Oral appliance–generated malocclusion traits during the long-term management of obstructive sleep apnea in adults:

ABSTRACT Objectives To identify malocclusion characteristics generated after using oral appliances (OAs) for at least 5 years for the management of snoring and obstructive sleep apnea (OSA) in adults. Materials and Methods PubMed, MEDLINE (Ovid), Scopus, CINAHL, and Informit were searched without language restrictions through January 20, 2021. Unpublished literature was searched on ClinicalTrials.gov, the National Research Register, and the Pro-Quest Dissertation Abstracts and Thesis database. Authors were contacted when necessary, and reference lists of the included studies were screened. Risk of bias was assessed through the revised Cochrane Risk of Bias tool for randomized controlled trials (RoB2) and Non-Randomized Studies of Interventions for non-RCTs and uncontrolled before–after studies (ROBINS-I). A random-effects meta-analysis was conducted only on studies that used the same OAs to exclude biomechanical differences. Risk of bias across studies was assessed with the Grading of Recommendations, Assessment, Development and Evaluation tool. Results A total of 12 studies were included in the final qualitative synthesis. Eight included studies had high, one had moderate, and three had low risks of bias. Significant progressive decreases of overjet (OJ; −1.43 mm; 95% confidence interval [CI], −1.66 to −1.20) and overbite (OB; −1.94 mm; 95% CI, −2.14 to −1.74) associated with maxillary incisor retroclination and mandibular incisor proclination were reported long term. Although most studies showed no sagittal skeletal changes, some degree of vertical skeletal changes were noted. Conclusions Based on a very low evidence level, inevitable anterior teeth positional changes seem to be a common long-term adverse effect of OAs. The magnitude of those changes could be considered clinically irrelevant for most pretreatment occlusions, but in occlusions with limited OJ and OB, it may be worth clinical consideration.

Redescription and new record of the spongobiotic shrimp Periclimenaeus rastrifer Bruce, 1980 (Crustacea: Decapoda: Palaemonidae) from Taiwan

The palaemonid shrimp Periclimenaeus rastrifer is here reported from Taiwan based on three specimens. It bears a feeble but distinct anterodorsal lobe on the first pleonite (not reported before). The mouthparts, not previously described, are also remarkable by a multidentate apex of the mandibular incisor, asymmetric distal endite of the second maxilla, and expanded dorsal lobe on the second maxilliped merus. The species is thus redescribed here. One of the examined specimens possesses an unusual rostrum, and malformed telson and uropodal spinulation; the latter specimen is described and illustrated in detail, including the mouthparts. Previously, the only species in the genus published in faunistic repors from Taiwan were P. wolffi Bruce 1993 and P. gorgonidarum (Balss, 1913) recorded from the Taiwan Strait, and the Green Island, respectively; P. rastrifer is reported here as the first of the genus from Taiwan mainland

Effects of Herbst Appliance Treatment on the Mandibular Incisor Segment: a Three-Dimensionally Analysis

