A three-year-old female beaver (Castor canadensis) was referred to the Veterinary Teaching Hospital of Chungbuk National University. It had been raised in the Cheong-ju zoo and had a history of malocclusion caused by improper feeding. General anesthesia was induced, and preoperative intraoral dental radiographs of the rostal maxillary and mandibular dentition were taken and lateral and ventrodorsal extraoral radiographs of the cheek teeth were also taken. The radiographs were negative for apical pathology and revealed a normal appearance of the cheek teeth. The lesion was likely to be related to the excessive length of the maxillary and mandibular incisors. Odontoplasty was performed to reduce overgrowth of the crowns of the incisors. Sequential transverse sections were removed until the crown was reduced by approximately its original length. The pulp chamber was not approached during the operation, as confirmed by postoperative intraoral radiographic evaluation of the incisors. Recovery from anesthesia was uneventful and the beaver returned to normal masticatory activities immediately after the operation.
Animals ; Animals, Zoo ; Female ; Incisor/pathology/*surgery ; Malocclusion/pathology/surgery/*veterinary ; Rodentia/*surgery

OBJECTIVETo investigate the compensation of the upper and lower incisors in skeletal Class III patients treated with orthodontic-surgical approach.

METHODSThe samples consisted of 54 skeletal Class III patients treated with orthodontic-surgical approach from November 2011 to January 2015. Lateral cephalograms were taken before treatment. The differences between the samples and the norms from Peking University normal occlusion sample library were assessed using independent-sample t test. Correlation analyses were performed to find associations between skeletal and dental parameters. According to skeletal anteroposterior discrepancy/vertical type (ANB/SN-MP), the samples were allocated into group A (ANB < -4°, SN-MP ≤ 37.7°, n = 11), group B (ANB ≥ -4°, SN-MP ≤ 37.7°, n = 16), group C (ANB < -4°, SN-MP > 37.7°, n = 14), and group D (ANB ≥ -4°, SN-MP > 37.7°, n = 13). After measurement of variables, one-way ANOVA with SNK multiple comparison test were performed.

RESULTSThe maxillary incisors were more proclined and the mandibular incisors more retroclined in skeletal Class III patients compared with norm values (P < 0.01). Both skeletal anteroposterior discrepancy and vertical type were correlated with the position of upper and lower incisors (P < 0.01). According to skeletal anteroposterior discrepancy/vertical type, no significant differences were found in the upper incisors' inclination among the four groups, while patients in group A and group D exhibited significant difference in lower incisor compensation.

CONCLUSIONSDifferent skeletal anteroposterior discrepancy/vertical type resulted in varied incisors' compensation. Therefore, decompensation should be treated differently.

Analysis of Variance ; Beijing ; Cephalometry ; Humans ; Incisor ; pathology ; Malocclusion, Angle Class III ; classification ; pathology ; surgery ; Mandible ; Maxilla ; Orthognathic Surgery

OBJECTIVETo study the alveolar bone surrounding situation and the length of the root of the maxillary labial inverted impacted incisor in mixed dentition after orthodontic treatment.

METHODSFourteen cases with maxillary labial inverted impacted incisor in mixed dentition were collected. Modified Nance arch and conventional appliance were used. Cone-bean CT (CBCT) was taken after the treatment. Simplant13.0 three-dimensional reconstruction and multi-planer reconstruction (MPR) method were used to observe the labial and lingual alveolar bone crest morphology, besides, the labial and lingual length from the alveolar bone crest to cemento-enamel junction (CEJ) of the impacted incisor and the homonym tooth after treatment, along with their root length and their labial and lingual length ratio of the root surrounded by the alveolar bone to the total root length were measured. The idependent samples t-test were used to analyze the variable differences.

