Tetsuo Iizuka

Case Report: Nonsurgical treatment of an adult with severe anterior open bite

A malocclusion characterized by open bite and vertical maxillary excess can be one of the most difficult problems to correct through orthodontic treatment because of the difficulty in permanently changing the morphological disharmony and/or functional disorder associated with open bite. However, in some patients with less severe skeletal impairment it may be possible to orthodontically correct the occlusal disharmony so that the new relationship of the dental arches becomes compatible with normal function of the oral environment. Stability may be enhanced if mechanics are used which do not extrude posterior teeth.

Oblique Facial Cleft, Cleft Palate, and Supernumerary Teeth Secondary to Amniotic Bands

A case of oblique facial cleft with supernumerary deciduous molars, probably caused by amniotic bands is reported. Besides facial cleft, and cleft palate and lip, there are sulci on the left side of the face and on the left posterior alveolar ridge. The sulci may be impressions of amniotic bands at a late gestational age and supernumerary teeth may also be related to these amniotic bands.

Treatment mechanics in Class III open bite malocclusion with Tip Edge technique

Nonextraction treatment with nonorthognathic intervention for treatment of a skeletal Class III open bite malocclusion was performed. Light traction with effective uprighting of the lower dentition with Tip Edge brackets (TP Orthodontics, La Porte, Ind.) and anteriorly placed Class III elastics was the modus operandi. Class III elastics can prevent elongation of the upper molars and yet can cause the upper dentition to move forward. Ni-Ti wire with a reverse curve of Spee helped both the uprighting and depression of the mandibular molars. The present case was treated with the Kim philosophy but employing Tip Edge brackets. This combination was found to be very easy to manipulate and achieved good results in a very short period of time.

Ossification of the distal phalanx of the first digit as a maturity indicator for initiation of orthodontic treatment of Class III malocclusion in Japanese women

The influence of mandibular growth on the stability of orthodontic treatment has been well established. A particular problem is late mandibular growth in patients with Class III malocclusions, because of skeletal jaw discrepancies that may influence the timing and course of treatment, as well as the stability of posttreatment. We have used the ossification of the distal phalanx of the first digit as an indicator of the skeletal maturity of the patient and of their potential for further growth. Our previous studies have shown that fusion of the epiphysis and the diaphysis of the distal phalanx of the first digit occurs from 1 to 3 years after the pubertal growth maximum in Japanese women. In these case reports, the orthodontic treatment of two female patients with mild Class III skeletal malocclusions is presented to show the possible clinical application of the ossification of the first digit as an indicator of the completion or near cessation of mandibular growth in the timing of treatment of Class III malocclusions. The case reports show that, although both patients experienced some mild degree of mandibular growth after treatment, this method can be helpful in determining residual mandibular growth potential in Japanese female patients with Class III malocclusions and mild skeletal discrepancies.

Morphological differences in the skull of ascorbic acid-deficient ODS rats

The physiological importance of ascorbic acid (AsA) in bone formation has been thought to be due mainly to its effects on collagen production and, consequently, matrix formation. However, effects of AsA deficiency on growing animals are poorly understood. The purpose of this experiment was to find how AsA deficiency affects craniofacial growth cephalometrically, and the periodontal ligament and the bone density of alveolar septum histologically. Five-week-old growing male rats with hereditary defects in AsA synthesis (ODS rats) placed on an AsA-deficient or minimally supplemented diet for 4 weeks showed a marked reduction in plasma AsA level and a negative or slight increment in body weight. Cephalometric evaluation revealed that craniofacial growth was influenced by AsA deficiency. Histological observations of periodontal structure and bone density in AsA-deficient animals showed no difference from controls, whereas the periodontal ligament of the upper first molar in the deficient animals was narrower than that of controls. These observations indicate that AsA deficiency reduces craniofacial size and the width of the periodontal ligament significantly in growing rats, whereas bone density is not affected. Thus, AsA, through collagen production, may be important to the increase in size of the craniofacial structures in growing animals.

Long-term followup of orthodontic treatment of a patient with maxillary protrusion, severe deep overbite and thumb-sucking.

Oral habits should be of primary clinical concern to orthodontists because they may cause malocclusion, and/or interfere with treatment progress. Generally habit control should be achieved prior to correction of the malocclusion in an effort to remove any etiological factors in development and maintenance of the malocclusion. It is also important for the clinician to understand that habit-breaking treatment may require an extended treatment time because habits may have been present for long periods of time and may be related to underlying psychological problems. The present report documents the treatment of maxillary protrusion in a patient in which a thumb-sucking habit had persisted from infancy until almost age 12. Elimination of the habit was accomplished prior to correcting the malocclusion and for stability of the result. Orthodontic treatment consisted of extracting two maxillary premolars followed by full treatment with fixed appliances. Long-term postretention records show good stability of the corrected malocclusion.