Three-dimensionally evaluation of the treatment changes of a Herbst appliance using a lower anchorage unit not touching the lingual surface of the lower incisors. The sample consisted of 23 Class II:1 patients (12 males, 11 females) with a mean age of 15.7±1.7 years treated with a Flip-Lock Herbst® appliance (TP Orthodontics, Inc., La Porte, IN, USA). The lower anchorage unit for the Herbst appliance consisted of two anchor bands connected by a lingual arch with 3mm distance from the incisor’s lingual surface. Treatment changes in mandibular incisor inclination, overjet and overbite were evaluated by means of cone beam computed tomography images (i-CAT® Classic unit, Imaging Sciences International, Hatfield, PA, USA) obtained before and after treatment with the Herbst appliance. On average, there was a statistically significant increase in mandibular incisor inclination (2.6+1.8°) and a reduction in overjet (3.2+2.2mm) and overbite (1.3+0.9mm). Genders did not differ significantly. Incisor proclination was however only seen in 74% of the patients. The changes in mandibular incisor inclination were associated with the changes in overjet (/r/ = 0.1 to 0.5) and overbite (/r/ = 0.3 to 0.7). A Herbst appliance with a mandibular anchorage unit distant from the incisor’s lingual surface results in smaller amounts of mandibular incisor proclination compared to literature. However, as it induces canine anchorage loss, the decreased amount of proclination may not prevail after multibracket treatment. Keywords: Cone-Beam Computed Tomography. Mandibular Advancement. Tooth Movement Techniques. ResumoAvaliação tridimensional das alterações induzidas pelo aparelho Herbst utilizando a unidade de ancoragem inferior afastada da superfície lingual dos incisivos. A amostra incluiu 23 pacientes Classe II:1 (12 masculino, 11 feminino), média de idade 15,7 ± 1,7, tratados com aparelho Herbst Flip-Lock® (TP Orthodontics, Inc., La Porte, IN, EUA). A unidade de ancoragem inferior do aparelho Herbst consistiu-se de duas bandas conectadas por um arco lingual afastado 3mm da superfície lingual do incisivo. As alterações induzidas pelo tratamento na inclinação dos incisivos inferiores, trespasse horizontal e trespasse vertical foram avaliadas por meio de imagens de tomografias computadorizadas de feixe cônico (i-CAT® Classic unit, Imaging Sciences International, Hatfield, PA, USA) obtidas antes e após o tratamento com aparelho Herbst. Na média, houve diferença significativa com aumento da inclinação dos incisivos inferiores (2,6+1,8°) e diminuição do trespasse horizontal (3,2+2,2mm) e do trespasse vertical (1,3+0,9mm). Não houve diferença estatística entre os sexos. No entanto, a vestibularização do incisivo ocorreu em apenas 74% dos pacientes. As alterações na inclinação dos incisivos inferiores apresentam correlação estatisticamente significativa com as alterações no trepasse horizontal (/r/ = 0,1 a 0,5) e no trespasse vertical (/r/ = 0,3 a 0,7). O aparelho Herbst com uma unidade de ancoragem inferior afastada da superfície lingual dos incisivos resulta em menor quantidade de vestibularização do incisivo inferior em comparação com a literatura. Entretanto, como isto induz perda de ancoragem do canino, a diminuição da vestibularização pode não prevalecer ao final tratamento ortodôntico com braquetes. Palavras-chave: Tomografia Computadorizada de Feixe Cônico. Avanço Mandibular. Técnicas de Movimentação Dentária.

Correlation between mandibular third molar and mandibular incisor crowding: A retrospective CBCT-based study

Background. Late mandibular incisor crowding is a fairly common phenomenon experienced by growing adults. The etiology of late mandibular incisor crowding, however, is controversial and inconclusive. Hence, this study aimed to investigate the correlation between mandibular third molar and mandibular incisor crowding using Cone-beam computed tomography (CBCT) data. Methods. The study consisted of 40 samples of CBCT images divided into two groups (n=20). Group A comprised CBCT images without third molars, and group B included CBCT images with third molars. The images were observed in the axial view and manually marked to calculate the amount of crowding using Little’s irregularity index. The obtained values were statistically analyzed using Pearson’s correlation test. SPSS 23 was used for statistical analysis. Results. The results showed a positive correlation between the mandibular third molars and mandibular incisor crowding, which was significant (P=0.033). The mean Little’s irregularity index score for groups A and B were 4.26 and 6.799, respectively (P=0.033). Conclusion. The positive correlation between the two groups suggests an association between the mandibular third molars and mandibular incisor crowding.

Mandibular incisor inclination and gingival recession after treatment with the Jasper Jumper: a 10-year follow-up

Objective To evaluate the long-term outcomes of Class II treatment with the Jasper Jumper appliance and comprehensive orthodontic treatment concerning inclination of the mandibular incisors and gingival recession. Methods Sixteen patients with Class II malocclusion at a mean age of 12.54y (SD = 1.17) were treated with the Jasper Jumper appliance and comprehensive orthodontic treatment. The mean treatment time was 2.05y (SD = 0.21). Dental records were taken before (T1), after treatment (T2) and 11.90y (SD = 0.48) after debonding (T3). The frequency of gingival recession, clinical crown height and mandibular incisor position were evaluated using intraoral photographs, digital models and lateral cephalograms. Interphase changes were evaluated using dependent t and McNemar’s tests. Correlation between clinical crown height and final position of the mandibular incisors was evaluated using Pearson correlation test (P < 0.05). Results The frequency of gingival recessions increased over time and was observed in 6 (9.4%), 12 (18.8%) and 24 (37.5%) of the mandibular incisors at T1, T2 and T3, respectively. A significant increase in labial inclination and protrusion of the mandibular incisors was observed between T1 and T2 interval. The clinical crown height significantly increased in the follow-up period (T3–T2) and in the complete observation time (T3–T1). There was no correlation between the amount of labial inclination and protrusion of the mandibular incisors and clinical crown height for all time intervals. Conclusion No significant correlation between the amount of labial movement of the mandibular incisor and clinical crown height increase was found.