RESULTSThe labial and lingual alveolar bone of fourteen cases crest of the diseased tooth after treatment presented general symmetry U shape from qualitative observation through the three-dimensional reconstruction. The labial and the lingual length of the diseased incisor from alveolar bone crest to CEJ [(2.47 ± 1.35) and (1.47 ± 0.84) mm] was significant increased than those of the homonym incisor [(1.03 ± 0.35) and (0.90 ± 0.37) mm] (P < 0.05); the length of the diseased incisor's post-treatment root [(9.82 ± 2.82) mm] was no statistically significant decreased than that of the homonym incisor root [(10.28 ± 1.38) mm, P = 0.59]; the labial and the lingual length ratio of the impacted tooth's root surrounded by the alveolar bone to the total root length [(72.83 ± 17.16)% and (85.32 ± 5.98)%] was statistically significant decrease than those of homonym teeth[(89.66 ± 3.98)% and (90.84 ± 4.61)%] (P < 0.05).

CONCLUSIONSThe diseased tooth's root had gotten enough length after the treatment. The labial and lingual alveolar bone of the maxillary labial inverted impacted incisor in mixed dentition can't offer sufficient adaptive hyperplasia after treatment, of which labial alveolar bone is more apparent, prompting careful protection when they were used.

Alveolar Process ; diagnostic imaging ; pathology ; Child ; Cone-Beam Computed Tomography ; Dentition, Mixed ; Female ; Follow-Up Studies ; Humans ; Incisor ; diagnostic imaging ; pathology ; surgery ; Male ; Maxilla ; diagnostic imaging ; pathology ; surgery ; Orthodontic Extrusion ; Tooth Root ; diagnostic imaging ; pathology ; Tooth, Impacted ; diagnostic imaging ; surgery

OBJECTIVETo evaluate the alveolar bone thickness and root length changes of anterior teeth with cone-beam computed tomography (CBCT).

METHODSCBCT scans were taken for 12 skeletal Class III patients who accepted the improved corticotomy (IC) procedures during pre-surgical orthodontics. The CBCT data in T1 (the maxillary dental arch was aligned and leveled) and T2 (extraction space closure) were superimposed and the alveolar bone thickness at root apex level and root length measurements were done.

RESULTSFrom T1 to T2, the buccal alveolar bone thickness for the upper lateral incisors increased from (1.89±0.83) to (2.47±1.02) mm (P<0.05), and for central incisors and for canines from (2.32±0.71) to (2.68±1.48) mm and from (2.28±1.08) to (2.41±1.40) mm, respectively. According to Sharpe Grading System, the root resorption grade for 69 teeth of 72 was located in Grade 1, two teeth in Grade 2, one tooth in Grade 3.

CONCLUSIONSThe improved corticotomy had the potential to increase the buccal alveolar bone thickness and the root resorption in most teeth was in Grade 1 according to Sharpe grading system.

Alveolar Process ; anatomy & histology ; diagnostic imaging ; surgery ; Cone-Beam Computed Tomography ; Cuspid ; Humans ; Incisor ; Malocclusion, Angle Class III ; diagnostic imaging ; surgery ; Root Resorption ; pathology ; Tooth Root ; Zygoma

OBJECTIVETo assess the skeletodental changes after extracting mandibular third molars in skeletal Class III patients in both post-puberty and adult.

METHODSNineteen skeletal Class III patients in post-puberty or adult (16 female, 3 male) successfully treated with extracting mandibular third molars were included in the study. Cephalograms were analyzed to assess the skeletal and dental changes before and after treatment. Paired t-test was performed for statistical analysis of the data.

RESULTSThe results revealed that the main changes were upright [(12.37 ± 6.81)°] and distal movement [(3.16 ± 1.23) mm] of the mandibular molars, and retraction [(1.98 ± 1.36) mm] of the mandibular incisors. There was a significant improvement in overjet [(2.75 ± 1.65) mm].

CONCLUSIONSThe lower molars and incisors could be distalized significantly with extraction of the lower third molars.

Adolescent ; Adult ; Cephalometry ; Female ; Humans ; Incisor ; pathology ; Male ; Malocclusion, Angle Class III ; therapy ; Mandible ; Molar ; pathology ; Molar, Third ; surgery ; Orthodontics, Corrective ; methods ; Puberty ; Tooth Extraction ; Tooth Movement Techniques ; Young Adult