. 5. A large pretreatment mandibular plane angle, per se, was not a primary factor in treatment failure. However, an unfavourable mandibular growth in combination with an atypical tongue function seemed to be the main reason for the relapse found in the large angle subjects.

Activator Appliances↗
PubMed1978

Masticatory function after activator treatment. An analysis of masticatory efficiency, occlusal contact conditions and EMG activity.

Masticatory function was investigated in nine patients with relapse and ten patients without relapse of overjet after activator treatment, Masticatory efficiency, evaluated by a chewing test, was related to the number of intermaxillary tooth contacts and the electromyographic (EMG) activity from the temporal and masseter muscles during chewing. The results of the investigation indicated that a reduced masticatory efficiency was connected with fewer intermaxillary tooth contacts and less EMG activity from the temporal and masseter muscles. In patients with relapse of overjet, masticatory efficiency and muscle activity was reduced in comparison with patients without relapse. The relationship between the number of tooth contacts and masticatory efficiency was poor in the relapse patients. Unstable occlusal conditions and atypical tongue function may be an explanation.

Activator Appliances↗
PubMed1977

[My dissertation].

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Activator Appliances↗
PubMed1976

Long-term effects of activator (Andresen appliance) treatment. A clinical, biometric, cephalometric roentgenographic and functional analysis.

The purpose of this investigation was to analyse the long-term effects of activator treatment on the dental arches and arch relationships, the dento-facial skeleton and the function of the masticatory system. A follow-up study was performed on 112 patients treated 10-20 years previously with activators as the sole orthodontic appliance. In connection with activator treatment extractions of permanent teeth were performed on 66 patients while 46 patients were treated without tooth extractions. The investigation consisted of four separate portions (Parts I-IV).

Activator Appliances↗