Knowledge Attitude and Practice of General Practitioners and Interns Toward Late Mandibular Incisors Crowding; A Cross sectional study in Saudi Arabia.

Objective: This study aimed to assess and compare the knowledge and awareness of dental interns and general practitioners in Saudi Arabia about late mandibular incisor crowding. Materials and methods: This is a cross-sectional study which was conducted between June 2020 and July 2020 in Saudi Arabia and it observed dental practitioners. Results: A total of 275 subjects were included in this study; 172 (62.5%) were dental interns, 157 (57.1%) were females and 211 (76.7%) dentists were aged between 23-26 years. While most general practitioners and dental interns have heard about late mandibular incisors crowding, the majority continue to abstain from not recommending extraction of lower third molar as a means of prevention. Around half of the respondents, 134 (48.7%), claimed that the eruption of lower third molars is a possible causative factor. A greater percentage of general dental practitioners, 32 (31.1%) believed that there is a correlation between late mandibular incisors crowding and cases of relapse after an orthodontic treatment. Moreover, male participants were more knowledgeable of the fact that cases may worsen if not treated (P = 0.019). The knowledge of lower third molars eruption (P = 0.002) and unerupted/impacted lower third molars (P = 0.034) ability to cause late mandibular incisors crowding and the prophylactic extraction of the lower third molars (P = 0.009) were also significantly differed across the various age groups. Conclusion: Late mandibular incisor crowding is one of the main clinical issues in dental practice which has been subject to decreased awareness among dentists. Keywords:Dentists, knowledge, late mandibular incisor crowding, Saudi Arabia.

An evaluation of the relationship between periocular anthropometric measurements and mandibular incisor crowding

Aim: To determine whether a relationship exists between the periocular anthropometric meas-urements (POAM), intercanine width, and Little’s irregularity index (measures the crowding of mandibular incisors) in the Turkish population. Methodology: Ninety-four children (49 with mandibular crowding and 45 controls) aged between 12-18 years were included in this study. Inter-outer canthal distance (IOCD), in-ter-inner canthal distance (IICD), interpupillary distance (IPD), inter-canine width (ICW), and Littles’irregularity index (LII) of subjects were measured from two standardized digital pho-tographs using a public domain Java processing program (ImageJ software). Spearman correla-tion coefficient and multiple linear regression tests were used to investigate the relationship between POAM, and ICW, and LII. Results: In the mandibular crowding group, the means of IICD, OICD, IPD, and ICW were 30.6 ± 1.7 mm, 82.4 ± 2.0 mm, 59.2 ± 1.6 mm, 23.3 ± 1.1 mm, respectively. In controls, the mean of the measurements was found to be 32.1 ± 1.5 mm, 84.4 ± 2.4 mm, 60.1 ± 1.9 mm, 24.6 ± 1.4 mm, respectively. There were statistically significant differences between groups among all variables (p <0.001). There was a negative correlation between POAM and ICW with LDI. Especially, high correlation was found in ICW and IICD variables (r = -. 732, p <.001 and r = -705, p <.001, respectively). As a result of multivariate regression analysis, IICD and ICW were found to be affected the crowding negatively and significantly (p = .003 and p = .026, respectively). Conclusion: According to the results obtained from our study, it was concluded that IICD which remains stable after the age of 10 years and ICW can be used to predict irregularities in mandibular incisors in children in the Turkish population. How to cite this article: Kızıltan Eliaçık BB. An evaluation of the relationship between periocular anthropometric measurements and mandibular incisor crowding. Int Dent Res 2021;11(Suppl.1):216-221. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.31 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Compound odontoma causing impaction of primary tooth in a 4-year-old child: case report

Objective: to report a rare case of impaction of a primary mandibular incisor due to the presence of a compound odontoma and describe its clinical management. Case report: a 4-year-old boy presented with a“missing” primary left mandibular lateral incisor. Radiographs showed impaction of the unerupted incisorby adjacent radiopaque structures consistent with a compound odontoma. The patient was recalled periodically for 2 years, at which time surgical excision was performed. The diagnosis of compound odontoma was confirmed histologically, and the permanent mandibular central incisors erupted uneventfully; the patient was referred for orthodontic treatment. Final considerations: this case report describes an unusual case of compound odontoma associated with an unerupted deciduous tooth; odontomas are rare in this age range, occurring predominantly in the second decade of life and in association with impaction of permanent teeth. We also propose a protocol for clinical management of such early-onset cases.